Makefile: fix MAKEFLAGS tests with multiple flags
[gitweb.git] / sha1_file.c
index 8de8ce0a728bb5df75557d85c2ad0d55648af90d..6d0a72ed093d353a672129f7e460d0c1015212d7 100644 (file)
 #endif
 #endif
 
+#ifdef NO_C99_FORMAT
+#define SZ_FMT "lu"
+#else
+#define SZ_FMT "zu"
+#endif
+
 const unsigned char null_sha1[20];
 
 static unsigned int sha1_file_open_flag = O_NOATIME;
@@ -355,10 +361,8 @@ static void read_info_alternates(const char * relative_base, int depth)
                close(fd);
                return;
        }
-       map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+       map = xmmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
        close(fd);
-       if (map == MAP_FAILED)
-               return;
 
        link_alt_odb_entries(map, map + st.st_size, '\n', relative_base, depth);
 
@@ -403,23 +407,23 @@ static unsigned int peak_pack_open_windows;
 static unsigned int pack_open_windows;
 static size_t peak_pack_mapped;
 static size_t pack_mapped;
-static size_t page_size;
 struct packed_git *packed_git;
 
 void pack_report()
 {
        fprintf(stderr,
-               "pack_report: getpagesize()            = %10lu\n"
-               "pack_report: core.packedGitWindowSize = %10lu\n"
-               "pack_report: core.packedGitLimit      = %10lu\n",
-               page_size,
+               "pack_report: getpagesize()            = %10" SZ_FMT "\n"
+               "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
+               "pack_report: core.packedGitLimit      = %10" SZ_FMT "\n",
+               (size_t) getpagesize(),
                packed_git_window_size,
                packed_git_limit);
        fprintf(stderr,
                "pack_report: pack_used_ctr            = %10u\n"
                "pack_report: pack_mmap_calls          = %10u\n"
                "pack_report: pack_open_windows        = %10u / %10u\n"
-               "pack_report: pack_mapped              = %10lu / %10lu\n",
+               "pack_report: pack_mapped              = "
+                       "%10" SZ_FMT " / %10" SZ_FMT "\n",
                pack_used_ctr,
                pack_mmap_calls,
                pack_open_windows, peak_pack_open_windows,
@@ -430,7 +434,7 @@ static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
                                void **idx_map_)
 {
        void *idx_map;
-       unsigned int *index;
+       uint32_t *index;
        unsigned long idx_size;
        int nr, i;
        int fd = open(path, O_RDONLY);
@@ -442,10 +446,8 @@ static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
                return -1;
        }
        idx_size = st.st_size;
-       idx_map = mmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
+       idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
        close(fd);
-       if (idx_map == MAP_FAILED)
-               return -1;
 
        index = idx_map;
        *idx_map_ = idx_map;
@@ -453,12 +455,23 @@ static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
 
        /* check index map */
        if (idx_size < 4*256 + 20 + 20)
-               return error("index file too small");
+               return error("index file %s is too small", path);
+
+       /* a future index format would start with this, as older git
+        * binaries would fail the non-monotonic index check below.
+        * give a nicer warning to the user if we can.
+        */
+       if (index[0] == htonl(PACK_IDX_SIGNATURE))
+               return error("index file %s is a newer version"
+                       " and is not supported by this binary"
+                       " (try upgrading GIT to a newer version)",
+                       path);
+
        nr = 0;
        for (i = 0; i < 256; i++) {
                unsigned int n = ntohl(index[i]);
                if (n < nr)
-                       return error("non-monotonic index");
+                       return error("non-monotonic index %s", path);
                nr = n;
        }
 
@@ -470,7 +483,7 @@ static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
         *  - 20-byte SHA1 file checksum
         */
        if (idx_size != 4*256 + nr * 24 + 20 + 20)
-               return error("wrong index file size");
+               return error("wrong index file size in %s", path);
 
        return 0;
 }
@@ -522,6 +535,13 @@ static int unuse_one_window(struct packed_git *current)
        return 0;
 }
 
+void release_pack_memory(size_t need)
+{
+       size_t cur = pack_mapped;
+       while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
+               ; /* nothing */
+}
+
 void unuse_pack(struct pack_window **w_cursor)
 {
        struct pack_window *w = *w_cursor;
@@ -531,46 +551,75 @@ void unuse_pack(struct pack_window **w_cursor)
        }
 }
 
-static void open_packed_git(struct packed_git *p)
+/*
+ * Do not call this directly as this leaks p->pack_fd on error return;
+ * call open_packed_git() instead.
+ */
+static int open_packed_git_1(struct packed_git *p)
 {
        struct stat st;
        struct pack_header hdr;
        unsigned char sha1[20];
        unsigned char *idx_sha1;
+       long fd_flag;
 
        p->pack_fd = open(p->pack_name, O_RDONLY);
        if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
-               die("packfile %s cannot be opened", p->pack_name);
+               return -1;
 
