index-pack: minor fixes to comment and function name
[gitweb.git] / sha1_file.c
index 27b1ebb720b1530d673f3dfb1c27862b4cf90dfd..e89d24c01595aa8ea6c6306928639b40f3313a50 100644 (file)
@@ -671,14 +671,8 @@ static void reprepare_packed_git(void)
 
 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);
+       hash_sha1_file(map, size, type, real_sha1);
        return hashcmp(sha1, real_sha1) ? -1 : 0;
 }
 
@@ -883,26 +877,61 @@ 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 packed_git *p, unsigned long offset,
                              char *type, unsigned long *sizep);
 
 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)
 {
        unsigned long base_offset;
-       unsigned char *base_sha1 = (unsigned char *) p->pack_base + offset;
 
-       if (p->pack_size < offset + 20)
-               die("truncated pack file");
-       /* The base entry _must_ be in the same pack */
-       base_offset = find_pack_entry_one(base_sha1, p);
-       if (!base_offset)
-               die("failed to find delta-pack base object %s",
-                   sha1_to_hex(base_sha1));
-       offset += 20;
+       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
@@ -914,7 +943,7 @@ static int packed_delta_info(struct packed_git *p,
 
        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;
@@ -965,25 +994,6 @@ static unsigned long unpack_object_header(struct packed_git *p, unsigned long of
        return offset + used;
 }
 
-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;
-
-       use_packed_git(p);
-       ptr = offset;
-       ptr = unpack_object_header(p, ptr, kindp, sizep);
-       if (*kindp != OBJ_DELTA)
-               goto done;
-       hashcpy(base, (unsigned char *) p->pack_base + ptr);
-       status = 0;
- done:
-       unuse_packed_git(p);
-       return status;
-}
-
 void packed_object_info_detail(struct packed_git *p,
                               unsigned long offset,
                               char *type,
@@ -992,11 +1002,12 @@ void packed_object_info_detail(struct packed_git *p,
                               unsigned int *delta_chain_length,
                               unsigned char *base_sha1)
 {
-       unsigned long val;
+       unsigned long obj_offset, val;
        unsigned char *next_sha1;
        enum object_type kind;
 
        *delta_chain_length = 0;
+       obj_offset = offset;
        offset = unpack_object_header(p, offset, &kind, size);
 
        for (;;) {
@@ -1011,7 +1022,13 @@ void packed_object_info_detail(struct packed_git *p,
                        strcpy(type, type_names[kind]);
                        *store_size = 0; /* notyet */
                        return;
-               case OBJ_DELTA:
+               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);
@@ -1021,6 +1038,7 @@ void packed_object_info_detail(struct packed_git *p,
                        offset = find_pack_entry_one(next_sha1, p);
                        break;
                }
+               obj_offset = offset;
                offset = unpack_object_header(p, offset, &kind, &val);
                (*delta_chain_length)++;
        }
@@ -1029,15 +1047,15 @@ void packed_object_info_detail(struct packed_git *p,
 static int packed_object_info(struct packed_git *p, unsigned long offset,
                              char *type, unsigned long *sizep)
 {
-       unsigned long size;
+       unsigned long size, obj_offset = offset;
        enum object_type kind;
 
        offset = unpack_object_header(p, offset, &kind, &size);
 
-       if (kind == OBJ_DELTA)
-               return packed_delta_info(p, offset, type, sizep);
-
        switch (kind) {
+       case OBJ_OFS_DELTA:
+       case OBJ_REF_DELTA:
+               return packed_delta_info(p, offset, kind, obj_offset, type, sizep);
        case OBJ_COMMIT:
        case OBJ_TREE:
        case OBJ_BLOB:
@@ -1083,23 +1101,15 @@ static void *unpack_compressed_entry(struct packed_git *p,
 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;
-       unsigned char *base_sha1;
-
-       if (p->pack_size < offset + 20)
-               die("truncated pack file");
-       /* The base entry _must_ be in the same pack */
-       base_sha1 = (unsigned char*)p->pack_base + offset;
-       base_offset = find_pack_entry_one(base_sha1, p);
-       if (!base_offset)
-               die("failed to find delta-pack base object %s",
-                   sha1_to_hex(base_sha1));
-       offset += 20;
 
+       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",
@@ -1136,13 +1146,14 @@ static void *unpack_entry(struct pack_entry *entry,
 void *unpack_entry_gently(struct packed_git *p, unsigned long offset,
                          char *type, unsigned long *sizep)
 {
-       unsigned long size;
+       unsigned long size, obj_offset = offset;
        enum object_type kind;
 
        offset = unpack_object_header(p, offset, &kind, &size);
        switch (kind) {
-       case OBJ_DELTA:
-               return unpack_delta_entry(p, offset, size, type, sizep);
+       case OBJ_OFS_DELTA:
+       case OBJ_REF_DELTA:
+               return unpack_delta_entry(p, offset, size, kind, obj_offset, type, sizep);
        case OBJ_COMMIT:
        case OBJ_TREE:
        case OBJ_BLOB:
@@ -1347,12 +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;
 
@@ -1364,8 +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);
 }
 
 /*
@@ -1501,6 +1507,15 @@ static void setup_object_header(z_stream *stream, const char *type, unsigned lon
        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;
+}
+
 int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
 {
        int size;
@@ -1515,7 +1530,8 @@ 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)
                hashcpy(returnsha1, sha1);
        if (has_sha1_file(sha1))
@@ -1784,8 +1800,6 @@ int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
        unsigned long size = 4096;
        char *buf = xmalloc(size);
        int ret;
-       unsigned char hdr[50];
-       int hdrlen;
 
        if (read_pipe(fd, &buf, &size)) {
                free(buf);
@@ -1796,10 +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;
 }
@@ -1809,8 +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)
@@ -1823,10 +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;
@@ -1855,12 +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);