sha1_file.c: rename to use dash in file name
authorStefan Beller <sbeller@google.com>
Tue, 10 Apr 2018 21:26:20 +0000 (14:26 -0700)
committerJunio C Hamano <gitster@pobox.com>
Wed, 11 Apr 2018 09:11:00 +0000 (18:11 +0900)
This is more consistent with the project style. The majority of Git's
source files use dashes in preference to underscores in their file names.

Signed-off-by: Stefan Beller <sbeller@google.com>
Documentation/technical/api-object-access.txt
Makefile
builtin/index-pack.c
sha1-file.c [new file with mode: 0644]
sha1_file.c [deleted file]
index a1162e5bcd19ba509fff39bceca49e1b33e2add2..5b29622d00ea61808176a27bdc2a86971d297749 100644 (file)
@@ -1,7 +1,7 @@
 object access API
 =================
 
-Talk about <sha1_file.c> and <object.h> family, things like
+Talk about <sha1-file.c> and <object.h> family, things like
 
 * read_sha1_file()
 * read_object_with_reference()
index ed0ac30a16fa3ec7433f7c373954e3364a8fe4f3..ce26efa7dc02fb79535e85bf401a33301572ee33 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -900,7 +900,7 @@ LIB_OBJS += server-info.o
 LIB_OBJS += setup.o
 LIB_OBJS += sha1-array.o
 LIB_OBJS += sha1-lookup.o
-LIB_OBJS += sha1_file.o
+LIB_OBJS += sha1-file.o
 LIB_OBJS += sha1-name.o
 LIB_OBJS += shallow.o
 LIB_OBJS += sideband.o
index 7700907f1b2c169dfb969d255cd9d61953cfb9f4..78e66b998664ee23244fd9fc9acd33578b9c53c0 100644 (file)
@@ -1593,7 +1593,7 @@ static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
        /*
         * Get rid of the idx file as we do not need it anymore.
         * NEEDSWORK: extract this bit from free_pack_by_name() in
-        * sha1_file.c, perhaps?  It shouldn't matter very much as we
+        * sha1-file.c, perhaps?  It shouldn't matter very much as we
         * know we haven't installed this pack (hence we never have
         * read anything from it).
         */
diff --git a/sha1-file.c b/sha1-file.c
new file mode 100644 (file)
index 0000000..77ccaab
--- /dev/null
@@ -0,0 +1,2254 @@
+/*
+ * GIT - The information manager from hell
+ *
+ * Copyright (C) Linus Torvalds, 2005
+ *
+ * This handles basic git sha1 object files - packing, unpacking,
+ * creation etc.
+ */
+#include "cache.h"
+#include "config.h"
+#include "string-list.h"
+#include "lockfile.h"
+#include "delta.h"
+#include "pack.h"
+#include "blob.h"
+#include "commit.h"
+#include "run-command.h"
+#include "tag.h"
+#include "tree.h"
+#include "tree-walk.h"
+#include "refs.h"
+#include "pack-revindex.h"
+#include "sha1-lookup.h"
+#include "bulk-checkin.h"
+#include "repository.h"
+#include "streaming.h"
+#include "dir.h"
+#include "list.h"
+#include "mergesort.h"
+#include "quote.h"
+#include "packfile.h"
+#include "fetch-object.h"
+#include "object-store.h"
+
+/* The maximum size for an object header. */
+#define MAX_HEADER_LEN 32
+
+const unsigned char null_sha1[GIT_MAX_RAWSZ];
+const struct object_id null_oid;
+const struct object_id empty_tree_oid = {
+       EMPTY_TREE_SHA1_BIN_LITERAL
+};
+const struct object_id empty_blob_oid = {
+       EMPTY_BLOB_SHA1_BIN_LITERAL
+};
+
+static void git_hash_sha1_init(git_hash_ctx *ctx)
+{
+       git_SHA1_Init(&ctx->sha1);
+}
+
+static void git_hash_sha1_update(git_hash_ctx *ctx, const void *data, size_t len)
+{
+       git_SHA1_Update(&ctx->sha1, data, len);
+}
+
+static void git_hash_sha1_final(unsigned char *hash, git_hash_ctx *ctx)
+{
+       git_SHA1_Final(hash, &ctx->sha1);
+}
+
+static void git_hash_unknown_init(git_hash_ctx *ctx)
+{
+       die("trying to init unknown hash");
+}
+
+static void git_hash_unknown_update(git_hash_ctx *ctx, const void *data, size_t len)
+{
+       die("trying to update unknown hash");
+}
+
+static void git_hash_unknown_final(unsigned char *hash, git_hash_ctx *ctx)
+{
+       die("trying to finalize unknown hash");
+}
+
+const struct git_hash_algo hash_algos[GIT_HASH_NALGOS] = {
+       {
+               NULL,
+               0x00000000,
+               0,
+               0,
+               git_hash_unknown_init,
+               git_hash_unknown_update,
+               git_hash_unknown_final,
+               NULL,
+               NULL,
+       },
+       {
+               "sha-1",
+               /* "sha1", big-endian */
+               0x73686131,
+               GIT_SHA1_RAWSZ,
+               GIT_SHA1_HEXSZ,
+               git_hash_sha1_init,
+               git_hash_sha1_update,
+               git_hash_sha1_final,
+               &empty_tree_oid,
+               &empty_blob_oid,
+       },
+};
+
+/*
+ * This is meant to hold a *small* number of objects that you would
+ * want read_sha1_file() to be able to return, but yet you do not want
+ * to write them into the object store (e.g. a browse-only
+ * application).
+ */
+static struct cached_object {
+       unsigned char sha1[20];
+       enum object_type type;
+       void *buf;
+       unsigned long size;
+} *cached_objects;
+static int cached_object_nr, cached_object_alloc;
+
+static struct cached_object empty_tree = {
+       EMPTY_TREE_SHA1_BIN_LITERAL,
+       OBJ_TREE,
+       "",
+       0
+};
+
+static struct cached_object *find_cached_object(const unsigned char *sha1)
+{
+       int i;
+       struct cached_object *co = cached_objects;
+
+       for (i = 0; i < cached_object_nr; i++, co++) {
+               if (!hashcmp(co->sha1, sha1))
+                       return co;
+       }
+       if (!hashcmp(sha1, empty_tree.sha1))
+               return &empty_tree;
+       return NULL;
+}
+
+
+static int get_conv_flags(unsigned flags)
+{
+       if (flags & HASH_RENORMALIZE)
+               return CONV_EOL_RENORMALIZE;
+       else if (flags & HASH_WRITE_OBJECT)
+         return global_conv_flags_eol;
+       else
+               return 0;
+}
+
+
+int mkdir_in_gitdir(const char *path)
+{
+       if (mkdir(path, 0777)) {
+               int saved_errno = errno;
+               struct stat st;
+               struct strbuf sb = STRBUF_INIT;
+
+               if (errno != EEXIST)
+                       return -1;
+               /*
+                * Are we looking at a path in a symlinked worktree
+                * whose original repository does not yet have it?
+                * e.g. .git/rr-cache pointing at its original
+                * repository in which the user hasn't performed any
+                * conflict resolution yet?
+                */
+               if (lstat(path, &st) || !S_ISLNK(st.st_mode) ||
+                   strbuf_readlink(&sb, path, st.st_size) ||
+                   !is_absolute_path(sb.buf) ||
+                   mkdir(sb.buf, 0777)) {
+                       strbuf_release(&sb);
+                       errno = saved_errno;
+                       return -1;
+               }
+               strbuf_release(&sb);
+       }
+       return adjust_shared_perm(path);
+}
+
+enum scld_error safe_create_leading_directories(char *path)
+{
+       char *next_component = path + offset_1st_component(path);
+       enum scld_error ret = SCLD_OK;
+
+       while (ret == SCLD_OK && next_component) {
+               struct stat st;
+               char *slash = next_component, slash_character;
+
+               while (*slash && !is_dir_sep(*slash))
+                       slash++;
+
+               if (!*slash)
+                       break;
+
+               next_component = slash + 1;
+               while (is_dir_sep(*next_component))
+                       next_component++;
+               if (!*next_component)
+                       break;
+
+               slash_character = *slash;
+               *slash = '\0';
+               if (!stat(path, &st)) {
+                       /* path exists */
+                       if (!S_ISDIR(st.st_mode)) {
+                               errno = ENOTDIR;
+                               ret = SCLD_EXISTS;
+                       }
+               } else if (mkdir(path, 0777)) {
+                       if (errno == EEXIST &&
+                           !stat(path, &st) && S_ISDIR(st.st_mode))
+                               ; /* somebody created it since we checked */
+                       else if (errno == ENOENT)
+                               /*
+                                * Either mkdir() failed because
+                                * somebody just pruned the containing
+                                * directory, or stat() failed because
+                                * the file that was in our way was
+                                * just removed.  Either way, inform
+                                * the caller that it might be worth
+                                * trying again:
+                                */
+                               ret = SCLD_VANISHED;
+                       else
+                               ret = SCLD_FAILED;
+               } else if (adjust_shared_perm(path)) {
+                       ret = SCLD_PERMS;
+               }
+               *slash = slash_character;
+       }
+       return ret;
+}
+
+enum scld_error safe_create_leading_directories_const(const char *path)
+{
+       int save_errno;
+       /* path points to cache entries, so xstrdup before messing with it */
+       char *buf = xstrdup(path);
+       enum scld_error result = safe_create_leading_directories(buf);
+
+       save_errno = errno;
+       free(buf);
+       errno = save_errno;
+       return result;
+}
+
+int raceproof_create_file(const char *path, create_file_fn fn, void *cb)
+{
+       /*
+        * The number of times we will try to remove empty directories
+        * in the way of path. This is only 1 because if another
+        * process is racily creating directories that conflict with
+        * us, we don't want to fight against them.
+        */
+       int remove_directories_remaining = 1;
+
+       /*
+        * The number of times that we will try to create the
+        * directories containing path. We are willing to attempt this
+        * more than once, because another process could be trying to
+        * clean up empty directories at the same time as we are
+        * trying to create them.
+        */
+       int create_directories_remaining = 3;
+
+       /* A scratch copy of path, filled lazily if we need it: */
+       struct strbuf path_copy = STRBUF_INIT;
+
+       int ret, save_errno;
+
+       /* Sanity check: */
+       assert(*path);
+
+retry_fn:
+       ret = fn(path, cb);
+       save_errno = errno;
+       if (!ret)
+               goto out;
+
+       if (errno == EISDIR && remove_directories_remaining-- > 0) {
+               /*
+                * A directory is in the way. Maybe it is empty; try
+                * to remove it:
+                */
+               if (!path_copy.len)
+                       strbuf_addstr(&path_copy, path);
+
+               if (!remove_dir_recursively(&path_copy, REMOVE_DIR_EMPTY_ONLY))
+                       goto retry_fn;
+       } else if (errno == ENOENT && create_directories_remaining-- > 0) {
+               /*
+                * Maybe the containing directory didn't exist, or
+                * maybe it was just deleted by a process that is
+                * racing with us to clean up empty directories. Try
+                * to create it:
+                */
+               enum scld_error scld_result;
+
+               if (!path_copy.len)
+                       strbuf_addstr(&path_copy, path);
+
+               do {
+                       scld_result = safe_create_leading_directories(path_copy.buf);
+                       if (scld_result == SCLD_OK)
+                               goto retry_fn;
+               } while (scld_result == SCLD_VANISHED && create_directories_remaining-- > 0);
+       }
+
+out:
+       strbuf_release(&path_copy);
+       errno = save_errno;
+       return ret;
+}
+
+static void fill_sha1_path(struct strbuf *buf, const unsigned char *sha1)
+{
+       int i;
+       for (i = 0; i < 20; i++) {
+               static char hex[] = "0123456789abcdef";
+               unsigned int val = sha1[i];
+               strbuf_addch(buf, hex[val >> 4]);
+               strbuf_addch(buf, hex[val & 0xf]);
+               if (!i)
+                       strbuf_addch(buf, '/');
+       }
+}
+
+void sha1_file_name(struct repository *r, struct strbuf *buf, const unsigned char *sha1)
+{
+       strbuf_addstr(buf, r->objects->objectdir);
+       strbuf_addch(buf, '/');
+       fill_sha1_path(buf, sha1);
+}
+
+struct strbuf *alt_scratch_buf(struct alternate_object_database *alt)
+{
+       strbuf_setlen(&alt->scratch, alt->base_len);
+       return &alt->scratch;
+}
+
+static const char *alt_sha1_path(struct alternate_object_database *alt,
+                                const unsigned char *sha1)
+{
+       struct strbuf *buf = alt_scratch_buf(alt);
+       fill_sha1_path(buf, sha1);
+       return buf->buf;
+}
+
+/*
+ * Return non-zero iff the path is usable as an alternate object database.
+ */
+static int alt_odb_usable(struct raw_object_store *o,
+                         struct strbuf *path,
+                         const char *normalized_objdir)
+{
+       struct alternate_object_database *alt;
+
+       /* Detect cases where alternate disappeared */
+       if (!is_directory(path->buf)) {
+               error("object directory %s does not exist; "
+                     "check .git/objects/info/alternates.",
+                     path->buf);
+               return 0;
+       }
+
+       /*
+        * Prevent the common mistake of listing the same
+        * thing twice, or object directory itself.
+        */
+       for (alt = o->alt_odb_list; alt; alt = alt->next) {
+               if (!fspathcmp(path->buf, alt->path))
+                       return 0;
+       }
+       if (!fspathcmp(path->buf, normalized_objdir))
+               return 0;
+
+       return 1;
+}
+
+/*
+ * Prepare alternate object database registry.
+ *
+ * The variable alt_odb_list points at the list of struct
+ * alternate_object_database.  The elements on this list come from
+ * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
+ * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
+ * whose contents is similar to that environment variable but can be
+ * LF separated.  Its base points at a statically allocated buffer that
+ * contains "/the/directory/corresponding/to/.git/objects/...", while
+ * its name points just after the slash at the end of ".git/objects/"
+ * in the example above, and has enough space to hold 40-byte hex
+ * SHA1, an extra slash for the first level indirection, and the
+ * terminating NUL.
+ */
+static void read_info_alternates(struct repository *r,
+                                const char *relative_base,
+                                int depth);
+static int link_alt_odb_entry(struct repository *r, const char *entry,
+       const char *relative_base, int depth, const char *normalized_objdir)
+{
+       struct alternate_object_database *ent;
+       struct strbuf pathbuf = STRBUF_INIT;
+
+       if (!is_absolute_path(entry) && relative_base) {
+               strbuf_realpath(&pathbuf, relative_base, 1);
+               strbuf_addch(&pathbuf, '/');
+       }
+       strbuf_addstr(&pathbuf, entry);
+
+       if (strbuf_normalize_path(&pathbuf) < 0 && relative_base) {
+               error("unable to normalize alternate object path: %s",
+                     pathbuf.buf);
+               strbuf_release(&pathbuf);
+               return -1;
+       }
+
+       /*
+        * The trailing slash after the directory name is given by
+        * this function at the end. Remove duplicates.
+        */
+       while (pathbuf.len && pathbuf.buf[pathbuf.len - 1] == '/')
+               strbuf_setlen(&pathbuf, pathbuf.len - 1);
+
+       if (!alt_odb_usable(r->objects, &pathbuf, normalized_objdir)) {
+               strbuf_release(&pathbuf);
+               return -1;
+       }
+
+       ent = alloc_alt_odb(pathbuf.buf);
+
+       /* add the alternate entry */
+       *r->objects->alt_odb_tail = ent;
+       r->objects->alt_odb_tail = &(ent->next);
+       ent->next = NULL;
+
+       /* recursively add alternates */
+       read_info_alternates(r, pathbuf.buf, depth + 1);
+
+       strbuf_release(&pathbuf);
+       return 0;
+}
+
+static const char *parse_alt_odb_entry(const char *string,
+                                      int sep,
+                                      struct strbuf *out)
+{
+       const char *end;
+
+       strbuf_reset(out);
+
+       if (*string == '#') {
+               /* comment; consume up to next separator */
+               end = strchrnul(string, sep);
+       } else if (*string == '"' && !unquote_c_style(out, string, &end)) {
+               /*
+                * quoted path; unquote_c_style has copied the
+                * data for us and set "end". Broken quoting (e.g.,
+                * an entry that doesn't end with a quote) falls
+                * back to the unquoted case below.
