transport: simplify duplicating a substring in transport_get() using xmemdupz()
[gitweb.git] / sha1_file.c
index 77dbb56946771d631ec544dc1958fcff9215c117..d7f1838c13f5a88448d0f2034347bfb6482b3edf 100644 (file)
@@ -8,6 +8,7 @@
  */
 #include "cache.h"
 #include "string-list.h"
+#include "lockfile.h"
 #include "delta.h"
 #include "pack.h"
 #include "blob.h"
@@ -36,9 +37,6 @@ static inline uintmax_t sz_fmt(size_t s) { return s; }
 
 const unsigned char null_sha1[20];
 
-static const char *no_log_pack_access = "no_log_pack_access";
-static const char *log_pack_access;
-
 /*
  * 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
@@ -60,6 +58,12 @@ static struct cached_object empty_tree = {
        0
 };
 
+/*
+ * A pointer to the last packed_git in which an object was found.
+ * When an object is sought, we look in this packfile first, because
+ * objects that are looked up at similar times are often in the same
+ * packfile as one another.
+ */
 static struct packed_git *last_found_pack;
 
 static struct cached_object *find_cached_object(const unsigned char *sha1)
@@ -178,17 +182,7 @@ static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
        }
 }
 
-/*
- * NOTE! This returns a statically allocated buffer, so you have to be
- * careful about using it. Do an "xstrdup()" if you need to save the
- * filename.
- *
- * Also note that this returns the location for creating.  Reading
- * SHA1 file can happen from any alternate directory listed in the
- * DB_ENVIRONMENT environment variable if it is not found in
- * the primary object database.
- */
-char *sha1_file_name(const unsigned char *sha1)
+const char *sha1_file_name(const unsigned char *sha1)
 {
        static char buf[PATH_MAX];
        const char *objdir;
@@ -208,6 +202,11 @@ char *sha1_file_name(const unsigned char *sha1)
        return buf;
 }
 
+/*
+ * Return the name of the pack or index file with the specified sha1
+ * in its filename.  *base and *name are scratch space that must be
+ * provided by the caller.  which should be "pack" or "idx".
+ */
 static char *sha1_get_pack_name(const unsigned char *sha1,
                                char **name, char **base, const char *which)
 {
@@ -252,8 +251,6 @@ char *sha1_pack_index_name(const unsigned char *sha1)
 struct alternate_object_database *alt_odb_list;
 static struct alternate_object_database **alt_odb_tail;
 
-static int git_open_noatime(const char *name);
-
 /*
  * Prepare alternate object database registry.
  *
@@ -269,9 +266,9 @@ static int git_open_noatime(const char *name);
  * SHA1, an extra slash for the first level indirection, and the
  * terminating NUL.
  */
-static int link_alt_odb_entry(const char *entry, const char *relative_base, int depth)
+static int link_alt_odb_entry(const char *entry, const char *relative_base,
+       int depth, const char *normalized_objdir)
 {
-       const char *objdir = get_object_directory();
        struct alternate_object_database *ent;
        struct alternate_object_database *alt;
        int pfxlen, entlen;
@@ -316,12 +313,13 @@ static int link_alt_odb_entry(const char *entry, const char *relative_base, int
         * thing twice, or object directory itself.
         */
        for (alt = alt_odb_list; alt; alt = alt->next) {
-               if (!memcmp(ent->base, alt->base, pfxlen)) {
+               if (pfxlen == alt->name - alt->base - 1 &&
+                   !memcmp(ent->base, alt->base, pfxlen)) {
                        free(ent);
                        return -1;
                }
        }
-       if (!strcmp(ent->base, objdir)) {
+       if (!strcmp_icase(ent->base, normalized_objdir)) {
                free(ent);
                return -1;
        }
@@ -345,6 +343,7 @@ static void link_alt_odb_entries(const char *alt, int len, int sep,
        struct string_list entries = STRING_LIST_INIT_NODUP;
        char *alt_copy;
        int i;
+       struct strbuf objdirbuf = STRBUF_INIT;
 
        if (depth > 5) {
                error("%s: ignoring alternate object stores, nesting too deep.",
@@ -352,6 +351,9 @@ static void link_alt_odb_entries(const char *alt, int len, int sep,
                return;
        }
 