        /* If we created the struct before we had the pack we lack size. */
        if (!p->pack_size) {
                if (!S_ISREG(st.st_mode))
-                       die("packfile %s not a regular file", p->pack_name);
+                       return error("packfile %s not a regular file", p->pack_name);
                p->pack_size = st.st_size;
        } else if (p->pack_size != st.st_size)
-               die("packfile %s size changed", p->pack_name);
+               return error("packfile %s size changed", p->pack_name);
+
+       /* We leave these file descriptors open with sliding mmap;
+        * there is no point keeping them open across exec(), though.
+        */
+       fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
+       if (fd_flag < 0)
+               return error("cannot determine file descriptor flags");
+       fd_flag |= FD_CLOEXEC;
+       if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
+               return error("cannot set FD_CLOEXEC");
 
        /* Verify we recognize this pack file format. */
-       read_or_die(p->pack_fd, &hdr, sizeof(hdr));
+       if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
+               return error("file %s is far too short to be a packfile", p->pack_name);
        if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
-               die("file %s is not a GIT packfile", p->pack_name);
+               return error("file %s is not a GIT packfile", p->pack_name);
        if (!pack_version_ok(hdr.hdr_version))
-               die("packfile %s is version %u and not supported"
+               return error("packfile %s is version %u and not supported"
                        " (try upgrading GIT to a newer version)",
                        p->pack_name, ntohl(hdr.hdr_version));
 
        /* Verify the pack matches its index. */
        if (num_packed_objects(p) != ntohl(hdr.hdr_entries))
-               die("packfile %s claims to have %u objects"
+               return error("packfile %s claims to have %u objects"
                        " while index size indicates %u objects",
                        p->pack_name, ntohl(hdr.hdr_entries),
                        num_packed_objects(p));
        if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
-               die("end of packfile %s is unavailable", p->pack_name);
-       read_or_die(p->pack_fd, sha1, sizeof(sha1));
+               return error("end of packfile %s is unavailable", p->pack_name);
+       if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
+               return error("packfile %s signature is unavailable", p->pack_name);
        idx_sha1 = ((unsigned char *)p->index_base) + p->index_size - 40;
        if (hashcmp(sha1, idx_sha1))
-               die("packfile %s does not match index", p->pack_name);
+               return error("packfile %s does not match index", p->pack_name);
+       return 0;
+}
+
+static int open_packed_git(struct packed_git *p)
+{
+       if (!open_packed_git_1(p))
+               return 0;
+       if (p->pack_fd != -1) {
+               close(p->pack_fd);
+               p->pack_fd = -1;
+       }
+       return -1;
 }
 
 static int in_window(struct pack_window *win, unsigned long offset)
@@ -593,8 +642,8 @@ unsigned char* use_pack(struct packed_git *p,
 {
        struct pack_window *win = *w_cursor;
 
-       if (p->pack_fd == -1)
-               open_packed_git(p);
+       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 its
         * pointless to ask for an offset into the middle of that
@@ -612,10 +661,9 @@ unsigned char* use_pack(struct packed_git *p,
                                break;
                }
                if (!win) {
-                       if (!page_size)
-                               page_size = getpagesize();
+                       size_t window_align = packed_git_window_size / 2;
                        win = xcalloc(1, sizeof(*win));
-                       win->offset = (offset / page_size) * page_size;
+                       win->offset = (offset / window_align) * window_align;
                        win->len = p->pack_size - win->offset;
                        if (win->len > packed_git_window_size)
                                win->len = packed_git_window_size;
@@ -623,7 +671,7 @@ unsigned char* use_pack(struct packed_git *p,
                        while (packed_git_limit < pack_mapped
                                && unuse_one_window(p))
                                ; /* nothing */
-                       win->base = mmap(NULL, win->len,
+                       win->base = xmmap(NULL, win->len,
                                PROT_READ, MAP_PRIVATE,
                                p->pack_fd, win->offset);
                        if (win->base == MAP_FAILED)
@@ -745,7 +793,7 @@ static void prepare_packed_git_one(char *objdir, int local)
                if (!has_extension(de->d_name, ".idx"))
                        continue;
 