+                */
+       } else {
+               /* normal, unquoted path */
+               end = strchrnul(string, sep);
+               strbuf_add(out, string, end - string);
+       }
+
+       if (*end)
+               end++;
+       return end;
+}
+
+static void link_alt_odb_entries(struct repository *r, const char *alt,
+                                int sep, const char *relative_base, int depth)
+{
+       struct strbuf objdirbuf = STRBUF_INIT;
+       struct strbuf entry = STRBUF_INIT;
+
+       if (!alt || !*alt)
+               return;
+
+       if (depth > 5) {
+               error("%s: ignoring alternate object stores, nesting too deep.",
+                               relative_base);
+               return;
+       }
+
+       strbuf_add_absolute_path(&objdirbuf, r->objects->objectdir);
+       if (strbuf_normalize_path(&objdirbuf) < 0)
+               die("unable to normalize object directory: %s",
+                   objdirbuf.buf);
+
+       while (*alt) {
+               alt = parse_alt_odb_entry(alt, sep, &entry);
+               if (!entry.len)
+                       continue;
+               link_alt_odb_entry(r, entry.buf,
+                                  relative_base, depth, objdirbuf.buf);
+       }
+       strbuf_release(&entry);
+       strbuf_release(&objdirbuf);
+}
+
+static void read_info_alternates(struct repository *r,
+                                const char *relative_base,
+                                int depth)
+{
+       char *path;
+       struct strbuf buf = STRBUF_INIT;
+
+       path = xstrfmt("%s/info/alternates", relative_base);
+       if (strbuf_read_file(&buf, path, 1024) < 0) {
+               warn_on_fopen_errors(path);
+               free(path);
+               return;
+       }
+
+       link_alt_odb_entries(r, buf.buf, '\n', relative_base, depth);
+       strbuf_release(&buf);
+       free(path);
+}
+
+struct alternate_object_database *alloc_alt_odb(const char *dir)
+{
+       struct alternate_object_database *ent;
+
+       FLEX_ALLOC_STR(ent, path, dir);
+       strbuf_init(&ent->scratch, 0);
+       strbuf_addf(&ent->scratch, "%s/", dir);
+       ent->base_len = ent->scratch.len;
+
+       return ent;
+}
+
+void add_to_alternates_file(const char *reference)
+{
+       struct lock_file lock = LOCK_INIT;
+       char *alts = git_pathdup("objects/info/alternates");
+       FILE *in, *out;
+       int found = 0;
+
+       hold_lock_file_for_update(&lock, alts, LOCK_DIE_ON_ERROR);
+       out = fdopen_lock_file(&lock, "w");
+       if (!out)
+               die_errno("unable to fdopen alternates lockfile");
+
+       in = fopen(alts, "r");
+       if (in) {
+               struct strbuf line = STRBUF_INIT;
+
+               while (strbuf_getline(&line, in) != EOF) {
+                       if (!strcmp(reference, line.buf)) {
+                               found = 1;
+                               break;
+                       }
+                       fprintf_or_die(out, "%s\n", line.buf);
+               }
+
+               strbuf_release(&line);
+               fclose(in);
+       }
+       else if (errno != ENOENT)
+               die_errno("unable to read alternates file");
+
+       if (found) {
+               rollback_lock_file(&lock);
+       } else {
+               fprintf_or_die(out, "%s\n", reference);
+               if (commit_lock_file(&lock))
+                       die_errno("unable to move new alternates file into place");
+               if (the_repository->objects->alt_odb_tail)
+                       link_alt_odb_entries(the_repository, reference,
+                                            '\n', NULL, 0);
+       }
+       free(alts);
+}
+
+void add_to_alternates_memory(const char *reference)
+{
+       /*
+        * Make sure alternates are initialized, or else our entry may be
+        * overwritten when they are.
+        */
+       prepare_alt_odb(the_repository);
+
+       link_alt_odb_entries(the_repository, reference,
+                            '\n', NULL, 0);
+}
+
+/*
+ * Compute the exact path an alternate is at and returns it. In case of
+ * error NULL is returned and the human readable error is added to `err`
+ * `path` may be relative and should point to $GITDIR.
+ * `err` must not be null.
+ */
+char *compute_alternate_path(const char *path, struct strbuf *err)
+{
+       char *ref_git = NULL;
+       const char *repo, *ref_git_s;
+       int seen_error = 0;
+
+       ref_git_s = real_path_if_valid(path);
+       if (!ref_git_s) {
+               seen_error = 1;
+               strbuf_addf(err, _("path '%s' does not exist"), path);
+               goto out;
+       } else
+               /*
+                * Beware: read_gitfile(), real_path() and mkpath()
+                * return static buffer
+                */
+               ref_git = xstrdup(ref_git_s);
+
+       repo = read_gitfile(ref_git);
+       if (!repo)
+               repo = read_gitfile(mkpath("%s/.git", ref_git));
+       if (repo) {
+               free(ref_git);
+               ref_git = xstrdup(repo);
+       }
+
+       if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
+               char *ref_git_git = mkpathdup("%s/.git", ref_git);
+               free(ref_git);
+               ref_git = ref_git_git;
+       } else if (!is_directory(mkpath("%s/objects", ref_git))) {
+               struct strbuf sb = STRBUF_INIT;
+               seen_error = 1;
+               if (get_common_dir(&sb, ref_git)) {
+                       strbuf_addf(err,
+                                   _("reference repository '%s' as a linked "
+                                     "checkout is not supported yet."),
+                                   path);
+                       goto out;
+               }
+
+               strbuf_addf(err, _("reference repository '%s' is not a "
+                                       "local repository."), path);
+               goto out;
+       }
+
+       if (!access(mkpath("%s/shallow", ref_git), F_OK)) {
+               strbuf_addf(err, _("reference repository '%s' is shallow"),
+                           path);
+               seen_error = 1;
+               goto out;
+       }
+
+       if (!access(mkpath("%s/info/grafts", ref_git), F_OK)) {
+               strbuf_addf(err,
+                           _("reference repository '%s' is grafted"),
+                           path);
+               seen_error = 1;
+               goto out;
+       }
+
+out:
+       if (seen_error) {
+               FREE_AND_NULL(ref_git);
+       }
+
+       return ref_git;
+}
+
+int foreach_alt_odb(alt_odb_fn fn, void *cb)
+{
+       struct alternate_object_database *ent;
+       int r = 0;
+
+       prepare_alt_odb(the_repository);
+       for (ent = the_repository->objects->alt_odb_list; ent; ent = ent->next) {
+               r = fn(ent, cb);
+               if (r)
+                       break;
+       }
+       return r;
+}
+
+void prepare_alt_odb(struct repository *r)
+{
+       if (r->objects->alt_odb_tail)
+               return;
+
+       r->objects->alt_odb_tail = &r->objects->alt_odb_list;
+       link_alt_odb_entries(r, r->objects->alternate_db, PATH_SEP, NULL, 0);
+
+       read_info_alternates(r, r->objects->objectdir, 0);
+}
+
+/* Returns 1 if we have successfully freshened the file, 0 otherwise. */
+static int freshen_file(const char *fn)
+{
+       struct utimbuf t;
+       t.actime = t.modtime = time(NULL);
+       return !utime(fn, &t);
+}
+
+/*
+ * All of the check_and_freshen functions return 1 if the file exists and was
+ * freshened (if freshening was requested), 0 otherwise. If they return
+ * 0, you should not assume that it is safe to skip a write of the object (it
+ * either does not exist on disk, or has a stale mtime and may be subject to
+ * pruning).
+ */
+int check_and_freshen_file(const char *fn, int freshen)
+{
+       if (access(fn, F_OK))
+               return 0;
+       if (freshen && !freshen_file(fn))
+               return 0;
+       return 1;
+}
+
+static int check_and_freshen_local(const unsigned char *sha1, int freshen)
+{
+       static struct strbuf buf = STRBUF_INIT;
+
+       strbuf_reset(&buf);
+       sha1_file_name(the_repository, &buf, sha1);
+
+       return check_and_freshen_file(buf.buf, freshen);
+}
+
+static int check_and_freshen_nonlocal(const unsigned char *sha1, int freshen)
+{
+       struct alternate_object_database *alt;
+       prepare_alt_odb(the_repository);
+       for (alt = the_repository->objects->alt_odb_list; alt; alt = alt->next) {
+               const char *path = alt_sha1_path(alt, sha1);
+               if (check_and_freshen_file(path, freshen))
+                       return 1;
+       }
+       return 0;
+}
+
+static int check_and_freshen(const unsigned char *sha1, int freshen)
+{
+       return check_and_freshen_local(sha1, freshen) ||
+              check_and_freshen_nonlocal(sha1, freshen);
+}
+
+int has_loose_object_nonlocal(const unsigned char *sha1)
+{
+       return check_and_freshen_nonlocal(sha1, 0);
+}
+
+static int has_loose_object(const unsigned char *sha1)
+{
+       return check_and_freshen(sha1, 0);
+}
+
+static void mmap_limit_check(size_t length)
+{
+       static size_t limit = 0;
+       if (!limit) {
+               limit = git_env_ulong("GIT_MMAP_LIMIT", 0);
+               if (!limit)
+                       limit = SIZE_MAX;
+       }
+       if (length > limit)
+               die("attempting to mmap %"PRIuMAX" over limit %"PRIuMAX,
+                   (uintmax_t)length, (uintmax_t)limit);
+}
+
+void *xmmap_gently(void *start, size_t length,
+                 int prot, int flags, int fd, off_t offset)
+{
+       void *ret;
+
+       mmap_limit_check(length);
+       ret = mmap(start, length, prot, flags, fd, offset);
+       if (ret == MAP_FAILED) {
+               if (!length)
+                       return NULL;
+               release_pack_memory(length);
+               ret = mmap(start, length, prot, flags, fd, offset);
+       }
+       return ret;
+}
+
+void *xmmap(void *start, size_t length,
+       int prot, int flags, int fd, off_t offset)
+{
+       void *ret = xmmap_gently(start, length, prot, flags, fd, offset);
+       if (ret == MAP_FAILED)
+               die_errno("mmap failed");
+       return ret;
+}
+
+/*
+ * With an in-core object data in "map", rehash it to make sure the
+ * object name actually matches "sha1" to detect object corruption.
+ * With "map" == NULL, try reading the object named with "sha1" using
+ * the streaming interface and rehash it to do the same.
+ */
+int check_object_signature(const struct object_id *oid, void *map,
+                          unsigned long size, const char *type)
+{
+       struct object_id real_oid;
+       enum object_type obj_type;
+       struct git_istream *st;
+       git_hash_ctx c;
+       char hdr[MAX_HEADER_LEN];
+       int hdrlen;
+
+       if (map) {
+               hash_object_file(map, size, type, &real_oid);
+               return oidcmp(oid, &real_oid) ? -1 : 0;
+       }
+
+       st = open_istream(oid, &obj_type, &size, NULL);
+       if (!st)
+               return -1;
+
+       /* Generate the header */
+       hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", type_name(obj_type), size) + 1;
+
+       /* Sha1.. */
+       the_hash_algo->init_fn(&c);
+       the_hash_algo->update_fn(&c, hdr, hdrlen);
+       for (;;) {
+               char buf[1024 * 16];
+               ssize_t readlen = read_istream(st, buf, sizeof(buf));
+
+               if (readlen < 0) {
+                       close_istream(st);
+                       return -1;
+               }
+               if (!readlen)
+                       break;
+               the_hash_algo->update_fn(&c, buf, readlen);
+       }
+       the_hash_algo->final_fn(real_oid.hash, &c);
+       close_istream(st);
+       return oidcmp(oid, &real_oid) ? -1 : 0;
+}
+
+int git_open_cloexec(const char *name, int flags)
+{
+       int fd;
+       static int o_cloexec = O_CLOEXEC;
+
+       fd = open(name, flags | o_cloexec);
+       if ((o_cloexec & O_CLOEXEC) && fd < 0 && errno == EINVAL) {
+               /* Try again w/o O_CLOEXEC: the kernel might not support it */
+               o_cloexec &= ~O_CLOEXEC;
+               fd = open(name, flags | o_cloexec);
+       }
+
+#if defined(F_GETFD) && defined(F_SETFD) && defined(FD_CLOEXEC)
+       {
+               static int fd_cloexec = FD_CLOEXEC;
+
+               if (!o_cloexec && 0 <= fd && fd_cloexec) {
+                       /* Opened w/o O_CLOEXEC?  try with fcntl(2) to add it */
+                       int flags = fcntl(fd, F_GETFD);
+                       if (fcntl(fd, F_SETFD, flags | fd_cloexec))
+                               fd_cloexec = 0;
+               }
+       }
+#endif
+       return fd;
+}
+
+/*
+ * Find "sha1" as a loose object in the local repository or in an alternate.
+ * Returns 0 on success, negative on failure.
+ *
+ * The "path" out-parameter will give the path of the object we found (if any).
+ * Note that it may point to static storage and is only valid until another
+ * call to sha1_file_name(), etc.
+ */
+static int stat_sha1_file(struct repository *r, const unsigned char *sha1,
+                         struct stat *st, const char **path)
+{
+       struct alternate_object_database *alt;
+       static struct strbuf buf = STRBUF_INIT;
+
+       strbuf_reset(&buf);
+       sha1_file_name(r, &buf, sha1);
+       *path = buf.buf;
+
+       if (!lstat(*path, st))
+               return 0;
+
+       prepare_alt_odb(r);
+       errno = ENOENT;
+       for (alt = r->objects->alt_odb_list; alt; alt = alt->next) {
+               *path = alt_sha1_path(alt, sha1);
+               if (!lstat(*path, st))
+                       return 0;
+       }
+
+       return -1;
+}
+
+/*
+ * Like stat_sha1_file(), but actually open the object and return the
+ * descriptor. See the caveats on the "path" parameter above.
+ */
+static int open_sha1_file(struct repository *r,
+                         const unsigned char *sha1, const char **path)
+{
+       int fd;
+       struct alternate_object_database *alt;
+       int most_interesting_errno;
+       static struct strbuf buf = STRBUF_INIT;
+
+       strbuf_reset(&buf);
+       sha1_file_name(r, &buf, sha1);
+       *path = buf.buf;
+
+       fd = git_open(*path);
+       if (fd >= 0)
+               return fd;
+       most_interesting_errno = errno;
+
+       prepare_alt_odb(r);
+       for (alt = r->objects->alt_odb_list; alt; alt = alt->next) {
+               *path = alt_sha1_path(alt, sha1);
+               fd = git_open(*path);
+               if (fd >= 0)
+                       return fd;
+               if (most_interesting_errno == ENOENT)
+                       most_interesting_errno = errno;
+       }
+       errno = most_interesting_errno;
+       return -1;
+}
+
+/*
+ * Map the loose object at "path" if it is not NULL, or the path found by
+ * searching for a loose object named "sha1".
+ */
+static void *map_sha1_file_1(struct repository *r, const char *path,
+                            const unsigned char *sha1, unsigned long *size)
+{
+       void *map;
+       int fd;
+
+       if (path)
+               fd = git_open(path);
+       else
+               fd = open_sha1_file(r, sha1, &path);
+       map = NULL;
+       if (fd >= 0) {
+               struct stat st;
+
+               if (!fstat(fd, &st)) {
+                       *size = xsize_t(st.st_size);
+                       if (!*size) {
+                               /* mmap() is forbidden on empty files */
+                               error("object file %s is empty", path);
+                               return NULL;
+                       }
+                       map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
+               }
+               close(fd);
+       }
+       return map;
+}
+
+void *map_sha1_file(struct repository *r,
+                   const unsigned char *sha1, unsigned long *size)
+{
+       return map_sha1_file_1(r, NULL, sha1, size);
+}
+
+static int unpack_sha1_short_header(git_zstream *stream,
+                                   unsigned char *map, unsigned long mapsize,
+                                   void *buffer, unsigned long bufsiz)
+{
+       /* Get the data stream */
+       memset(stream, 0, sizeof(*stream));
+       stream->next_in = map;
+       stream->avail_in = mapsize;
+       stream->next_out = buffer;
+       stream->avail_out = bufsiz;
+
+       git_inflate_init(stream);
+       return git_inflate(stream, 0);
+}
+
+int unpack_sha1_header(git_zstream *stream,
+                      unsigned char *map, unsigned long mapsize,
+                      void *buffer, unsigned long bufsiz)
+{
+       int status = unpack_sha1_short_header(stream, map, mapsize,
+                                             buffer, bufsiz);
+
+       if (status < Z_OK)
+               return status;
+
+       /* Make sure we have the terminating NUL */
+       if (!memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
+               return -1;
+       return 0;
+}
+
+static int unpack_sha1_header_to_strbuf(git_zstream *stream, unsigned char *map,
+                                       unsigned long mapsize, void *buffer,
+                                       unsigned long bufsiz, struct strbuf *header)
+{
+       int status;
+
+       status = unpack_sha1_short_header(stream, map, mapsize, buffer, bufsiz);
+       if (status < Z_OK)
+               return -1;
+
+       /*
+        * Check if entire header is unpacked in the first iteration.
+        */
+       if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
+               return 0;
+
+       /*
+        * buffer[0..bufsiz] was not large enough.  Copy the partial
+        * result out to header, and then append the result of further
+        * reading the stream.
+        */
+       strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
+       stream->next_out = buffer;
+       stream->avail_out = bufsiz;
+
+       do {
+               status = git_inflate(stream, 0);
+               strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
+               if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
+                       return 0;
+               stream->next_out = buffer;
+               stream->avail_out = bufsiz;
+       } while (status != Z_STREAM_END);
+       return -1;
+}
+
+static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
+{
+       int bytes = strlen(buffer) + 1;
+       unsigned char *buf = xmallocz(size);
+       unsigned long n;
+       int status = Z_OK;
+
+       n = stream->total_out - bytes;
+       if (n > size)
+               n = size;
+       memcpy(buf, (char *) buffer + bytes, n);
+       bytes = n;
+       if (bytes <= size) {
+               /*
+                * The above condition must be (bytes <= size), not
+                * (bytes < size).  In other words, even though we
+                * expect no more output and set avail_out to zero,
+                * the input zlib stream may have bytes that express
+                * "this concludes the stream", and we *do* want to
+                * eat that input.
+                *
+                * Otherwise we would not be able to test that we
+                * consumed all the input to reach the expected size;
+                * we also want to check that zlib tells us that all
+                * went well with status == Z_STREAM_END at the end.
+                */
+               stream->next_out = buf + bytes;
+               stream->avail_out = size - bytes;
+               while (status == Z_OK)
+                       status = git_inflate(stream, Z_FINISH);
+       }
+       if (status == Z_STREAM_END && !stream->avail_in) {
+               git_inflate_end(stream);
+               return buf;
+       }
+
+       if (status < 0)
+               error("corrupt loose object '%s'", sha1_to_hex(sha1));
+       else if (stream->avail_in)
+               error("garbage at end of loose object '%s'",
+                     sha1_to_hex(sha1));
+       free(buf);
+       return NULL;
+}
+
+/*
+ * We used to just use "sscanf()", but that's actually way
+ * too permissive for what we want to check. So do an anal
+ * object header parse by hand.
+ */
+static int parse_sha1_header_extended(const char *hdr, struct object_info *oi,
+                              unsigned int flags)
+{
+       const char *type_buf = hdr;
+       unsigned long size;
+       int type, type_len = 0;
+
+       /*
+        * The type can be of any size but is followed by
+        * a space.
+        */
+       for (;;) {
+               char c = *hdr++;
+               if (!c)
+                       return -1;
+               if (c == ' ')
+                       break;
+               type_len++;
+       }
+
+       type = type_from_string_gently(type_buf, type_len, 1);
+       if (oi->type_name)
+               strbuf_add(oi->type_name, type_buf, type_len);
+       /*
+        * Set type to 0 if its an unknown object and
+        * we're obtaining the type using '--allow-unknown-type'
+        * option.
