gitweb: Move git_get_last_activity subroutine earlier
[gitweb.git] / sha1_file.c
index f77c18934af507e6f55628e6b0c60ca69bf60aae..e89d24c01595aa8ea6c6306928639b40f3313a50 100644 (file)
 #endif
 #endif
 
-const unsigned char null_sha1[20] = { 0, };
+const unsigned char null_sha1[20];
 
 static unsigned int sha1_file_open_flag = O_NOATIME;
 
-static unsigned hexval(char c)
-{
-       if (c >= '0' && c <= '9')
-               return c - '0';
-       if (c >= 'a' && c <= 'f')
-               return c - 'a' + 10;
-       if (c >= 'A' && c <= 'F')
-               return c - 'A' + 10;
-       return ~0;
-}
+signed char hexval_table[256] = {
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* 00-07 */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* 08-0f */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* 10-17 */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* 18-1f */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* 20-27 */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* 28-2f */
+         0,  1,  2,  3,  4,  5,  6,  7,                /* 30-37 */
+         8,  9, -1, -1, -1, -1, -1, -1,                /* 38-3f */
+        -1, 10, 11, 12, 13, 14, 15, -1,                /* 40-47 */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* 48-4f */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* 50-57 */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* 58-5f */
+        -1, 10, 11, 12, 13, 14, 15, -1,                /* 60-67 */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* 68-67 */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* 70-77 */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* 78-7f */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* 80-87 */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* 88-8f */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* 90-97 */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* 98-9f */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* a0-a7 */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* a8-af */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* b0-b7 */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* b8-bf */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* c0-c7 */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* c8-cf */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* d0-d7 */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* d8-df */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* e0-e7 */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* e8-ef */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* f0-f7 */
+        -1, -1, -1, -1, -1, -1, -1, -1,                /* f8-ff */
+};
 
 int get_sha1_hex(const char *hex, unsigned char *sha1)
 {
@@ -50,29 +74,6 @@ int get_sha1_hex(const char *hex, unsigned char *sha1)
        return 0;
 }
 
-int adjust_shared_perm(const char *path)
-{
-       struct stat st;
-       int mode;
-
-       if (!shared_repository)
-               return 0;
-       if (lstat(path, &st) < 0)
-               return -1;
-       mode = st.st_mode;
-       if (mode & S_IRUSR)
-               mode |= S_IRGRP;
-       if (mode & S_IWUSR)
-               mode |= S_IWGRP;
-       if (mode & S_IXUSR)
-               mode |= S_IXGRP;
-       if (S_ISDIR(mode))
-               mode |= S_ISGID;
-       if (chmod(path, mode) < 0)
-               return -2;
-       return 0;
-}
-
 int safe_create_leading_directories(char *path)
 {
        char *pos = path;
@@ -138,7 +139,7 @@ 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 a "strdup()" if you need to save the
+ * careful about using it. Do a "xstrdup()" if you need to save the
  * filename.
  *
  * Also note that this returns the location for creating.  Reading
@@ -366,7 +367,7 @@ static void read_info_alternates(const char * relative_base, int depth)
 
 void prepare_alt_odb(void)
 {
-       char *alt;
+       const char *alt;
 
        alt = getenv(ALTERNATE_DB_ENVIRONMENT);
        if (!alt) alt = "";
@@ -476,7 +477,7 @@ int use_packed_git(struct packed_git *p)
 {
        if (!p->pack_size) {
                struct stat st;
-               // We created the struct before we had the pack
+               /* We created the struct before we had the pack */
                stat(p->pack_name, &st);
                if (!S_ISREG(st.st_mode))
                        die("packfile %s not a regular file", p->pack_name);
@@ -486,6 +487,7 @@ int use_packed_git(struct packed_git *p)
                int fd;
                struct stat st;
                void *map;
+               struct pack_header *hdr;
 
                pack_mapped += p->pack_size;
                while (PACK_MAX_SZ < pack_mapped && unuse_one_packed_git())
@@ -505,12 +507,24 @@ int use_packed_git(struct packed_git *p)
                        die("packfile %s cannot be mapped.", p->pack_name);
                p->pack_base = map;
 
+               /* Check if we understand this pack file.  If we don't we're
+                * likely too old to handle it.
+                */
+               hdr = map;
+               if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
+                       die("packfile %s isn't actually a pack.", p->pack_name);
+               if (!pack_version_ok(hdr->hdr_version))
+                       die("packfile %s is version %i and not supported"
+                               " (try upgrading GIT to a newer version)",
+                               p->pack_name, ntohl(hdr->hdr_version));
+
                /* Check if the pack file matches with the index file.
                 * this is cheap.
                 */
-               if (memcmp((char*)(p->index_base) + p->index_size - 40,
-                          p->pack_base + p->pack_size - 20, 20)) {
-                             
+               if (hashcmp((unsigned char *)(p->index_base) +
+                           p->index_size - 40,
+                           (unsigned char *)p->pack_base +
+                           p->pack_size - 20)) {
                        die("packfile %s does not match index.", p->pack_name);
                }
        }
@@ -550,7 +564,7 @@ struct packed_git *add_packed_git(char *path, int path_len, int local)
        p->pack_use_cnt = 0;
        p->pack_local = local;
        if ((path_len > 44) && !get_sha1_hex(path + path_len - 44, sha1))
-               memcpy(p->sha1, sha1, 20);
+               hashcpy(p->sha1, sha1);
        return p;
 }
 
