Sync with 1.7.6.1
[gitweb.git] / sha1_file.c
index ca87e3d51b7eda8a43fbce8f9c014167ec0c0ecb..44444ae8f4a01938e4f1b08cb7a270253dfe174b 100644 (file)
@@ -11,6 +11,7 @@
 #include "pack.h"
 #include "blob.h"
 #include "commit.h"
+#include "run-command.h"
 #include "tag.h"
 #include "tree.h"
 #include "tree-walk.h"
 #endif
 #endif
 
-#ifdef NO_C99_FORMAT
-#define SZ_FMT "lu"
-static unsigned long sz_fmt(size_t s) { return (unsigned long)s; }
-#else
-#define SZ_FMT "zu"
-static size_t sz_fmt(size_t s) { return s; }
-#endif
+#define SZ_FMT PRIuMAX
+static inline uintmax_t sz_fmt(size_t s) { return s; }
 
 const unsigned char null_sha1[20];
 
-static int git_open_noatime(const char *name, struct packed_git *p);
-
 /*
  * 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
@@ -73,6 +67,35 @@ static struct cached_object *find_cached_object(const unsigned char *sha1)
        return NULL;
 }
 
+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);
+}
+
 int safe_create_leading_directories(char *path)
 {
        char *pos = path + offset_1st_component(path);
@@ -203,6 +226,7 @@ struct alternate_object_database *alt_odb_list;
 static struct alternate_object_database **alt_odb_tail;
 
 static void read_info_alternates(const char * alternates, int depth);
+static int git_open_noatime(const char *name);
 
 /*
  * Prepare alternate object database registry.
@@ -336,7 +360,7 @@ static void read_info_alternates(const char * relative_base, int depth)
        int fd;
 
        sprintf(path, "%s/%s", relative_base, alt_file_name);
-       fd = git_open_noatime(path, NULL);
+       fd = git_open_noatime(path);
        if (fd < 0)
                return;
        if (fstat(fd, &st) || (st.st_size == 0)) {
@@ -418,6 +442,8 @@ static unsigned int pack_used_ctr;
 static unsigned int pack_mmap_calls;
 static unsigned int peak_pack_open_windows;
 static unsigned int pack_open_windows;
+static unsigned int pack_open_fds;
+static unsigned int pack_max_fds;
 static size_t peak_pack_mapped;
 static size_t pack_mapped;
 struct packed_git *packed_git;
@@ -449,7 +475,7 @@ static int check_packed_git_idx(const char *path,  struct packed_git *p)
        struct pack_idx_header *hdr;
        size_t idx_size;
        uint32_t version, nr, i, *index;
-       int fd = git_open_noatime(path, p);
+       int fd = git_open_noatime(path);
        struct stat st;
 
        if (fd < 0)
@@ -595,8 +621,10 @@ static int unuse_one_window(struct packed_git *current, int keep_fd)
                        lru_l->next = lru_w->next;
                else {
                        lru_p->windows = lru_w->next;
-                       if (!lru_p->windows && lru_p->pack_fd != keep_fd) {
+                       if (!lru_p->windows && lru_p->pack_fd != -1
+                               && lru_p->pack_fd != keep_fd) {
                                close(lru_p->pack_fd);
+                               pack_open_fds--;
                                lru_p->pack_fd = -1;
                        }
                }
@@ -681,8 +709,10 @@ void free_pack_by_name(const char *pack_name)
                if (strcmp(pack_name, p->pack_name) == 0) {
                        clear_delta_base_cache();
                        close_pack_windows(p);
-                       if (p->pack_fd != -1)
+                       if (p->pack_fd != -1) {
                                close(p->pack_fd);
+                               pack_open_fds--;
+                       }
                        close_pack_index(p);
                        free(p->bad_object_sha1);
                        *pp = p->next;
@@ -708,9 +738,29 @@ static int open_packed_git_1(struct packed_git *p)
        if (!p->index_data && open_pack_index(p))
                return error("packfile %s index unavailable", p->pack_name);
 
