diff options
Diffstat (limited to 'pack-write.c')
| -rw-r--r-- | pack-write.c | 93 |
1 files changed, 72 insertions, 21 deletions
diff --git a/pack-write.c b/pack-write.c index a8f0269..7053538 100644 --- a/pack-write.c +++ b/pack-write.c @@ -25,7 +25,7 @@ char *write_idx_file(char *index_name, struct pack_idx_entry **objects, 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) { @@ -44,9 +44,7 @@ char *write_idx_file(char *index_name, struct pack_idx_entry **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); @@ -86,7 +84,7 @@ char *write_idx_file(char *index_name, struct pack_idx_entry **objects, 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.. @@ -99,7 +97,7 @@ char *write_idx_file(char *index_name, struct pack_idx_entry **objects, 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) { @@ -140,45 +138,98 @@ char *write_idx_file(char *index_name, struct pack_idx_entry **objects, 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("Failed seeking to start of %s: %s", pack_name, strerror(errno)); if (read_in_full(pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr)) die("Unable to reread header of %s: %s", pack_name, strerror(errno)); if (lseek(pack_fd, 0, SEEK_SET) != 0) - die("Failed seeking to start: %s", strerror(errno)); + die("Failed seeking to start of %s: %s", pack_name, strerror(errno)); + 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); + 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) @@ -186,7 +237,7 @@ 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 |