@@ -581,7 +595,7 @@ struct packed_git *parse_pack_index_file(const unsigned char *sha1, char *idx_pa
        p->pack_base = NULL;
        p->pack_last_used = 0;
        p->pack_use_cnt = 0;
-       memcpy(p->sha1, sha1, 20);
+       hashcpy(p->sha1, sha1);
        return p;
 }
 
@@ -612,11 +626,17 @@ static void prepare_packed_git_one(char *objdir, int local)
                int namelen = strlen(de->d_name);
                struct packed_git *p;
 
-               if (strcmp(de->d_name + namelen - 4, ".idx"))
+               if (!has_extension(de->d_name, ".idx"))
                        continue;
 
                /* we have .idx.  Is it a file we can map? */
                strcpy(path + len, de->d_name);
+               for (p = packed_git; p; p = p->next) {
+                       if (!memcmp(path, p->pack_name, len + namelen - 4))
+                               break;
+               }
+               if (p)
+                       continue;
                p = add_packed_git(path, len + namelen, local);
                if (!p)
                        continue;
@@ -626,12 +646,12 @@ static void prepare_packed_git_one(char *objdir, int local)
        closedir(dir);
 }
 
+static int prepare_packed_git_run_once = 0;
 void prepare_packed_git(void)
 {
-       static int run_once = 0;
        struct alternate_object_database *alt;
 
-       if (run_once)
+       if (prepare_packed_git_run_once)
                return;
        prepare_packed_git_one(get_object_directory(), 1);
        prepare_alt_odb();
@@ -640,24 +660,23 @@ void prepare_packed_git(void)
                prepare_packed_git_one(alt->base, 0);
                alt->name[-1] = '/';
        }
-       run_once = 1;
+       prepare_packed_git_run_once = 1;
+}
+
+static void reprepare_packed_git(void)
+{
+       prepare_packed_git_run_once = 0;
+       prepare_packed_git();
 }
 
 int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
 {
-       char header[100];
        unsigned char real_sha1[20];
-       SHA_CTX c;
-
-       SHA1_Init(&c);
-       SHA1_Update(&c, header, 1+sprintf(header, "%s %lu", type, size));
-       SHA1_Update(&c, map, size);
-       SHA1_Final(real_sha1, &c);
-       return memcmp(sha1, real_sha1, 20) ? -1 : 0;
+       hash_sha1_file(map, size, type, real_sha1);
+       return hashcmp(sha1, real_sha1) ? -1 : 0;
 }
 
-static void *map_sha1_file_internal(const unsigned char *sha1,
-                                   unsigned long *size)
+void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
 {
        struct stat st;
        void *map;
@@ -694,26 +713,96 @@ static void *map_sha1_file_internal(const unsigned char *sha1,
        return map;
 }
 
-int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size)
+int legacy_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
+        */
+       word = (map[0] << 8) + map[1];
+       if (map[0] == 0x78 && !(word % 31))
+               return 1;
+       else
+               return 0;
+}
+
+unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep)
+{
+       unsigned shift;
+       unsigned char c;
+       unsigned long size;
+       unsigned long used = 0;
+
+       c = buf[used++];
+       *type = (c >> 4) & 7;
+       size = c & 15;
+       shift = 4;
+       while (c & 0x80) {
+               if (len <= used)
+                       return 0;
+               if (sizeof(long) * 8 <= shift)
+                       return 0;
+               c = buf[used++];
+               size += (c & 0x7f) << shift;
+               shift += 7;
+       }
+       *sizep = size;
+       return used;
+}
+
+static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
 {
+       unsigned long size, used;
+       static const char valid_loose_object_type[8] = {
+               0, /* OBJ_EXT */
+               1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
+               0, /* "delta" and others are invalid in a loose object */
+       };
+       enum object_type type;
+
        /* Get the data stream */
        memset(stream, 0, sizeof(*stream));
        stream->next_in = map;
        stream->avail_in = mapsize;
        stream->next_out = buffer;
-       stream->avail_out = size;
+       stream->avail_out = bufsiz;
 
+       if (legacy_loose_object(map)) {
+               inflateInit(stream);
+               return inflate(stream, 0);
+       }
+
+       used = unpack_object_header_gently(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;
        inflateInit(stream);
-       return inflate(stream, 0);
+
+       /* And generate the fake traditional header */
+       stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
+                                        type_names[type], size);
+       return 0;
 }
 
 static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
 {
        int bytes = strlen(buffer) + 1;
        unsigned char *buf = xmalloc(1+size);
+       unsigned long n;
 