-       p->pack_fd = git_open_noatime(p->pack_name, p);
+       if (!pack_max_fds) {
+               struct rlimit lim;
+               unsigned int max_fds;
+
+               if (getrlimit(RLIMIT_NOFILE, &lim))
+                       die_errno("cannot get RLIMIT_NOFILE");
+
+               max_fds = lim.rlim_cur;
+
+               /* Save 3 for stdin/stdout/stderr, 22 for work */
+               if (25 < max_fds)
+                       pack_max_fds = max_fds - 25;
+               else
+                       pack_max_fds = 1;
+       }
+
+       while (pack_max_fds <= pack_open_fds && unuse_one_window(NULL, -1))
+               ; /* nothing */
+
+       p->pack_fd = git_open_noatime(p->pack_name);
        if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
                return -1;
+       pack_open_fds++;
 
        /* If we created the struct before we had the pack we lack size. */
        if (!p->pack_size) {
@@ -762,6 +812,7 @@ static int open_packed_git(struct packed_git *p)
                return 0;
        if (p->pack_fd != -1) {
                close(p->pack_fd);
+               pack_open_fds--;
                p->pack_fd = -1;
        }
        return -1;
@@ -783,18 +834,17 @@ static int in_window(struct pack_window *win, off_t offset)
 unsigned char *use_pack(struct packed_git *p,
                struct pack_window **w_cursor,
                off_t offset,
-               unsigned int *left)
+               unsigned long *left)
 {
        struct pack_window *win = *w_cursor;
 
-       if (p->pack_fd == -1 && open_packed_git(p))
-               die("packfile %s cannot be accessed", p->pack_name);
-
        /* Since packfiles end in a hash of their content and it's
         * pointless to ask for an offset into the middle of that
         * hash, and the in_window function above wouldn't match
         * don't allow an offset too close to the end of the file.
         */
+       if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
+               die("packfile %s cannot be accessed", p->pack_name);
        if (offset > (p->pack_size - 20))
                die("offset beyond end of packfile (truncated pack?)");
 
@@ -808,6 +858,10 @@ unsigned char *use_pack(struct packed_git *p,
                if (!win) {
                        size_t window_align = packed_git_window_size / 2;
                        off_t len;
+
+                       if (p->pack_fd == -1 && open_packed_git(p))
+                               die("packfile %s cannot be accessed", p->pack_name);
+
                        win = xcalloc(1, sizeof(*win));
                        win->offset = (offset / window_align) * window_align;
                        len = p->pack_size - win->offset;
@@ -825,6 +879,12 @@ unsigned char *use_pack(struct packed_git *p,
                                die("packfile %s cannot be mapped: %s",
                                        p->pack_name,
                                        strerror(errno));
+                       if (!win->offset && win->len == p->pack_size
+                               && !p->do_not_close) {
+                               close(p->pack_fd);
+                               pack_open_fds--;
+                               p->pack_fd = -1;
+                       }
                        pack_mmap_calls++;
                        pack_open_windows++;
                        if (pack_mapped > peak_pack_mapped)
@@ -919,6 +979,9 @@ struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
 
 void install_packed_git(struct packed_git *pack)
 {
+       if (pack->pack_fd != -1)
+               pack_open_fds++;
+
        pack->next = packed_git;
        packed_git = pack;
 }
@@ -936,8 +999,6 @@ static void prepare_packed_git_one(char *objdir, int local)
        sprintf(path, "%s/pack", objdir);
        len = strlen(path);
        dir = opendir(path);
-       while (!dir && errno == EMFILE && unuse_one_window(NULL, -1))
-               dir = opendir(path);
        if (!dir) {
                if (errno != ENOENT)
                        error("unable to open object pack directory: %s: %s",
@@ -1084,7 +1145,7 @@ int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long siz
        return hashcmp(sha1, real_sha1) ? -1 : 0;
 }
 
