struct object_entry
{
unsigned long offset;
+ unsigned long size;
+ unsigned int hdr_size;
enum object_type type;
enum object_type real_type;
unsigned char sha1[20];
};
static const char *pack_name;
-static unsigned char *pack_base;
-static unsigned long pack_size;
static struct object_entry *objects;
static struct delta_entry *deltas;
static int nr_objects;
static int nr_deltas;
-static void open_pack_file(void)
+/* We always read in 4kB chunks. */
+static unsigned char input_buffer[4096];
+static unsigned long input_offset, input_len, consumed_bytes;
+static SHA_CTX input_ctx;
+static int input_fd;
+
+/*
+ * Make sure at least "min" bytes are available in the buffer, and
+ * return the pointer to the buffer.
+ */
+static void * fill(int min)
{
- int fd;
- struct stat st;
+ if (min <= input_len)
+ return input_buffer + input_offset;
+ if (min > sizeof(input_buffer))
+ die("cannot fill %d bytes", min);
+ if (input_offset) {
+ SHA1_Update(&input_ctx, input_buffer, input_offset);
+ memcpy(input_buffer, input_buffer + input_offset, input_len);
+ input_offset = 0;
+ }
+ do {
+ int ret = xread(input_fd, input_buffer + input_len,
+ sizeof(input_buffer) - input_len);
+ if (ret <= 0) {
+ if (!ret)
+ die("early EOF");
+ die("read error on input: %s", strerror(errno));
+ }
+ input_len += ret;
+ } while (input_len < min);
+ return input_buffer;
+}
+
+static void use(int bytes)
+{
+ if (bytes > input_len)
+ die("used more bytes than were available");
+ input_len -= bytes;
+ input_offset += bytes;
+ consumed_bytes += bytes;
+}
- fd = open(pack_name, O_RDONLY);
- if (fd < 0)
+static void open_pack_file(void)
+{
+ input_fd = open(pack_name, O_RDONLY);
+ if (input_fd < 0)
die("cannot open packfile '%s': %s", pack_name,
strerror(errno));
- if (fstat(fd, &st)) {
- int err = errno;
- close(fd);
- die("cannot fstat packfile '%s': %s", pack_name,
- strerror(err));
- }
- pack_size = st.st_size;
- pack_base = mmap(NULL, pack_size, PROT_READ, MAP_PRIVATE, fd, 0);
- if (pack_base == MAP_FAILED) {
- int err = errno;
- close(fd);
- die("cannot mmap packfile '%s': %s", pack_name,
- strerror(err));
- }
- close(fd);
+ SHA1_Init(&input_ctx);
}
static void parse_pack_header(void)
{
- const struct pack_header *hdr;
- unsigned char sha1[20];
- SHA_CTX ctx;
-
- /* Ensure there are enough bytes for the header and final SHA1 */
- if (pack_size < sizeof(struct pack_header) + 20)
- die("packfile '%s' is too small", pack_name);
+ struct pack_header *hdr = fill(sizeof(struct pack_header));
/* Header consistency check */
- hdr = (void *)pack_base;
if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
die("packfile '%s' signature mismatch", pack_name);
if (!pack_version_ok(hdr->hdr_version))
pack_name, ntohl(hdr->hdr_version));
nr_objects = ntohl(hdr->hdr_entries);
-
- /* Check packfile integrity */
- SHA1_Init(&ctx);
- SHA1_Update(&ctx, pack_base, pack_size - 20);
- SHA1_Final(sha1, &ctx);
- if (hashcmp(sha1, pack_base + pack_size - 20))
- die("packfile '%s' SHA1 mismatch", pack_name);
+ use(sizeof(struct pack_header));
+ /*fprintf(stderr, "Indexing %d objects\n", nr_objects);*/
}
static void bad_object(unsigned long offset, const char *format,
pack_name, offset, buf);
}
-static void *unpack_entry_data(unsigned long offset,
- unsigned long *current_pos, unsigned long size)
+static void *unpack_entry_data(unsigned long offset, unsigned long size)
{
- unsigned long pack_limit = pack_size - 20;
- unsigned long pos = *current_pos;
z_stream stream;
void *buf = xmalloc(size);
memset(&stream, 0, sizeof(stream));
stream.next_out = buf;
stream.avail_out = size;
- stream.next_in = pack_base + pos;