+        */
+       if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE) && (type < 0))
+               type = 0;
+       else if (type < 0)
+               die("invalid object type");
+       if (oi->typep)
+               *oi->typep = type;
+
+       /*
+        * The length must follow immediately, and be in canonical
+        * decimal format (ie "010" is not valid).
+        */
+       size = *hdr++ - '0';
+       if (size > 9)
+               return -1;
+       if (size) {
+               for (;;) {
+                       unsigned long c = *hdr - '0';
+                       if (c > 9)
+                               break;
+                       hdr++;
+                       size = size * 10 + c;
+               }
+       }
+
+       if (oi->sizep)
+               *oi->sizep = size;
+
+       /*
+        * The length must be followed by a zero byte
+        */
+       return *hdr ? -1 : type;
+}
+
+int parse_sha1_header(const char *hdr, unsigned long *sizep)
+{
+       struct object_info oi = OBJECT_INFO_INIT;
+
+       oi.sizep = sizep;
+       return parse_sha1_header_extended(hdr, &oi, 0);
+}
+
+static int sha1_loose_object_info(struct repository *r,
+                                 const unsigned char *sha1,
+                                 struct object_info *oi, int flags)
+{
+       int status = 0;
+       unsigned long mapsize;
+       void *map;
+       git_zstream stream;
+       char hdr[MAX_HEADER_LEN];
+       struct strbuf hdrbuf = STRBUF_INIT;
+       unsigned long size_scratch;
+
+       if (oi->delta_base_sha1)
+               hashclr(oi->delta_base_sha1);
+
+       /*
+        * If we don't care about type or size, then we don't
+        * need to look inside the object at all. Note that we
+        * do not optimize out the stat call, even if the
+        * caller doesn't care about the disk-size, since our
+        * return value implicitly indicates whether the
+        * object even exists.
+        */
+       if (!oi->typep && !oi->type_name && !oi->sizep && !oi->contentp) {
+               const char *path;
+               struct stat st;
+               if (stat_sha1_file(r, sha1, &st, &path) < 0)
+                       return -1;
+               if (oi->disk_sizep)
+                       *oi->disk_sizep = st.st_size;
+               return 0;
+       }
+
+       map = map_sha1_file(r, sha1, &mapsize);
+       if (!map)
+               return -1;
+
+       if (!oi->sizep)
+               oi->sizep = &size_scratch;
+
+       if (oi->disk_sizep)
+               *oi->disk_sizep = mapsize;
+       if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE)) {
+               if (unpack_sha1_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
+                       status = error("unable to unpack %s header with --allow-unknown-type",
+                                      sha1_to_hex(sha1));
+       } else if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
+               status = error("unable to unpack %s header",
+                              sha1_to_hex(sha1));
+       if (status < 0)
+               ; /* Do nothing */
+       else if (hdrbuf.len) {
+               if ((status = parse_sha1_header_extended(hdrbuf.buf, oi, flags)) < 0)
+                       status = error("unable to parse %s header with --allow-unknown-type",
+                                      sha1_to_hex(sha1));
+       } else if ((status = parse_sha1_header_extended(hdr, oi, flags)) < 0)
+               status = error("unable to parse %s header", sha1_to_hex(sha1));
+
+       if (status >= 0 && oi->contentp) {
+               *oi->contentp = unpack_sha1_rest(&stream, hdr,
+                                                *oi->sizep, sha1);
+               if (!*oi->contentp) {
+                       git_inflate_end(&stream);
+                       status = -1;
+               }
+       } else
+               git_inflate_end(&stream);
+
+       munmap(map, mapsize);
+       if (status && oi->typep)
+               *oi->typep = status;
+       if (oi->sizep == &size_scratch)
+               oi->sizep = NULL;
+       strbuf_release(&hdrbuf);
+       oi->whence = OI_LOOSE;
+       return (status < 0) ? status : 0;
+}
+
+int fetch_if_missing = 1;
+
+int oid_object_info_extended(const struct object_id *oid, struct object_info *oi, unsigned flags)
+{
+       static struct object_info blank_oi = OBJECT_INFO_INIT;
+       struct pack_entry e;
+       int rtype;
+       const struct object_id *real = oid;
+       int already_retried = 0;
+
+       if (flags & OBJECT_INFO_LOOKUP_REPLACE)
+               real = lookup_replace_object(oid);
+
+       if (is_null_oid(real))
+               return -1;
+
+       if (!oi)
+               oi = &blank_oi;
+
+       if (!(flags & OBJECT_INFO_SKIP_CACHED)) {
+               struct cached_object *co = find_cached_object(real->hash);
+               if (co) {
+                       if (oi->typep)
+                               *(oi->typep) = co->type;
+                       if (oi->sizep)
+                               *(oi->sizep) = co->size;
+                       if (oi->disk_sizep)
+                               *(oi->disk_sizep) = 0;
+                       if (oi->delta_base_sha1)
+                               hashclr(oi->delta_base_sha1);
+                       if (oi->type_name)
+                               strbuf_addstr(oi->type_name, type_name(co->type));
+                       if (oi->contentp)
+                               *oi->contentp = xmemdupz(co->buf, co->size);
+                       oi->whence = OI_CACHED;
+                       return 0;
+               }
+       }
+
+       while (1) {
+               if (find_pack_entry(the_repository, real->hash, &e))
+                       break;
+
+               if (flags & OBJECT_INFO_IGNORE_LOOSE)
+                       return -1;
+
+               /* Most likely it's a loose object. */
+               if (!sha1_loose_object_info(the_repository, real->hash, oi, flags))
+                       return 0;
+
+               /* Not a loose object; someone else may have just packed it. */
+               if (!(flags & OBJECT_INFO_QUICK)) {
+                       reprepare_packed_git(the_repository);
+                       if (find_pack_entry(the_repository, real->hash, &e))
+                               break;
+               }
+
+               /* Check if it is a missing object */
+               if (fetch_if_missing && repository_format_partial_clone &&
+                   !already_retried) {
+                       /*
+                        * TODO Investigate haveing fetch_object() return
+                        * TODO error/success and stopping the music here.
+                        */
+                       fetch_object(repository_format_partial_clone, real->hash);
+                       already_retried = 1;
+                       continue;
+               }
+
+               return -1;
+       }
+
+       if (oi == &blank_oi)
+               /*
+                * We know that the caller doesn't actually need the
+                * information below, so return early.
+                */
+               return 0;
+       rtype = packed_object_info(e.p, e.offset, oi);
+       if (rtype < 0) {
+               mark_bad_packed_object(e.p, real->hash);
+               return oid_object_info_extended(real, oi, 0);
+       } else if (oi->whence == OI_PACKED) {
+               oi->u.packed.offset = e.offset;
+               oi->u.packed.pack = e.p;
+               oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
+                                        rtype == OBJ_OFS_DELTA);
+       }
+
+       return 0;
+}
+
+/* returns enum object_type or negative */
+int oid_object_info(const struct object_id *oid, unsigned long *sizep)
+{
+       enum object_type type;
+       struct object_info oi = OBJECT_INFO_INIT;
+
+       oi.typep = &type;
+       oi.sizep = sizep;
+       if (oid_object_info_extended(oid, &oi,
+                                    OBJECT_INFO_LOOKUP_REPLACE) < 0)
+               return -1;
+       return type;
+}
+
+static void *read_object(const unsigned char *sha1, enum object_type *type,
+                        unsigned long *size)
+{
+       struct object_id oid;
+       struct object_info oi = OBJECT_INFO_INIT;
+       void *content;
+       oi.typep = type;
+       oi.sizep = size;
+       oi.contentp = &content;
+
+       hashcpy(oid.hash, sha1);
+
+       if (oid_object_info_extended(&oid, &oi, 0) < 0)
+               return NULL;
+       return content;
+}
+
+int pretend_object_file(void *buf, unsigned long len, enum object_type type,
+                       struct object_id *oid)
+{
+       struct cached_object *co;
+
+       hash_object_file(buf, len, type_name(type), oid);
+       if (has_sha1_file(oid->hash) || find_cached_object(oid->hash))
+               return 0;
+       ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
+       co = &cached_objects[cached_object_nr++];
+       co->size = len;
+       co->type = type;
+       co->buf = xmalloc(len);
+       memcpy(co->buf, buf, len);
+       hashcpy(co->sha1, oid->hash);
+       return 0;
+}
+
+/*
+ * This function dies on corrupt objects; the callers who want to
+ * deal with them should arrange to call read_object() and give error
+ * messages themselves.
+ */
+void *read_object_file_extended(const struct object_id *oid,
+                               enum object_type *type,
+                               unsigned long *size,
+                               int lookup_replace)
+{
+       void *data;
+       const struct packed_git *p;
+       const char *path;
+       struct stat st;
+       const struct object_id *repl = lookup_replace ? lookup_replace_object(oid)
+                                                     : oid;
+
+       errno = 0;
+       data = read_object(repl->hash, type, size);
+       if (data)
+               return data;
+
+       if (errno && errno != ENOENT)
+               die_errno("failed to read object %s", oid_to_hex(oid));
+
+       /* die if we replaced an object with one that does not exist */
+       if (repl != oid)
+               die("replacement %s not found for %s",
+                   oid_to_hex(repl), oid_to_hex(oid));
+
+       if (!stat_sha1_file(the_repository, repl->hash, &st, &path))
+               die("loose object %s (stored in %s) is corrupt",
+                   oid_to_hex(repl), path);
+
+       if ((p = has_packed_and_bad(repl->hash)) != NULL)
+               die("packed object %s (stored in %s) is corrupt",
+                   oid_to_hex(repl), p->pack_name);
+
+       return NULL;
+}
+
+void *read_object_with_reference(const struct object_id *oid,
+                                const char *required_type_name,
+                                unsigned long *size,
+                                struct object_id *actual_oid_return)
+{
+       enum object_type type, required_type;
+       void *buffer;
+       unsigned long isize;
+       struct object_id actual_oid;
+
+       required_type = type_from_string(required_type_name);
+       oidcpy(&actual_oid, oid);
+       while (1) {
+               int ref_length = -1;
+               const char *ref_type = NULL;
+
+               buffer = read_object_file(&actual_oid, &type, &isize);
+               if (!buffer)
+                       return NULL;
+               if (type == required_type) {
+                       *size = isize;
+                       if (actual_oid_return)
+                               oidcpy(actual_oid_return, &actual_oid);
+                       return buffer;
+               }
+               /* Handle references */
+               else if (type == OBJ_COMMIT)
+                       ref_type = "tree ";
+               else if (type == OBJ_TAG)
+                       ref_type = "object ";
+               else {
+                       free(buffer);
+                       return NULL;
+               }
+               ref_length = strlen(ref_type);
+
+               if (ref_length + GIT_SHA1_HEXSZ > isize ||
+                   memcmp(buffer, ref_type, ref_length) ||
+                   get_oid_hex((char *) buffer + ref_length, &actual_oid)) {
+                       free(buffer);
+                       return NULL;
+               }
+               free(buffer);
+               /* Now we have the ID of the referred-to object in
+                * actual_oid.  Check again. */
+       }
+}
+
+static void write_object_file_prepare(const void *buf, unsigned long len,
+                                     const char *type, struct object_id *oid,
+                                     char *hdr, int *hdrlen)
+{
+       git_hash_ctx c;
+
+       /* Generate the header */
+       *hdrlen = xsnprintf(hdr, *hdrlen, "%s %lu", type, len)+1;
+
+       /* Sha1.. */
+       the_hash_algo->init_fn(&c);
+       the_hash_algo->update_fn(&c, hdr, *hdrlen);
+       the_hash_algo->update_fn(&c, buf, len);
+       the_hash_algo->final_fn(oid->hash, &c);
+}
+
+/*
+ * Move the just written object into its final resting place.
+ */
+int finalize_object_file(const char *tmpfile, const char *filename)
+{
+       int ret = 0;
+
+       if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
+               goto try_rename;
+       else if (link(tmpfile, filename))
+               ret = errno;
+
+       /*
+        * Coda hack - coda doesn't like cross-directory links,
+        * so we fall back to a rename, which will mean that it
+        * won't be able to check collisions, but that's not a
+        * big deal.
+        *
+        * The same holds for FAT formatted media.
+        *
+        * When this succeeds, we just return.  We have nothing
+        * left to unlink.
+        */
+       if (ret && ret != EEXIST) {
+       try_rename:
+               if (!rename(tmpfile, filename))
+                       goto out;
+               ret = errno;
+       }
+       unlink_or_warn(tmpfile);
+       if (ret) {
+               if (ret != EEXIST) {
+                       return error_errno("unable to write sha1 filename %s", filename);
+               }
+               /* FIXME!!! Collision check here ? */
+       }
+
+out:
+       if (adjust_shared_perm(filename))
+               return error("unable to set permission to '%s'", filename);
+       return 0;
+}
+
+static int write_buffer(int fd, const void *buf, size_t len)
+{
+       if (write_in_full(fd, buf, len) < 0)
+               return error_errno("file write error");
+       return 0;
+}
+
+int hash_object_file(const void *buf, unsigned long len, const char *type,
+                    struct object_id *oid)
+{
+       char hdr[MAX_HEADER_LEN];
+       int hdrlen = sizeof(hdr);
+       write_object_file_prepare(buf, len, type, oid, hdr, &hdrlen);
+       return 0;
+}
+
+/* Finalize a file on disk, and close it. */
+static void close_sha1_file(int fd)
+{
+       if (fsync_object_files)
+               fsync_or_die(fd, "sha1 file");
+       if (close(fd) != 0)
+               die_errno("error when closing sha1 file");
+}
+
+/* Size of directory component, including the ending '/' */
+static inline int directory_size(const char *filename)
+{
+       const char *s = strrchr(filename, '/');
+       if (!s)
+               return 0;
+       return s - filename + 1;
+}
+
+/*
+ * This creates a temporary file in the same directory as the final
+ * 'filename'
+ *
+ * We want to avoid cross-directory filename renames, because those
+ * can have problems on various filesystems (FAT, NFS, Coda).
+ */
+static int create_tmpfile(struct strbuf *tmp, const char *filename)
+{
+       int fd, dirlen = directory_size(filename);
+
+       strbuf_reset(tmp);
+       strbuf_add(tmp, filename, dirlen);
+       strbuf_addstr(tmp, "tmp_obj_XXXXXX");
+       fd = git_mkstemp_mode(tmp->buf, 0444);
+       if (fd < 0 && dirlen && errno == ENOENT) {
+               /*
+                * Make sure the directory exists; note that the contents
+                * of the buffer are undefined after mkstemp returns an
+                * error, so we have to rewrite the whole buffer from
+                * scratch.
+                */
+               strbuf_reset(tmp);
+               strbuf_add(tmp, filename, dirlen - 1);
+               if (mkdir(tmp->buf, 0777) && errno != EEXIST)
+                       return -1;
+               if (adjust_shared_perm(tmp->buf))
+                       return -1;
+
+               /* Try again */
+               strbuf_addstr(tmp, "/tmp_obj_XXXXXX");
+               fd = git_mkstemp_mode(tmp->buf, 0444);
+       }
+       return fd;
+}
+
+static int write_loose_object(const struct object_id *oid, char *hdr,
+                             int hdrlen, const void *buf, unsigned long len,
+                             time_t mtime)
+{
+       int fd, ret;
+       unsigned char compressed[4096];
+       git_zstream stream;
+       git_hash_ctx c;
+       struct object_id parano_oid;
+       static struct strbuf tmp_file = STRBUF_INIT;
+       static struct strbuf filename = STRBUF_INIT;
+
+       strbuf_reset(&filename);
+       sha1_file_name(the_repository, &filename, oid->hash);
+
+       fd = create_tmpfile(&tmp_file, filename.buf);
+       if (fd < 0) {
+               if (errno == EACCES)
+                       return error("insufficient permission for adding an object to repository database %s", get_object_directory());
+               else
+                       return error_errno("unable to create temporary file");
+       }
+
+       /* Set it up */
+       git_deflate_init(&stream, zlib_compression_level);
+       stream.next_out = compressed;
+       stream.avail_out = sizeof(compressed);
+       the_hash_algo->init_fn(&c);
+
+       /* First header.. */
+       stream.next_in = (unsigned char *)hdr;
+       stream.avail_in = hdrlen;
+       while (git_deflate(&stream, 0) == Z_OK)
+               ; /* nothing */
+       the_hash_algo->update_fn(&c, hdr, hdrlen);
+
+       /* Then the data itself.. */
+       stream.next_in = (void *)buf;
+       stream.avail_in = len;
+       do {
+               unsigned char *in0 = stream.next_in;
+               ret = git_deflate(&stream, Z_FINISH);
+               the_hash_algo->update_fn(&c, in0, stream.next_in - in0);
+               if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
+                       die("unable to write sha1 file");
+               stream.next_out = compressed;
+               stream.avail_out = sizeof(compressed);
+       } while (ret == Z_OK);
+
+       if (ret != Z_STREAM_END)
+               die("unable to deflate new object %s (%d)", oid_to_hex(oid),
+                   ret);
+       ret = git_deflate_end_gently(&stream);
+       if (ret != Z_OK)
+               die("deflateEnd on object %s failed (%d)", oid_to_hex(oid),
+                   ret);
+       the_hash_algo->final_fn(parano_oid.hash, &c);
+       if (oidcmp(oid, &parano_oid) != 0)
+               die("confused by unstable object source data for %s",
+                   oid_to_hex(oid));
+
+       close_sha1_file(fd);
+
+       if (mtime) {
+               struct utimbuf utb;
+               utb.actime = mtime;
+               utb.modtime = mtime;
+               if (utime(tmp_file.buf, &utb) < 0)
+                       warning_errno("failed utime() on %s", tmp_file.buf);
+       }
+
+       return finalize_object_file(tmp_file.buf, filename.buf);
+}
+
+static int freshen_loose_object(const unsigned char *sha1)
+{
+       return check_and_freshen(sha1, 1);
+}
+
+static int freshen_packed_object(const unsigned char *sha1)
+{
+       struct pack_entry e;
+       if (!find_pack_entry(the_repository, sha1, &e))
+               return 0;
+       if (e.p->freshened)
+               return 1;
+       if (!freshen_file(e.p->pack_name))
+               return 0;
+       e.p->freshened = 1;
+       return 1;
+}
+
+int write_object_file(const void *buf, unsigned long len, const char *type,
+                     struct object_id *oid)
+{
+       char hdr[MAX_HEADER_LEN];
+       int hdrlen = sizeof(hdr);
+
+       /* Normally if we have it in the pack then we do not bother writing
+        * it out into .git/objects/??/?{38} file.