-static int git_open_noatime(const char *name, struct packed_git *p)
+static int git_open_noatime(const char *name)
 {
        static int sha1_file_open_flag = O_NOATIME;
 
@@ -1093,14 +1154,6 @@ static int git_open_noatime(const char *name, struct packed_git *p)
                if (fd >= 0)
                        return fd;
 
-               /* Might the failure be insufficient file descriptors? */
-               if (errno == EMFILE) {
-                       if (unuse_one_window(p, -1))
-                               continue;
-                       else
-                               return -1;
-               }
-
                /* Might the failure be due to O_NOATIME? */
                if (errno != ENOENT && sha1_file_open_flag) {
                        sha1_file_open_flag = 0;
@@ -1117,7 +1170,7 @@ static int open_sha1_file(const unsigned char *sha1)
        char *name = sha1_file_name(sha1);
        struct alternate_object_database *alt;
 
-       fd = git_open_noatime(name, NULL);
+       fd = git_open_noatime(name);
        if (fd >= 0)
                return fd;
 
@@ -1126,14 +1179,14 @@ static int open_sha1_file(const unsigned char *sha1)
        for (alt = alt_odb_list; alt; alt = alt->next) {
                name = alt->name;
                fill_sha1_path(name, sha1);
-               fd = git_open_noatime(alt->base, NULL);
+               fd = git_open_noatime(alt->base);
                if (fd >= 0)
                        return fd;
        }
        return -1;
 }
 
-static void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
+void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
 {
        void *map;
        int fd;
@@ -1152,20 +1205,49 @@ static void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
        return map;
 }
 
-static int legacy_loose_object(unsigned char *map)
+/*
+ * There used to be a second loose object header format which
+ * was meant to mimic the in-pack format, allowing for direct
+ * copy of the object data.  This format turned up not to be
+ * really worth it and we no longer write loose objects in that
+ * format.
+ */
+static int experimental_loose_object(unsigned char *map)
 {
        unsigned int word;
 
        /*
-        * Is it a zlib-compressed buffer? If so, the first byte
-        * must be 0x78 (15-bit window size, deflated), and the
-        * first 16-bit word is evenly divisible by 31
+        * We must determine if the buffer contains the standard
+        * zlib-deflated stream or the experimental format based
+        * on the in-pack object format. Compare the header byte
+        * for each format:
+        *
+        * RFC1950 zlib w/ deflate : 0www1000 : 0 <= www <= 7
+        * Experimental pack-based : Stttssss : ttt = 1,2,3,4
+        *
+        * If bit 7 is clear and bits 0-3 equal 8, the buffer MUST be
+        * in standard loose-object format, UNLESS it is a Git-pack
+        * format object *exactly* 8 bytes in size when inflated.
+        *
+        * However, RFC1950 also specifies that the 1st 16-bit word
+        * must be divisible by 31 - this checksum tells us our buffer
+        * is in the standard format, giving a false positive only if
+        * the 1st word of the Git-pack format object happens to be
+        * divisible by 31, ie:
+        *      ((byte0 * 256) + byte1) % 31 = 0
+        *   =>        0ttt10000www1000 % 31 = 0
+        *
+        * As it happens, this case can only arise for www=3 & ttt=1
+        * - ie, a Commit object, which would have to be 8 bytes in
+        * size. As no Commit can be that small, we find that the
+        * combination of these two criteria (bitmask & checksum)
+        * can always correctly determine the buffer format.
         */
        word = (map[0] << 8) + map[1];
-       if (map[0] == 0x78 && !(word % 31))
-               return 1;
-       else
+       if ((map[0] & 0x8F) == 0x08 && !(word % 31))
                return 0;
+       else
+               return 1;
 }
 
 unsigned long unpack_object_header_buffer(const unsigned char *buf,
@@ -1192,7 +1274,7 @@ unsigned long unpack_object_header_buffer(const unsigned char *buf,
        return used;
 }
 