-               /* we have .idx.  Is it a file we can map? */
+               /* Don't reopen a pack we already have. */
                strcpy(path + len, de->d_name);
                for (p = packed_git; p; p = p->next) {
                        if (!memcmp(path, p->pack_name, len + namelen - 4))
@@ -753,11 +801,13 @@ static void prepare_packed_git_one(char *objdir, int local)
                }
                if (p)
                        continue;
+               /* 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);
                if (!p)
                        continue;
-               p->next = packed_git;
-               packed_git = p;
+               install_packed_git(p);
        }
        closedir(dir);
 }
@@ -821,10 +871,8 @@ void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
                 */
                sha1_file_open_flag = 0;
        }
-       map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+       map = xmmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
        close(fd);
-       if (map == MAP_FAILED)
-               return NULL;
        *size = st.st_size;
        return map;
 }
@@ -904,7 +952,7 @@ static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned lon
 
        /* And generate the fake traditional header */
        stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
-                                        type_names[type], size);
+                                        typename(type), size);
        return 0;
 }
 
@@ -935,26 +983,27 @@ 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(char *hdr, char *type, unsigned long *sizep)
+static int parse_sha1_header(const char *hdr, unsigned long *sizep)
 {
+       char type[10];
        int i;
        unsigned long size;
 
        /*
         * The type can be at most ten bytes (including the 
         * terminating '\0' that we add), and is followed by
-        * a space. 
+        * a space.
         */
-       i = 10;
+       i = 0;
        for (;;) {
                char c = *hdr++;
                if (c == ' ')
                        break;
-               if (!--i)
+               type[i++] = c;
+               if (i >= sizeof(type))
                        return -1;
-               *type++ = c;
        }
-       *type = 0;
+       type[i] = 0;
 
        /*
         * The length must follow immediately, and be in canonical
@@ -977,17 +1026,17 @@ static int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
        /*
         * The length must be followed by a zero byte
         */
-       return *hdr ? -1 : 0;
+       return *hdr ? -1 : type_from_string(type);
 }
 
-void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
+void * unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size)
 {
        int ret;
        z_stream stream;
        char hdr[8192];
 
        ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
-       if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
+       if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
                return NULL;
 
        return unpack_sha1_rest(&stream, hdr, *size);
@@ -995,12 +1044,11 @@ void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned l
 
 static unsigned long get_delta_base(struct packed_git *p,
                                    struct pack_window **w_curs,
-                                   unsigned long offset,
-                                   enum object_type kind,
-                                   unsigned long delta_obj_offset,
-                                   unsigned long *base_obj_offset)
+                                   unsigned long *curpos,
+                                   enum object_type type,
+                                   unsigned long delta_obj_offset)
 {
-       unsigned char *base_info = use_pack(p, w_curs, offset, NULL);
+       unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
        unsigned long base_offset;
 
        /* use_pack() assured us we have [base_info, base_info + 20)
@@ -1009,7 +1057,7 @@ static unsigned long get_delta_base(struct packed_git *p,
         * that is assured.  An OFS_DELTA longer than the hash size
         * is stupid, as then a REF_DELTA would be smaller to store.
         */
-       if (kind == OBJ_OFS_DELTA) {
+       if (type == OBJ_OFS_DELTA) {
                unsigned used = 0;
                unsigned char c = base_info[used++];
                base_offset = c & 127;
@@ -1023,49 +1071,43 @@ static unsigned long get_delta_base(struct packed_git *p,
                base_offset = delta_obj_offset - base_offset;
                if (base_offset >= delta_obj_offset)
                        die("delta base offset out of bound");
-               offset += used;
-       } else if (kind == OBJ_REF_DELTA) {
+               *curpos += used;
+       } else if (type == OBJ_REF_DELTA) {
                /* The base entry _must_ be in the same pack */
                base_offset = find_pack_entry_one(base_info, p);
                if (!base_offset)
                        die("failed to find delta-pack base object %s",
                                sha1_to_hex(base_info));
-               offset += 20;
+               *curpos += 20;
        } else
                die("I am totally screwed");
-       *base_obj_offset = base_offset;
-       return offset;
+       return base_offset;
 }
 
 /* forward declaration for a mutually recursive function */
 static int packed_object_info(struct packed_git *p, unsigned long offset,
-                             char *type, unsigned long *sizep);
+                             unsigned long *sizep);
 
 static int packed_delta_info(struct packed_git *p,
                             struct pack_window **w_curs,
-                            unsigned long offset,
-                            enum object_type kind,
+                            unsigned long curpos,
+                            enum object_type type,
                             unsigned long obj_offset,
-                            char *type,
                             unsigned long *sizep)
 {
        unsigned long base_offset;
 
-       offset = get_delta_base(p, w_curs, offset, kind,
-               obj_offset, &base_offset);
+       base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
+       type = packed_object_info(p, base_offset, NULL);
 