- stream.avail_in = pack_limit - pos;
+ stream.next_in = fill(1);
+ stream.avail_in = input_len;
inflateInit(&stream);
for (;;) {
int ret = inflate(&stream, 0);
- if (ret == Z_STREAM_END)
+ use(input_len - stream.avail_in);
+ if (stream.total_out == size && ret == Z_STREAM_END)
break;
if (ret != Z_OK)
bad_object(offset, "inflate returned %d", ret);
+ stream.next_in = fill(1);
+ stream.avail_in = input_len;
}
inflateEnd(&stream);
- if (stream.total_out != size)
- bad_object(offset, "size mismatch (expected %lu, got %lu)",
- size, stream.total_out);
- *current_pos = pack_limit - stream.avail_in;
return buf;
}
-static void *unpack_raw_entry(unsigned long offset,
- enum object_type *obj_type,
- unsigned long *obj_size,
- union delta_base *delta_base,
- unsigned long *next_obj_offset)
+static void *unpack_raw_entry(struct object_entry *obj, union delta_base *delta_base)
{
- unsigned long pack_limit = pack_size - 20;
- unsigned long pos = offset;
- unsigned char c;
+ unsigned char *p, c;
unsigned long size, base_offset;
unsigned shift;
- enum object_type type;
- void *data;
- c = pack_base[pos++];
- type = (c >> 4) & 7;
+ obj->offset = consumed_bytes;
+
+ p = fill(1);
+ c = *p;
+ use(1);
+ obj->type = (c >> 4) & 7;
size = (c & 15);
shift = 4;
while (c & 0x80) {
- if (pos >= pack_limit)
- bad_object(offset, "object extends past end of pack");
- c = pack_base[pos++];
+ p = fill(1);
+ c = *p;
+ use(1);
size += (c & 0x7fUL) << shift;
shift += 7;
}
+ obj->size = size;
- switch (type) {
+ switch (obj->type) {
case OBJ_REF_DELTA:
- if (pos + 20 >= pack_limit)
- bad_object(offset, "object extends past end of pack");
- hashcpy(delta_base->sha1, pack_base + pos);
- pos += 20;
+ hashcpy(delta_base->sha1, fill(20));
+ use(20);
break;
case OBJ_OFS_DELTA:
memset(delta_base, 0, sizeof(*delta_base));
- c = pack_base[pos++];
+ p = fill(1);
+ c = *p;
+ use(1);
base_offset = c & 127;
while (c & 128) {
base_offset += 1;
if (!base_offset || base_offset & ~(~0UL >> 7))
- bad_object(offset, "offset value overflow for delta base object");
- if (pos >= pack_limit)
- bad_object(offset, "object extends past end of pack");
- c = pack_base[pos++];
+ bad_object(obj->offset, "offset value overflow for delta base object");
+ p = fill(1);
+ c = *p;
+ use(1);
base_offset = (base_offset << 7) + (c & 127);
}
- delta_base->offset = offset - base_offset;
- if (delta_base->offset >= offset)
- bad_object(offset, "delta base offset is out of bound");
+ delta_base->offset = obj->offset - base_offset;
+ if (delta_base->offset >= obj->offset)
+ bad_object(obj->offset, "delta base offset is out of bound");
break;
case OBJ_COMMIT:
case OBJ_TREE:
case OBJ_TAG:
break;
default:
- bad_object(offset, "bad object type %d", type);
+ bad_object(obj->offset, "bad object type %d", obj->type);
}
+ obj->hdr_size = consumed_bytes - obj->offset;
+
+ return unpack_entry_data(obj->offset, obj->size);
+}
+
+static void * get_data_from_pack(struct object_entry *obj)
+{
+ unsigned long from = obj[0].offset + obj[0].hdr_size;
+ unsigned long len = obj[1].offset - from;
+ unsigned pg_offset = from % getpagesize();
+ unsigned char *map, *data;
+ z_stream stream;
+ int st;
- data = unpack_entry_data(offset, &pos, size);
- *obj_type = type;
- *obj_size = size;
- *next_obj_offset = pos;
+ map = mmap(NULL, len + pg_offset, PROT_READ, MAP_PRIVATE,
+ input_fd, from - pg_offset);
+ if (map == MAP_FAILED)
+ die("cannot mmap packfile '%s': %s", pack_name, strerror(errno));
+ data = xmalloc(obj->size);
+ memset(&stream, 0, sizeof(stream));
+ stream.next_out = data;
+ stream.avail_out = obj->size;
+ stream.next_in = map + pg_offset;
