* This handles basic git sha1 object files - packing, unpacking,
* creation etc.
*/
-#include <stdarg.h>
-#include <limits.h>
#include "cache.h"
+#include "delta.h"
#ifndef O_NOATIME
#if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
return get_sha1_hex(buffer, result);
}
-static char *git_dir, *git_object_dir, *git_index_file;
+static char *git_dir, *git_object_dir, *git_index_file, *git_refs_dir;
static void setup_git_env(void)
{
git_dir = gitenv(GIT_DIR_ENVIRONMENT);
git_object_dir = xmalloc(strlen(git_dir) + 9);
sprintf(git_object_dir, "%s/objects", git_dir);
}
+ git_refs_dir = xmalloc(strlen(git_dir) + 6);
+ sprintf(git_refs_dir, "%s/refs", git_dir);
git_index_file = gitenv(INDEX_ENVIRONMENT);
if (!git_index_file) {
git_index_file = xmalloc(strlen(git_dir) + 7);
return git_object_dir;
}
+char *get_refs_directory(void)
+{
+ if (!git_refs_dir)
+ setup_git_env();
+ return git_refs_dir;
+}
+
char *get_index_file(void)
{
if (!git_index_file)
return NULL;
}
-int check_sha1_signature(unsigned char *sha1, void *map, unsigned long size, const char *type)
+int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
{
char header[100];
unsigned char real_sha1[20];
return map;
}
+int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size)
+{
+ /* 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;
+
+ inflateInit(stream);
+ return inflate(stream, 0);
+}
+
+void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
+{
+ int bytes = strlen(buffer) + 1;
+ char *buf = xmalloc(1+size);
+
+ memcpy(buf, buffer + bytes, stream->total_out - bytes);
+ bytes = stream->total_out - bytes;
+ if (bytes < size) {
+ stream->next_out = buf + bytes;
+ stream->avail_out = size - bytes;
+ while (inflate(stream, Z_FINISH) == Z_OK)
+ /* nothing */;
+ }
+ buf[size] = 0;
+ inflateEnd(stream);
+ return buf;
+}
+
+/*
+ * We used to just use "sscanf()", but that's actually way
+ * 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)
+{
+ 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.
+ */
+ i = 10;
+ for (;;) {
+ char c = *hdr++;
+ if (c == ' ')
+ break;
+ if (!--i)
+ return -1;
+ *type++ = c;
+ }
+ *type = 0;
+
+ /*
+ * The length must follow immediately, and be in canonical
+ * decimal format (ie "010" is not valid).
+ */
+ size = *hdr++ - '0';
+ if (size > 9)
+ return -1;
+ if (size) {
+ for (;;) {
+ unsigned long c = *hdr - '0';
+ if (c > 9)
+ break;
+ hdr++;
+ size = size * 10 + c;
+ }
+ }
+ *sizep = size;
+
+ /*
+ * The length must be followed by a zero byte
+ */
+ return *hdr ? -1 : 0;
+}
+
void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
{
- int ret, bytes;
+ int ret;
z_stream stream;
- char buffer[8192];
- unsigned char *buf;
-
- /* Get the data stream */
- memset(&stream, 0, sizeof(stream));
- stream.next_in = map;
- stream.avail_in = mapsize;
- stream.next_out = (unsigned char *)buffer;
- stream.avail_out = sizeof(buffer);
+ char hdr[8192];
- inflateInit(&stream);
- ret = inflate(&stream, 0);
- if (ret < Z_OK)
- return NULL;
- if (sscanf(buffer, "%10s %lu", type, size) != 2)
+ ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
+ if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
return NULL;
- bytes = strlen(buffer) + 1;
- buf = xmalloc(*size);
+ return unpack_sha1_rest(&stream, hdr, *size);
+}
- memcpy(buf, buffer + bytes, stream.total_out - bytes);
- bytes = stream.total_out - bytes;
- if (bytes < *size && ret == Z_OK) {
- stream.next_out = buf + bytes;
- stream.avail_out = *size - bytes;
- while (inflate(&stream, Z_FINISH) == Z_OK)
- /* nothing */;
+int sha1_delta_base(const unsigned char *sha1, unsigned char *base_sha1)
+{
+ int ret;
+ unsigned long mapsize, size;
+ void *map;
+ z_stream stream;
+ char hdr[64], type[20];
+ void *delta_data_head;
+
+ map = map_sha1_file(sha1, &mapsize);
+ if (!map)
+ return -1;
+ ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
+ if (ret < Z_OK || parse_sha1_header(hdr, type, &size) < 0) {
+ ret = -1;
+ goto out;
+ }
+ if (strcmp(type, "delta")) {
+ ret = 0;
+ goto out;
}
+
+ delta_data_head = hdr + strlen(hdr) + 1;
+ ret = 1;
+ memcpy(base_sha1, delta_data_head, 20);
+ out:
inflateEnd(&stream);
- return buf;
+ munmap(map, mapsize);
+ return ret;
+}
+
+int sha1_file_size(const unsigned char *sha1, unsigned long *sizep)
+{
+ int ret, status;
+ unsigned long mapsize, size;
+ void *map;
+ z_stream stream;
+ char hdr[64], type[20];
+ const unsigned char *data;
+ unsigned char cmd;
+ int i;
+
+ map = map_sha1_file(sha1, &mapsize);
+ if (!map)
+ return -1;
+ ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
+ status = -1;
+ if (ret < Z_OK || parse_sha1_header(hdr, type, &size) < 0)
+ goto out;
+ if (strcmp(type, "delta")) {
+ *sizep = size;
+ status = 0;
+ goto out;
+ }
+
+ /* We are dealing with a delta object. Inflated, the first
+ * 20 bytes hold the base object SHA1, and delta data follows
+ * immediately after it.
+ *
+ * The initial part of the delta starts at delta_data_head +
+ * 20. Borrow code from patch-delta to read the result size.
+ */
+ data = hdr + strlen(hdr) + 1 + 20;
+
+ /* Skip over the source size; we are not interested in
+ * it and we cannot verify it because we do not want
+ * to read the base object.
+ */
+ cmd = *data++;
+ while (cmd) {
+ if (cmd & 1)
+ data++;
+ cmd >>= 1;
+ }
+ /* Read the result size */
+ size = i = 0;
+ cmd = *data++;
+ while (cmd) {
+ if (cmd & 1)
+ size |= *data++ << i;
+ i += 8;
+ cmd >>= 1;
+ }
+ *sizep = size;
+ status = 0;
+ out:
+ inflateEnd(&stream);
+ munmap(map, mapsize);
+ return status;
}
void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
if (map) {
buf = unpack_sha1_file(map, mapsize, type, size);
munmap(map, mapsize);
+ if (buf && !strcmp(type, "delta")) {
+ void *ref = NULL, *delta = buf;
+ unsigned long ref_size, delta_size = *size;
+ buf = NULL;
+ if (delta_size > 20)
+ ref = read_sha1_file(delta, type, &ref_size);
+ if (ref)
+ buf = patch_delta(ref, ref_size,
+ delta+20, delta_size-20,
+ size);
+ free(delta);
+ free(ref);
+ }
return buf;
}
return NULL;
projects / git.git / blobdiff