        /* We choose to only get the type of the base object and
         * ignore potentially corrupt pack file that expects the delta
         * based on a base with a wrong size.  This saves tons of
         * inflate() calls.
         */
-       if (packed_object_info(p, base_offset, type, NULL))
-               die("cannot get info for delta-pack base");
-
        if (sizep) {
                const unsigned char *data;
                unsigned char delta_head[20], *in;
-               unsigned long result_size;
                z_stream stream;
                int st;
 
@@ -1075,10 +1117,10 @@ static int packed_delta_info(struct packed_git *p,
 
                inflateInit(&stream);
                do {
-                       in = use_pack(p, w_curs, offset, &stream.avail_in);
+                       in = use_pack(p, w_curs, curpos, &stream.avail_in);
                        stream.next_in = in;
                        st = inflate(&stream, Z_FINISH);
-                       offset += stream.next_in - in;
+                       curpos += stream.next_in - in;
                } while ((st == Z_OK || st == Z_BUF_ERROR)
                        && stream.total_out < sizeof(delta_head));
                inflateEnd(&stream);
@@ -1095,122 +1137,117 @@ static int packed_delta_info(struct packed_git *p,
                get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
 
                /* Read the result size */
-               result_size = get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
-               *sizep = result_size;
+               *sizep = get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
        }
-       return 0;
+
+       return type;
 }
 
-static unsigned long unpack_object_header(struct packed_git *p,
-               struct pack_window **w_curs,
-               unsigned long offset,
-               enum object_type *type,
-               unsigned long *sizep)
+static int unpack_object_header(struct packed_git *p,
+                               struct pack_window **w_curs,
+                               unsigned long *curpos,
+                               unsigned long *sizep)
 {
        unsigned char *base;
        unsigned int 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
-        * size that is assurred.)  With our object header encoding
+        * 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.
         */
-       base = use_pack(p, w_curs, offset, &left);
-       used = unpack_object_header_gently(base, left, type, sizep);
+       base = use_pack(p, w_curs, *curpos, &left);
+       used = unpack_object_header_gently(base, left, &type, sizep);
        if (!used)
                die("object offset outside of pack file");
+       *curpos += used;
 
-       return offset + used;
+       return type;
 }
 
-void packed_object_info_detail(struct packed_git *p,
-                              unsigned long offset,
-                              char *type,
-                              unsigned long *size,
-                              unsigned long *store_size,
-                              unsigned int *delta_chain_length,
-                              unsigned char *base_sha1)
+const char *packed_object_info_detail(struct packed_git *p,
+                                     unsigned long obj_offset,
+                                     unsigned long *size,
+                                     unsigned long *store_size,
+                                     unsigned int *delta_chain_length,
+                                     unsigned char *base_sha1)
 {
        struct pack_window *w_curs = NULL;
-       unsigned long obj_offset, val;
+       unsigned long curpos, dummy;
        unsigned char *next_sha1;
-       enum object_type kind;
+       enum object_type type;
 
        *delta_chain_length = 0;
-       obj_offset = offset;
-       offset = unpack_object_header(p, &w_curs, offset, &kind, size);
+       curpos = obj_offset;
+       type = unpack_object_header(p, &w_curs, &curpos, size);
 
        for (;;) {
-               switch (kind) {
+               switch (type) {
                default:
                        die("pack %s contains unknown object type %d",
-                           p->pack_name, kind);
+                           p->pack_name, type);
                case OBJ_COMMIT:
                case OBJ_TREE:
                case OBJ_BLOB:
                case OBJ_TAG:
-                       strcpy(type, type_names[kind]);
                        *store_size = 0; /* notyet */
                        unuse_pack(&w_curs);
-                       return;
+                       return typename(type);
                case OBJ_OFS_DELTA:
-                       get_delta_base(p, &w_curs, offset, kind,
-                               obj_offset, &offset);
+                       obj_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
                        if (*delta_chain_length == 0) {
-                               /* TODO: find base_sha1 as pointed by offset */
+                               /* TODO: find base_sha1 as pointed by curpos */
                        }
                        break;
                case OBJ_REF_DELTA:
-                       next_sha1 = use_pack(p, &w_curs, offset, NULL);
+                       next_sha1 = use_pack(p, &w_curs, curpos, NULL);
                        if (*delta_chain_length == 0)
                                hashcpy(base_sha1, next_sha1);
-                       offset = find_pack_entry_one(next_sha1, p);
+                       obj_offset = find_pack_entry_one(next_sha1, p);
                        break;
                }
-               obj_offset = offset;
-               offset = unpack_object_header(p, &w_curs, offset, &kind, &val);
                (*delta_chain_length)++;
+               curpos = obj_offset;
+               type = unpack_object_header(p, &w_curs, &curpos, &dummy);
        }
 }
 