+ stream.avail_in = len;
+ inflateInit(&stream);
+ while ((st = inflate(&stream, Z_FINISH)) == Z_OK);
+ inflateEnd(&stream);
+ if (st != Z_STREAM_END || stream.total_out != obj->size)
+ die("serious inflate inconsistency");
+ munmap(map, len + pg_offset);
return data;
}
unsigned long delta_size;
void *result;
unsigned long result_size;
- enum object_type delta_type;
union delta_base delta_base;
- unsigned long next_obj_offset;
int j, first, last;
obj->real_type = type;
- delta_data = unpack_raw_entry(obj->offset, &delta_type,
- &delta_size, &delta_base,
- &next_obj_offset);
+ delta_data = get_data_from_pack(obj);
+ delta_size = obj->size;
result = patch_delta(base_data, base_size, delta_data, delta_size,
&result_size);
free(delta_data);
return memcmp(&delta_a->base, &delta_b->base, UNION_BASE_SZ);
}
-static void parse_pack_objects(void)
+/* Parse all objects and return the pack content SHA1 hash */
+static void parse_pack_objects(unsigned char *sha1)
{
int i;
- unsigned long offset = sizeof(struct pack_header);
struct delta_entry *delta = deltas;
void *data;
- unsigned long data_size;
+ struct stat st;
/*
* First pass:
*/
for (i = 0; i < nr_objects; i++) {
struct object_entry *obj = &objects[i];
- obj->offset = offset;
- data = unpack_raw_entry(offset, &obj->type, &data_size,
- &delta->base, &offset);
+ data = unpack_raw_entry(obj, &delta->base);
obj->real_type = obj->type;
if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA) {
nr_deltas++;
delta->obj = obj;
delta++;
} else
- sha1_object(data, data_size, obj->type, obj->sha1);
+ sha1_object(data, obj->size, obj->type, obj->sha1);
free(data);
}
- if (offset != pack_size - 20)
+ objects[i].offset = consumed_bytes;
+
+ /* Check pack integrity */
+ SHA1_Update(&input_ctx, input_buffer, input_offset);
+ SHA1_Final(sha1, &input_ctx);
+ if (hashcmp(fill(20), sha1))
+ die("packfile '%s' SHA1 mismatch", pack_name);
+ use(20);
+
+ /* If input_fd is a file, we should have reached its end now. */
+ if (fstat(input_fd, &st))
+ die("cannot fstat packfile '%s': %s", pack_name, strerror(errno));
+ if (S_ISREG(st.st_mode) && st.st_size != consumed_bytes)
die("packfile '%s' has junk at the end", pack_name);
/* Sort deltas by base SHA1/offset for fast searching */
ofs = !find_delta_childs(&base, &ofs_first, &ofs_last);
if (!ref && !ofs)
continue;
- data = unpack_raw_entry(obj->offset, &obj->type, &data_size,
- &base, &offset);
+ data = get_data_from_pack(obj);
if (ref)
for (j = ref_first; j <= ref_last; j++)
if (deltas[j].obj->type == OBJ_REF_DELTA)
resolve_delta(&deltas[j], data,
- data_size, obj->type);
+ obj->size, obj->type);
if (ofs)
for (j = ofs_first; j <= ofs_last; j++)
if (deltas[j].obj->type == OBJ_OFS_DELTA)
resolve_delta(&deltas[j], data,
- data_size, obj->type);
+ obj->size, obj->type);
free(data);
}
return hashcmp(a->sha1, b->sha1);
}
+/*
+ * On entry *sha1 contains the pack content SHA1 hash, on exit it is
+ * the SHA1 hash of sorted object names.
+ */
static void write_index_file(const char *index_name, unsigned char *sha1)
{
struct sha1file *f;
sha1write(f, obj->sha1, 20);
SHA1_Update(&ctx, obj->sha1, 20);
}
- sha1write(f, pack_base + pack_size - 20, 20);
+ sha1write(f, sha1, 20);
sha1close(f, NULL, 1);
free(sorted_by_sha);
SHA1_Final(sha1, &ctx);
open_pack_file();
parse_pack_header();
- objects = xcalloc(nr_objects, sizeof(struct object_entry));
+ objects = xcalloc(nr_objects + 1, sizeof(struct object_entry));
deltas = xcalloc(nr_objects, sizeof(struct delta_entry));
- parse_pack_objects();
+ parse_pack_objects(sha1);
free(deltas);
write_index_file(index_name, sha1);
free(objects);
projects / git.git / commitdiff