-static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
+int unpack_sha1_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
 {
        unsigned long size, used;
        static const char valid_loose_object_type[8] = {
@@ -1209,37 +1291,32 @@ static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned lon
        stream->next_out = buffer;
        stream->avail_out = bufsiz;
 
-       if (legacy_loose_object(map)) {
-               git_inflate_init(stream);
-               return git_inflate(stream, 0);
-       }
-
+       if (experimental_loose_object(map)) {
+               /*
+                * The old experimental format we no longer produce;
+                * we can still read it.
+                */
+               used = unpack_object_header_buffer(map, mapsize, &type, &size);
+               if (!used || !valid_loose_object_type[type])
+                       return -1;
+               map += used;
+               mapsize -= used;
 
-       /*
-        * There used to be a second loose object header format which
-        * was meant to mimic the in-pack format, allowing for direct
-        * copy of the object data.  This format turned up not to be
-        * really worth it and we don't write it any longer.  But we
-        * can still read it.
-        */
-       used = unpack_object_header_buffer(map, mapsize, &type, &size);
-       if (!used || !valid_loose_object_type[type])
-               return -1;
-       map += used;
-       mapsize -= used;
+               /* Set up the stream for the rest.. */
+               stream->next_in = map;
+               stream->avail_in = mapsize;
+               git_inflate_init(stream);
 
-       /* Set up the stream for the rest.. */
-       stream->next_in = map;
-       stream->avail_in = mapsize;
+               /* And generate the fake traditional header */
+               stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
+                                                typename(type), size);
+               return 0;
+       }
        git_inflate_init(stream);
-
-       /* And generate the fake traditional header */
-       stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
-                                        typename(type), size);
-       return 0;
+       return git_inflate(stream, 0);
 }
 
-static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
+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);
@@ -1255,7 +1332,7 @@ static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long 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 zer0,
+                * 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.
@@ -1289,7 +1366,7 @@ static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size
  * too permissive for what we want to check. So do an anal
  * object header parse by hand.
  */
-static int parse_sha1_header(const char *hdr, unsigned long *sizep)
+int parse_sha1_header(const char *hdr, unsigned long *sizep)
 {
        char type[10];
        int i;
@@ -1338,7 +1415,7 @@ static int parse_sha1_header(const char *hdr, unsigned long *sizep)
 static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
 {
        int ret;
-       z_stream stream;
+       git_zstream stream;
        char hdr[8192];
 
        ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
@@ -1354,7 +1431,7 @@ unsigned long get_size_from_delta(struct packed_git *p,
 {
        const unsigned char *data;
        unsigned char delta_head[20], *in;
-       z_stream stream;
+       git_zstream stream;
        int st;
 
        memset(&stream, 0, sizeof(stream));
@@ -1428,7 +1505,7 @@ static off_t get_delta_base(struct packed_git *p,
 
 /* forward declaration for a mutually recursive function */
 static int packed_object_info(struct packed_git *p, off_t offset,
-                             unsigned long *sizep);
+                             unsigned long *sizep, int *rtype);
 
 static int packed_delta_info(struct packed_git *p,
                             struct pack_window **w_curs,
@@ -1442,7 +1519,7 @@ static int packed_delta_info(struct packed_git *p,
        base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
        if (!base_offset)
                return OBJ_BAD;
-       type = packed_object_info(p, base_offset, NULL);
+       type = packed_object_info(p, base_offset, NULL, NULL);
        if (type <= OBJ_NONE) {
                struct revindex_entry *revidx;
                const unsigned char *base_sha1;
@@ -1470,18 +1547,18 @@ static int packed_delta_info(struct packed_git *p,
        return type;
 }
 
-static int unpack_object_header(struct packed_git *p,
-                               struct pack_window **w_curs,
-                               off_t *curpos,
-                               unsigned long *sizep)
+int unpack_object_header(struct packed_git *p,
+                        struct pack_window **w_curs,
+                        off_t *curpos,
+                        unsigned long *sizep)
 {
        unsigned char *base;
-       unsigned int left;
+       unsigned long left;
        unsigned long used;
        enum object_type type;
 