-static int packed_object_info(struct packed_git *p, unsigned long offset,
-                             char *type, unsigned long *sizep)
+static int packed_object_info(struct packed_git *p, unsigned long obj_offset,
+                             unsigned long *sizep)
 {
        struct pack_window *w_curs = NULL;
-       unsigned long size, obj_offset = offset;
-       enum object_type kind;
-       int r;
+       unsigned long size, curpos = obj_offset;
+       enum object_type type;
 
-       offset = unpack_object_header(p, &w_curs, offset, &kind, &size);
+       type = unpack_object_header(p, &w_curs, &curpos, &size);
 
-       switch (kind) {
+       switch (type) {
        case OBJ_OFS_DELTA:
        case OBJ_REF_DELTA:
-               r = packed_delta_info(p, &w_curs, offset, kind,
-                       obj_offset, type, sizep);
-               unuse_pack(&w_curs);
-               return r;
+               type = packed_delta_info(p, &w_curs, curpos,
+                                        type, obj_offset, sizep);
+               break;
        case OBJ_COMMIT:
        case OBJ_TREE:
        case OBJ_BLOB:
        case OBJ_TAG:
-               strcpy(type, type_names[kind]);
-               unuse_pack(&w_curs);
+               if (sizep)
+                       *sizep = size;
                break;
        default:
                die("pack %s contains unknown object type %d",
-                   p->pack_name, kind);
+                   p->pack_name, type);
        }
-       if (sizep)
-               *sizep = size;
-       return 0;
+       unuse_pack(&w_curs);
+       return type;
 }
 
 static void *unpack_compressed_entry(struct packed_git *p,
                                    struct pack_window **w_curs,
-                                   unsigned long offset,
+                                   unsigned long curpos,
                                    unsigned long size)
 {
        int st;
@@ -1225,10 +1262,10 @@ static void *unpack_compressed_entry(struct packed_git *p,
 
        inflateInit(&stream);
        do {
-               in = use_pack(p, w_curs, offset, &stream.avail_in);
+               in = use_pack(p, w_curs, curpos, &stream.avail_in);
                stream.next_in = in;
                st = inflate(&stream, Z_FINISH);
-               offset += stream.next_in - in;
+               curpos += stream.next_in - in;
        } while (st == Z_OK || st == Z_BUF_ERROR);
        inflateEnd(&stream);
        if ((st != Z_STREAM_END) || stream.total_out != size) {
@@ -1241,63 +1278,57 @@ static void *unpack_compressed_entry(struct packed_git *p,
 
 static void *unpack_delta_entry(struct packed_git *p,
                                struct pack_window **w_curs,
-                               unsigned long offset,
+                               unsigned long curpos,
                                unsigned long delta_size,
-                               enum object_type kind,
                                unsigned long obj_offset,
-                               char *type,
+                               enum object_type *type,
                                unsigned long *sizep)
 {
        void *delta_data, *result, *base;
-       unsigned long result_size, base_size, base_offset;
+       unsigned long base_size, base_offset;
 
-       offset = get_delta_base(p, w_curs, offset, kind,
-               obj_offset, &base_offset);
+       base_offset = get_delta_base(p, w_curs, &curpos, *type, obj_offset);
        base = unpack_entry(p, base_offset, type, &base_size);
        if (!base)
                die("failed to read delta base object at %lu from %s",
                    base_offset, p->pack_name);
 
-       delta_data = unpack_compressed_entry(p, w_curs, offset, delta_size);
+       delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size);
        result = patch_delta(base, base_size,
                             delta_data, delta_size,
-                            &result_size);
+                            sizep);
        if (!result)
                die("failed to apply delta");
        free(delta_data);
        free(base);
-       *sizep = result_size;
        return result;
 }
 
-void *unpack_entry(struct packed_git *p, unsigned long offset,
-                         char *type, unsigned long *sizep)
+void *unpack_entry(struct packed_git *p, unsigned long obj_offset,
+                  enum object_type *type, unsigned long *sizep)
 {
        struct pack_window *w_curs = NULL;
-       unsigned long size, obj_offset = offset;
-       enum object_type kind;
-       void *retval;
+       unsigned long curpos = obj_offset;
+       void *data;
 