+       strbuf_add_absolute_path(&objdirbuf, get_object_directory());
+       normalize_path_copy(objdirbuf.buf, objdirbuf.buf);
+
        alt_copy = xmemdupz(alt, len);
        string_list_split_in_place(&entries, alt_copy, sep, -1);
        for (i = 0; i < entries.nr; i++) {
@@ -362,11 +364,12 @@ static void link_alt_odb_entries(const char *alt, int len, int sep,
                        error("%s: ignoring relative alternate object store %s",
                                        relative_base, entry);
                } else {
-                       link_alt_odb_entry(entry, relative_base, depth);
+                       link_alt_odb_entry(entry, relative_base, depth, objdirbuf.buf);
                }
        }
        string_list_clear(&entries, 0);
        free(alt_copy);
+       strbuf_release(&objdirbuf);
 }
 
 void read_info_alternates(const char * relative_base, int depth)
@@ -410,14 +413,18 @@ void add_to_alternates_file(const char *reference)
                link_alt_odb_entries(alt, strlen(alt), '\n', NULL, 0);
 }
 
-void foreach_alt_odb(alt_odb_fn fn, void *cb)
+int foreach_alt_odb(alt_odb_fn fn, void *cb)
 {
        struct alternate_object_database *ent;
+       int r = 0;
 
        prepare_alt_odb();
-       for (ent = alt_odb_list; ent; ent = ent->next)
-               if (fn(ent, cb))
-                       return;
+       for (ent = alt_odb_list; ent; ent = ent->next) {
+               r = fn(ent, cb);
+               if (r)
+                       break;
+       }
+       return r;
 }
 
 void prepare_alt_odb(void)
@@ -436,28 +443,53 @@ void prepare_alt_odb(void)
        read_info_alternates(get_object_directory(), 0);
 }
 
-static int has_loose_object_local(const unsigned char *sha1)
+static int freshen_file(const char *fn)
 {
-       char *name = sha1_file_name(sha1);
-       return !access(name, F_OK);
+       struct utimbuf t;
+       t.actime = t.modtime = time(NULL);
+       return !utime(fn, &t);
 }
 
-int has_loose_object_nonlocal(const unsigned char *sha1)
+static 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)
+{
+       return check_and_freshen_file(sha1_file_name(sha1), freshen);
+}
+
+static int check_and_freshen_nonlocal(const unsigned char *sha1, int freshen)
 {
        struct alternate_object_database *alt;
        prepare_alt_odb();
        for (alt = alt_odb_list; alt; alt = alt->next) {
                fill_sha1_path(alt->name, sha1);
-               if (!access(alt->base, F_OK))
+               if (check_and_freshen_file(alt->base, 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 has_loose_object_local(sha1) ||
-              has_loose_object_nonlocal(sha1);
+       return check_and_freshen(sha1, 0);
 }
 
 static unsigned int pack_used_ctr;
@@ -491,7 +523,12 @@ void pack_report(void)
                sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
 }
 
-static int check_packed_git_idx(const char *path,  struct packed_git *p)
+/*
+ * Open and mmap the index file at path, perform a couple of
+ * consistency checks, then record its information to p.  Return 0 on
+ * success.
+ */
+static int check_packed_git_idx(const char *path, struct packed_git *p)
 {
        void *idx_map;
        struct pack_idx_header *hdr;
@@ -657,10 +694,26 @@ void release_pack_memory(size_t need)
                ; /* nothing */
 }
 
+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(void *start, size_t length,
        int prot, int flags, int fd, off_t offset)
 {
-       void *ret = mmap(start, length, prot, flags, fd, offset);
+       void *ret;
+
+       mmap_limit_check(length);
+       ret = mmap(start, length, prot, flags, fd, offset);
        if (ret == MAP_FAILED) {
                if (!length)
                        return NULL;
@@ -1174,48 +1227,42 @@ static void report_pack_garbage(struct string_list *list)
 
 static void prepare_packed_git_one(char *objdir, int local)
 {
-       /* Ensure that this buffer is large enough so that we can
-          append "/pack/" without clobbering the stack even if
-          strlen(objdir) were PATH_MAX.  */
-       char path[PATH_MAX + 1 + 4 + 1 + 1];
-       int len;
+       struct strbuf path = STRBUF_INIT;
+       size_t dirnamelen;
        DIR *dir;
        struct dirent *de;
        struct string_list garbage = STRING_LIST_INIT_DUP;
 
