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diff --git a/pack-write.c b/pack-write.c
index a8f02699366c87de960d7637e9f69c26c2241693..a905ca4486754f099a30f90a2fcd22d0c771a070 100644 (file)
--- a/pack-write.c
+++ b/pack-write.c
* the SHA1 hash of sorted object names. The objects array passed in
* will be sorted by SHA1 on exit.
*/
-char *write_idx_file(char *index_name, struct pack_idx_entry **objects,
- int nr_objects, unsigned char *sha1)
+const char *write_idx_file(const char *index_name, struct pack_idx_entry **objects,
+ int nr_objects, unsigned char *sha1)
{
struct sha1file *f;
struct pack_idx_entry **sorted_by_sha, **list, **last;
off_t last_obj_offset = 0;
uint32_t array[256];
int i, fd;
- SHA_CTX ctx;
+ git_SHA_CTX ctx;
uint32_t index_version;
if (nr_objects) {
if (!index_name) {
static char tmpfile[PATH_MAX];
- snprintf(tmpfile, sizeof(tmpfile),
- "%s/tmp_idx_XXXXXX", get_object_directory());
- fd = xmkstemp(tmpfile);
+ fd = odb_mkstemp(tmpfile, sizeof(tmpfile), "pack/tmp_idx_XXXXXX");
index_name = xstrdup(tmpfile);
} else {
unlink(index_name);
fd = open(index_name, O_CREAT|O_EXCL|O_WRONLY, 0600);
}
if (fd < 0)
- die("unable to create %s: %s", index_name, strerror(errno));
+ die_errno("unable to create '%s'", index_name);
f = sha1fd(fd, index_name);
/* if last object's offset is >= 2^31 we should use index V2 */
sha1write(f, array, 256 * 4);
/* compute the SHA1 hash of sorted object names. */
- SHA1_Init(&ctx);
+ git_SHA1_Init(&ctx);
/*
* Write the actual SHA1 entries..
sha1write(f, &offset, 4);
}
sha1write(f, obj->sha1, 20);
- SHA1_Update(&ctx, obj->sha1, 20);
+ git_SHA1_Update(&ctx, obj->sha1, 20);
}
if (index_version >= 2) {
sha1write(f, sha1, 20);
sha1close(f, NULL, CSUM_FSYNC);
- SHA1_Final(sha1, &ctx);
+ git_SHA1_Final(sha1, &ctx);
return index_name;
}
+/*
+ * Update pack header with object_count and compute new SHA1 for pack data
+ * associated to pack_fd, and write that SHA1 at the end. That new SHA1
+ * is also returned in new_pack_sha1.
+ *
+ * If partial_pack_sha1 is non null, then the SHA1 of the existing pack
+ * (without the header update) is computed and validated against the
+ * one provided in partial_pack_sha1. The validation is performed at
+ * partial_pack_offset bytes in the pack file. The SHA1 of the remaining
+ * data (i.e. from partial_pack_offset to the end) is then computed and
+ * returned in partial_pack_sha1.
+ *
+ * Note that new_pack_sha1 is updated last, so both new_pack_sha1 and
+ * partial_pack_sha1 can refer to the same buffer if the caller is not
+ * interested in the resulting SHA1 of pack data above partial_pack_offset.