-       offset = unpack_object_header(p, &w_curs, offset, &kind, &size);
-       switch (kind) {
+       *type = unpack_object_header(p, &w_curs, &curpos, sizep);
+       switch (*type) {
        case OBJ_OFS_DELTA:
        case OBJ_REF_DELTA:
-               retval = unpack_delta_entry(p, &w_curs, offset, size,
-                       kind, obj_offset, type, sizep);
+               data = unpack_delta_entry(p, &w_curs, curpos, *sizep,
+                                         obj_offset, type, sizep);
                break;
        case OBJ_COMMIT:
        case OBJ_TREE:
        case OBJ_BLOB:
        case OBJ_TAG:
-               strcpy(type, type_names[kind]);
-               *sizep = size;
-               retval = unpack_compressed_entry(p, &w_curs, offset, size);
+               data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
                break;
        default:
-               die("unknown object type %i in %s", kind, p->pack_name);
+               die("unknown object type %i in %s", *type, p->pack_name);
        }
        unuse_pack(&w_curs);
-       return retval;
+       return data;
 }
 
 int num_packed_objects(const struct packed_git *p)
@@ -1319,7 +1350,7 @@ int nth_packed_object_sha1(const struct packed_git *p, int n,
 unsigned long find_pack_entry_one(const unsigned char *sha1,
                                  struct packed_git *p)
 {
-       unsigned int *level1_ofs = p->index_base;
+       uint32_t *level1_ofs = p->index_base;
        int hi = ntohl(level1_ofs[*sha1]);
        int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
        void *index = p->index_base + 256;
@@ -1328,7 +1359,7 @@ unsigned long find_pack_entry_one(const unsigned char *sha1,
                int mi = (lo + hi) / 2;
                int cmp = hashcmp((unsigned char *)index + (24 * mi) + 4, sha1);
                if (!cmp)
-                       return ntohl(*((unsigned int *) ((char *) index + (24 * mi))));
+                       return ntohl(*((uint32_t *)((char *)index + (24 * mi))));
                if (cmp > 0)
                        hi = mi;
                else
@@ -1373,6 +1404,18 @@ static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, cons
                }
                offset = find_pack_entry_one(sha1, p);
                if (offset) {
+                       /*
+                        * We are about to tell the caller where they can
+                        * locate the requested object.  We better make
+                        * sure the packfile is still here and can be
+                        * accessed before supplying that answer, as
+                        * it may have been deleted since the index
+                        * was loaded!
+                        */
+                       if (p->pack_fd == -1 && open_packed_git(p)) {
+                               error("packfile %s cannot be accessed", p->pack_name);
+                               continue;
+                       }
                        e->offset = offset;
                        e->p = p;
                        hashcpy(e->sha1, sha1);
@@ -1392,16 +1435,16 @@ struct packed_git *find_sha1_pack(const unsigned char *sha1,
                        return p;
        }
        return NULL;
-       
+
 }
 
-static int sha1_loose_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
+static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *sizep)
 {
        int status;
        unsigned long mapsize, size;
        void *map;
        z_stream stream;
-       char hdr[128];
+       char hdr[32];
 
        map = map_sha1_file(sha1, &mapsize);
        if (!map)
@@ -1409,49 +1452,107 @@ static int sha1_loose_object_info(const unsigned char *sha1, char *type, unsigne
        if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
                status = error("unable to unpack %s header",
                               sha1_to_hex(sha1));
-       if (parse_sha1_header(hdr, type, &size) < 0)
+       else if ((status = parse_sha1_header(hdr, &size)) < 0)
                status = error("unable to parse %s header", sha1_to_hex(sha1));
-       else {
-               status = 0;
-               if (sizep)
-                       *sizep = size;
-       }
+       else if (sizep)
+               *sizep = size;
        inflateEnd(&stream);
        munmap(map, mapsize);
        return status;
 }
 
-int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
+int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
 {
        struct pack_entry e;
 
        if (!find_pack_entry(sha1, &e, NULL)) {
                reprepare_packed_git();
                if (!find_pack_entry(sha1, &e, NULL))
-                       return sha1_loose_object_info(sha1, type, sizep);
+                       return sha1_loose_object_info(sha1, sizep);
        }
-       return packed_object_info(e.p, e.offset, type, sizep);
+       return packed_object_info(e.p, e.offset, sizep);
 }
 
-static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
+static void *read_packed_sha1(const unsigned char *sha1,
+                             enum object_type *type, unsigned long *size)
 {
        struct pack_entry e;
 
-       if (!find_pack_entry(sha1, &e, NULL)) {
-               error("cannot read sha1_file for %s", sha1_to_hex(sha1));
+       if (!find_pack_entry(sha1, &e, NULL))
                return NULL;
+       else
+               return unpack_entry(e.p, e.offset, type, size);
+}
+
+/*
+ * 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 *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;
        }
-       return unpack_entry(e.p, e.offset, type, size);
+       return NULL;
 }
 