-       sprintf(path, "%s/pack", objdir);
-       len = strlen(path);
-       dir = opendir(path);
+       strbuf_addstr(&path, objdir);
+       strbuf_addstr(&path, "/pack");
+       dir = opendir(path.buf);
        if (!dir) {
                if (errno != ENOENT)
                        error("unable to open object pack directory: %s: %s",
-                             path, strerror(errno));
+                             path.buf, strerror(errno));
+               strbuf_release(&path);
                return;
        }
-       path[len++] = '/';
+       strbuf_addch(&path, '/');
+       dirnamelen = path.len;
        while ((de = readdir(dir)) != NULL) {
-               int namelen = strlen(de->d_name);
                struct packed_git *p;
-
-               if (len + namelen + 1 > sizeof(path)) {
-                       if (report_garbage) {
-                               struct strbuf sb = STRBUF_INIT;
-                               strbuf_addf(&sb, "%.*s/%s", len - 1, path, de->d_name);
-                               report_garbage("path too long", sb.buf);
-                               strbuf_release(&sb);
-                       }
-                       continue;
-               }
+               size_t base_len;
 
                if (is_dot_or_dotdot(de->d_name))
                        continue;
 
-               strcpy(path + len, de->d_name);
+               strbuf_setlen(&path, dirnamelen);
+               strbuf_addstr(&path, de->d_name);
 
-               if (has_extension(de->d_name, ".idx")) {
+               base_len = path.len;
+               if (strip_suffix_mem(path.buf, &base_len, ".idx")) {
                        /* Don't reopen a pack we already have. */
                        for (p = packed_git; p; p = p->next) {
-                               if (!memcmp(path, p->pack_name, len + namelen - 4))
+                               size_t len;
+                               if (strip_suffix(p->pack_name, ".pack", &len) &&
+                                   len == base_len &&
+                                   !memcmp(p->pack_name, path.buf, len))
                                        break;
                        }
                        if (p == NULL &&
@@ -1223,23 +1270,25 @@ static void prepare_packed_git_one(char *objdir, int local)
                             * See if it really is a valid .idx file with
                             * corresponding .pack file that we can map.
                             */
-                           (p = add_packed_git(path, len + namelen, local)) != NULL)
+                           (p = add_packed_git(path.buf, path.len, local)) != NULL)
                                install_packed_git(p);
                }
 
                if (!report_garbage)
                        continue;
 
-               if (has_extension(de->d_name, ".idx") ||
-                   has_extension(de->d_name, ".pack") ||
-                   has_extension(de->d_name, ".keep"))
-                       string_list_append(&garbage, path);
+               if (ends_with(de->d_name, ".idx") ||
+                   ends_with(de->d_name, ".pack") ||
+                   ends_with(de->d_name, ".bitmap") ||
+                   ends_with(de->d_name, ".keep"))
+                       string_list_append(&garbage, path.buf);
                else
-                       report_garbage("garbage found", path);
+                       report_garbage("garbage found", path.buf);
        }
        closedir(dir);
        report_pack_garbage(&garbage);
        string_list_clear(&garbage, 0);
+       strbuf_release(&path);
 }
 
 static int sort_pack(const void *a_, const void *b_)
@@ -1316,7 +1365,6 @@ void prepare_packed_git(void)
 
 void reprepare_packed_git(void)
 {
-       discard_revindex();
        prepare_packed_git_run_once = 0;
        prepare_packed_git();
 }
@@ -1393,7 +1441,7 @@ int check_sha1_signature(const unsigned char *sha1, void *map,
        return hashcmp(sha1, real_sha1) ? -1 : 0;
 }
 
-static int git_open_noatime(const char *name)
+int git_open_noatime(const char *name)
 {
        static int sha1_file_open_flag = O_NOATIME;
 