+        */
+       write_object_file_prepare(buf, len, type, oid, hdr, &hdrlen);
+       if (freshen_packed_object(oid->hash) || freshen_loose_object(oid->hash))
+               return 0;
+       return write_loose_object(oid, hdr, hdrlen, buf, len, 0);
+}
+
+int hash_object_file_literally(const void *buf, unsigned long len,
+                              const char *type, struct object_id *oid,
+                              unsigned flags)
+{
+       char *header;
+       int hdrlen, status = 0;
+
+       /* type string, SP, %lu of the length plus NUL must fit this */
+       hdrlen = strlen(type) + MAX_HEADER_LEN;
+       header = xmalloc(hdrlen);
+       write_object_file_prepare(buf, len, type, oid, header, &hdrlen);
+
+       if (!(flags & HASH_WRITE_OBJECT))
+               goto cleanup;
+       if (freshen_packed_object(oid->hash) || freshen_loose_object(oid->hash))
+               goto cleanup;
+       status = write_loose_object(oid, header, hdrlen, buf, len, 0);
+
+cleanup:
+       free(header);
+       return status;
+}
+
+int force_object_loose(const struct object_id *oid, time_t mtime)
+{
+       void *buf;
+       unsigned long len;
+       enum object_type type;
+       char hdr[MAX_HEADER_LEN];
+       int hdrlen;
+       int ret;
+
+       if (has_loose_object(oid->hash))
+               return 0;
+       buf = read_object(oid->hash, &type, &len);
+       if (!buf)
+               return error("cannot read sha1_file for %s", oid_to_hex(oid));
+       hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", type_name(type), len) + 1;
+       ret = write_loose_object(oid, hdr, hdrlen, buf, len, mtime);
+       free(buf);
+
+       return ret;
+}
+
+int has_sha1_file_with_flags(const unsigned char *sha1, int flags)
+{
+       struct object_id oid;
+       if (!startup_info->have_repository)
+               return 0;
+       hashcpy(oid.hash, sha1);
+       return oid_object_info_extended(&oid, NULL,
+                                       flags | OBJECT_INFO_SKIP_CACHED) >= 0;
+}
+
+int has_object_file(const struct object_id *oid)
+{
+       return has_sha1_file(oid->hash);
+}
+
+int has_object_file_with_flags(const struct object_id *oid, int flags)
+{
+       return has_sha1_file_with_flags(oid->hash, flags);
+}
+
+static void check_tree(const void *buf, size_t size)
+{
+       struct tree_desc desc;
+       struct name_entry entry;
+
+       init_tree_desc(&desc, buf, size);
+       while (tree_entry(&desc, &entry))
+               /* do nothing
+                * tree_entry() will die() on malformed entries */
+               ;
+}
+
+static void check_commit(const void *buf, size_t size)
+{
+       struct commit c;
+       memset(&c, 0, sizeof(c));
+       if (parse_commit_buffer(&c, buf, size))
+               die("corrupt commit");
+}
+
+static void check_tag(const void *buf, size_t size)
+{
+       struct tag t;
+       memset(&t, 0, sizeof(t));
+       if (parse_tag_buffer(&t, buf, size))
+               die("corrupt tag");
+}
+
+static int index_mem(struct object_id *oid, void *buf, size_t size,
+                    enum object_type type,
+                    const char *path, unsigned flags)
+{
+       int ret, re_allocated = 0;
+       int write_object = flags & HASH_WRITE_OBJECT;
+
+       if (!type)
+               type = OBJ_BLOB;
+
+       /*
+        * Convert blobs to git internal format
+        */
+       if ((type == OBJ_BLOB) && path) {
+               struct strbuf nbuf = STRBUF_INIT;
+               if (convert_to_git(&the_index, path, buf, size, &nbuf,
+                                  get_conv_flags(flags))) {
+                       buf = strbuf_detach(&nbuf, &size);
+                       re_allocated = 1;
+               }
+       }
+       if (flags & HASH_FORMAT_CHECK) {
+               if (type == OBJ_TREE)
+                       check_tree(buf, size);
+               if (type == OBJ_COMMIT)
+                       check_commit(buf, size);
+               if (type == OBJ_TAG)
+                       check_tag(buf, size);
+       }
+
+       if (write_object)
+               ret = write_object_file(buf, size, type_name(type), oid);
+       else
+               ret = hash_object_file(buf, size, type_name(type), oid);
+       if (re_allocated)
+               free(buf);
+       return ret;
+}
+
+static int index_stream_convert_blob(struct object_id *oid, int fd,
+                                    const char *path, unsigned flags)
+{
+       int ret;
+       const int write_object = flags & HASH_WRITE_OBJECT;
+       struct strbuf sbuf = STRBUF_INIT;
+
+       assert(path);
+       assert(would_convert_to_git_filter_fd(path));
+
+       convert_to_git_filter_fd(&the_index, path, fd, &sbuf,
+                                get_conv_flags(flags));
+
+       if (write_object)
+               ret = write_object_file(sbuf.buf, sbuf.len, type_name(OBJ_BLOB),
+                                       oid);
+       else
+               ret = hash_object_file(sbuf.buf, sbuf.len, type_name(OBJ_BLOB),
+                                      oid);
+       strbuf_release(&sbuf);
+       return ret;
+}
+
+static int index_pipe(struct object_id *oid, int fd, enum object_type type,
+                     const char *path, unsigned flags)
+{
+       struct strbuf sbuf = STRBUF_INIT;
+       int ret;
+
+       if (strbuf_read(&sbuf, fd, 4096) >= 0)
+               ret = index_mem(oid, sbuf.buf, sbuf.len, type, path, flags);
+       else
+               ret = -1;
+       strbuf_release(&sbuf);
+       return ret;
+}
+
+#define SMALL_FILE_SIZE (32*1024)
+
+static int index_core(struct object_id *oid, int fd, size_t size,
+                     enum object_type type, const char *path,
+                     unsigned flags)
+{
+       int ret;
+
+       if (!size) {
+               ret = index_mem(oid, "", size, type, path, flags);
+       } else if (size <= SMALL_FILE_SIZE) {
+               char *buf = xmalloc(size);
+               ssize_t read_result = read_in_full(fd, buf, size);
+               if (read_result < 0)
+                       ret = error_errno("read error while indexing %s",
+                                         path ? path : "<unknown>");
+               else if (read_result != size)
+                       ret = error("short read while indexing %s",
+                                   path ? path : "<unknown>");
+               else
+                       ret = index_mem(oid, buf, size, type, path, flags);
+               free(buf);
+       } else {
+               void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
+               ret = index_mem(oid, buf, size, type, path, flags);
+               munmap(buf, size);
+       }
+       return ret;
+}
+
+/*
+ * This creates one packfile per large blob unless bulk-checkin
+ * machinery is "plugged".
+ *
+ * This also bypasses the usual "convert-to-git" dance, and that is on
+ * purpose. We could write a streaming version of the converting
+ * functions and insert that before feeding the data to fast-import
+ * (or equivalent in-core API described above). However, that is
+ * somewhat complicated, as we do not know the size of the filter
+ * result, which we need to know beforehand when writing a git object.
+ * Since the primary motivation for trying to stream from the working
+ * tree file and to avoid mmaping it in core is to deal with large
+ * binary blobs, they generally do not want to get any conversion, and
+ * callers should avoid this code path when filters are requested.
+ */
+static int index_stream(struct object_id *oid, int fd, size_t size,
+                       enum object_type type, const char *path,
+                       unsigned flags)
+{
+       return index_bulk_checkin(oid, fd, size, type, path, flags);
+}
+
+int index_fd(struct object_id *oid, int fd, struct stat *st,
+            enum object_type type, const char *path, unsigned flags)
+{
+       int ret;
+
+       /*
+        * Call xsize_t() only when needed to avoid potentially unnecessary
+        * die() for large files.
+        */
+       if (type == OBJ_BLOB && path && would_convert_to_git_filter_fd(path))
+               ret = index_stream_convert_blob(oid, fd, path, flags);
+       else if (!S_ISREG(st->st_mode))
+               ret = index_pipe(oid, fd, type, path, flags);
+       else if (st->st_size <= big_file_threshold || type != OBJ_BLOB ||
+                (path && would_convert_to_git(&the_index, path)))
+               ret = index_core(oid, fd, xsize_t(st->st_size), type, path,
+                                flags);
+       else
+               ret = index_stream(oid, fd, xsize_t(st->st_size), type, path,
+                                  flags);
+       close(fd);
+       return ret;
+}
+
+int index_path(struct object_id *oid, const char *path, struct stat *st, unsigned flags)
+{
+       int fd;
+       struct strbuf sb = STRBUF_INIT;
+       int rc = 0;
+
+       switch (st->st_mode & S_IFMT) {
+       case S_IFREG:
+               fd = open(path, O_RDONLY);
+               if (fd < 0)
+                       return error_errno("open(\"%s\")", path);
+               if (index_fd(oid, fd, st, OBJ_BLOB, path, flags) < 0)
+                       return error("%s: failed to insert into database",
+                                    path);
+               break;
+       case S_IFLNK:
+               if (strbuf_readlink(&sb, path, st->st_size))
+                       return error_errno("readlink(\"%s\")", path);
+               if (!(flags & HASH_WRITE_OBJECT))
+                       hash_object_file(sb.buf, sb.len, blob_type, oid);
+               else if (write_object_file(sb.buf, sb.len, blob_type, oid))
+                       rc = error("%s: failed to insert into database", path);
+               strbuf_release(&sb);
+               break;
+       case S_IFDIR:
+               return resolve_gitlink_ref(path, "HEAD", oid);
+       default:
+               return error("%s: unsupported file type", path);
+       }
+       return rc;
+}
+
+int read_pack_header(int fd, struct pack_header *header)
+{
+       if (read_in_full(fd, header, sizeof(*header)) != sizeof(*header))
+               /* "eof before pack header was fully read" */
+               return PH_ERROR_EOF;
+
+       if (header->hdr_signature != htonl(PACK_SIGNATURE))
+               /* "protocol error (pack signature mismatch detected)" */
+               return PH_ERROR_PACK_SIGNATURE;
+       if (!pack_version_ok(header->hdr_version))
+               /* "protocol error (pack version unsupported)" */
+               return PH_ERROR_PROTOCOL;
+       return 0;
+}
+
+void assert_oid_type(const struct object_id *oid, enum object_type expect)
+{
+       enum object_type type = oid_object_info(oid, NULL);
+       if (type < 0)
+               die("%s is not a valid object", oid_to_hex(oid));
+       if (type != expect)
+               die("%s is not a valid '%s' object", oid_to_hex(oid),
+                   type_name(expect));
+}
+
+int for_each_file_in_obj_subdir(unsigned int subdir_nr,
+                               struct strbuf *path,
+                               each_loose_object_fn obj_cb,
+                               each_loose_cruft_fn cruft_cb,
+                               each_loose_subdir_fn subdir_cb,
+                               void *data)
+{
+       size_t origlen, baselen;
+       DIR *dir;
+       struct dirent *de;
+       int r = 0;
+       struct object_id oid;
+
+       if (subdir_nr > 0xff)
+               BUG("invalid loose object subdirectory: %x", subdir_nr);
+
+       origlen = path->len;
+       strbuf_complete(path, '/');
+       strbuf_addf(path, "%02x", subdir_nr);
+
+       dir = opendir(path->buf);
+       if (!dir) {
+               if (errno != ENOENT)
+                       r = error_errno("unable to open %s", path->buf);
+               strbuf_setlen(path, origlen);
+               return r;
+       }
+
+       oid.hash[0] = subdir_nr;
+       strbuf_addch(path, '/');
+       baselen = path->len;
+
+       while ((de = readdir(dir))) {
+               size_t namelen;
+               if (is_dot_or_dotdot(de->d_name))
+                       continue;
+
+               namelen = strlen(de->d_name);
+               strbuf_setlen(path, baselen);
+               strbuf_add(path, de->d_name, namelen);
+               if (namelen == GIT_SHA1_HEXSZ - 2 &&
+                   !hex_to_bytes(oid.hash + 1, de->d_name,
+                                 GIT_SHA1_RAWSZ - 1)) {
+                       if (obj_cb) {
+                               r = obj_cb(&oid, path->buf, data);
+                               if (r)
+                                       break;
+                       }
+                       continue;
+               }
+
+               if (cruft_cb) {
+                       r = cruft_cb(de->d_name, path->buf, data);
+                       if (r)
+                               break;
+               }
+       }
+       closedir(dir);
+
+       strbuf_setlen(path, baselen - 1);
+       if (!r && subdir_cb)
+               r = subdir_cb(subdir_nr, path->buf, data);
+
+       strbuf_setlen(path, origlen);
+
+       return r;
+}
+
+int for_each_loose_file_in_objdir_buf(struct strbuf *path,
+                           each_loose_object_fn obj_cb,
+                           each_loose_cruft_fn cruft_cb,
+                           each_loose_subdir_fn subdir_cb,
+                           void *data)
+{
+       int r = 0;
+       int i;
+
+       for (i = 0; i < 256; i++) {
+               r = for_each_file_in_obj_subdir(i, path, obj_cb, cruft_cb,
+                                               subdir_cb, data);
+               if (r)
+                       break;
+       }
+
+       return r;
+}
+
+int for_each_loose_file_in_objdir(const char *path,
+                                 each_loose_object_fn obj_cb,
+                                 each_loose_cruft_fn cruft_cb,
+                                 each_loose_subdir_fn subdir_cb,
+                                 void *data)
+{
+       struct strbuf buf = STRBUF_INIT;
+       int r;
+
+       strbuf_addstr(&buf, path);
+       r = for_each_loose_file_in_objdir_buf(&buf, obj_cb, cruft_cb,
+                                             subdir_cb, data);
+       strbuf_release(&buf);
+
+       return r;
+}
+
+struct loose_alt_odb_data {
+       each_loose_object_fn *cb;
+       void *data;
+};
+
+static int loose_from_alt_odb(struct alternate_object_database *alt,
+                             void *vdata)
+{
+       struct loose_alt_odb_data *data = vdata;
+       struct strbuf buf = STRBUF_INIT;
+       int r;
+
+       strbuf_addstr(&buf, alt->path);
+       r = for_each_loose_file_in_objdir_buf(&buf,
+                                             data->cb, NULL, NULL,
+                                             data->data);
+       strbuf_release(&buf);
+       return r;
+}
+
+int for_each_loose_object(each_loose_object_fn cb, void *data, unsigned flags)
+{
+       struct loose_alt_odb_data alt;
+       int r;
+
+       r = for_each_loose_file_in_objdir(get_object_directory(),
+                                         cb, NULL, NULL, data);
+       if (r)
+               return r;
+
+       if (flags & FOR_EACH_OBJECT_LOCAL_ONLY)
+               return 0;
+
+       alt.cb = cb;
+       alt.data = data;
+       return foreach_alt_odb(loose_from_alt_odb, &alt);
+}
+
+static int check_stream_sha1(git_zstream *stream,
+                            const char *hdr,
+                            unsigned long size,
+                            const char *path,
+                            const unsigned char *expected_sha1)
+{
+       git_hash_ctx c;
+       unsigned char real_sha1[GIT_MAX_RAWSZ];
+       unsigned char buf[4096];
+       unsigned long total_read;
+       int status = Z_OK;
+
+       the_hash_algo->init_fn(&c);
+       the_hash_algo->update_fn(&c, hdr, stream->total_out);
+
+       /*
+        * We already read some bytes into hdr, but the ones up to the NUL
+        * do not count against the object's content size.
+        */
+       total_read = stream->total_out - strlen(hdr) - 1;
+
+       /*
+        * This size comparison must be "<=" to read the final zlib packets;
+        * see the comment in unpack_sha1_rest for details.
+        */
+       while (total_read <= size &&
+              (status == Z_OK || status == Z_BUF_ERROR)) {
+               stream->next_out = buf;
+               stream->avail_out = sizeof(buf);
+               if (size - total_read < stream->avail_out)
+                       stream->avail_out = size - total_read;
+               status = git_inflate(stream, Z_FINISH);
+               the_hash_algo->update_fn(&c, buf, stream->next_out - buf);
+               total_read += stream->next_out - buf;
+       }
+       git_inflate_end(stream);
+
+       if (status != Z_STREAM_END) {
+               error("corrupt loose object '%s'", sha1_to_hex(expected_sha1));
+               return -1;
+       }
+       if (stream->avail_in) {
+               error("garbage at end of loose object '%s'",
+                     sha1_to_hex(expected_sha1));
+               return -1;
+       }
+
+       the_hash_algo->final_fn(real_sha1, &c);
+       if (hashcmp(expected_sha1, real_sha1)) {
+               error("sha1 mismatch for %s (expected %s)", path,
+                     sha1_to_hex(expected_sha1));
+               return -1;
+       }
+
+       return 0;
+}
+
+int read_loose_object(const char *path,
+                     const struct object_id *expected_oid,
+                     enum object_type *type,
+                     unsigned long *size,
+                     void **contents)
+{
+       int ret = -1;
+       void *map = NULL;
+       unsigned long mapsize;
+       git_zstream stream;
+       char hdr[MAX_HEADER_LEN];
+
+       *contents = NULL;
+
+       map = map_sha1_file_1(the_repository, path, NULL, &mapsize);
+       if (!map) {
+               error_errno("unable to mmap %s", path);
+               goto out;
+       }
+
+       if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0) {
+               error("unable to unpack header of %s", path);
+               goto out;
+       }
+
+       *type = parse_sha1_header(hdr, size);
+       if (*type < 0) {
+               error("unable to parse header of %s", path);
+               git_inflate_end(&stream);
+               goto out;
+       }
+
+       if (*type == OBJ_BLOB) {
+               if (check_stream_sha1(&stream, hdr, *size, path, expected_oid->hash) < 0)
+                       goto out;
+       } else {
+               *contents = unpack_sha1_rest(&stream, hdr, *size, expected_oid->hash);
+               if (!*contents) {
+                       error("unable to unpack contents of %s", path);
+                       git_inflate_end(&stream);
+                       goto out;
+               }
+               if (check_object_signature(expected_oid, *contents,
+                                        *size, type_name(*type))) {
+                       error("sha1 mismatch for %s (expected %s)", path,
+                             oid_to_hex(expected_oid));
+                       free(*contents);
+                       goto out;
+               }
+       }
+
+       ret = 0; /* everything checks out */
+
+out:
+       if (map)
+               munmap(map, mapsize);
+       return ret;
+}
diff --git a/sha1_file.c b/sha1_file.c
deleted file mode 100644 (file)
index 77ccaab..0000000
+++ /dev/null
@@ -1,2254 +0,0 @@
-/*
- * GIT - The information manager from hell
- *
- * Copyright (C) Linus Torvalds, 2005
- *
- * This handles basic git sha1 object files - packing, unpacking,
- * creation etc.