        /* use_pack() assures us we have [base, base + 20) available
-        * as a range that we can look at at.  (Its actually the hash
+        * as a range that we can look at.  (Its actually the hash
         * size that is assured.)  With our object header encoding
         * the maximum deflated object size is 2^137, which is just
         * insane, so we know won't exceed what we have been given.
@@ -1497,7 +1574,7 @@ static int unpack_object_header(struct packed_git *p,
 }
 
 static int packed_object_info(struct packed_git *p, off_t obj_offset,
-                             unsigned long *sizep)
+                             unsigned long *sizep, int *rtype)
 {
        struct pack_window *w_curs = NULL;
        unsigned long size;
@@ -1505,6 +1582,8 @@ static int packed_object_info(struct packed_git *p, off_t obj_offset,
        enum object_type type;
 
        type = unpack_object_header(p, &w_curs, &curpos, &size);
+       if (rtype)
+               *rtype = type; /* representation type */
 
        switch (type) {
        case OBJ_OFS_DELTA:
@@ -1534,7 +1613,7 @@ static void *unpack_compressed_entry(struct packed_git *p,
                                    unsigned long size)
 {
        int st;
-       z_stream stream;
+       git_zstream stream;
        unsigned char *buffer, *in;
 
        buffer = xmallocz(size);
@@ -1587,6 +1666,13 @@ static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
        return hash % MAX_DELTA_CACHE;
 }
 
+static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
+{
+       unsigned long hash = pack_entry_hash(p, base_offset);
+       struct delta_base_cache_entry *ent = delta_base_cache + hash;
+       return (ent->data && ent->p == p && ent->base_offset == base_offset);
+}
+
 static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
        unsigned long *base_size, enum object_type *type, int keep_cache)
 {
@@ -1731,6 +1817,24 @@ static void *unpack_delta_entry(struct packed_git *p,
        return result;
 }
 
+static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
+{
+       static FILE *log_file;
+
+       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 = NULL;
+                       return;
+               }
+       }
+       fprintf(log_file, "%s %"PRIuMAX"\n",
+               p->pack_name, (uintmax_t)obj_offset);
+       fflush(log_file);
+}
+
 int do_check_packed_object_crc;
 
 void *unpack_entry(struct packed_git *p, off_t obj_offset,
@@ -1740,6 +1844,9 @@ void *unpack_entry(struct packed_git *p, off_t obj_offset,
        off_t curpos = obj_offset;
        void *data;
 
+       if (log_pack_access)
+               write_pack_access_log(p, obj_offset);
+
        if (do_check_packed_object_crc && p->index_version > 1) {
                struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
                unsigned long len = revidx[1].offset - obj_offset;
@@ -1877,6 +1984,27 @@ off_t find_pack_entry_one(const unsigned char *sha1,
        return 0;
 }
 
+static int is_pack_valid(struct packed_git *p)
+{
+       /* An already open pack is known to be valid. */
+       if (p->pack_fd != -1)
+               return 1;
+
+       /* If the pack has one window completely covering the
+        * file size, the pack is known to be valid even if
+        * the descriptor is not currently open.
+        */
+       if (p->windows) {
+               struct pack_window *w = p->windows;
+
+               if (!w->offset && w->len == p->pack_size)
+                       return 1;
+       }
+
+       /* Force the pack to open to prove its valid. */
+       return !open_packed_git(p);
+}
+
 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
 {
        static struct packed_git *last_found = (void *)1;
@@ -1906,7 +2034,7 @@ static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
                         * it may have been deleted since the index
                         * was loaded!
                         */
-                       if (p->pack_fd == -1 && open_packed_git(p)) {
+                       if (!is_pack_valid(p)) {
                                error("packfile %s cannot be accessed", p->pack_name);
                                goto next;
                        }
@@ -1946,7 +2074,7 @@ static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *size
        int status;
        unsigned long mapsize, size;
        void *map;
-       z_stream stream;
+       git_zstream stream;
        char hdr[32];
 
        map = map_sha1_file(sha1, &mapsize);
@@ -1964,24 +2092,28 @@ static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *size
        return status;
 }
 