@@ -1414,17 +1462,15 @@ static int git_open_noatime(const char *name)
 
 static int stat_sha1_file(const unsigned char *sha1, struct stat *st)
 {
-       char *name = sha1_file_name(sha1);
        struct alternate_object_database *alt;
 
-       if (!lstat(name, st))
+       if (!lstat(sha1_file_name(sha1), st))
                return 0;
 
        prepare_alt_odb();
        errno = ENOENT;
        for (alt = alt_odb_list; alt; alt = alt->next) {
-               name = alt->name;
-               fill_sha1_path(name, sha1);
+               fill_sha1_path(alt->name, sha1);
                if (!lstat(alt->base, st))
                        return 0;
        }
@@ -1435,22 +1481,24 @@ static int stat_sha1_file(const unsigned char *sha1, struct stat *st)
 static int open_sha1_file(const unsigned char *sha1)
 {
        int fd;
-       char *name = sha1_file_name(sha1);
        struct alternate_object_database *alt;
+       int most_interesting_errno;
 
-       fd = git_open_noatime(name);
+       fd = git_open_noatime(sha1_file_name(sha1));
        if (fd >= 0)
                return fd;
+       most_interesting_errno = errno;
 
        prepare_alt_odb();
-       errno = ENOENT;
        for (alt = alt_odb_list; alt; alt = alt->next) {
-               name = alt->name;
-               fill_sha1_path(name, sha1);
+               fill_sha1_path(alt->name, sha1);
                fd = git_open_noatime(alt->base);
                if (fd >= 0)
                        return fd;
+               if (most_interesting_errno == ENOENT)
+                       most_interesting_errno = errno;
        }
+       errno = most_interesting_errno;
        return -1;
 }
 
@@ -1922,7 +1970,9 @@ static void *unpack_compressed_entry(struct packed_git *p,
        git_zstream stream;
        unsigned char *buffer, *in;
 
-       buffer = xmallocz(size);
+       buffer = xmallocz_gently(size);
+       if (!buffer)
+               return NULL;
        memset(&stream, 0, sizeof(stream));
        stream.next_out = buffer;
        stream.avail_out = size + 1;
@@ -2082,27 +2132,9 @@ static void *read_object(const unsigned char *sha1, enum object_type *type,
 
 static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
 {
-       static FILE *log_file;
-
-       if (!log_pack_access)
-               log_pack_access = getenv("GIT_TRACE_PACK_ACCESS");
-       if (!log_pack_access)
-               log_pack_access = no_log_pack_access;
-       if (log_pack_access == no_log_pack_access)
-               return;
-
-       if (!log_file) {
-               log_file = fopen(log_pack_access, "w");
-               if (!log_file) {
-                       error("cannot open pack access log '%s' for writing: %s",
-                             log_pack_access, strerror(errno));
-                       log_pack_access = no_log_pack_access;
-                       return;
-               }
-       }
-       fprintf(log_file, "%s %"PRIuMAX"\n",
-               p->pack_name, (uintmax_t)obj_offset);
-       fflush(log_file);
+       static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS);
+       trace_printf_key(&pack_access, "%s %"PRIuMAX"\n",
+                        p->pack_name, (uintmax_t)obj_offset);
 }
 
 int do_check_packed_object_crc;
@@ -2127,8 +2159,7 @@ void *unpack_entry(struct packed_git *p, off_t obj_offset,
        int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
        int base_from_cache = 0;
 
-       if (log_pack_access != no_log_pack_access)
-               write_pack_access_log(p, obj_offset);
+       write_pack_access_log(p, obj_offset);
 
        /* PHASE 1: drill down to the innermost base object */
        for (;;) {
@@ -2289,6 +2320,10 @@ void *unpack_entry(struct packed_git *p, off_t obj_offset,
        *final_size = size;
 
        unuse_pack(&w_curs);
+
+       if (delta_stack != small_delta_stack)
+               free(delta_stack);
+
        return data;
 }
 
@@ -2448,6 +2483,10 @@ static int fill_pack_entry(const unsigned char *sha1,
        return 1;
 }
 
