Change pack file format. Hopefully for the last time.

[git.git] / sha1_file.c

diff --git a/sha1_file.c b/sha1_file.c
index e27affb..6e3fd18 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -10,6 +10,7 @@
 #include <dirent.h>
 #include "cache.h"
 #include "delta.h"
+#include "pack.h"
 
 #ifndef O_NOATIME
 #if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
@@ -665,37 +666,60 @@ static int packed_delta_info(unsigned char *base_sha1,
        return 0;
 }
 
+static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
+       enum object_type *type, unsigned long *sizep)
+{
+       unsigned char *pack, c;
+       unsigned long size;
+
+       if (offset >= p->pack_size)
+               die("object offset outside of pack file");
+
+       pack =  p->pack_base + offset;
+       c = *pack++;
+       offset++;
+       *type = (c >> 4) & 7;
+       size = c & 15;
+       while (c & 0x80) {
+               if (offset >= p->pack_size)
+                       die("object offset outside of pack file");
+               c = *pack++;
+               offset++;
+               size = (size << 7) | (c & 0x7f);
+       }
+       *sizep = size;
+       return offset;
+}
+
 static int packed_object_info(struct pack_entry *entry,
                              char *type, unsigned long *sizep)
 {
        struct packed_git *p = entry->p;
        unsigned long offset, size, left;
        unsigned char *pack;
-
-       offset = entry->offset;
-       if (p->pack_size - 5 < offset)
-               die("object offset outside of pack file");
+       enum object_type kind;
 
        if (use_packed_git(p))
                die("cannot map packed file");
 
+       offset = unpack_object_header(p, entry->offset, &kind, &size);
        pack = p->pack_base + offset;
-       size = (pack[1] << 24) + (pack[2] << 16) + (pack[3] << 8) + pack[4];
-       left = p->pack_size - offset - 5;
-       switch (*pack) {
-       case 'D':
-               return packed_delta_info(pack+5, size, left, type, sizep);
+       left = p->pack_size - offset;
+
+       switch (kind) {
+       case OBJ_DELTA:
+               return packed_delta_info(pack, size, left, type, sizep);
                break;
-       case 'C':
+       case OBJ_COMMIT:
                strcpy(type, "commit");
                break;
-       case 'T':
+       case OBJ_TREE:
                strcpy(type, "tree");
                break;
-       case 'B':
+       case OBJ_BLOB:
                strcpy(type, "blob");
                break;
-       case 'G':
+       case OBJ_TAG:
                strcpy(type, "tag");
                break;
        default:
@@ -787,37 +811,34 @@ static void *unpack_entry(struct pack_entry *entry,
        struct packed_git *p = entry->p;
        unsigned long offset, size, left;
        unsigned char *pack;
-
-       offset = entry->offset;
-       if (p->pack_size - 5 < offset)
-               die("object offset outside of pack file");
+       enum object_type kind;
 
        if (use_packed_git(p))
                die("cannot map packed file");
 
+       offset = unpack_object_header(p, entry->offset, &kind, &size);
        pack = p->pack_base + offset;
-       size = (pack[1] << 24) + (pack[2] << 16) + (pack[3] << 8) + pack[4];
-       left = p->pack_size - offset - 5;
-       switch (*pack) {
-       case 'D':
-               return unpack_delta_entry(pack+5, size, left, type, sizep);
-       case 'C':
+       left = p->pack_size - offset;
+       switch (kind) {
+       case OBJ_DELTA:
+               return unpack_delta_entry(pack, size, left, type, sizep);
+       case OBJ_COMMIT:
                strcpy(type, "commit");
                break;
-       case 'T':
+       case OBJ_TREE:
                strcpy(type, "tree");
                break;
-       case 'B':
+       case OBJ_BLOB:
                strcpy(type, "blob");
                break;
-       case 'G':
+       case OBJ_TAG:
                strcpy(type, "tag");
                break;
        default:
                die("corrupted pack file");
        }
        *sizep = size;
-       return unpack_non_delta_entry(pack+5, size, left);
+       return unpack_non_delta_entry(pack, size, left);
 }
 
 static int find_pack_entry_1(const unsigned char *sha1,