-int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
+/* returns enum object_type or negative */
+int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi)
 {
        struct cached_object *co;
        struct pack_entry e;
-       int status;
+       int status, rtype;
 
        co = find_cached_object(sha1);
        if (co) {
-               if (sizep)
-                       *sizep = co->size;
+               if (oi->sizep)
+                       *(oi->sizep) = co->size;
+               oi->whence = OI_CACHED;
                return co->type;
        }
 
        if (!find_pack_entry(sha1, &e)) {
                /* Most likely it's a loose object. */
-               status = sha1_loose_object_info(sha1, sizep);
-               if (status >= 0)
+               status = sha1_loose_object_info(sha1, oi->sizep);
+               if (status >= 0) {
+                       oi->whence = OI_LOOSE;
                        return status;
+               }
 
                /* Not a loose object; someone else may have just packed it. */
                reprepare_packed_git();
@@ -1989,15 +2121,31 @@ int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
                        return status;
        }
 
-       status = packed_object_info(e.p, e.offset, sizep);
+       status = packed_object_info(e.p, e.offset, oi->sizep, &rtype);
        if (status < 0) {
                mark_bad_packed_object(e.p, sha1);
-               status = sha1_object_info(sha1, sizep);
+               status = sha1_object_info_extended(sha1, oi);
+       } else if (in_delta_base_cache(e.p, e.offset)) {
+               oi->whence = OI_DBCACHED;
+       } else {
+               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 status;
 }
 
+int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
+{
+       struct object_info oi;
+
+       oi.sizep = sizep;
+       return sha1_object_info_extended(sha1, &oi);
+}
+
 static void *read_packed_sha1(const unsigned char *sha1,
                              enum object_type *type, unsigned long *size)
 {
@@ -2077,23 +2225,21 @@ static void *read_object(const unsigned char *sha1, enum object_type *type,
  * deal with them should arrange to call read_object() and give error
  * messages themselves.
  */
-void *read_sha1_file_repl(const unsigned char *sha1,
-                         enum object_type *type,
-                         unsigned long *size,
-                         const unsigned char **replacement)
+void *read_sha1_file_extended(const unsigned char *sha1,
+                             enum object_type *type,
+                             unsigned long *size,
+                             unsigned flag)
 {
-       const unsigned char *repl = lookup_replace_object(sha1);
        void *data;
        char *path;
        const struct packed_git *p;
+       const unsigned char *repl = (flag & READ_SHA1_FILE_REPLACE)
+               ? lookup_replace_object(sha1) : sha1;
 
        errno = 0;
        data = read_object(repl, type, size);
-       if (data) {
-               if (replacement)
-                       *replacement = repl;
+       if (data)
                return data;
-       }
 
        if (errno && errno != ENOENT)
                die_errno("failed to read object %s", sha1_to_hex(sha1));
@@ -2297,7 +2443,7 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
 {
        int fd, ret;
        unsigned char compressed[4096];
-       z_stream stream;
+       git_zstream stream;
        git_SHA_CTX c;
        unsigned char parano_sha1[20];
        char *filename;
@@ -2305,8 +2451,6 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
 
        filename = sha1_file_name(sha1);
        fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
-       while (fd < 0 && errno == EMFILE && unuse_one_window(NULL, -1))
-               fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
        if (fd < 0) {
                if (errno == EACCES)
                        return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
@@ -2316,7 +2460,7 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
 