+/*
+ * Iff a pack file contains the object named by sha1, return true and
+ * store its location to e.
+ */
 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
 {
        struct packed_git *p;
@@ -2460,11 +2499,13 @@ static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
                return 1;
 
        for (p = packed_git; p; p = p->next) {
-               if (p == last_found_pack || !fill_pack_entry(sha1, e, p))
-                       continue;
+               if (p == last_found_pack)
+                       continue; /* we already checked this one */
 
-               last_found_pack = p;
-               return 1;
+               if (fill_pack_entry(sha1, e, p)) {
+                       last_found_pack = p;
+                       return 1;
+               }
        }
        return 0;
 }
@@ -2626,12 +2667,7 @@ int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
        hash_sha1_file(buf, len, typename(type), sha1);
        if (has_sha1_file(sha1) || find_cached_object(sha1))
                return 0;
-       if (cached_object_alloc <= cached_object_nr) {
-               cached_object_alloc = alloc_nr(cached_object_alloc);
-               cached_objects = xrealloc(cached_objects,
-                                         sizeof(*cached_objects) *
-                                         cached_object_alloc);
-       }
+       ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
        co = &cached_objects[cached_object_nr++];
        co->size = len;
        co->type = type;
@@ -2679,7 +2715,6 @@ void *read_sha1_file_extended(const unsigned char *sha1,
                              unsigned flag)
 {
        void *data;
-       char *path;
        const struct packed_git *p;
        const unsigned char *repl = lookup_replace_object_extended(sha1, flag);
 
@@ -2697,7 +2732,8 @@ void *read_sha1_file_extended(const unsigned char *sha1,
                    sha1_to_hex(repl), sha1_to_hex(sha1));
 
        if (has_loose_object(repl)) {
-               path = sha1_file_name(sha1);
+               const char *path = sha1_file_name(sha1);
+
                die("loose object %s (stored in %s) is corrupt",
                    sha1_to_hex(repl), path);
        }
@@ -2895,10 +2931,9 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
        git_zstream stream;
        git_SHA_CTX c;
        unsigned char parano_sha1[20];
-       char *filename;
        static char tmp_file[PATH_MAX];
+       const char *filename = sha1_file_name(sha1);
 
-       filename = sha1_file_name(sha1);
        fd = create_tmpfile(tmp_file, sizeof(tmp_file), filename);
        if (fd < 0) {
                if (errno == EACCES)
@@ -2957,6 +2992,17 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
        return move_temp_to_file(tmp_file, filename);
 }
 
+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;
+       return find_pack_entry(sha1, &e) && freshen_file(e.p->pack_name);
+}
+
 int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
 {
        unsigned char sha1[20];
@@ -2969,7 +3015,7 @@ int write_sha1_file(const void *buf, unsigned long len, const char *type, unsign
        write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
        if (returnsha1)
                hashcpy(returnsha1, sha1);
-       if (has_sha1_file(sha1))
+       if (freshen_loose_object(sha1) || freshen_packed_object(sha1))
                return 0;
        return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
 }
@@ -3088,6 +3134,29 @@ static int index_mem(unsigned char *sha1, void *buf, size_t size,
        return ret;
 }
 
+static int index_stream_convert_blob(unsigned char *sha1, 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(path, fd, &sbuf,
+                                write_object ? safe_crlf : SAFE_CRLF_FALSE);
+
+       if (write_object)
+               ret = write_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
+                                     sha1);
+       else
+               ret = hash_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
+                                    sha1);
+       strbuf_release(&sbuf);
+       return ret;
+}
+
 static int index_pipe(unsigned char *sha1, int fd, enum object_type type,
                      const char *path, unsigned flags)
 {
@@ -3153,15 +3222,22 @@ int index_fd(unsigned char *sha1, int fd, struct stat *st,
             enum object_type type, const char *path, unsigned flags)
 {
        int ret;
-       size_t size = xsize_t(st->st_size);
 