-       memcpy(buf, buffer + bytes, stream->total_out - bytes);
-       bytes = stream->total_out - bytes;
+       n = stream->total_out - bytes;
+       if (n > size)
+               n = size;
+       memcpy(buf, (char *) buffer + bytes, n);
+       bytes = n;
        if (bytes < size) {
                stream->next_out = buf + bytes;
                stream->avail_out = size - bytes;
@@ -730,7 +819,7 @@ 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.
  */
-int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
+static int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
 {
        int i;
        unsigned long size;
@@ -788,47 +877,81 @@ void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned l
        return unpack_sha1_rest(&stream, hdr, *size);
 }
 
+static unsigned long get_delta_base(struct packed_git *p,
+                                   unsigned long offset,
+                                   enum object_type kind,
+                                   unsigned long delta_obj_offset,
+                                   unsigned long *base_obj_offset)
+{
+       unsigned char *base_info = (unsigned char *) p->pack_base + offset;
+       unsigned long base_offset;
+
+       /* there must be at least 20 bytes left regardless of delta type */
+       if (p->pack_size <= offset + 20)
+               die("truncated pack file");
+
+       if (kind == OBJ_OFS_DELTA) {
+               unsigned used = 0;
+               unsigned char c = base_info[used++];
+               base_offset = c & 127;
+               while (c & 128) {
+                       base_offset += 1;
+                       if (!base_offset || base_offset & ~(~0UL >> 7))
+                               die("offset value overflow for delta base object");
+                       c = base_info[used++];
+                       base_offset = (base_offset << 7) + (c & 127);
+               }
+               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) {
+               /* 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;
+       } else
+               die("I am totally screwed");
+       *base_obj_offset = base_offset;
+       return offset;
+}
+
 /* forward declaration for a mutually recursive function */
-static int packed_object_info(struct pack_entry *entry,
+static int packed_object_info(struct packed_git *p, unsigned long offset,
                              char *type, unsigned long *sizep);
 
-static int packed_delta_info(unsigned char *base_sha1,
-                            unsigned long delta_size,
-                            unsigned long left,
+static int packed_delta_info(struct packed_git *p,
+                            unsigned long offset,
+                            enum object_type kind,
+                            unsigned long obj_offset,
                             char *type,
-                            unsigned long *sizep,
-                            struct packed_git *p)
+                            unsigned long *sizep)
 {
-       struct pack_entry base_ent;
-
-       if (left < 20)
-               die("truncated pack file");
+       unsigned long base_offset;
 
-       /* The base entry _must_ be in the same pack */
-       if (!find_pack_entry_one(base_sha1, &base_ent, p))
-               die("failed to find delta-pack base object %s",
-                   sha1_to_hex(base_sha1));
+       offset = get_delta_base(p, offset, kind, obj_offset, &base_offset);
 
        /* 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(&base_ent, type, NULL))
+       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[64];
+               unsigned char delta_head[20];
                unsigned long result_size;
                z_stream stream;
                int st;
 
                memset(&stream, 0, sizeof(stream));
 
-               data = stream.next_in = base_sha1 + 20;
-               stream.avail_in = left - 20;
+               stream.next_in = (unsigned char *) p->pack_base + offset;
+               stream.avail_in = p->pack_size - offset;
                stream.next_out = delta_head;
                stream.avail_out = sizeof(delta_head);
 
@@ -857,136 +980,87 @@ static int packed_delta_info(unsigned char *base_sha1,
 static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
        enum object_type *type, unsigned long *sizep)
 {
-       unsigned shift;
-       unsigned char *pack, c;
-       unsigned long size;
+       unsigned long used;
 
-       if (offset >= p->pack_size)
+       if (p->pack_size <= offset)
                die("object offset outside of pack file");
 
-       pack =  p->pack_base + offset;
-       c = *pack++;
-       offset++;
-       *type = (c >> 4) & 7;
-       size = c & 15;
-       shift = 4;
-       while (c & 0x80) {
-               if (offset >= p->pack_size)
-                       die("object offset outside of pack file");
-               c = *pack++;
-               offset++;
-               size += (c & 0x7f) << shift;
-               shift += 7;
-       }
-       *sizep = size;
-       return offset;
-}
-
-int check_reuse_pack_delta(struct packed_git *p, unsigned long offset,
-                          unsigned char *base, unsigned long *sizep,
-                          enum object_type *kindp)
-{
-       unsigned long ptr;
-       int status = -1;
+       used = unpack_object_header_gently((unsigned char *)p->pack_base +
+                                          offset,
+                                          p->pack_size - offset, type, sizep);
+       if (!used)
+               die("object offset outside of pack file");
 
-       use_packed_git(p);
-       ptr = offset;
-       ptr = unpack_object_header(p, ptr, kindp, sizep);
-       if (*kindp != OBJ_DELTA)
-               goto done;
-       memcpy(base, p->pack_base + ptr, 20);
-       status = 0;
- done:
-       unuse_packed_git(p);
-       return status;
+       return offset + used;
 }
 
-void packed_object_info_detail(struct pack_entry *e,
+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)
 {
-       struct packed_git *p = e->p;
-       unsigned long offset;
-       unsigned char *pack;
+       unsigned long obj_offset, val;
+       unsigned char *next_sha1;
        enum object_type kind;
 