        /* Set it up */
        memset(&stream, 0, sizeof(stream));
-       deflateInit(&stream, zlib_compression_level);
+       git_deflate_init(&stream, zlib_compression_level);
        stream.next_out = compressed;
        stream.avail_out = sizeof(compressed);
        git_SHA1_Init(&c);
@@ -2324,8 +2468,8 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
        /* First header.. */
        stream.next_in = (unsigned char *)hdr;
        stream.avail_in = hdrlen;
-       while (deflate(&stream, 0) == Z_OK)
-               /* nothing */;
+       while (git_deflate(&stream, 0) == Z_OK)
+               ; /* nothing */
        git_SHA1_Update(&c, hdr, hdrlen);
 
        /* Then the data itself.. */
@@ -2333,7 +2477,7 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
        stream.avail_in = len;
        do {
                unsigned char *in0 = stream.next_in;
-               ret = deflate(&stream, Z_FINISH);
+               ret = git_deflate(&stream, Z_FINISH);
                git_SHA1_Update(&c, in0, stream.next_in - in0);
                if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
                        die("unable to write sha1 file");
@@ -2343,7 +2487,7 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
 
        if (ret != Z_STREAM_END)
                die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
-       ret = deflateEnd(&stream);
+       ret = git_deflate_end_gently(&stream);
        if (ret != Z_OK)
                die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
        git_SHA1_Final(parano_sha1, &c);
@@ -2454,10 +2598,11 @@ static void check_tag(const void *buf, size_t size)
 }
 
 static int index_mem(unsigned char *sha1, void *buf, size_t size,
-                    int write_object, enum object_type type,
-                    const char *path, int format_check)
+                    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;
@@ -2473,7 +2618,7 @@ static int index_mem(unsigned char *sha1, void *buf, size_t size,
                        re_allocated = 1;
                }
        }
-       if (format_check) {
+       if (flags & HASH_FORMAT_CHECK) {
                if (type == OBJ_TREE)
                        check_tree(buf, size);
                if (type == OBJ_COMMIT)
@@ -2491,44 +2636,141 @@ static int index_mem(unsigned char *sha1, void *buf, size_t size,
        return ret;
 }
 
+static int index_pipe(unsigned char *sha1, 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(sha1, sbuf.buf, sbuf.len, type, path, flags);
+       else
+               ret = -1;
+       strbuf_release(&sbuf);
+       return ret;
+}
+
 #define SMALL_FILE_SIZE (32*1024)
 