+ */
void fixup_pack_header_footer(int pack_fd,
- unsigned char *pack_file_sha1,
+ unsigned char *new_pack_sha1,
const char *pack_name,
- uint32_t object_count)
+ uint32_t object_count,
+ unsigned char *partial_pack_sha1,
+ off_t partial_pack_offset)
{
- static const int buf_sz = 128 * 1024;
- SHA_CTX c;
+ int aligned_sz, buf_sz = 8 * 1024;
+ git_SHA_CTX old_sha1_ctx, new_sha1_ctx;
struct pack_header hdr;
char *buf;
+ git_SHA1_Init(&old_sha1_ctx);
+ git_SHA1_Init(&new_sha1_ctx);
+
if (lseek(pack_fd, 0, SEEK_SET) != 0)
- die("Failed seeking to start: %s", strerror(errno));
+ die_errno("Failed seeking to start of '%s'", pack_name);
if (read_in_full(pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
- die("Unable to reread header of %s: %s", pack_name, strerror(errno));
+ die_errno("Unable to reread header of '%s'", pack_name);
if (lseek(pack_fd, 0, SEEK_SET) != 0)
- die("Failed seeking to start: %s", strerror(errno));
+ die_errno("Failed seeking to start of '%s'", pack_name);
+ git_SHA1_Update(&old_sha1_ctx, &hdr, sizeof(hdr));
hdr.hdr_entries = htonl(object_count);
+ git_SHA1_Update(&new_sha1_ctx, &hdr, sizeof(hdr));
write_or_die(pack_fd, &hdr, sizeof(hdr));
-
- SHA1_Init(&c);
- SHA1_Update(&c, &hdr, sizeof(hdr));
+ partial_pack_offset -= sizeof(hdr);
buf = xmalloc(buf_sz);
+ aligned_sz = buf_sz - sizeof(hdr);
for (;;) {
- ssize_t n = xread(pack_fd, buf, buf_sz);
+ ssize_t m, n;
+ m = (partial_pack_sha1 && partial_pack_offset < aligned_sz) ?
+ partial_pack_offset : aligned_sz;
+ n = xread(pack_fd, buf, m);
if (!n)
break;
if (n < 0)
- die("Failed to checksum %s: %s", pack_name, strerror(errno));
- SHA1_Update(&c, buf, n);
+ die_errno("Failed to checksum '%s'", pack_name);
+ git_SHA1_Update(&new_sha1_ctx, buf, n);
+
+ aligned_sz -= n;
+ if (!aligned_sz)
+ aligned_sz = buf_sz;
+
+ if (!partial_pack_sha1)
+ continue;
+
+ git_SHA1_Update(&old_sha1_ctx, buf, n);
+ partial_pack_offset -= n;
+ if (partial_pack_offset == 0) {
+ unsigned char sha1[20];
+ git_SHA1_Final(sha1, &old_sha1_ctx);
+ if (hashcmp(sha1, partial_pack_sha1) != 0)
+ die("Unexpected checksum for %s "
+ "(disk corruption?)", pack_name);
+ /*
+ * Now let's compute the SHA1 of the remainder of the
+ * pack, which also means making partial_pack_offset
+ * big enough not to matter anymore.
+ */
+ git_SHA1_Init(&old_sha1_ctx);
+ partial_pack_offset = ~partial_pack_offset;
+ partial_pack_offset -= MSB(partial_pack_offset, 1);
+ }
}
free(buf);
- SHA1_Final(pack_file_sha1, &c);
- write_or_die(pack_fd, pack_file_sha1, 20);
+ if (partial_pack_sha1)
+ git_SHA1_Final(partial_pack_sha1, &old_sha1_ctx);
+ git_SHA1_Final(new_pack_sha1, &new_sha1_ctx);
+ write_or_die(pack_fd, new_pack_sha1, 20);
+ fsync_or_die(pack_fd, pack_name);
}
char *index_pack_lockfile(int ip_out)
char packname[46];
/*
- * The first thing we expects from index-pack's output
+ * The first thing we expect from index-pack's output
* is "pack\t%40s\n" or "keep\t%40s\n" (46 bytes) where
* %40s is the newly created pack SHA1 name. In the "keep"
* case, we need it to remove the corresponding .keep file
}
return NULL;
}
+
+/*
+ * The per-object header is a pretty dense thing, which is
+ * - first byte: low four bits are "size", then three bits of "type",
+ * and the high bit is "size continues".
+ * - each byte afterwards: low seven bits are size continuation,
+ * with the high bit being "size continues"
+ */
+int encode_in_pack_object_header(enum object_type type, uintmax_t size, unsigned char *hdr)
+{
+ int n = 1;
+ unsigned char c;
+
+ if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
+ die("bad type %d", type);
+
+ c = (type << 4) | (size & 15);
+ size >>= 4;
+ while (size) {
+ *hdr++ = c | 0x80;
+ c = size & 0x7f;
+ size >>= 7;
+ n++;
+ }
+ *hdr = c;
+ return n;
+}