From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-3.7 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI shortcircuit=no autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id 6BDC121847 for ; Wed, 2 May 2018 00:28:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753412AbeEBA2O (ORCPT ); Tue, 1 May 2018 20:28:14 -0400 Received: from injection.crustytoothpaste.net ([192.241.140.119]:37658 "EHLO injection.crustytoothpaste.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753377AbeEBA03 (ORCPT ); Tue, 1 May 2018 20:26:29 -0400 Received: from genre.crustytoothpaste.net (unknown [IPv6:2001:470:b978:101:e6b3:18ff:fe98:41a3]) (using TLSv1.2 with cipher ECDHE-RSA-CHACHA20-POLY1305 (256/256 bits)) (No client certificate requested) by injection.crustytoothpaste.net (Postfix) with ESMTPSA id 08486609CB; Wed, 2 May 2018 00:26:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=crustytoothpaste.net; s=default; t=1525220787; bh=v661Dj6jG2rZyiQy4CqGx8/qPKaaJeSOHruBnrZ6TOE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From:Reply-To: Subject:Date:To:CC:Resent-Date:Resent-From:Resent-To:Resent-Cc: In-Reply-To:References:Content-Type:Content-Disposition; b=PixAiiKJMShcHXAPUwPuWF15qyVNeoWdAAnDuSi0YlbDW4wrGQeyU22DEKW15wsk0 hNMWf0zkeESAftfcnypfCNJCSxlxUBgoNLvY8lZ0fnN0cG4E+d99rVlGc5D0cU+3wg TkpO5pUdx70Od1VTEXNmwC5FDuODM72/+ko1+AFu3Bva9+bxuOvDYkSvtG3FnmrfHw 796xIKUGClyRhaxFWgbBUgOqlnWr7SXsQ7rPKDyvkY+z19yZnjm1XSs3KJC0ayRq3x RqzXNNyDumBrnaYvbQx4t/t4pkqCQMs1iDuf9e0YBGafSavE8GnCv3kQ9MO6oAaKDv t7S6d6rq+39WJboOn68TmTneoEaswq5QN/joC3BatBE+I2uJdDBKxtKbLctOEHvn6+ n0IVLsf4LxLzW5xLDRvxWxBAUuRX4UnO1zxD9R9oFN3kHWep3naVjnX8wZMTwvFYTZ t1zBA8dtyvUTuLPlfUwaTEvuoI+ZCZz0FjZrNd9esLGcw2BVd3u From: "brian m. carlson" To: git@vger.kernel.org Cc: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?= , Junio C Hamano , Eric Sunshine , =?UTF-8?q?Martin=20=C3=85gren?= , =?UTF-8?q?SZEDER=20G=C3=A1bor?= Subject: [PATCH v2 08/42] packfile: abstract away hash constant values Date: Wed, 2 May 2018 00:25:36 +0000 Message-Id: <20180502002610.915892-9-sandals@crustytoothpaste.net> X-Mailer: git-send-email 2.17.0.441.gb46fe60e1d In-Reply-To: <20180502002610.915892-1-sandals@crustytoothpaste.net> References: <20180502002610.915892-1-sandals@crustytoothpaste.net> X-Scanned-By: MIMEDefang 2.79 on 127.0.1.1 Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org There are several instances of the constant 20 and 20-based values in the packfile code. Abstract away dependence on SHA-1 by using the values from the_hash_algo instead. Use unsigned values for temporary constants to provide the compiler with more information about what kinds of values it should expect. Signed-off-by: brian m. carlson --- packfile.c | 66 ++++++++++++++++++++++++++++++------------------------ 1 file changed, 37 insertions(+), 29 deletions(-) diff --git a/packfile.c b/packfile.c index 84acd405e0..b7bc4eab17 100644 --- a/packfile.c +++ b/packfile.c @@ -84,6 +84,7 @@ static int check_packed_git_idx(const char *path, struct packed_git *p) uint32_t version, nr, i, *index; int fd = git_open(path); struct stat st; + const unsigned int hashsz = the_hash_algo->rawsz; if (fd < 0) return -1; @@ -92,7 +93,7 @@ static int check_packed_git_idx(const char *path, struct packed_git *p) return -1; } idx_size = xsize_t(st.st_size); - if (idx_size < 4 * 256 + 20 + 20) { + if (idx_size < 4 * 256 + hashsz + hashsz) { close(fd); return error("index file %s is too small", path); } @@ -129,11 +130,11 @@ static int check_packed_git_idx(const char *path, struct packed_git *p) /* * Total size: * - 256 index entries 4 bytes each - * - 24-byte entries * nr (20-byte sha1 + 4-byte offset) - * - 20-byte SHA1 of the packfile - * - 20-byte SHA1 file checksum + * - 24-byte entries * nr (object ID + 4-byte offset) + * - hash of the packfile + * - file checksum */ - if (idx_size != 4*256 + nr * 24 + 20 + 20) { + if (idx_size != 4*256 + nr * (hashsz + 4) + hashsz + hashsz) { munmap(idx_map, idx_size); return error("wrong index v1 file size in %s", path); } @@ -142,16 +143,16 @@ static int check_packed_git_idx(const char *path, struct packed_git *p) * Minimum size: * - 8 bytes of header * - 256 index entries 4 bytes each - * - 20-byte sha1 entry * nr + * - object ID entry * nr * - 4-byte crc entry * nr * - 4-byte offset entry * nr - * - 20-byte SHA1 of the packfile - * - 20-byte SHA1 file checksum + * - hash of the packfile + * - file checksum * And after the 4-byte offset table might be a * variable sized table containing 8-byte entries * for offsets larger than 2^31. */ - unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20; + unsigned long min_size = 8 + 4*256 + nr*(hashsz + 4 + 4) + hashsz + hashsz; unsigned long max_size = min_size; if (nr) max_size += (nr - 1)*8; @@ -444,10 +445,11 @@ static int open_packed_git_1(struct packed_git *p) { struct stat st; struct pack_header hdr; - unsigned char sha1[20]; - unsigned char *idx_sha1; + unsigned char hash[GIT_MAX_RAWSZ]; + unsigned char *idx_hash; long fd_flag; ssize_t read_result; + const unsigned hashsz = the_hash_algo->rawsz; if (!p->index_data && open_pack_index(p)) return error("packfile %s index unavailable", p->pack_name); @@ -507,15 +509,15 @@ static int open_packed_git_1(struct packed_git *p) " while index indicates %"PRIu32" objects", p->pack_name, ntohl(hdr.hdr_entries), p->num_objects); - if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1) + if (lseek(p->pack_fd, p->pack_size - hashsz, SEEK_SET) == -1) return error("end of packfile %s is unavailable", p->pack_name); - read_result = read_in_full(p->pack_fd, sha1, sizeof(sha1)); + read_result = read_in_full(p->pack_fd, hash, hashsz); if (read_result < 0) return error_errno("error reading from %s", p->pack_name); - if (read_result != sizeof(sha1)) + if (read_result != hashsz) return error("packfile %s signature is unavailable", p->pack_name); - idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40; - if (hashcmp(sha1, idx_sha1)) + idx_hash = ((unsigned char *)p->index_data) + p->index_size - hashsz * 2; + if (hashcmp(hash, idx_hash)) return error("packfile %s does not match index", p->pack_name); return 0; } @@ -530,7 +532,7 @@ static int open_packed_git(struct packed_git *p) static int in_window(struct pack_window *win, off_t offset) { - /* We must promise at least 20 bytes (one hash) after the + /* We must promise at least one full hash after the * offset is available from this window, otherwise the offset * is not actually in this window and a different window (which * has that one hash excess) must be used. This is to support @@ -538,7 +540,7 @@ static int in_window(struct pack_window *win, off_t offset) */ off_t win_off = win->offset; return win_off <= offset - && (offset + 20) <= (win_off + win->len); + && (offset + the_hash_algo->rawsz) <= (win_off + win->len); } unsigned char *use_pack(struct packed_git *p, @@ -555,7 +557,7 @@ unsigned char *use_pack(struct packed_git *p, */ if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p)) die("packfile %s cannot be accessed", p->pack_name); - if (offset > (p->pack_size - 20)) + if (offset > (p->pack_size - the_hash_algo->rawsz)) die("offset beyond end of packfile (truncated pack?)"); if (offset < 0) die(_("offset before end of packfile (broken .idx?)")); @@ -675,7 +677,8 @@ struct packed_git *add_packed_git(const char *path, size_t path_len, int local) p->pack_size = st.st_size; p->pack_local = local; p->mtime = st.st_mtime; - if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1)) + if (path_len < the_hash_algo->hexsz || + get_sha1_hex(path + path_len - the_hash_algo->hexsz, p->sha1)) hashclr(p->sha1); return p; } @@ -1028,7 +1031,8 @@ const struct packed_git *has_packed_and_bad(const unsigned char *sha1) for (p = the_repository->objects->packed_git; p; p = p->next) for (i = 0; i < p->num_bad_objects; i++) - if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i)) + if (!hashcmp(sha1, + p->bad_object_sha1 + the_hash_algo->rawsz * i)) return p; return NULL; } @@ -1066,7 +1070,7 @@ static off_t get_delta_base(struct packed_git *p, } else if (type == OBJ_REF_DELTA) { /* The base entry _must_ be in the same pack */ base_offset = find_pack_entry_one(base_info, p); - *curpos += 20; + *curpos += the_hash_algo->rawsz; } else die("I am totally screwed"); return base_offset; @@ -1671,6 +1675,7 @@ int bsearch_pack(const struct object_id *oid, const struct packed_git *p, uint32 { const unsigned char *index_fanout = p->index_data; const unsigned char *index_lookup; + const unsigned int hashsz = the_hash_algo->rawsz; int index_lookup_width; if (!index_fanout) @@ -1678,10 +1683,10 @@ int bsearch_pack(const struct object_id *oid, const struct packed_git *p, uint32 index_lookup = index_fanout + 4 * 256; if (p->index_version == 1) { - index_lookup_width = 24; + index_lookup_width = hashsz + 4; index_lookup += 4; } else { - index_lookup_width = 20; + index_lookup_width = hashsz; index_fanout += 8; index_lookup += 8; } @@ -1694,6 +1699,7 @@ const unsigned char *nth_packed_object_sha1(struct packed_git *p, uint32_t n) { const unsigned char *index = p->index_data; + const unsigned int hashsz = the_hash_algo->rawsz; if (!index) { if (open_pack_index(p)) return NULL; @@ -1703,10 +1709,10 @@ const unsigned char *nth_packed_object_sha1(struct packed_git *p, return NULL; index += 4 * 256; if (p->index_version == 1) { - return index + 24 * n + 4; + return index + (hashsz + 4) * n + 4; } else { index += 8; - return index + 20 * n; + return index + hashsz * n; } } @@ -1738,12 +1744,13 @@ void check_pack_index_ptr(const struct packed_git *p, const void *vptr) off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n) { const unsigned char *index = p->index_data; + const unsigned int hashsz = the_hash_algo->rawsz; index += 4 * 256; if (p->index_version == 1) { - return ntohl(*((uint32_t *)(index + 24 * n))); + return ntohl(*((uint32_t *)(index + (hashsz + 4) * n))); } else { uint32_t off; - index += 8 + p->num_objects * (20 + 4); + index += 8 + p->num_objects * (hashsz + 4); off = ntohl(*((uint32_t *)(index + 4 * n))); if (!(off & 0x80000000)) return off; @@ -1814,7 +1821,8 @@ static int fill_pack_entry(const struct object_id *oid, if (p->num_bad_objects) { unsigned i; for (i = 0; i < p->num_bad_objects; i++) - if (!hashcmp(oid->hash, p->bad_object_sha1 + 20 * i)) + if (!hashcmp(oid->hash, + p->bad_object_sha1 + the_hash_algo->rawsz * i)) return 0; }