- */
-#include "cache.h"
-#include "config.h"
-#include "string-list.h"
-#include "lockfile.h"
-#include "delta.h"
-#include "pack.h"
-#include "blob.h"
-#include "commit.h"
-#include "run-command.h"
-#include "tag.h"
-#include "tree.h"
-#include "tree-walk.h"
-#include "refs.h"
-#include "pack-revindex.h"
-#include "sha1-lookup.h"
-#include "bulk-checkin.h"
-#include "repository.h"
-#include "streaming.h"
-#include "dir.h"
-#include "list.h"
-#include "mergesort.h"
-#include "quote.h"
-#include "packfile.h"
-#include "fetch-object.h"
-#include "object-store.h"
-
-/* The maximum size for an object header. */
-#define MAX_HEADER_LEN 32
-
-const unsigned char null_sha1[GIT_MAX_RAWSZ];
-const struct object_id null_oid;
-const struct object_id empty_tree_oid = {
-       EMPTY_TREE_SHA1_BIN_LITERAL
-};
-const struct object_id empty_blob_oid = {
-       EMPTY_BLOB_SHA1_BIN_LITERAL
-};
-
-static void git_hash_sha1_init(git_hash_ctx *ctx)
-{
-       git_SHA1_Init(&ctx->sha1);
-}
-
-static void git_hash_sha1_update(git_hash_ctx *ctx, const void *data, size_t len)
-{
-       git_SHA1_Update(&ctx->sha1, data, len);
-}
-
-static void git_hash_sha1_final(unsigned char *hash, git_hash_ctx *ctx)
-{
-       git_SHA1_Final(hash, &ctx->sha1);
-}
-
-static void git_hash_unknown_init(git_hash_ctx *ctx)
-{
-       die("trying to init unknown hash");
-}
-
-static void git_hash_unknown_update(git_hash_ctx *ctx, const void *data, size_t len)
-{
-       die("trying to update unknown hash");
-}
-
-static void git_hash_unknown_final(unsigned char *hash, git_hash_ctx *ctx)
-{
-       die("trying to finalize unknown hash");
-}
-
-const struct git_hash_algo hash_algos[GIT_HASH_NALGOS] = {
-       {
-               NULL,
-               0x00000000,
-               0,
-               0,
-               git_hash_unknown_init,
-               git_hash_unknown_update,
-               git_hash_unknown_final,
-               NULL,
-               NULL,
-       },
-       {
-               "sha-1",
-               /* "sha1", big-endian */
-               0x73686131,
-               GIT_SHA1_RAWSZ,
-               GIT_SHA1_HEXSZ,
-               git_hash_sha1_init,
-               git_hash_sha1_update,
-               git_hash_sha1_final,
-               &empty_tree_oid,
-               &empty_blob_oid,
-       },
-};
-
-/*
- * This is meant to hold a *small* number of objects that you would
- * want read_sha1_file() to be able to return, but yet you do not want
- * to write them into the object store (e.g. a browse-only
- * application).
- */
-static struct cached_object {
-       unsigned char sha1[20];
-       enum object_type type;
-       void *buf;
-       unsigned long size;
-} *cached_objects;
-static int cached_object_nr, cached_object_alloc;
-
-static struct cached_object empty_tree = {
-       EMPTY_TREE_SHA1_BIN_LITERAL,
-       OBJ_TREE,
-       "",
-       0
-};
-
-static struct cached_object *find_cached_object(const unsigned char *sha1)
-{
-       int i;
-       struct cached_object *co = cached_objects;
-
-       for (i = 0; i < cached_object_nr; i++, co++) {
-               if (!hashcmp(co->sha1, sha1))
-                       return co;
-       }
-       if (!hashcmp(sha1, empty_tree.sha1))
-               return &empty_tree;
-       return NULL;
-}
-
-
-static int get_conv_flags(unsigned flags)
-{
-       if (flags & HASH_RENORMALIZE)
-               return CONV_EOL_RENORMALIZE;
-       else if (flags & HASH_WRITE_OBJECT)
-         return global_conv_flags_eol;
-       else
-               return 0;
-}
-
-
-int mkdir_in_gitdir(const char *path)
-{
-       if (mkdir(path, 0777)) {
-               int saved_errno = errno;
-               struct stat st;
-               struct strbuf sb = STRBUF_INIT;
-
-               if (errno != EEXIST)
-                       return -1;
-               /*
-                * Are we looking at a path in a symlinked worktree
-                * whose original repository does not yet have it?
-                * e.g. .git/rr-cache pointing at its original
-                * repository in which the user hasn't performed any
-                * conflict resolution yet?
-                */
-               if (lstat(path, &st) || !S_ISLNK(st.st_mode) ||
-                   strbuf_readlink(&sb, path, st.st_size) ||
-                   !is_absolute_path(sb.buf) ||
-                   mkdir(sb.buf, 0777)) {
-                       strbuf_release(&sb);
-                       errno = saved_errno;
-                       return -1;
-               }
-               strbuf_release(&sb);
-       }
-       return adjust_shared_perm(path);
-}
-
-enum scld_error safe_create_leading_directories(char *path)
-{
-       char *next_component = path + offset_1st_component(path);
-       enum scld_error ret = SCLD_OK;
-
-       while (ret == SCLD_OK && next_component) {
-               struct stat st;
-               char *slash = next_component, slash_character;
-
-               while (*slash && !is_dir_sep(*slash))
-                       slash++;
-
-               if (!*slash)
-                       break;
-
-               next_component = slash + 1;
-               while (is_dir_sep(*next_component))
-                       next_component++;
-               if (!*next_component)
-                       break;
-
-               slash_character = *slash;
-               *slash = '\0';
-               if (!stat(path, &st)) {
-                       /* path exists */
-                       if (!S_ISDIR(st.st_mode)) {
-                               errno = ENOTDIR;
-                               ret = SCLD_EXISTS;
-                       }
-               } else if (mkdir(path, 0777)) {
-                       if (errno == EEXIST &&
-                           !stat(path, &st) && S_ISDIR(st.st_mode))
-                               ; /* somebody created it since we checked */
-                       else if (errno == ENOENT)
-                               /*
-                                * Either mkdir() failed because
-                                * somebody just pruned the containing
-                                * directory, or stat() failed because
-                                * the file that was in our way was
-                                * just removed.  Either way, inform
-                                * the caller that it might be worth
-                                * trying again:
-                                */
-                               ret = SCLD_VANISHED;
-                       else
-                               ret = SCLD_FAILED;
-               } else if (adjust_shared_perm(path)) {
-                       ret = SCLD_PERMS;
-               }
-               *slash = slash_character;
-       }
-       return ret;
-}
-
-enum scld_error safe_create_leading_directories_const(const char *path)
-{
-       int save_errno;
-       /* path points to cache entries, so xstrdup before messing with it */
-       char *buf = xstrdup(path);
-       enum scld_error result = safe_create_leading_directories(buf);
-
-       save_errno = errno;
-       free(buf);
-       errno = save_errno;
-       return result;
-}
-
-int raceproof_create_file(const char *path, create_file_fn fn, void *cb)
-{
-       /*
-        * The number of times we will try to remove empty directories
-        * in the way of path. This is only 1 because if another
-        * process is racily creating directories that conflict with
-        * us, we don't want to fight against them.
-        */
-       int remove_directories_remaining = 1;
-
-       /*
-        * The number of times that we will try to create the
-        * directories containing path. We are willing to attempt this
-        * more than once, because another process could be trying to
-        * clean up empty directories at the same time as we are
-        * trying to create them.
-        */
-       int create_directories_remaining = 3;
-
-       /* A scratch copy of path, filled lazily if we need it: */
-       struct strbuf path_copy = STRBUF_INIT;
-
-       int ret, save_errno;
-
-       /* Sanity check: */
-       assert(*path);
-
-retry_fn:
-       ret = fn(path, cb);
-       save_errno = errno;
-       if (!ret)
-               goto out;
-
-       if (errno == EISDIR && remove_directories_remaining-- > 0) {
-               /*
-                * A directory is in the way. Maybe it is empty; try
-                * to remove it:
-                */
-               if (!path_copy.len)
-                       strbuf_addstr(&path_copy, path);
-
-               if (!remove_dir_recursively(&path_copy, REMOVE_DIR_EMPTY_ONLY))
-                       goto retry_fn;
-       } else if (errno == ENOENT && create_directories_remaining-- > 0) {
-               /*
-                * Maybe the containing directory didn't exist, or
-                * maybe it was just deleted by a process that is
-                * racing with us to clean up empty directories. Try
-                * to create it:
-                */
-               enum scld_error scld_result;
-
-               if (!path_copy.len)
-                       strbuf_addstr(&path_copy, path);
-
-               do {
-                       scld_result = safe_create_leading_directories(path_copy.buf);
-                       if (scld_result == SCLD_OK)
-                               goto retry_fn;
-               } while (scld_result == SCLD_VANISHED && create_directories_remaining-- > 0);
-       }
-
-out:
-       strbuf_release(&path_copy);
-       errno = save_errno;
-       return ret;
-}
-
-static void fill_sha1_path(struct strbuf *buf, const unsigned char *sha1)
-{
-       int i;
-       for (i = 0; i < 20; i++) {
-               static char hex[] = "0123456789abcdef";
-               unsigned int val = sha1[i];
-               strbuf_addch(buf, hex[val >> 4]);
-               strbuf_addch(buf, hex[val & 0xf]);
-               if (!i)
-                       strbuf_addch(buf, '/');
-       }
-}
-
-void sha1_file_name(struct repository *r, struct strbuf *buf, const unsigned char *sha1)
-{
-       strbuf_addstr(buf, r->objects->objectdir);
-       strbuf_addch(buf, '/');
-       fill_sha1_path(buf, sha1);
-}
-
-struct strbuf *alt_scratch_buf(struct alternate_object_database *alt)
-{
-       strbuf_setlen(&alt->scratch, alt->base_len);
-       return &alt->scratch;
-}
-
-static const char *alt_sha1_path(struct alternate_object_database *alt,
-                                const unsigned char *sha1)
-{
-       struct strbuf *buf = alt_scratch_buf(alt);
-       fill_sha1_path(buf, sha1);
-       return buf->buf;
-}
-
-/*
- * Return non-zero iff the path is usable as an alternate object database.
- */
-static int alt_odb_usable(struct raw_object_store *o,
-                         struct strbuf *path,
-                         const char *normalized_objdir)
-{
-       struct alternate_object_database *alt;
-
-       /* Detect cases where alternate disappeared */
-       if (!is_directory(path->buf)) {
-               error("object directory %s does not exist; "
-                     "check .git/objects/info/alternates.",
-                     path->buf);
-               return 0;
-       }
-
-       /*
-        * Prevent the common mistake of listing the same
-        * thing twice, or object directory itself.
-        */
-       for (alt = o->alt_odb_list; alt; alt = alt->next) {
-               if (!fspathcmp(path->buf, alt->path))
-                       return 0;
-       }
-       if (!fspathcmp(path->buf, normalized_objdir))
-               return 0;
-
-       return 1;
-}
-
-/*
- * Prepare alternate object database registry.
- *
- * The variable alt_odb_list points at the list of struct
- * alternate_object_database.  The elements on this list come from
- * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
- * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
- * whose contents is similar to that environment variable but can be
- * LF separated.  Its base points at a statically allocated buffer that
- * contains "/the/directory/corresponding/to/.git/objects/...", while
- * its name points just after the slash at the end of ".git/objects/"
- * in the example above, and has enough space to hold 40-byte hex
- * SHA1, an extra slash for the first level indirection, and the
- * terminating NUL.
- */
-static void read_info_alternates(struct repository *r,
-                                const char *relative_base,
-                                int depth);
-static int link_alt_odb_entry(struct repository *r, const char *entry,
-       const char *relative_base, int depth, const char *normalized_objdir)
-{
-       struct alternate_object_database *ent;
-       struct strbuf pathbuf = STRBUF_INIT;
-
-       if (!is_absolute_path(entry) && relative_base) {
-               strbuf_realpath(&pathbuf, relative_base, 1);
-               strbuf_addch(&pathbuf, '/');
-       }
-       strbuf_addstr(&pathbuf, entry);
-
-       if (strbuf_normalize_path(&pathbuf) < 0 && relative_base) {
-               error("unable to normalize alternate object path: %s",
-                     pathbuf.buf);
-               strbuf_release(&pathbuf);
-               return -1;
-       }
-
-       /*
-        * The trailing slash after the directory name is given by
-        * this function at the end. Remove duplicates.
-        */
-       while (pathbuf.len && pathbuf.buf[pathbuf.len - 1] == '/')
-               strbuf_setlen(&pathbuf, pathbuf.len - 1);
-
-       if (!alt_odb_usable(r->objects, &pathbuf, normalized_objdir)) {
-               strbuf_release(&pathbuf);
-               return -1;
-       }
-
-       ent = alloc_alt_odb(pathbuf.buf);
-
-       /* add the alternate entry */
-       *r->objects->alt_odb_tail = ent;
-       r->objects->alt_odb_tail = &(ent->next);
-       ent->next = NULL;
-
-       /* recursively add alternates */
-       read_info_alternates(r, pathbuf.buf, depth + 1);
-
-       strbuf_release(&pathbuf);
-       return 0;
-}
-
-static const char *parse_alt_odb_entry(const char *string,
-                                      int sep,
-                                      struct strbuf *out)
-{
-       const char *end;
-
-       strbuf_reset(out);
-
-       if (*string == '#') {
-               /* comment; consume up to next separator */
-               end = strchrnul(string, sep);
-       } else if (*string == '"' && !unquote_c_style(out, string, &end)) {
-               /*
-                * quoted path; unquote_c_style has copied the
-                * data for us and set "end". Broken quoting (e.g.,
-                * an entry that doesn't end with a quote) falls
-                * back to the unquoted case below.
-                */
-       } else {
-               /* normal, unquoted path */
-               end = strchrnul(string, sep);
-               strbuf_add(out, string, end - string);
-       }
-
-       if (*end)
-               end++;
-       return end;
-}
-
-static void link_alt_odb_entries(struct repository *r, const char *alt,
-                                int sep, const char *relative_base, int depth)
-{
-       struct strbuf objdirbuf = STRBUF_INIT;
-       struct strbuf entry = STRBUF_INIT;
-
-       if (!alt || !*alt)
-               return;
-
-       if (depth > 5) {
-               error("%s: ignoring alternate object stores, nesting too deep.",
-                               relative_base);
-               return;
-       }
-
-       strbuf_add_absolute_path(&objdirbuf, r->objects->objectdir);
-       if (strbuf_normalize_path(&objdirbuf) < 0)
-               die("unable to normalize object directory: %s",
-                   objdirbuf.buf);
-
-       while (*alt) {
-               alt = parse_alt_odb_entry(alt, sep, &entry);
-               if (!entry.len)
-                       continue;
-               link_alt_odb_entry(r, entry.buf,
-                                  relative_base, depth, objdirbuf.buf);
-       }
-       strbuf_release(&entry);
-       strbuf_release(&objdirbuf);
-}
-
-static void read_info_alternates(struct repository *r,
-                                const char *relative_base,
-                                int depth)
-{
-       char *path;
-       struct strbuf buf = STRBUF_INIT;
-
-       path = xstrfmt("%s/info/alternates", relative_base);
-       if (strbuf_read_file(&buf, path, 1024) < 0) {
-               warn_on_fopen_errors(path);
-               free(path);
-               return;
-       }
-
-       link_alt_odb_entries(r, buf.buf, '\n', relative_base, depth);
-       strbuf_release(&buf);
-       free(path);
-}
-
-struct alternate_object_database *alloc_alt_odb(const char *dir)
-{
-       struct alternate_object_database *ent;
-
-       FLEX_ALLOC_STR(ent, path, dir);
-       strbuf_init(&ent->scratch, 0);
-       strbuf_addf(&ent->scratch, "%s/", dir);
-       ent->base_len = ent->scratch.len;
-
-       return ent;
-}
-
-void add_to_alternates_file(const char *reference)
-{
-       struct lock_file lock = LOCK_INIT;
-       char *alts = git_pathdup("objects/info/alternates");
-       FILE *in, *out;
-       int found = 0;
-
-       hold_lock_file_for_update(&lock, alts, LOCK_DIE_ON_ERROR);
-       out = fdopen_lock_file(&lock, "w");
-       if (!out)
-               die_errno("unable to fdopen alternates lockfile");
-
-       in = fopen(alts, "r");
-       if (in) {
-               struct strbuf line = STRBUF_INIT;
-
-               while (strbuf_getline(&line, in) != EOF) {
-                       if (!strcmp(reference, line.buf)) {
-                               found = 1;
-                               break;
-                       }
-                       fprintf_or_die(out, "%s\n", line.buf);
-               }
-
-               strbuf_release(&line);
-               fclose(in);
-       }
-       else if (errno != ENOENT)
-               die_errno("unable to read alternates file");
-
-       if (found) {
-               rollback_lock_file(&lock);
-       } else {
-               fprintf_or_die(out, "%s\n", reference);
-               if (commit_lock_file(&lock))
-                       die_errno("unable to move new alternates file into place");
-               if (the_repository->objects->alt_odb_tail)
-                       link_alt_odb_entries(the_repository, reference,
-                                            '\n', NULL, 0);
-       }
-       free(alts);
-}
-
-void add_to_alternates_memory(const char *reference)
-{
-       /*
-        * Make sure alternates are initialized, or else our entry may be
-        * overwritten when they are.