-       offset = unpack_object_header(p, e->offset, &kind, size);
-       pack = p->pack_base + offset;
-       if (kind != OBJ_DELTA)
-               *delta_chain_length = 0;
-       else {
-               unsigned int chain_length = 0;
-               if (p->pack_size <= offset + 20)
-                       die("pack file %s records an incomplete delta base",
-                           p->pack_name);
-               memcpy(base_sha1, pack, 20);
-               do {
-                       struct pack_entry base_ent;
-                       unsigned long junk;
-
-                       find_pack_entry_one(pack, &base_ent, p);
-                       offset = unpack_object_header(p, base_ent.offset,
-                                                     &kind, &junk);
-                       pack = p->pack_base + offset;
-                       chain_length++;
-               } while (kind == OBJ_DELTA);
-               *delta_chain_length = chain_length;
-       }
-       switch (kind) {
-       case OBJ_COMMIT:
-               strcpy(type, commit_type);
-               break;
-       case OBJ_TREE:
-               strcpy(type, tree_type);
-               break;
-       case OBJ_BLOB:
-               strcpy(type, blob_type);
-               break;
-       case OBJ_TAG:
-               strcpy(type, tag_type);
-               break;
-       default:
-               die("corrupted pack file %s containing object of kind %d",
-                   p->pack_name, kind);
+       *delta_chain_length = 0;
+       obj_offset = offset;
+       offset = unpack_object_header(p, offset, &kind, size);
+
+       for (;;) {
+               switch (kind) {
+               default:
+                       die("corrupted pack file %s containing object of kind %d",
+                           p->pack_name, kind);
+               case OBJ_COMMIT:
+               case OBJ_TREE:
+               case OBJ_BLOB:
+               case OBJ_TAG:
+                       strcpy(type, type_names[kind]);
+                       *store_size = 0; /* notyet */
+                       return;
+               case OBJ_OFS_DELTA:
+                       get_delta_base(p, offset, kind, obj_offset, &offset);
+                       if (*delta_chain_length == 0) {
+                               /* TODO: find base_sha1 as pointed by offset */
+                       }
+                       break;
+               case OBJ_REF_DELTA:
+                       if (p->pack_size <= offset + 20)
+                               die("pack file %s records an incomplete delta base",
+                                   p->pack_name);
+                       next_sha1 = (unsigned char *) p->pack_base + offset;
+                       if (*delta_chain_length == 0)
+                               hashcpy(base_sha1, next_sha1);
+                       offset = find_pack_entry_one(next_sha1, p);
+                       break;
+               }
+               obj_offset = offset;
+               offset = unpack_object_header(p, offset, &kind, &val);
+               (*delta_chain_length)++;
        }
-       *store_size = 0; /* notyet */
 }
 
-static int packed_object_info(struct pack_entry *entry,
+static int packed_object_info(struct packed_git *p, unsigned long offset,
                              char *type, unsigned long *sizep)
 {
-       struct packed_git *p = entry->p;
-       unsigned long offset, size, left;
-       unsigned char *pack;
+       unsigned long size, obj_offset = offset;
        enum object_type kind;
-       int retval;
-
-       if (use_packed_git(p))
-               die("cannot map packed file");
 
-       offset = unpack_object_header(p, entry->offset, &kind, &size);
-       pack = p->pack_base + offset;
-       left = p->pack_size - offset;
+       offset = unpack_object_header(p, offset, &kind, &size);
 
        switch (kind) {
-       case OBJ_DELTA:
-               retval = packed_delta_info(pack, size, left, type, sizep, p);
-               unuse_packed_git(p);
-               return retval;
+       case OBJ_OFS_DELTA:
+       case OBJ_REF_DELTA:
+               return packed_delta_info(p, offset, kind, obj_offset, type, sizep);
        case OBJ_COMMIT:
-               strcpy(type, commit_type);
-               break;
        case OBJ_TREE:
-               strcpy(type, tree_type);
-               break;
        case OBJ_BLOB:
-               strcpy(type, blob_type);
-               break;
        case OBJ_TAG:
-               strcpy(type, tag_type);
+               strcpy(type, type_names[kind]);
                break;
        default:
                die("corrupted pack file %s containing object of kind %d",
@@ -994,69 +1068,12 @@ static int packed_object_info(struct pack_entry *entry,
        }
        if (sizep)
                *sizep = size;
-       unuse_packed_git(p);
        return 0;
 }
 