-void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
+int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
+                     unsigned char *sha1)
+{
+       struct cached_object *co;
+
+       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);
+       }
+       co = &cached_objects[cached_object_nr++];
+       co->size = len;
+       co->type = type;
+       co->buf = xmalloc(len);
+       memcpy(co->buf, buf, len);
+       hashcpy(co->sha1, sha1);
+       return 0;
+}
+
+void *read_sha1_file(const unsigned char *sha1, enum object_type *type,
+                    unsigned long *size)
 {
        unsigned long mapsize;
        void *map, *buf;
-       struct pack_entry e;
+       struct cached_object *co;
+
+       co = find_cached_object(sha1);
+       if (co) {
+               buf = xmalloc(co->size + 1);
+               memcpy(buf, co->buf, co->size);
+               ((char*)buf)[co->size] = 0;
+               *type = co->type;
+               *size = co->size;
+               return buf;
+       }
 
-       if (find_pack_entry(sha1, &e, NULL))
-               return read_packed_sha1(sha1, type, size);
+       buf = read_packed_sha1(sha1, type, size);
+       if (buf)
+               return buf;
        map = map_sha1_file(sha1, &mapsize);
        if (map) {
                buf = unpack_sha1_file(map, mapsize, type, size);
@@ -1459,39 +1560,38 @@ void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size
                return buf;
        }
        reprepare_packed_git();
-       if (find_pack_entry(sha1, &e, NULL))
-               return read_packed_sha1(sha1, type, size);
-       return NULL;
+       return read_packed_sha1(sha1, type, size);
 }
 
 void *read_object_with_reference(const unsigned char *sha1,
-                                const char *required_type,
+                                const char *required_type_name,
                                 unsigned long *size,
                                 unsigned char *actual_sha1_return)
 {
-       char type[20];
+       enum object_type type, required_type;
        void *buffer;
        unsigned long isize;
        unsigned char actual_sha1[20];
 
+       required_type = type_from_string(required_type_name);
        hashcpy(actual_sha1, sha1);
        while (1) {
                int ref_length = -1;
                const char *ref_type = NULL;
 
-               buffer = read_sha1_file(actual_sha1, type, &isize);
+               buffer = read_sha1_file(actual_sha1, &type, &isize);
                if (!buffer)
                        return NULL;
-               if (!strcmp(type, required_type)) {
+               if (type == required_type) {
                        *size = isize;
                        if (actual_sha1_return)
                                hashcpy(actual_sha1_return, actual_sha1);
                        return buffer;
                }
                /* Handle references */
-               else if (!strcmp(type, commit_type))
+               else if (type == OBJ_COMMIT)
                        ref_type = "tree ";
-               else if (!strcmp(type, tag_type))
+               else if (type == OBJ_TAG)
                        ref_type = "object ";
                else {
                        free(buffer);
@@ -1512,12 +1612,12 @@ void *read_object_with_reference(const unsigned char *sha1,
 
 static void write_sha1_file_prepare(void *buf, unsigned long len,
                                     const char *type, unsigned char *sha1,
-                                    unsigned char *hdr, int *hdrlen)
+                                    char *hdr, int *hdrlen)
 {
        SHA_CTX c;
 
        /* Generate the header */
-       *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
+       *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
 
        /* Sha1.. */
        SHA1_Init(&c);
@@ -1599,20 +1699,8 @@ int move_temp_to_file(const char *tmpfile, const char *filename)
 
 static int write_buffer(int fd, const void *buf, size_t len)
 {
-       while (len) {
-               ssize_t size;
-
-               size = write(fd, buf, len);
-               if (!size)
-                       return error("file write: disk full");
-               if (size < 0) {
-                       if (errno == EINTR || errno == EAGAIN)
-                               continue;
-                       return error("file write error (%s)", strerror(errno));
-               }
-               len -= size;
-               buf = (char *) buf + size;
-       }
+       if (write_in_full(fd, buf, len) < 0)
+               return error("file write error (%s)", strerror(errno));
        return 0;
 }
 