-        */
-       prepare_alt_odb(the_repository);
-
-       link_alt_odb_entries(the_repository, reference,
-                            '\n', NULL, 0);
-}
-
-/*
- * Compute the exact path an alternate is at and returns it. In case of
- * error NULL is returned and the human readable error is added to `err`
- * `path` may be relative and should point to $GITDIR.
- * `err` must not be null.
- */
-char *compute_alternate_path(const char *path, struct strbuf *err)
-{
-       char *ref_git = NULL;
-       const char *repo, *ref_git_s;
-       int seen_error = 0;
-
-       ref_git_s = real_path_if_valid(path);
-       if (!ref_git_s) {
-               seen_error = 1;
-               strbuf_addf(err, _("path '%s' does not exist"), path);
-               goto out;
-       } else
-               /*
-                * Beware: read_gitfile(), real_path() and mkpath()
-                * return static buffer
-                */
-               ref_git = xstrdup(ref_git_s);
-
-       repo = read_gitfile(ref_git);
-       if (!repo)
-               repo = read_gitfile(mkpath("%s/.git", ref_git));
-       if (repo) {
-               free(ref_git);
-               ref_git = xstrdup(repo);
-       }
-
-       if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
-               char *ref_git_git = mkpathdup("%s/.git", ref_git);
-               free(ref_git);
-               ref_git = ref_git_git;
-       } else if (!is_directory(mkpath("%s/objects", ref_git))) {
-               struct strbuf sb = STRBUF_INIT;
-               seen_error = 1;
-               if (get_common_dir(&sb, ref_git)) {
-                       strbuf_addf(err,
-                                   _("reference repository '%s' as a linked "
-                                     "checkout is not supported yet."),
-                                   path);
-                       goto out;
-               }
-
-               strbuf_addf(err, _("reference repository '%s' is not a "
-                                       "local repository."), path);
-               goto out;
-       }
-
-       if (!access(mkpath("%s/shallow", ref_git), F_OK)) {
-               strbuf_addf(err, _("reference repository '%s' is shallow"),
-                           path);
-               seen_error = 1;
-               goto out;
-       }
-
-       if (!access(mkpath("%s/info/grafts", ref_git), F_OK)) {
-               strbuf_addf(err,
-                           _("reference repository '%s' is grafted"),
-                           path);
-               seen_error = 1;
-               goto out;
-       }
-
-out:
-       if (seen_error) {
-               FREE_AND_NULL(ref_git);
-       }
-
-       return ref_git;
-}
-
-int foreach_alt_odb(alt_odb_fn fn, void *cb)
-{
-       struct alternate_object_database *ent;
-       int r = 0;
-
-       prepare_alt_odb(the_repository);
-       for (ent = the_repository->objects->alt_odb_list; ent; ent = ent->next) {
-               r = fn(ent, cb);
-               if (r)
-                       break;
-       }
-       return r;
-}
-
-void prepare_alt_odb(struct repository *r)
-{
-       if (r->objects->alt_odb_tail)
-               return;
-
-       r->objects->alt_odb_tail = &r->objects->alt_odb_list;
-       link_alt_odb_entries(r, r->objects->alternate_db, PATH_SEP, NULL, 0);
-
-       read_info_alternates(r, r->objects->objectdir, 0);
-}
-
-/* Returns 1 if we have successfully freshened the file, 0 otherwise. */
-static int freshen_file(const char *fn)
-{
-       struct utimbuf t;
-       t.actime = t.modtime = time(NULL);
-       return !utime(fn, &t);
-}
-
-/*
- * All of the check_and_freshen functions return 1 if the file exists and was
- * freshened (if freshening was requested), 0 otherwise. If they return
- * 0, you should not assume that it is safe to skip a write of the object (it
- * either does not exist on disk, or has a stale mtime and may be subject to
- * pruning).
- */
-int check_and_freshen_file(const char *fn, int freshen)
-{
-       if (access(fn, F_OK))
-               return 0;
-       if (freshen && !freshen_file(fn))
-               return 0;
-       return 1;
-}
-
-static int check_and_freshen_local(const unsigned char *sha1, int freshen)
-{
-       static struct strbuf buf = STRBUF_INIT;
-
-       strbuf_reset(&buf);
-       sha1_file_name(the_repository, &buf, sha1);
-
-       return check_and_freshen_file(buf.buf, freshen);
-}
-
-static int check_and_freshen_nonlocal(const unsigned char *sha1, int freshen)
-{
-       struct alternate_object_database *alt;
-       prepare_alt_odb(the_repository);
-       for (alt = the_repository->objects->alt_odb_list; alt; alt = alt->next) {
-               const char *path = alt_sha1_path(alt, sha1);
-               if (check_and_freshen_file(path, freshen))
-                       return 1;
-       }
-       return 0;
-}
-
-static int check_and_freshen(const unsigned char *sha1, int freshen)
-{
-       return check_and_freshen_local(sha1, freshen) ||
-              check_and_freshen_nonlocal(sha1, freshen);
-}
-
-int has_loose_object_nonlocal(const unsigned char *sha1)
-{
-       return check_and_freshen_nonlocal(sha1, 0);
-}
-
-static int has_loose_object(const unsigned char *sha1)
-{
-       return check_and_freshen(sha1, 0);
-}
-
-static void mmap_limit_check(size_t length)
-{
-       static size_t limit = 0;
-       if (!limit) {
-               limit = git_env_ulong("GIT_MMAP_LIMIT", 0);
-               if (!limit)
-                       limit = SIZE_MAX;
-       }
-       if (length > limit)
-               die("attempting to mmap %"PRIuMAX" over limit %"PRIuMAX,
-                   (uintmax_t)length, (uintmax_t)limit);
-}
-
-void *xmmap_gently(void *start, size_t length,
-                 int prot, int flags, int fd, off_t offset)
-{
-       void *ret;
-
-       mmap_limit_check(length);
-       ret = mmap(start, length, prot, flags, fd, offset);
-       if (ret == MAP_FAILED) {
-               if (!length)
-                       return NULL;
-               release_pack_memory(length);
-               ret = mmap(start, length, prot, flags, fd, offset);
-       }
-       return ret;
-}
-
-void *xmmap(void *start, size_t length,
-       int prot, int flags, int fd, off_t offset)
-{
-       void *ret = xmmap_gently(start, length, prot, flags, fd, offset);
-       if (ret == MAP_FAILED)
-               die_errno("mmap failed");
-       return ret;
-}
-
-/*
- * With an in-core object data in "map", rehash it to make sure the
- * object name actually matches "sha1" to detect object corruption.
- * With "map" == NULL, try reading the object named with "sha1" using
- * the streaming interface and rehash it to do the same.
- */
-int check_object_signature(const struct object_id *oid, void *map,
-                          unsigned long size, const char *type)
-{
-       struct object_id real_oid;
-       enum object_type obj_type;
-       struct git_istream *st;
-       git_hash_ctx c;
-       char hdr[MAX_HEADER_LEN];
-       int hdrlen;
-
-       if (map) {
-               hash_object_file(map, size, type, &real_oid);
-               return oidcmp(oid, &real_oid) ? -1 : 0;
-       }
-
-       st = open_istream(oid, &obj_type, &size, NULL);
-       if (!st)
-               return -1;
-
-       /* Generate the header */
-       hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", type_name(obj_type), size) + 1;
-
-       /* Sha1.. */
-       the_hash_algo->init_fn(&c);
-       the_hash_algo->update_fn(&c, hdr, hdrlen);
-       for (;;) {
-               char buf[1024 * 16];
-               ssize_t readlen = read_istream(st, buf, sizeof(buf));
-
-               if (readlen < 0) {
-                       close_istream(st);
-                       return -1;
-               }
-               if (!readlen)
-                       break;
-               the_hash_algo->update_fn(&c, buf, readlen);
-       }
-       the_hash_algo->final_fn(real_oid.hash, &c);
-       close_istream(st);
-       return oidcmp(oid, &real_oid) ? -1 : 0;
-}
-
-int git_open_cloexec(const char *name, int flags)
-{
-       int fd;
-       static int o_cloexec = O_CLOEXEC;
-
-       fd = open(name, flags | o_cloexec);
-       if ((o_cloexec & O_CLOEXEC) && fd < 0 && errno == EINVAL) {
-               /* Try again w/o O_CLOEXEC: the kernel might not support it */
-               o_cloexec &= ~O_CLOEXEC;
-               fd = open(name, flags | o_cloexec);
-       }
-
-#if defined(F_GETFD) && defined(F_SETFD) && defined(FD_CLOEXEC)
-       {
-               static int fd_cloexec = FD_CLOEXEC;
-
-               if (!o_cloexec && 0 <= fd && fd_cloexec) {
-                       /* Opened w/o O_CLOEXEC?  try with fcntl(2) to add it */
-                       int flags = fcntl(fd, F_GETFD);
-                       if (fcntl(fd, F_SETFD, flags | fd_cloexec))
-                               fd_cloexec = 0;
-               }
-       }
-#endif
-       return fd;
-}
-
-/*
- * Find "sha1" as a loose object in the local repository or in an alternate.
- * Returns 0 on success, negative on failure.
- *
- * The "path" out-parameter will give the path of the object we found (if any).
- * Note that it may point to static storage and is only valid until another
- * call to sha1_file_name(), etc.
- */
-static int stat_sha1_file(struct repository *r, const unsigned char *sha1,
-                         struct stat *st, const char **path)
-{
-       struct alternate_object_database *alt;
-       static struct strbuf buf = STRBUF_INIT;
-
-       strbuf_reset(&buf);
-       sha1_file_name(r, &buf, sha1);
-       *path = buf.buf;
-
-       if (!lstat(*path, st))
-               return 0;
-
-       prepare_alt_odb(r);
-       errno = ENOENT;
-       for (alt = r->objects->alt_odb_list; alt; alt = alt->next) {
-               *path = alt_sha1_path(alt, sha1);
-               if (!lstat(*path, st))
-                       return 0;
-       }
-
-       return -1;
-}
-
-/*
- * Like stat_sha1_file(), but actually open the object and return the
- * descriptor. See the caveats on the "path" parameter above.
- */
-static int open_sha1_file(struct repository *r,
-                         const unsigned char *sha1, const char **path)
-{
-       int fd;
-       struct alternate_object_database *alt;
-       int most_interesting_errno;
-       static struct strbuf buf = STRBUF_INIT;
-
-       strbuf_reset(&buf);
-       sha1_file_name(r, &buf, sha1);
-       *path = buf.buf;
-
-       fd = git_open(*path);
-       if (fd >= 0)
-               return fd;
-       most_interesting_errno = errno;
-
-       prepare_alt_odb(r);
-       for (alt = r->objects->alt_odb_list; alt; alt = alt->next) {
-               *path = alt_sha1_path(alt, sha1);
-               fd = git_open(*path);
-               if (fd >= 0)
-                       return fd;
-               if (most_interesting_errno == ENOENT)
-                       most_interesting_errno = errno;
-       }
-       errno = most_interesting_errno;
-       return -1;
-}
-
-/*
- * Map the loose object at "path" if it is not NULL, or the path found by
- * searching for a loose object named "sha1".
- */
-static void *map_sha1_file_1(struct repository *r, const char *path,
-                            const unsigned char *sha1, unsigned long *size)
-{
-       void *map;
-       int fd;
-
-       if (path)
-               fd = git_open(path);
-       else
-               fd = open_sha1_file(r, sha1, &path);
-       map = NULL;
-       if (fd >= 0) {
-               struct stat st;
-
-               if (!fstat(fd, &st)) {
-                       *size = xsize_t(st.st_size);
-                       if (!*size) {
-                               /* mmap() is forbidden on empty files */
-                               error("object file %s is empty", path);
-                               return NULL;
-                       }
-                       map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
-               }
-               close(fd);
-       }
-       return map;
-}
-
-void *map_sha1_file(struct repository *r,
-                   const unsigned char *sha1, unsigned long *size)
-{
-       return map_sha1_file_1(r, NULL, sha1, size);
-}
-
-static int unpack_sha1_short_header(git_zstream *stream,
-                                   unsigned char *map, unsigned long mapsize,
-                                   void *buffer, unsigned long bufsiz)
-{
-       /* Get the data stream */
-       memset(stream, 0, sizeof(*stream));
-       stream->next_in = map;
-       stream->avail_in = mapsize;
-       stream->next_out = buffer;
-       stream->avail_out = bufsiz;
-
-       git_inflate_init(stream);
-       return git_inflate(stream, 0);
-}
-
-int unpack_sha1_header(git_zstream *stream,
-                      unsigned char *map, unsigned long mapsize,
-                      void *buffer, unsigned long bufsiz)
-{
-       int status = unpack_sha1_short_header(stream, map, mapsize,
-                                             buffer, bufsiz);
-
-       if (status < Z_OK)
-               return status;
-
-       /* Make sure we have the terminating NUL */
-       if (!memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
-               return -1;
-       return 0;
-}
-
-static int unpack_sha1_header_to_strbuf(git_zstream *stream, unsigned char *map,
-                                       unsigned long mapsize, void *buffer,
-                                       unsigned long bufsiz, struct strbuf *header)
-{
-       int status;
-
-       status = unpack_sha1_short_header(stream, map, mapsize, buffer, bufsiz);
-       if (status < Z_OK)
-               return -1;
-
-       /*
-        * Check if entire header is unpacked in the first iteration.
-        */
-       if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
-               return 0;
-
-       /*
-        * buffer[0..bufsiz] was not large enough.  Copy the partial
-        * result out to header, and then append the result of further
-        * reading the stream.
-        */
-       strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
-       stream->next_out = buffer;
-       stream->avail_out = bufsiz;
-
-       do {
-               status = git_inflate(stream, 0);
-               strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
-               if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
-                       return 0;
-               stream->next_out = buffer;
-               stream->avail_out = bufsiz;
-       } while (status != Z_STREAM_END);
-       return -1;
-}
-
-static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
-{
-       int bytes = strlen(buffer) + 1;
-       unsigned char *buf = xmallocz(size);
-       unsigned long n;
-       int status = Z_OK;
-
-       n = stream->total_out - bytes;
-       if (n > size)
-               n = size;
-       memcpy(buf, (char *) buffer + bytes, n);
-       bytes = n;
-       if (bytes <= size) {
-               /*
-                * The above condition must be (bytes <= size), not
-                * (bytes < size).  In other words, even though we
-                * expect no more output and set avail_out to zero,
-                * the input zlib stream may have bytes that express
-                * "this concludes the stream", and we *do* want to
-                * eat that input.
-                *
-                * Otherwise we would not be able to test that we
-                * consumed all the input to reach the expected size;
-                * we also want to check that zlib tells us that all
-                * went well with status == Z_STREAM_END at the end.
-                */
-               stream->next_out = buf + bytes;
-               stream->avail_out = size - bytes;
-               while (status == Z_OK)
-                       status = git_inflate(stream, Z_FINISH);
-       }
-       if (status == Z_STREAM_END && !stream->avail_in) {
-               git_inflate_end(stream);
-               return buf;
-       }
-
-       if (status < 0)
-               error("corrupt loose object '%s'", sha1_to_hex(sha1));
-       else if (stream->avail_in)
-               error("garbage at end of loose object '%s'",
-                     sha1_to_hex(sha1));
-       free(buf);
-       return NULL;
-}
-
-/*
- * We used to just use "sscanf()", but that's actually way
- * too permissive for what we want to check. So do an anal
- * object header parse by hand.
- */
-static int parse_sha1_header_extended(const char *hdr, struct object_info *oi,
-                              unsigned int flags)
-{
-       const char *type_buf = hdr;
-       unsigned long size;
-       int type, type_len = 0;
-
-       /*
-        * The type can be of any size but is followed by
-        * a space.
-        */
-       for (;;) {
-               char c = *hdr++;
-               if (!c)
-                       return -1;
-               if (c == ' ')
-                       break;
-               type_len++;
-       }
-
-       type = type_from_string_gently(type_buf, type_len, 1);
-       if (oi->type_name)
-               strbuf_add(oi->type_name, type_buf, type_len);
-       /*
-        * Set type to 0 if its an unknown object and
-        * we're obtaining the type using '--allow-unknown-type'
-        * option.
-        */
-       if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE) && (type < 0))
-               type = 0;
-       else if (type < 0)
-               die("invalid object type");
-       if (oi->typep)
-               *oi->typep = type;
-
-       /*
-        * The length must follow immediately, and be in canonical
-        * decimal format (ie "010" is not valid).