-/* forward declaration for a mutually recursive function */
-static void *unpack_entry(struct pack_entry *, char *, unsigned long *);
-
-static void *unpack_delta_entry(unsigned char *base_sha1,
-                               unsigned long delta_size,
-                               unsigned long left,
-                               char *type,
-                               unsigned long *sizep,
-                               struct packed_git *p)
-{
-       struct pack_entry base_ent;
-       void *data, *delta_data, *result, *base;
-       unsigned long data_size, result_size, base_size;
-       z_stream stream;
-       int st;
-
-       if (left < 20)
-               die("truncated pack file");
-
-       /* The base entry _must_ be in the same pack */
-       if (!find_pack_entry_one(base_sha1, &base_ent, p))
-               die("failed to find delta-pack base object %s",
-                   sha1_to_hex(base_sha1));
-       base = unpack_entry_gently(&base_ent, type, &base_size);
-       if (!base)
-               die("failed to read delta-pack base object %s",
-                   sha1_to_hex(base_sha1));
-
-       data = base_sha1 + 20;
-       data_size = left - 20;
-       delta_data = xmalloc(delta_size);
-
-       memset(&stream, 0, sizeof(stream));
-
-       stream.next_in = data;
-       stream.avail_in = data_size;
-       stream.next_out = delta_data;
-       stream.avail_out = delta_size;
-
-       inflateInit(&stream);
-       st = inflate(&stream, Z_FINISH);
-       inflateEnd(&stream);
-       if ((st != Z_STREAM_END) || stream.total_out != delta_size)
-               die("delta data unpack failed");
-
-       result = patch_delta(base, base_size,
-                            delta_data, delta_size,
-                            &result_size);
-       if (!result)
-               die("failed to apply delta");
-       free(delta_data);
-       free(base);
-       *sizep = result_size;
-       return result;
-}
-
-static void *unpack_non_delta_entry(unsigned char *data,
-                                   unsigned long size,
-                                   unsigned long left)
+static void *unpack_compressed_entry(struct packed_git *p,
+                                   unsigned long offset,
+                                   unsigned long size)
 {
        int st;
        z_stream stream;
@@ -1065,8 +1082,8 @@ static void *unpack_non_delta_entry(unsigned char *data,
        buffer = xmalloc(size + 1);
        buffer[size] = 0;
        memset(&stream, 0, sizeof(stream));
-       stream.next_in = data;
-       stream.avail_in = left;
+       stream.next_in = (unsigned char*)p->pack_base + offset;
+       stream.avail_in = p->pack_size - offset;
        stream.next_out = buffer;
        stream.avail_out = size;
 
@@ -1081,6 +1098,35 @@ static void *unpack_non_delta_entry(unsigned char *data,
        return buffer;
 }
 
+static void *unpack_delta_entry(struct packed_git *p,
+                               unsigned long offset,
+                               unsigned long delta_size,
+                               enum object_type kind,
+                               unsigned long obj_offset,
+                               char *type,
+                               unsigned long *sizep)
+{
+       void *delta_data, *result, *base;
+       unsigned long result_size, base_size, base_offset;
+
+       offset = get_delta_base(p, offset, kind, obj_offset, &base_offset);
+       base = unpack_entry_gently(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, offset, delta_size);
+       result = patch_delta(base, base_size,
+                            delta_data, delta_size,
+                            &result_size);
+       if (!result)
+               die("failed to apply delta");
+       free(delta_data);
+       free(base);
+       *sizep = result_size;
+       return result;
+}
+
 static void *unpack_entry(struct pack_entry *entry,
                          char *type, unsigned long *sizep)
 {
@@ -1089,7 +1135,7 @@ static void *unpack_entry(struct pack_entry *entry,
 
        if (use_packed_git(p))
                die("cannot map packed file");
-       retval = unpack_entry_gently(entry, type, sizep);
+       retval = unpack_entry_gently(p, entry->offset, type, sizep);
        unuse_packed_git(p);
        if (!retval)
                die("corrupted pack file %s", p->pack_name);
@@ -1097,40 +1143,27 @@ static void *unpack_entry(struct pack_entry *entry,
 }
 
 /* The caller is responsible for use_packed_git()/unuse_packed_git() pair */
-void *unpack_entry_gently(struct pack_entry *entry,
+void *unpack_entry_gently(struct packed_git *p, unsigned long offset,
                          char *type, unsigned long *sizep)
 {
-       struct packed_git *p = entry->p;
-       unsigned long offset, size, left;
-       unsigned char *pack;
+       unsigned long size, obj_offset = offset;
        enum object_type kind;
-       void *retval;
 
-       offset = unpack_object_header(p, entry->offset, &kind, &size);
-       pack = p->pack_base + offset;
-       left = p->pack_size - offset;
+       offset = unpack_object_header(p, offset, &kind, &size);
        switch (kind) {
-       case OBJ_DELTA:
-               retval = unpack_delta_entry(pack, size, left, type, sizep, p);
-               return retval;
+       case OBJ_OFS_DELTA:
+       case OBJ_REF_DELTA:
+               return unpack_delta_entry(p, offset, size, kind, obj_offset, type, sizep);
        case OBJ_COMMIT:
-               strcpy(type, commit_type);
-               break;
        case OBJ_TREE:
-               strcpy(type, tree_type);
-               break;
        case OBJ_BLOB:
-               strcpy(type, blob_type);
-               break;
        case OBJ_TAG:
-               strcpy(type, tag_type);
-               break;
+               strcpy(type, type_names[kind]);
+               *sizep = size;
+               return unpack_compressed_entry(p, offset, size);
        default:
                return NULL;
        }
-       *sizep = size;
-       retval = unpack_non_delta_entry(pack, size, left);
-       return retval;
 }
 
 int num_packed_objects(const struct packed_git *p)
@@ -1145,12 +1178,12 @@ int nth_packed_object_sha1(const struct packed_git *p, int n,
        void *index = p->index_base + 256;
        if (n < 0 || num_packed_objects(p) <= n)
                return -1;
-       memcpy(sha1, (index + 24 * n + 4), 20);
+       hashcpy(sha1, (unsigned char *) index + (24 * n) + 4);
        return 0;
 }
 