-int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
-            enum object_type type, const char *path, int format_check)
+static int index_core(unsigned char *sha1, int fd, size_t size,
+                     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)) {
-               struct strbuf sbuf = STRBUF_INIT;
-               if (strbuf_read(&sbuf, fd, 4096) >= 0)
-                       ret = index_mem(sha1, sbuf.buf, sbuf.len, write_object,
-                                       type, path, format_check);
-               else
-                       ret = -1;
-               strbuf_release(&sbuf);
-       } else if (!size) {
-               ret = index_mem(sha1, NULL, size, write_object, type, path,
-                               format_check);
+       if (!size) {
+               ret = index_mem(sha1, NULL, size, type, path, flags);
        } else if (size <= SMALL_FILE_SIZE) {
                char *buf = xmalloc(size);
                if (size == read_in_full(fd, buf, size))
-                       ret = index_mem(sha1, buf, size, write_object, type,
-                                       path, format_check);
+                       ret = index_mem(sha1, buf, size, type, path, flags);
                else
                        ret = error("short read %s", strerror(errno));
                free(buf);
        } else {
                void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
-               ret = index_mem(sha1, buf, size, write_object, type, path,
-                               format_check);
+               ret = index_mem(sha1, buf, size, type, path, flags);
                munmap(buf, size);
        }
+       return ret;
+}
+
+/*
+ * This creates one packfile per large blob, because the caller
+ * immediately wants the result sha1, and fast-import can report the
+ * object name via marks mechanism only by closing the created
+ * packfile.
+ *
+ * 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), but 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, and
+ * by definition they do _not_ want to get any conversion.
+ */
+static int index_stream(unsigned char *sha1, int fd, size_t size,
+                       enum object_type type, const char *path,
+                       unsigned flags)
+{
+       struct child_process fast_import;
+       char export_marks[512];
+       const char *argv[] = { "fast-import", "--quiet", export_marks, NULL };
+       char tmpfile[512];
+       char fast_import_cmd[512];
+       char buf[512];
+       int len, tmpfd;
+
+       strcpy(tmpfile, git_path("hashstream_XXXXXX"));
+       tmpfd = git_mkstemp_mode(tmpfile, 0600);
+       if (tmpfd < 0)
+               die_errno("cannot create tempfile: %s", tmpfile);
+       if (close(tmpfd))
+               die_errno("cannot close tempfile: %s", tmpfile);
+       sprintf(export_marks, "--export-marks=%s", tmpfile);
+
+       memset(&fast_import, 0, sizeof(fast_import));
+       fast_import.in = -1;
+       fast_import.argv = argv;
+       fast_import.git_cmd = 1;
+       if (start_command(&fast_import))
+               die_errno("index-stream: git fast-import failed");
+
+       len = sprintf(fast_import_cmd, "blob\nmark :1\ndata %lu\n",
+                     (unsigned long) size);
+       write_or_whine(fast_import.in, fast_import_cmd, len,
+                      "index-stream: feeding fast-import");
+       while (size) {
+               char buf[10240];
+               size_t sz = size < sizeof(buf) ? size : sizeof(buf);
+               ssize_t actual;
+
+               actual = read_in_full(fd, buf, sz);
+               if (actual < 0)
+                       die_errno("index-stream: reading input");
+               if (write_in_full(fast_import.in, buf, actual) != actual)
+                       die_errno("index-stream: feeding fast-import");
+               size -= actual;
+       }
+       if (close(fast_import.in))
+               die_errno("index-stream: closing fast-import");
+       if (finish_command(&fast_import))
+               die_errno("index-stream: finishing fast-import");
+
+       tmpfd = open(tmpfile, O_RDONLY);
+       if (tmpfd < 0)
+               die_errno("index-stream: cannot open fast-import mark");
+       len = read(tmpfd, buf, sizeof(buf));
+       if (len < 0)
+               die_errno("index-stream: reading fast-import mark");
+       if (close(tmpfd) < 0)
+               die_errno("index-stream: closing fast-import mark");
+       if (unlink(tmpfile))
+               die_errno("index-stream: unlinking fast-import mark");
+       if (len != 44 ||
+           memcmp(":1 ", buf, 3) ||
+           get_sha1_hex(buf + 3, sha1))
+               die_errno("index-stream: unexpected fast-import mark: <%s>", buf);
+       return 0;
+}
+
+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))
+               ret = index_pipe(sha1, fd, type, path, flags);
+       else if (size <= big_file_threshold || type != OBJ_BLOB)
+               ret = index_core(sha1, fd, size, type, path, flags);
+       else
+               ret = index_stream(sha1, fd, size, type, path, flags);
        close(fd);
        return ret;
 }
 
-int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
+int index_path(unsigned char *sha1, const char *path, struct stat *st, unsigned flags)
 {
        int fd;
        struct strbuf sb = STRBUF_INIT;
@@ -2539,7 +2781,7 @@ int index_path(unsigned char *sha1, const char *path, struct stat *st, int write
                if (fd < 0)
                        return error("open(\"%s\"): %s", path,
                                     strerror(errno));
-               if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path, 0) < 0)
+               if (index_fd(sha1, fd, st, OBJ_BLOB, path, flags) < 0)
                        return error("%s: failed to insert into database",
                                     path);
                break;
@@ -2549,7 +2791,7 @@ int index_path(unsigned char *sha1, const char *path, struct stat *st, int write
                        return error("readlink(\"%s\"): %s", path,
                                     errstr);
                }
-               if (!write_object)
+               if (!(flags & HASH_WRITE_OBJECT))
                        hash_sha1_file(sb.buf, sb.len, blob_type, sha1);
                else if (write_sha1_file(sb.buf, sb.len, blob_type, sha1))
                        return error("%s: failed to insert into database",