-        */
-       size = *hdr++ - '0';
-       if (size > 9)
-               return -1;
-       if (size) {
-               for (;;) {
-                       unsigned long c = *hdr - '0';
-                       if (c > 9)
-                               break;
-                       hdr++;
-                       size = size * 10 + c;
-               }
-       }
-
-       if (oi->sizep)
-               *oi->sizep = size;
-
-       /*
-        * The length must be followed by a zero byte
-        */
-       return *hdr ? -1 : type;
-}
-
-int parse_sha1_header(const char *hdr, unsigned long *sizep)
-{
-       struct object_info oi = OBJECT_INFO_INIT;
-
-       oi.sizep = sizep;
-       return parse_sha1_header_extended(hdr, &oi, 0);
-}
-
-static int sha1_loose_object_info(struct repository *r,
-                                 const unsigned char *sha1,
-                                 struct object_info *oi, int flags)
-{
-       int status = 0;
-       unsigned long mapsize;
-       void *map;
-       git_zstream stream;
-       char hdr[MAX_HEADER_LEN];
-       struct strbuf hdrbuf = STRBUF_INIT;
-       unsigned long size_scratch;
-
-       if (oi->delta_base_sha1)
-               hashclr(oi->delta_base_sha1);
-
-       /*
-        * If we don't care about type or size, then we don't
-        * need to look inside the object at all. Note that we
-        * do not optimize out the stat call, even if the
-        * caller doesn't care about the disk-size, since our
-        * return value implicitly indicates whether the
-        * object even exists.
-        */
-       if (!oi->typep && !oi->type_name && !oi->sizep && !oi->contentp) {
-               const char *path;
-               struct stat st;
-               if (stat_sha1_file(r, sha1, &st, &path) < 0)
-                       return -1;
-               if (oi->disk_sizep)
-                       *oi->disk_sizep = st.st_size;
-               return 0;
-       }
-
-       map = map_sha1_file(r, sha1, &mapsize);
-       if (!map)
-               return -1;
-
-       if (!oi->sizep)
-               oi->sizep = &size_scratch;
-
-       if (oi->disk_sizep)
-               *oi->disk_sizep = mapsize;
-       if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE)) {
-               if (unpack_sha1_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
-                       status = error("unable to unpack %s header with --allow-unknown-type",
-                                      sha1_to_hex(sha1));
-       } else if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
-               status = error("unable to unpack %s header",
-                              sha1_to_hex(sha1));
-       if (status < 0)
-               ; /* Do nothing */
-       else if (hdrbuf.len) {
-               if ((status = parse_sha1_header_extended(hdrbuf.buf, oi, flags)) < 0)
-                       status = error("unable to parse %s header with --allow-unknown-type",
-                                      sha1_to_hex(sha1));
-       } else if ((status = parse_sha1_header_extended(hdr, oi, flags)) < 0)
-               status = error("unable to parse %s header", sha1_to_hex(sha1));
-
-       if (status >= 0 && oi->contentp) {
-               *oi->contentp = unpack_sha1_rest(&stream, hdr,
-                                                *oi->sizep, sha1);
-               if (!*oi->contentp) {
-                       git_inflate_end(&stream);
-                       status = -1;
-               }
-       } else
-               git_inflate_end(&stream);
-
-       munmap(map, mapsize);
-       if (status && oi->typep)
-               *oi->typep = status;
-       if (oi->sizep == &size_scratch)
-               oi->sizep = NULL;
-       strbuf_release(&hdrbuf);
-       oi->whence = OI_LOOSE;
-       return (status < 0) ? status : 0;
-}
-
-int fetch_if_missing = 1;
-
-int oid_object_info_extended(const struct object_id *oid, struct object_info *oi, unsigned flags)
-{
-       static struct object_info blank_oi = OBJECT_INFO_INIT;
-       struct pack_entry e;
-       int rtype;
-       const struct object_id *real = oid;
-       int already_retried = 0;
-
-       if (flags & OBJECT_INFO_LOOKUP_REPLACE)
-               real = lookup_replace_object(oid);
-
-       if (is_null_oid(real))
-               return -1;
-
-       if (!oi)
-               oi = &blank_oi;
-
-       if (!(flags & OBJECT_INFO_SKIP_CACHED)) {
-               struct cached_object *co = find_cached_object(real->hash);
-               if (co) {
-                       if (oi->typep)
-                               *(oi->typep) = co->type;
-                       if (oi->sizep)
-                               *(oi->sizep) = co->size;
-                       if (oi->disk_sizep)
-                               *(oi->disk_sizep) = 0;
-                       if (oi->delta_base_sha1)
-                               hashclr(oi->delta_base_sha1);
-                       if (oi->type_name)
-                               strbuf_addstr(oi->type_name, type_name(co->type));
-                       if (oi->contentp)
-                               *oi->contentp = xmemdupz(co->buf, co->size);
-                       oi->whence = OI_CACHED;
-                       return 0;
-               }
-       }
-
-       while (1) {
-               if (find_pack_entry(the_repository, real->hash, &e))
-                       break;
-
-               if (flags & OBJECT_INFO_IGNORE_LOOSE)
-                       return -1;
-
-               /* Most likely it's a loose object. */
-               if (!sha1_loose_object_info(the_repository, real->hash, oi, flags))
-                       return 0;
-
-               /* Not a loose object; someone else may have just packed it. */
-               if (!(flags & OBJECT_INFO_QUICK)) {
-                       reprepare_packed_git(the_repository);
-                       if (find_pack_entry(the_repository, real->hash, &e))
-                               break;
-               }
-
-               /* Check if it is a missing object */
-               if (fetch_if_missing && repository_format_partial_clone &&
-                   !already_retried) {
-                       /*
-                        * TODO Investigate haveing fetch_object() return
-                        * TODO error/success and stopping the music here.
-                        */
-                       fetch_object(repository_format_partial_clone, real->hash);
-                       already_retried = 1;
-                       continue;
-               }
-
-               return -1;
-       }
-
-       if (oi == &blank_oi)
-               /*
-                * We know that the caller doesn't actually need the
-                * information below, so return early.
-                */
-               return 0;
-       rtype = packed_object_info(e.p, e.offset, oi);
-       if (rtype < 0) {
-               mark_bad_packed_object(e.p, real->hash);
-               return oid_object_info_extended(real, oi, 0);
-       } else if (oi->whence == OI_PACKED) {
-               oi->u.packed.offset = e.offset;
-               oi->u.packed.pack = e.p;
-               oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
-                                        rtype == OBJ_OFS_DELTA);
-       }
-
-       return 0;
-}
-
-/* returns enum object_type or negative */
-int oid_object_info(const struct object_id *oid, unsigned long *sizep)
-{
-       enum object_type type;
-       struct object_info oi = OBJECT_INFO_INIT;
-
-       oi.typep = &type;
-       oi.sizep = sizep;
-       if (oid_object_info_extended(oid, &oi,
-                                    OBJECT_INFO_LOOKUP_REPLACE) < 0)
-               return -1;
-       return type;
-}
-
-static void *read_object(const unsigned char *sha1, enum object_type *type,
-                        unsigned long *size)
-{
-       struct object_id oid;
-       struct object_info oi = OBJECT_INFO_INIT;
-       void *content;
-       oi.typep = type;
-       oi.sizep = size;
-       oi.contentp = &content;
-
-       hashcpy(oid.hash, sha1);
-
-       if (oid_object_info_extended(&oid, &oi, 0) < 0)
-               return NULL;
-       return content;
-}
-
-int pretend_object_file(void *buf, unsigned long len, enum object_type type,
-                       struct object_id *oid)
-{
-       struct cached_object *co;
-
-       hash_object_file(buf, len, type_name(type), oid);
-       if (has_sha1_file(oid->hash) || find_cached_object(oid->hash))
-               return 0;
-       ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
-       co = &cached_objects[cached_object_nr++];
-       co->size = len;
-       co->type = type;
-       co->buf = xmalloc(len);
-       memcpy(co->buf, buf, len);
-       hashcpy(co->sha1, oid->hash);
-       return 0;
-}
-
-/*
- * This function dies on corrupt objects; the callers who want to
- * deal with them should arrange to call read_object() and give error
- * messages themselves.
- */
-void *read_object_file_extended(const struct object_id *oid,
-                               enum object_type *type,
-                               unsigned long *size,
-                               int lookup_replace)
-{
-       void *data;
-       const struct packed_git *p;
-       const char *path;
-       struct stat st;
-       const struct object_id *repl = lookup_replace ? lookup_replace_object(oid)
-                                                     : oid;
-
-       errno = 0;
-       data = read_object(repl->hash, type, size);
-       if (data)
-               return data;
-
-       if (errno && errno != ENOENT)
-               die_errno("failed to read object %s", oid_to_hex(oid));
-
-       /* die if we replaced an object with one that does not exist */
-       if (repl != oid)
-               die("replacement %s not found for %s",
-                   oid_to_hex(repl), oid_to_hex(oid));
-
-       if (!stat_sha1_file(the_repository, repl->hash, &st, &path))
-               die("loose object %s (stored in %s) is corrupt",
-                   oid_to_hex(repl), path);
-
-       if ((p = has_packed_and_bad(repl->hash)) != NULL)
-               die("packed object %s (stored in %s) is corrupt",
-                   oid_to_hex(repl), p->pack_name);
-
-       return NULL;
-}
-
-void *read_object_with_reference(const struct object_id *oid,
-                                const char *required_type_name,
-                                unsigned long *size,
-                                struct object_id *actual_oid_return)
-{
-       enum object_type type, required_type;
-       void *buffer;
-       unsigned long isize;
-       struct object_id actual_oid;
-
-       required_type = type_from_string(required_type_name);
-       oidcpy(&actual_oid, oid);
-       while (1) {
-               int ref_length = -1;
-               const char *ref_type = NULL;
-
-               buffer = read_object_file(&actual_oid, &type, &isize);
-               if (!buffer)
-                       return NULL;
-               if (type == required_type) {
-                       *size = isize;
-                       if (actual_oid_return)
-                               oidcpy(actual_oid_return, &actual_oid);
-                       return buffer;
-               }
-               /* Handle references */
-               else if (type == OBJ_COMMIT)
-                       ref_type = "tree ";
-               else if (type == OBJ_TAG)
-                       ref_type = "object ";
-               else {
-                       free(buffer);
-                       return NULL;
-               }
-               ref_length = strlen(ref_type);
-
-               if (ref_length + GIT_SHA1_HEXSZ > isize ||
-                   memcmp(buffer, ref_type, ref_length) ||
-                   get_oid_hex((char *) buffer + ref_length, &actual_oid)) {
-                       free(buffer);
-                       return NULL;
-               }
-               free(buffer);
-               /* Now we have the ID of the referred-to object in
-                * actual_oid.  Check again. */
-       }
-}
-
-static void write_object_file_prepare(const void *buf, unsigned long len,
-                                     const char *type, struct object_id *oid,
-                                     char *hdr, int *hdrlen)
-{
-       git_hash_ctx c;
-
-       /* Generate the header */
-       *hdrlen = xsnprintf(hdr, *hdrlen, "%s %lu", type, len)+1;
-
-       /* Sha1.. */
-       the_hash_algo->init_fn(&c);
-       the_hash_algo->update_fn(&c, hdr, *hdrlen);
-       the_hash_algo->update_fn(&c, buf, len);
-       the_hash_algo->final_fn(oid->hash, &c);
-}
-
-/*
- * Move the just written object into its final resting place.
- */
-int finalize_object_file(const char *tmpfile, const char *filename)
-{
-       int ret = 0;
-
-       if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
-               goto try_rename;
-       else if (link(tmpfile, filename))
-               ret = errno;
-
-       /*
-        * Coda hack - coda doesn't like cross-directory links,
-        * so we fall back to a rename, which will mean that it
-        * won't be able to check collisions, but that's not a
-        * big deal.
-        *
-        * The same holds for FAT formatted media.
-        *
-        * When this succeeds, we just return.  We have nothing
-        * left to unlink.
-        */
-       if (ret && ret != EEXIST) {
-       try_rename:
-               if (!rename(tmpfile, filename))
-                       goto out;
-               ret = errno;
-       }
-       unlink_or_warn(tmpfile);
-       if (ret) {
-               if (ret != EEXIST) {
-                       return error_errno("unable to write sha1 filename %s", filename);
-               }
-               /* FIXME!!! Collision check here ? */
-       }
-
-out:
-       if (adjust_shared_perm(filename))
-               return error("unable to set permission to '%s'", filename);
-       return 0;
-}
-
-static int write_buffer(int fd, const void *buf, size_t len)
-{
-       if (write_in_full(fd, buf, len) < 0)
-               return error_errno("file write error");
-       return 0;
-}
-
-int hash_object_file(const void *buf, unsigned long len, const char *type,
-                    struct object_id *oid)
-{
-       char hdr[MAX_HEADER_LEN];
-       int hdrlen = sizeof(hdr);
-       write_object_file_prepare(buf, len, type, oid, hdr, &hdrlen);
-       return 0;
-}
-
-/* Finalize a file on disk, and close it. */
-static void close_sha1_file(int fd)
-{
-       if (fsync_object_files)
-               fsync_or_die(fd, "sha1 file");
-       if (close(fd) != 0)
-               die_errno("error when closing sha1 file");
-}
-
-/* Size of directory component, including the ending '/' */
-static inline int directory_size(const char *filename)
-{
-       const char *s = strrchr(filename, '/');
-       if (!s)
-               return 0;
-       return s - filename + 1;
-}
-
-/*
- * This creates a temporary file in the same directory as the final
- * 'filename'
- *
- * We want to avoid cross-directory filename renames, because those
- * can have problems on various filesystems (FAT, NFS, Coda).
- */
-static int create_tmpfile(struct strbuf *tmp, const char *filename)
-{
-       int fd, dirlen = directory_size(filename);
-
-       strbuf_reset(tmp);
-       strbuf_add(tmp, filename, dirlen);
-       strbuf_addstr(tmp, "tmp_obj_XXXXXX");
-       fd = git_mkstemp_mode(tmp->buf, 0444);
-       if (fd < 0 && dirlen && errno == ENOENT) {
-               /*
-                * Make sure the directory exists; note that the contents
-                * of the buffer are undefined after mkstemp returns an
-                * error, so we have to rewrite the whole buffer from
-                * scratch.
-                */
-               strbuf_reset(tmp);
-               strbuf_add(tmp, filename, dirlen - 1);
-               if (mkdir(tmp->buf, 0777) && errno != EEXIST)
-                       return -1;
-               if (adjust_shared_perm(tmp->buf))
-                       return -1;
-
-               /* Try again */
-               strbuf_addstr(tmp, "/tmp_obj_XXXXXX");
-               fd = git_mkstemp_mode(tmp->buf, 0444);
-       }
-       return fd;
-}
-
-static int write_loose_object(const struct object_id *oid, char *hdr,
-                             int hdrlen, const void *buf, unsigned long len,
-                             time_t mtime)
-{
-       int fd, ret;
-       unsigned char compressed[4096];
-       git_zstream stream;
-       git_hash_ctx c;
-       struct object_id parano_oid;
-       static struct strbuf tmp_file = STRBUF_INIT;
-       static struct strbuf filename = STRBUF_INIT;
-
-       strbuf_reset(&filename);
-       sha1_file_name(the_repository, &filename, oid->hash);
-
-       fd = create_tmpfile(&tmp_file, filename.buf);
-       if (fd < 0) {
-               if (errno == EACCES)
-                       return error("insufficient permission for adding an object to repository database %s", get_object_directory());
-               else
-                       return error_errno("unable to create temporary file");
-       }
-
-       /* Set it up */
-       git_deflate_init(&stream, zlib_compression_level);
-       stream.next_out = compressed;
-       stream.avail_out = sizeof(compressed);
-       the_hash_algo->init_fn(&c);
-
-       /* First header.. */
-       stream.next_in = (unsigned char *)hdr;
-       stream.avail_in = hdrlen;
-       while (git_deflate(&stream, 0) == Z_OK)
-               ; /* nothing */
-       the_hash_algo->update_fn(&c, hdr, hdrlen);
-
-       /* Then the data itself.. */
-       stream.next_in = (void *)buf;
-       stream.avail_in = len;
-       do {
-               unsigned char *in0 = stream.next_in;
-               ret = git_deflate(&stream, Z_FINISH);
-               the_hash_algo->update_fn(&c, in0, stream.next_in - in0);
-               if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
-                       die("unable to write sha1 file");
-               stream.next_out = compressed;
-               stream.avail_out = sizeof(compressed);
-       } while (ret == Z_OK);
-
-       if (ret != Z_STREAM_END)
-               die("unable to deflate new object %s (%d)", oid_to_hex(oid),
-                   ret);
-       ret = git_deflate_end_gently(&stream);
-       if (ret != Z_OK)
-               die("deflateEnd on object %s failed (%d)", oid_to_hex(oid),
-                   ret);
-       the_hash_algo->final_fn(parano_oid.hash, &c);
-       if (oidcmp(oid, &parano_oid) != 0)
-               die("confused by unstable object source data for %s",
-                   oid_to_hex(oid));
-
-       close_sha1_file(fd);
-
-       if (mtime) {
-               struct utimbuf utb;
-               utb.actime = mtime;
-               utb.modtime = mtime;
-               if (utime(tmp_file.buf, &utb) < 0)
-                       warning_errno("failed utime() on %s", tmp_file.buf);
-       }
-
-       return finalize_object_file(tmp_file.buf, filename.buf);
-}
-
-static int freshen_loose_object(const unsigned char *sha1)
-{
-       return check_and_freshen(sha1, 1);
-}
-
-static int freshen_packed_object(const unsigned char *sha1)
-{
-       struct pack_entry e;
-       if (!find_pack_entry(the_repository, sha1, &e))
-               return 0;
-       if (e.p->freshened)
-               return 1;
-       if (!freshen_file(e.p->pack_name))
-               return 0;
-       e.p->freshened = 1;
-       return 1;
-}
-
-int write_object_file(const void *buf, unsigned long len, const char *type,
-                     struct object_id *oid)
-{
-       char hdr[MAX_HEADER_LEN];
-       int hdrlen = sizeof(hdr);
-
-       /* Normally if we have it in the pack then we do not bother writing
-        * it out into .git/objects/??/?{38} file.