-int find_pack_entry_one(const unsigned char *sha1,
-                       struct pack_entry *e, struct packed_git *p)
+unsigned long find_pack_entry_one(const unsigned char *sha1,
+                                 struct packed_git *p)
 {
        unsigned int *level1_ofs = p->index_base;
        int hi = ntohl(level1_ofs[*sha1]);
@@ -1159,13 +1192,9 @@ int find_pack_entry_one(const unsigned char *sha1,
 
        do {
                int mi = (lo + hi) / 2;
-               int cmp = memcmp(index + 24 * mi + 4, sha1, 20);
-               if (!cmp) {
-                       e->offset = ntohl(*((unsigned int *)(index + 24 * mi)));
-                       memcpy(e->sha1, sha1, 20);
-                       e->p = p;
-                       return 1;
-               }
+               int cmp = hashcmp((unsigned char *)index + (24 * mi) + 4, sha1);
+               if (!cmp)
+                       return ntohl(*((unsigned int *) ((char *) index + (24 * mi))));
                if (cmp > 0)
                        hi = mi;
                else
@@ -1174,14 +1203,29 @@ int find_pack_entry_one(const unsigned char *sha1,
        return 0;
 }
 
-static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
+static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
 {
        struct packed_git *p;
+       unsigned long offset;
+
        prepare_packed_git();
 
        for (p = packed_git; p; p = p->next) {
-               if (find_pack_entry_one(sha1, e, p))
+               if (ignore_packed) {
+                       const char **ig;
+                       for (ig = ignore_packed; *ig; ig++)
+                               if (!strcmp(p->pack_name, *ig))
+                                       break;
+                       if (*ig)
+                               continue;
+               }
+               offset = find_pack_entry_one(sha1, p);
+               if (offset) {
+                       e->offset = offset;
+                       e->p = p;
+                       hashcpy(e->sha1, sha1);
                        return 1;
+               }
        }
        return 0;
 }
@@ -1190,10 +1234,9 @@ struct packed_git *find_sha1_pack(const unsigned char *sha1,
                                  struct packed_git *packs)
 {
        struct packed_git *p;
-       struct pack_entry e;
 
        for (p = packs; p; p = p->next) {
-               if (find_pack_entry_one(sha1, &e, p))
+               if (find_pack_entry_one(sha1, p))
                        return p;
        }
        return NULL;
@@ -1208,13 +1251,20 @@ int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep
        z_stream stream;
        char hdr[128];
 
-       map = map_sha1_file_internal(sha1, &mapsize);
+       map = map_sha1_file(sha1, &mapsize);
        if (!map) {
                struct pack_entry e;
 
-               if (!find_pack_entry(sha1, &e))
-                       return error("unable to find %s", sha1_to_hex(sha1));
-               return packed_object_info(&e, type, sizep);
+               if (!find_pack_entry(sha1, &e, NULL)) {
+                       reprepare_packed_git();
+                       if (!find_pack_entry(sha1, &e, NULL))
+                               return error("unable to find %s", sha1_to_hex(sha1));
+               }
+               if (use_packed_git(e.p))
+                       die("cannot map packed file");
+               status = packed_object_info(e.p, e.offset, type, sizep);
+               unuse_packed_git(e.p);
+               return status;
        }
        if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
                status = error("unable to unpack %s header",
@@ -1235,7 +1285,7 @@ static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned lo
 {
        struct pack_entry e;
 
-       if (!find_pack_entry(sha1, &e)) {
+       if (!find_pack_entry(sha1, &e, NULL)) {
                error("cannot read sha1_file for %s", sha1_to_hex(sha1));
                return NULL;
        }
@@ -1248,14 +1298,17 @@ void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size
        void *map, *buf;
        struct pack_entry e;
 
-       if (find_pack_entry(sha1, &e))
+       if (find_pack_entry(sha1, &e, NULL))
                return read_packed_sha1(sha1, type, size);
-       map = map_sha1_file_internal(sha1, &mapsize);
+       map = map_sha1_file(sha1, &mapsize);
        if (map) {
                buf = unpack_sha1_file(map, mapsize, type, size);
                munmap(map, mapsize);
                return buf;
        }
+       reprepare_packed_git();
+       if (find_pack_entry(sha1, &e, NULL))
+               return read_packed_sha1(sha1, type, size);
        return NULL;
 }
 
@@ -1269,7 +1322,7 @@ void *read_object_with_reference(const unsigned char *sha1,
        unsigned long isize;
        unsigned char actual_sha1[20];
 