@@ -1636,33 +1724,24 @@ static int write_binary_header(unsigned char *hdr, enum object_type type, unsign
 
 static void setup_object_header(z_stream *stream, const char *type, unsigned long len)
 {
-       int obj_type, hdr;
+       int obj_type, hdrlen;
 
        if (use_legacy_headers) {
                while (deflate(stream, 0) == Z_OK)
                        /* nothing */;
                return;
        }
-       if (!strcmp(type, blob_type))
-               obj_type = OBJ_BLOB;
-       else if (!strcmp(type, tree_type))
-               obj_type = OBJ_TREE;
-       else if (!strcmp(type, commit_type))
-               obj_type = OBJ_COMMIT;
-       else if (!strcmp(type, tag_type))
-               obj_type = OBJ_TAG;
-       else
-               die("trying to generate bogus object of type '%s'", type);
-       hdr = write_binary_header(stream->next_out, obj_type, len);
-       stream->total_out = hdr;
-       stream->next_out += hdr;
-       stream->avail_out -= hdr;
+       obj_type = type_from_string(type);
+       hdrlen = write_binary_header(stream->next_out, obj_type, len);
+       stream->total_out = hdrlen;
+       stream->next_out += hdrlen;
+       stream->avail_out -= hdrlen;
 }
 
 int hash_sha1_file(void *buf, unsigned long len, const char *type,
                    unsigned char *sha1)
 {
-       unsigned char hdr[50];
+       char hdr[32];
        int hdrlen;
        write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
        return 0;
@@ -1676,7 +1755,7 @@ int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned cha
        unsigned char sha1[20];
        char *filename;
        static char tmpfile[PATH_MAX];
-       unsigned char hdr[50];
+       char hdr[32];
        int fd, hdrlen;
 
        /* Normally if we have it in the pack then we do not bother writing
@@ -1723,7 +1802,7 @@ int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned cha
        stream.avail_out = size;
 
        /* First header.. */
-       stream.next_in = hdr;
+       stream.next_in = (unsigned char *)hdr;
        stream.avail_in = hdrlen;
        setup_object_header(&stream, type, len);
 
@@ -1754,15 +1833,17 @@ static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
        z_stream stream;
        unsigned char *unpacked;
        unsigned long len;
-       char type[20];
-       char hdr[50];
+       enum object_type type;
+       char hdr[32];
        int hdrlen;
        void *buf;
 
        /* need to unpack and recompress it by itself */
-       unpacked = read_packed_sha1(sha1, type, &len);
+       unpacked = read_packed_sha1(sha1, &type, &len);
+       if (!unpacked)
+               error("cannot read sha1_file for %s", sha1_to_hex(sha1));
 
-       hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
+       hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
 
        /* Set it up */
        memset(&stream, 0, sizeof(stream));
@@ -1857,7 +1938,7 @@ int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
                        if (ret != Z_OK)
                                break;
                }
-               size = read(fd, buffer + *bufposn, bufsize - *bufposn);
+               size = xread(fd, buffer + *bufposn, bufsize - *bufposn);
                if (size <= 0) {
                        close(local);
                        unlink(tmpfile);
@@ -1972,25 +2053,44 @@ int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
        return ret;
 }
 
-int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
+int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
+            enum object_type type, const char *path)
 {
        unsigned long size = st->st_size;
        void *buf;
-       int ret;
+       int ret, re_allocated = 0;
 
        buf = "";
        if (size)
-               buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
+               buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
        close(fd);
-       if (buf == MAP_FAILED)
-               return -1;
 
        if (!type)
-               type = blob_type;
+               type = OBJ_BLOB;
+
+       /*
+        * Convert blobs to git internal format
+        */
+       if ((type == OBJ_BLOB) && S_ISREG(st->st_mode)) {
+               unsigned long nsize = size;
+               char *nbuf = buf;
+               if (convert_to_git(path, &nbuf, &nsize)) {
+                       if (size)
+                               munmap(buf, size);
+                       size = nsize;
+                       buf = nbuf;
+                       re_allocated = 1;
+               }
+       }
+
        if (write_object)
-               ret = write_sha1_file(buf, size, type, sha1);
+               ret = write_sha1_file(buf, size, typename(type), sha1);
        else
-               ret = hash_sha1_file(buf, size, type, sha1);
+               ret = hash_sha1_file(buf, size, typename(type), sha1);
+       if (re_allocated) {
+               free(buf);
+               return ret;
+       }
        if (size)
                munmap(buf, size);
        return ret;
@@ -2007,7 +2107,7 @@ 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, NULL) < 0)
+               if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path) < 0)
                        return error("%s: failed to insert into database",
                                     path);
                break;
@@ -2031,3 +2131,24 @@ int index_path(unsigned char *sha1, const char *path, struct stat *st, int write
        }
        return 0;
 }
+
+int read_pack_header(int fd, struct pack_header *header)
+{
+       char *c = (char*)header;
+       ssize_t remaining = sizeof(struct pack_header);
+       do {
+               ssize_t r = xread(fd, c, remaining);
+               if (r <= 0)
+                       /* "eof before pack header was fully read" */
+                       return PH_ERROR_EOF;
+               remaining -= r;
+               c += r;
+       } while (remaining > 0);
+       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;
+}