-        */
-       write_object_file_prepare(buf, len, type, oid, hdr, &hdrlen);
-       if (freshen_packed_object(oid->hash) || freshen_loose_object(oid->hash))
-               return 0;
-       return write_loose_object(oid, hdr, hdrlen, buf, len, 0);
-}
-
-int hash_object_file_literally(const void *buf, unsigned long len,
-                              const char *type, struct object_id *oid,
-                              unsigned flags)
-{
-       char *header;
-       int hdrlen, status = 0;
-
-       /* type string, SP, %lu of the length plus NUL must fit this */
-       hdrlen = strlen(type) + MAX_HEADER_LEN;
-       header = xmalloc(hdrlen);
-       write_object_file_prepare(buf, len, type, oid, header, &hdrlen);
-
-       if (!(flags & HASH_WRITE_OBJECT))
-               goto cleanup;
-       if (freshen_packed_object(oid->hash) || freshen_loose_object(oid->hash))
-               goto cleanup;
-       status = write_loose_object(oid, header, hdrlen, buf, len, 0);
-
-cleanup:
-       free(header);
-       return status;
-}
-
-int force_object_loose(const struct object_id *oid, time_t mtime)
-{
-       void *buf;
-       unsigned long len;
-       enum object_type type;
-       char hdr[MAX_HEADER_LEN];
-       int hdrlen;
-       int ret;
-
-       if (has_loose_object(oid->hash))
-               return 0;
-       buf = read_object(oid->hash, &type, &len);
-       if (!buf)
-               return error("cannot read sha1_file for %s", oid_to_hex(oid));
-       hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", type_name(type), len) + 1;
-       ret = write_loose_object(oid, hdr, hdrlen, buf, len, mtime);
-       free(buf);
-
-       return ret;
-}
-
-int has_sha1_file_with_flags(const unsigned char *sha1, int flags)
-{
-       struct object_id oid;
-       if (!startup_info->have_repository)
-               return 0;
-       hashcpy(oid.hash, sha1);
-       return oid_object_info_extended(&oid, NULL,
-                                       flags | OBJECT_INFO_SKIP_CACHED) >= 0;
-}
-
-int has_object_file(const struct object_id *oid)
-{
-       return has_sha1_file(oid->hash);
-}
-
-int has_object_file_with_flags(const struct object_id *oid, int flags)
-{
-       return has_sha1_file_with_flags(oid->hash, flags);
-}
-
-static void check_tree(const void *buf, size_t size)
-{
-       struct tree_desc desc;
-       struct name_entry entry;
-
-       init_tree_desc(&desc, buf, size);
-       while (tree_entry(&desc, &entry))
-               /* do nothing
-                * tree_entry() will die() on malformed entries */
-               ;
-}
-
-static void check_commit(const void *buf, size_t size)
-{
-       struct commit c;
-       memset(&c, 0, sizeof(c));
-       if (parse_commit_buffer(&c, buf, size))
-               die("corrupt commit");
-}
-
-static void check_tag(const void *buf, size_t size)
-{
-       struct tag t;
-       memset(&t, 0, sizeof(t));
-       if (parse_tag_buffer(&t, buf, size))
-               die("corrupt tag");
-}
-
-static int index_mem(struct object_id *oid, void *buf, size_t size,
-                    enum object_type type,
-                    const char *path, unsigned flags)
-{
-       int ret, re_allocated = 0;
-       int write_object = flags & HASH_WRITE_OBJECT;
-
-       if (!type)
-               type = OBJ_BLOB;
-
-       /*
-        * Convert blobs to git internal format
-        */
-       if ((type == OBJ_BLOB) && path) {
-               struct strbuf nbuf = STRBUF_INIT;
-               if (convert_to_git(&the_index, path, buf, size, &nbuf,
-                                  get_conv_flags(flags))) {
-                       buf = strbuf_detach(&nbuf, &size);
-                       re_allocated = 1;
-               }
-       }
-       if (flags & HASH_FORMAT_CHECK) {
-               if (type == OBJ_TREE)
-                       check_tree(buf, size);
-               if (type == OBJ_COMMIT)
-                       check_commit(buf, size);
-               if (type == OBJ_TAG)
-                       check_tag(buf, size);
-       }
-
-       if (write_object)
-               ret = write_object_file(buf, size, type_name(type), oid);
-       else
-               ret = hash_object_file(buf, size, type_name(type), oid);
-       if (re_allocated)
-               free(buf);
-       return ret;
-}
-
-static int index_stream_convert_blob(struct object_id *oid, int fd,
-                                    const char *path, unsigned flags)
-{
-       int ret;
-       const int write_object = flags & HASH_WRITE_OBJECT;
-       struct strbuf sbuf = STRBUF_INIT;
-
-       assert(path);
-       assert(would_convert_to_git_filter_fd(path));
-
-       convert_to_git_filter_fd(&the_index, path, fd, &sbuf,
-                                get_conv_flags(flags));
-
-       if (write_object)
-               ret = write_object_file(sbuf.buf, sbuf.len, type_name(OBJ_BLOB),
-                                       oid);
-       else
-               ret = hash_object_file(sbuf.buf, sbuf.len, type_name(OBJ_BLOB),
-                                      oid);
-       strbuf_release(&sbuf);
-       return ret;
-}
-
-static int index_pipe(struct object_id *oid, int fd, enum object_type type,
-                     const char *path, unsigned flags)
-{
-       struct strbuf sbuf = STRBUF_INIT;
-       int ret;
-
-       if (strbuf_read(&sbuf, fd, 4096) >= 0)
-               ret = index_mem(oid, sbuf.buf, sbuf.len, type, path, flags);
-       else
-               ret = -1;
-       strbuf_release(&sbuf);
-       return ret;
-}
-
-#define SMALL_FILE_SIZE (32*1024)
-
-static int index_core(struct object_id *oid, int fd, size_t size,
-                     enum object_type type, const char *path,
-                     unsigned flags)
-{
-       int ret;
-
-       if (!size) {
-               ret = index_mem(oid, "", size, type, path, flags);
-       } else if (size <= SMALL_FILE_SIZE) {
-               char *buf = xmalloc(size);
-               ssize_t read_result = read_in_full(fd, buf, size);
-               if (read_result < 0)
-                       ret = error_errno("read error while indexing %s",
-                                         path ? path : "<unknown>");
-               else if (read_result != size)
-                       ret = error("short read while indexing %s",
-                                   path ? path : "<unknown>");
-               else
-                       ret = index_mem(oid, buf, size, type, path, flags);
-               free(buf);
-       } else {
-               void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
-               ret = index_mem(oid, buf, size, type, path, flags);
-               munmap(buf, size);
-       }
-       return ret;
-}
-
-/*
- * This creates one packfile per large blob unless bulk-checkin
- * machinery is "plugged".
- *
- * This also bypasses the usual "convert-to-git" dance, and that is on
- * purpose. We could write a streaming version of the converting
- * functions and insert that before feeding the data to fast-import
- * (or equivalent in-core API described above). However, that is
- * somewhat complicated, as we do not know the size of the filter
- * result, which we need to know beforehand when writing a git object.
- * Since the primary motivation for trying to stream from the working
- * tree file and to avoid mmaping it in core is to deal with large
- * binary blobs, they generally do not want to get any conversion, and
- * callers should avoid this code path when filters are requested.
- */
-static int index_stream(struct object_id *oid, int fd, size_t size,
-                       enum object_type type, const char *path,
-                       unsigned flags)
-{
-       return index_bulk_checkin(oid, fd, size, type, path, flags);
-}
-
-int index_fd(struct object_id *oid, int fd, struct stat *st,
-            enum object_type type, const char *path, unsigned flags)
-{
-       int ret;
-
-       /*
-        * Call xsize_t() only when needed to avoid potentially unnecessary
-        * die() for large files.
-        */
-       if (type == OBJ_BLOB && path && would_convert_to_git_filter_fd(path))
-               ret = index_stream_convert_blob(oid, fd, path, flags);
-       else if (!S_ISREG(st->st_mode))
-               ret = index_pipe(oid, fd, type, path, flags);
-       else if (st->st_size <= big_file_threshold || type != OBJ_BLOB ||
-                (path && would_convert_to_git(&the_index, path)))
-               ret = index_core(oid, fd, xsize_t(st->st_size), type, path,
-                                flags);
-       else
-               ret = index_stream(oid, fd, xsize_t(st->st_size), type, path,
-                                  flags);
-       close(fd);
-       return ret;
-}
-
-int index_path(struct object_id *oid, const char *path, struct stat *st, unsigned flags)
-{
-       int fd;
-       struct strbuf sb = STRBUF_INIT;
-       int rc = 0;
-
-       switch (st->st_mode & S_IFMT) {
-       case S_IFREG:
-               fd = open(path, O_RDONLY);
-               if (fd < 0)
-                       return error_errno("open(\"%s\")", path);
-               if (index_fd(oid, fd, st, OBJ_BLOB, path, flags) < 0)
-                       return error("%s: failed to insert into database",
-                                    path);
-               break;
-       case S_IFLNK:
-               if (strbuf_readlink(&sb, path, st->st_size))
-                       return error_errno("readlink(\"%s\")", path);
-               if (!(flags & HASH_WRITE_OBJECT))
-                       hash_object_file(sb.buf, sb.len, blob_type, oid);
-               else if (write_object_file(sb.buf, sb.len, blob_type, oid))
-                       rc = error("%s: failed to insert into database", path);
-               strbuf_release(&sb);
-               break;
-       case S_IFDIR:
-               return resolve_gitlink_ref(path, "HEAD", oid);
-       default:
-               return error("%s: unsupported file type", path);
-       }
-       return rc;
-}
-
-int read_pack_header(int fd, struct pack_header *header)
-{
-       if (read_in_full(fd, header, sizeof(*header)) != sizeof(*header))
-               /* "eof before pack header was fully read" */
-               return PH_ERROR_EOF;
-
-       if (header->hdr_signature != htonl(PACK_SIGNATURE))
-               /* "protocol error (pack signature mismatch detected)" */
-               return PH_ERROR_PACK_SIGNATURE;
-       if (!pack_version_ok(header->hdr_version))
-               /* "protocol error (pack version unsupported)" */
-               return PH_ERROR_PROTOCOL;
-       return 0;
-}
-
-void assert_oid_type(const struct object_id *oid, enum object_type expect)
-{
-       enum object_type type = oid_object_info(oid, NULL);
-       if (type < 0)
-               die("%s is not a valid object", oid_to_hex(oid));
-       if (type != expect)
-               die("%s is not a valid '%s' object", oid_to_hex(oid),
-                   type_name(expect));
-}
-
-int for_each_file_in_obj_subdir(unsigned int subdir_nr,
-                               struct strbuf *path,
-                               each_loose_object_fn obj_cb,
-                               each_loose_cruft_fn cruft_cb,
-                               each_loose_subdir_fn subdir_cb,
-                               void *data)
-{
-       size_t origlen, baselen;
-       DIR *dir;
-       struct dirent *de;
-       int r = 0;
-       struct object_id oid;
-
-       if (subdir_nr > 0xff)
-               BUG("invalid loose object subdirectory: %x", subdir_nr);
-
-       origlen = path->len;
-       strbuf_complete(path, '/');
-       strbuf_addf(path, "%02x", subdir_nr);
-
-       dir = opendir(path->buf);
-       if (!dir) {
-               if (errno != ENOENT)
-                       r = error_errno("unable to open %s", path->buf);
-               strbuf_setlen(path, origlen);
-               return r;
-       }
-
-       oid.hash[0] = subdir_nr;
-       strbuf_addch(path, '/');
-       baselen = path->len;
-
-       while ((de = readdir(dir))) {
-               size_t namelen;
-               if (is_dot_or_dotdot(de->d_name))
-                       continue;
-
-               namelen = strlen(de->d_name);
-               strbuf_setlen(path, baselen);
-               strbuf_add(path, de->d_name, namelen);
-               if (namelen == GIT_SHA1_HEXSZ - 2 &&
-                   !hex_to_bytes(oid.hash + 1, de->d_name,
-                                 GIT_SHA1_RAWSZ - 1)) {
-                       if (obj_cb) {
-                               r = obj_cb(&oid, path->buf, data);
-                               if (r)
-                                       break;
-                       }
-                       continue;
-               }
-
-               if (cruft_cb) {
-                       r = cruft_cb(de->d_name, path->buf, data);
-                       if (r)
-                               break;
-               }
-       }
-       closedir(dir);
-
-       strbuf_setlen(path, baselen - 1);
-       if (!r && subdir_cb)
-               r = subdir_cb(subdir_nr, path->buf, data);
-
-       strbuf_setlen(path, origlen);
-
-       return r;
-}
-
-int for_each_loose_file_in_objdir_buf(struct strbuf *path,
-                           each_loose_object_fn obj_cb,
-                           each_loose_cruft_fn cruft_cb,
-                           each_loose_subdir_fn subdir_cb,
-                           void *data)
-{
-       int r = 0;
-       int i;
-
-       for (i = 0; i < 256; i++) {
-               r = for_each_file_in_obj_subdir(i, path, obj_cb, cruft_cb,
-                                               subdir_cb, data);
-               if (r)
-                       break;
-       }
-
-       return r;
-}
-
-int for_each_loose_file_in_objdir(const char *path,
-                                 each_loose_object_fn obj_cb,
-                                 each_loose_cruft_fn cruft_cb,
-                                 each_loose_subdir_fn subdir_cb,
-                                 void *data)
-{
-       struct strbuf buf = STRBUF_INIT;
-       int r;
-
-       strbuf_addstr(&buf, path);
-       r = for_each_loose_file_in_objdir_buf(&buf, obj_cb, cruft_cb,
-                                             subdir_cb, data);
-       strbuf_release(&buf);
-
-       return r;
-}
-
-struct loose_alt_odb_data {
-       each_loose_object_fn *cb;
-       void *data;
-};
-
-static int loose_from_alt_odb(struct alternate_object_database *alt,
-                             void *vdata)
-{
-       struct loose_alt_odb_data *data = vdata;
-       struct strbuf buf = STRBUF_INIT;
-       int r;
-
-       strbuf_addstr(&buf, alt->path);
-       r = for_each_loose_file_in_objdir_buf(&buf,
-                                             data->cb, NULL, NULL,
-                                             data->data);
-       strbuf_release(&buf);
-       return r;
-}
-
-int for_each_loose_object(each_loose_object_fn cb, void *data, unsigned flags)
-{
-       struct loose_alt_odb_data alt;
-       int r;
-
-       r = for_each_loose_file_in_objdir(get_object_directory(),
-                                         cb, NULL, NULL, data);
-       if (r)
-               return r;
-
-       if (flags & FOR_EACH_OBJECT_LOCAL_ONLY)
-               return 0;
-
-       alt.cb = cb;
-       alt.data = data;
-       return foreach_alt_odb(loose_from_alt_odb, &alt);
-}
-
-static int check_stream_sha1(git_zstream *stream,
-                            const char *hdr,
-                            unsigned long size,
-                            const char *path,
-                            const unsigned char *expected_sha1)
-{
-       git_hash_ctx c;
-       unsigned char real_sha1[GIT_MAX_RAWSZ];
-       unsigned char buf[4096];
-       unsigned long total_read;
-       int status = Z_OK;
-
-       the_hash_algo->init_fn(&c);
-       the_hash_algo->update_fn(&c, hdr, stream->total_out);
-
-       /*
-        * We already read some bytes into hdr, but the ones up to the NUL
-        * do not count against the object's content size.
-        */
-       total_read = stream->total_out - strlen(hdr) - 1;
-
-       /*
-        * This size comparison must be "<=" to read the final zlib packets;
-        * see the comment in unpack_sha1_rest for details.
-        */
-       while (total_read <= size &&
-              (status == Z_OK || status == Z_BUF_ERROR)) {
-               stream->next_out = buf;
-               stream->avail_out = sizeof(buf);
-               if (size - total_read < stream->avail_out)
-                       stream->avail_out = size - total_read;
-               status = git_inflate(stream, Z_FINISH);
-               the_hash_algo->update_fn(&c, buf, stream->next_out - buf);
-               total_read += stream->next_out - buf;
-       }
-       git_inflate_end(stream);
-
-       if (status != Z_STREAM_END) {
-               error("corrupt loose object '%s'", sha1_to_hex(expected_sha1));
-               return -1;
-       }
-       if (stream->avail_in) {
-               error("garbage at end of loose object '%s'",
-                     sha1_to_hex(expected_sha1));
-               return -1;
-       }
-
-       the_hash_algo->final_fn(real_sha1, &c);
-       if (hashcmp(expected_sha1, real_sha1)) {
-               error("sha1 mismatch for %s (expected %s)", path,
-                     sha1_to_hex(expected_sha1));
-               return -1;
-       }
-
-       return 0;
-}
-
-int read_loose_object(const char *path,
-                     const struct object_id *expected_oid,
-                     enum object_type *type,
-                     unsigned long *size,
-                     void **contents)
-{
-       int ret = -1;
-       void *map = NULL;
-       unsigned long mapsize;
-       git_zstream stream;
-       char hdr[MAX_HEADER_LEN];
-
-       *contents = NULL;
-
-       map = map_sha1_file_1(the_repository, path, NULL, &mapsize);
-       if (!map) {
-               error_errno("unable to mmap %s", path);
-               goto out;
-       }
-
-       if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0) {
-               error("unable to unpack header of %s", path);
-               goto out;
-       }
-
-       *type = parse_sha1_header(hdr, size);
-       if (*type < 0) {
-               error("unable to parse header of %s", path);
-               git_inflate_end(&stream);
-               goto out;
-       }
-
-       if (*type == OBJ_BLOB) {
-               if (check_stream_sha1(&stream, hdr, *size, path, expected_oid->hash) < 0)
-                       goto out;
-       } else {
-               *contents = unpack_sha1_rest(&stream, hdr, *size, expected_oid->hash);
-               if (!*contents) {
-                       error("unable to unpack contents of %s", path);
-                       git_inflate_end(&stream);
-                       goto out;
-               }
-               if (check_object_signature(expected_oid, *contents,
-                                        *size, type_name(*type))) {
-                       error("sha1 mismatch for %s (expected %s)", path,
-                             oid_to_hex(expected_oid));
-                       free(*contents);
-                       goto out;
-               }
-       }
-
-       ret = 0; /* everything checks out */
-
-out:
-       if (map)
-               munmap(map, mapsize);
-       return ret;
-}