-       memcpy(actual_sha1, sha1, 20);
+       hashcpy(actual_sha1, sha1);
        while (1) {
                int ref_length = -1;
                const char *ref_type = NULL;
@@ -1280,7 +1333,7 @@ void *read_object_with_reference(const unsigned char *sha1,
                if (!strcmp(type, required_type)) {
                        *size = isize;
                        if (actual_sha1_return)
-                               memcpy(actual_sha1_return, actual_sha1, 20);
+                               hashcpy(actual_sha1_return, actual_sha1);
                        return buffer;
                }
                /* Handle references */
@@ -1295,7 +1348,7 @@ void *read_object_with_reference(const unsigned char *sha1,
                ref_length = strlen(ref_type);
 
                if (memcmp(buffer, ref_type, ref_length) ||
-                   get_sha1_hex(buffer + ref_length, actual_sha1)) {
+                   get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
                        free(buffer);
                        return NULL;
                }
@@ -1305,12 +1358,9 @@ void *read_object_with_reference(const unsigned char *sha1,
        }
 }
 
-char *write_sha1_file_prepare(void *buf,
-                             unsigned long len,
-                             const char *type,
-                             unsigned char *sha1,
-                             unsigned char *hdr,
-                             int *hdrlen)
+static void write_sha1_file_prepare(void *buf, unsigned long len,
+                                    const char *type, unsigned char *sha1,
+                                    unsigned char *hdr, int *hdrlen)
 {
        SHA_CTX c;
 
@@ -1322,8 +1372,6 @@ char *write_sha1_file_prepare(void *buf,
        SHA1_Update(&c, hdr, *hdrlen);
        SHA1_Update(&c, buf, len);
        SHA1_Final(sha1, &c);
-
-       return sha1_file_name(sha1);
 }
 
 /*
@@ -1332,34 +1380,32 @@ char *write_sha1_file_prepare(void *buf,
  *
  * Returns the errno on failure, 0 on success.
  */
-static int link_temp_to_file(const char *tmpfile, char *filename)
+static int link_temp_to_file(const char *tmpfile, const char *filename)
 {
        int ret;
+       char *dir;
 
        if (!link(tmpfile, filename))
                return 0;
 
        /*
-        * Try to mkdir the last path component if that failed
-        * with an ENOENT.
+        * Try to mkdir the last path component if that failed.
         *
         * Re-try the "link()" regardless of whether the mkdir
         * succeeds, since a race might mean that somebody
         * else succeeded.
         */
        ret = errno;
-       if (ret == ENOENT) {
-               char *dir = strrchr(filename, '/');
-               if (dir) {
-                       *dir = 0;
-                       mkdir(filename, 0777);
-                       if (adjust_shared_perm(filename))
-                               return -2;
-                       *dir = '/';
-                       if (!link(tmpfile, filename))
-                               return 0;
-                       ret = errno;
-               }
+       dir = strrchr(filename, '/');
+       if (dir) {
+               *dir = 0;
+               mkdir(filename, 0777);
+               if (adjust_shared_perm(filename))
+                       return -2;
+               *dir = '/';
+               if (!link(tmpfile, filename))
+                       return 0;
+               ret = errno;
        }
        return ret;
 }
@@ -1367,7 +1413,7 @@ static int link_temp_to_file(const char *tmpfile, char *filename)
 /*
  * Move the just written object into its final resting place
  */
-int move_temp_to_file(const char *tmpfile, char *filename)
+int move_temp_to_file(const char *tmpfile, const char *filename)
 {
        int ret = link_temp_to_file(tmpfile, filename);
 
@@ -1413,8 +1459,60 @@ static int write_buffer(int fd, const void *buf, size_t len)
                        return error("file write error (%s)", strerror(errno));
                }
                len -= size;
-               buf += size;
+               buf = (char *) buf + size;
+       }
+       return 0;
+}
+
+static int write_binary_header(unsigned char *hdr, enum object_type type, unsigned long len)
+{
+       int hdr_len;
+       unsigned char c;
+
+       c = (type << 4) | (len & 15);
+       len >>= 4;
+       hdr_len = 1;
+       while (len) {
+               *hdr++ = c | 0x80;
+               hdr_len++;
+               c = (len & 0x7f);
+               len >>= 7;
+       }
+       *hdr = c;
+       return hdr_len;
+}
+
+static void setup_object_header(z_stream *stream, const char *type, unsigned long len)
+{
+       int obj_type, hdr;
+
+       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;
+}
+
+int hash_sha1_file(void *buf, unsigned long len, const char *type,
+                   unsigned char *sha1)
+{
+       unsigned char hdr[50];
+       int hdrlen;
+       write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
        return 0;
 }
 
@@ -1432,9 +1530,10 @@ int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned cha
        /* Normally if we have it in the pack then we do not bother writing
         * it out into .git/objects/??/?{38} file.
         */
-       filename = write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
+       write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
+       filename = sha1_file_name(sha1);
        if (returnsha1)
-               memcpy(returnsha1, sha1, 20);
+               hashcpy(returnsha1, sha1);
        if (has_sha1_file(sha1))
                return 0;
        fd = open(filename, O_RDONLY);
@@ -1462,8 +1561,8 @@ int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned cha
 
        /* Set it up */
        memset(&stream, 0, sizeof(stream));
-       deflateInit(&stream, Z_BEST_COMPRESSION);
-       size = deflateBound(&stream, len+hdrlen);
+       deflateInit(&stream, zlib_compression_level);
+       size = 8 + deflateBound(&stream, len+hdrlen);
        compressed = xmalloc(size);
 