-       if (!S_ISREG(st->st_mode))
+       /*
+        * 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(sha1, fd, path, flags);
+       else if (!S_ISREG(st->st_mode))
                ret = index_pipe(sha1, fd, type, path, flags);
-       else if (size <= big_file_threshold || type != OBJ_BLOB ||
-                (path && would_convert_to_git(path, NULL, 0, 0)))
-               ret = index_core(sha1, fd, size, type, path, flags);
+       else if (st->st_size <= big_file_threshold || type != OBJ_BLOB ||
+                (path && would_convert_to_git(path)))
+               ret = index_core(sha1, fd, xsize_t(st->st_size), type, path,
+                                flags);
        else
-               ret = index_stream(sha1, fd, size, type, path, flags);
+               ret = index_stream(sha1, fd, xsize_t(st->st_size), type, path,
+                                  flags);
        close(fd);
        return ret;
 }
@@ -3226,3 +3302,149 @@ void assert_sha1_type(const unsigned char *sha1, enum object_type expect)
                die("%s is not a valid '%s' object", sha1_to_hex(sha1),
                    typename(expect));
 }
+
+static int for_each_file_in_obj_subdir(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 baselen = path->len;
+       DIR *dir = opendir(path->buf);
+       struct dirent *de;
+       int r = 0;
+
+       if (!dir) {
+               if (errno == ENOENT)
+                       return 0;
+               return error("unable to open %s: %s", path->buf, strerror(errno));
+       }
+
+       while ((de = readdir(dir))) {
+               if (is_dot_or_dotdot(de->d_name))
+                       continue;
+
+               strbuf_setlen(path, baselen);
+               strbuf_addf(path, "/%s", de->d_name);
+
+               if (strlen(de->d_name) == 38)  {
+                       char hex[41];
+                       unsigned char sha1[20];
+
+                       snprintf(hex, sizeof(hex), "%02x%s",
+                                subdir_nr, de->d_name);
+                       if (!get_sha1_hex(hex, sha1)) {
+                               if (obj_cb) {
+                                       r = obj_cb(sha1, path->buf, data);
+                                       if (r)
+                                               break;
+                               }
+                               continue;
+                       }
+               }
+
+               if (cruft_cb) {
+                       r = cruft_cb(de->d_name, path->buf, data);
+                       if (r)
+                               break;
+               }
+       }
+       strbuf_setlen(path, baselen);
+
+       if (!r && subdir_cb)
+               r = subdir_cb(subdir_nr, path->buf, data);
+
+       closedir(dir);
+       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;
+       size_t baselen;
+       int r = 0;
+       int i;
+
+       strbuf_addstr(&buf, path);
+       strbuf_addch(&buf, '/');
+       baselen = buf.len;
+
+       for (i = 0; i < 256; i++) {
+               strbuf_addf(&buf, "%02x", i);
+               r = for_each_file_in_obj_subdir(i, &buf, obj_cb, cruft_cb,
+                                               subdir_cb, data);
+               strbuf_setlen(&buf, baselen);
+               if (r)
+                       break;
+       }
+
+       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;
+       return for_each_loose_file_in_objdir(alt->base,
+                                            data->cb, NULL, NULL,
+                                            data->data);
+}
+
+int for_each_loose_object(each_loose_object_fn cb, void *data)
+{
+       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;
+
+       alt.cb = cb;
+       alt.data = data;
+       return foreach_alt_odb(loose_from_alt_odb, &alt);
+}
+
+static int for_each_object_in_pack(struct packed_git *p, each_packed_object_fn cb, void *data)
+{
+       uint32_t i;
+       int r = 0;
+
+       for (i = 0; i < p->num_objects; i++) {
+               const unsigned char *sha1 = nth_packed_object_sha1(p, i);
+
+               if (!sha1)
+                       return error("unable to get sha1 of object %u in %s",
+                                    i, p->pack_name);
+
+               r = cb(sha1, p, i, data);
+               if (r)
+                       break;
+       }
+       return r;
+}
+
+int for_each_packed_object(each_packed_object_fn cb, void *data)
+{
+       struct packed_git *p;
+       int r = 0;
+
+       prepare_packed_git();
+       for (p = packed_git; p; p = p->next) {
+               r = for_each_object_in_pack(p, cb, data);
+               if (r)
+                       break;
+       }
+       return r;
+}