        /* Compress it */
@@ -1473,8 +1572,7 @@ int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned cha
        /* First header.. */
        stream.next_in = hdr;
        stream.avail_in = hdrlen;
-       while (deflate(&stream, 0) == Z_OK)
-               /* nothing */;
+       setup_object_header(&stream, type, len);
 
        /* Then the data itself.. */
        stream.next_in = buf;
@@ -1508,14 +1606,14 @@ static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
        int hdrlen;
        void *buf;
 
-       // need to unpack and recompress it by itself
+       /* need to unpack and recompress it by itself */
        unpacked = read_packed_sha1(sha1, type, &len);
 
        hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
 
        /* Set it up */
        memset(&stream, 0, sizeof(stream));
-       deflateInit(&stream, Z_BEST_COMPRESSION);
+       deflateInit(&stream, zlib_compression_level);
        size = deflateBound(&stream, len + hdrlen);
        buf = xmalloc(size);
 
@@ -1545,7 +1643,7 @@ int write_sha1_to_fd(int fd, const unsigned char *sha1)
 {
        int retval;
        unsigned long objsize;
-       void *buf = map_sha1_file_internal(sha1, &objsize);
+       void *buf = map_sha1_file(sha1, &objsize);
 
        if (buf) {
                retval = write_buffer(fd, buf, objsize);
@@ -1622,7 +1720,7 @@ int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
                unlink(tmpfile);
                return error("File %s corrupted", sha1_to_hex(sha1));
        }
-       if (memcmp(sha1, real_sha1, 20)) {
+       if (hashcmp(sha1, real_sha1)) {
                unlink(tmpfile);
                return error("File %s has bad hash", sha1_to_hex(sha1));
        }
@@ -1646,10 +1744,10 @@ int has_pack_file(const unsigned char *sha1)
        return 1;
 }
 
-int has_sha1_pack(const unsigned char *sha1)
+int has_sha1_pack(const unsigned char *sha1, const char **ignore_packed)
 {
        struct pack_entry e;
-       return find_pack_entry(sha1, &e);
+       return find_pack_entry(sha1, &e, ignore_packed);
 }
 
 int has_sha1_file(const unsigned char *sha1)
@@ -1657,14 +1755,14 @@ int has_sha1_file(const unsigned char *sha1)
        struct stat st;
        struct pack_entry e;
 
-       if (find_pack_entry(sha1, &e))
+       if (find_pack_entry(sha1, &e, NULL))
                return 1;
        return find_sha1_file(sha1, &st) ? 1 : 0;
 }
 
 /*
  * reads from fd as long as possible into a supplied buffer of size bytes.
- * If neccessary the buffer's size is increased using realloc()
+ * If necessary the buffer's size is increased using realloc()
  *
  * returns 0 if anything went fine and -1 otherwise
  *
@@ -1684,7 +1782,7 @@ int read_pipe(int fd, char** return_buf, unsigned long* return_size)
                        off += iret;
                        if (off == size) {
                                size *= 2;
-                               buf = realloc(buf, size);
+                               buf = xrealloc(buf, size);
                        }
                }
        } while (iret > 0);
@@ -1700,10 +1798,8 @@ int read_pipe(int fd, char** return_buf, unsigned long* return_size)
 int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
 {
        unsigned long size = 4096;
-       char *buf = malloc(size);
+       char *buf = xmalloc(size);
        int ret;
-       unsigned char hdr[50];
-       int hdrlen;
 
        if (read_pipe(fd, &buf, &size)) {
                free(buf);
@@ -1714,10 +1810,8 @@ int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
                type = blob_type;
        if (write_object)
                ret = write_sha1_file(buf, size, type, sha1);
-       else {
-               write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
-               ret = 0;
-       }
+       else
+               ret = hash_sha1_file(buf, size, type, sha1);
        free(buf);
        return ret;
 }
@@ -1727,8 +1821,6 @@ int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, con
        unsigned long size = st->st_size;
        void *buf;
        int ret;
-       unsigned char hdr[50];
-       int hdrlen;
 
        buf = "";
        if (size)
@@ -1741,10 +1833,8 @@ int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, con
                type = blob_type;
        if (write_object)
                ret = write_sha1_file(buf, size, type, sha1);
-       else {
-               write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
-               ret = 0;
-       }
+       else
+               ret = hash_sha1_file(buf, size, type, sha1);
        if (size)
                munmap(buf, size);
        return ret;
@@ -1773,12 +1863,9 @@ int index_path(unsigned char *sha1, const char *path, struct stat *st, int write
                        return error("readlink(\"%s\"): %s", path,
                                     errstr);
                }
-               if (!write_object) {
-                       unsigned char hdr[50];
-                       int hdrlen;
-                       write_sha1_file_prepare(target, st->st_size, blob_type,
-                                               sha1, hdr, &hdrlen);
-               } else if (write_sha1_file(target, st->st_size, blob_type, sha1))
+               if (!write_object)
+                       hash_sha1_file(target, st->st_size, blob_type, sha1);
+               else if (write_sha1_file(target, st->st_size, blob_type, sha1))
                        return error("%s: failed to insert into database",
                                     path);
                free(target);