From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Gummerer Subject: [PATCH v4 02/24] read-cache: split index file version specific functionality Date: Wed, 27 Nov 2013 13:00:37 +0100 Message-ID: <1385553659-9928-3-git-send-email-t.gummerer@gmail.com> References: <1385553659-9928-1-git-send-email-t.gummerer@gmail.com> Cc: t.gummerer@gmail.com, gitster@pobox.com, tr@thomasrast.ch, mhagger@alum.mit.edu, pclouds@gmail.com, robin.rosenberg@dewire.com, sunshine@sunshineco.com, ramsay@ramsay1.demon.co.uk To: git@vger.kernel.org X-From: git-owner@vger.kernel.org Wed Nov 27 13:01:39 2013 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1VldoH-0001gy-Sa for gcvg-git-2@plane.gmane.org; Wed, 27 Nov 2013 13:01:38 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751845Ab3K0MBd (ORCPT ); Wed, 27 Nov 2013 07:01:33 -0500 Received: from mail-la0-f41.google.com ([209.85.215.41]:37280 "EHLO mail-la0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751749Ab3K0MBa (ORCPT ); Wed, 27 Nov 2013 07:01:30 -0500 Received: by mail-la0-f41.google.com with SMTP id eo20so5314841lab.0 for ; Wed, 27 Nov 2013 04:01:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=dOKH5VIyzvA3MVXWXpUPpYW7/vSRt0+hUYfq+MyqBeY=; b=zyLwg5qNQqRPSNCASszJNnERRy37tkYDl0Eq41QncNncKOi8Sh558Pkbl+Eu7b5Vtn Sn5CpFyw53h4ITppxpdBDfNC3VKhGuLoNaNqu8FoRVkYMMblbordPEJd/TvMpu7UaQF4 5cEL7LOOpSP6mjwHouzbg4BG3czQgHsCVQHW0CFpVLc8g+BDrCMSHj6YhJ2+TcRJt2Ut /X5inp32rycVElkVO+QBrVkdOZYi4BArlPqN9z74lhu3f3sIWaTh5puq0U6mB84CDXVa 7dBRe/46i/QzhES49/mML6HOMAHXBGZC2PsyX+U4hFvsEqK/zXxon9Z+4Owb7FvgW4iL WGFQ== X-Received: by 10.112.154.129 with SMTP id vo1mr1292015lbb.31.1385553689211; Wed, 27 Nov 2013 04:01:29 -0800 (PST) Received: from localhost (213-66-41-37-no99.tbcn.telia.com. [213.66.41.37]) by mx.google.com with ESMTPSA id m5sm54843666laj.4.2013.11.27.04.01.26 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 27 Nov 2013 04:01:27 -0800 (PST) X-Mailer: git-send-email 1.8.4.2 In-Reply-To: <1385553659-9928-1-git-send-email-t.gummerer@gmail.com> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Split index file version specific functionality to their own functions, to prepare for moving the index file version specific parts to their own file. This makes it easier to add a new index file format later. Signed-off-by: Thomas Gummerer --- read-cache.c | 114 ++++++++++++++++++++++++++++++++++++++--------------------- 1 file changed, 74 insertions(+), 40 deletions(-) diff --git a/read-cache.c b/read-cache.c index 33dd676..5a8f405 100644 --- a/read-cache.c +++ b/read-cache.c @@ -1269,10 +1269,8 @@ struct ondisk_cache_entry_extended { ondisk_cache_entry_extended_size(ce_namelen(ce)) : \ ondisk_cache_entry_size(ce_namelen(ce))) -static int verify_hdr(struct cache_header *hdr, unsigned long size) +static int verify_hdr_version(struct cache_header *hdr, unsigned long size) { - git_SHA_CTX c; - unsigned char sha1[20]; int hdr_version; if (hdr->hdr_signature != htonl(CACHE_SIGNATURE)) @@ -1280,10 +1278,21 @@ static int verify_hdr(struct cache_header *hdr, unsigned long size) hdr_version = ntohl(hdr->hdr_version); if (hdr_version < INDEX_FORMAT_LB || INDEX_FORMAT_UB < hdr_version) return error("bad index version %d", hdr_version); + return 0; +} + +static int verify_hdr(void *mmap, unsigned long size) +{ + git_SHA_CTX c; + unsigned char sha1[20]; + + if (size < sizeof(struct cache_header) + 20) + die("index file smaller than expected"); + git_SHA1_Init(&c); - git_SHA1_Update(&c, hdr, size - 20); + git_SHA1_Update(&c, mmap, size - 20); git_SHA1_Final(sha1, &c); - if (hashcmp(sha1, (unsigned char *)hdr + size - 20)) + if (hashcmp(sha1, (unsigned char *)mmap + size - 20)) return error("bad index file sha1 signature"); return 0; } @@ -1425,44 +1434,14 @@ static struct cache_entry *create_from_disk(struct ondisk_cache_entry *ondisk, return ce; } -/* remember to discard_cache() before reading a different cache! */ -int read_index_from(struct index_state *istate, const char *path) +static int read_index_v2(struct index_state *istate, void *mmap, unsigned long mmap_size) { - int fd, i; - struct stat st; + int i; unsigned long src_offset; struct cache_header *hdr; - void *mmap; - size_t mmap_size; struct strbuf previous_name_buf = STRBUF_INIT, *previous_name; - if (istate->initialized) - return istate->cache_nr; - - istate->timestamp.sec = 0; - istate->timestamp.nsec = 0; - fd = open(path, O_RDONLY); - if (fd < 0) { - if (errno == ENOENT) - return 0; - die_errno("index file open failed"); - } - - if (fstat(fd, &st)) - die_errno("cannot stat the open index"); - - mmap_size = xsize_t(st.st_size); - if (mmap_size < sizeof(struct cache_header) + 20) - die("index file smaller than expected"); - - mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); - if (mmap == MAP_FAILED) - die_errno("unable to map index file"); - close(fd); - hdr = mmap; - if (verify_hdr(hdr, mmap_size) < 0) - goto unmap; istate->version = ntohl(hdr->hdr_version); istate->cache_nr = ntohl(hdr->hdr_entries); @@ -1488,8 +1467,6 @@ int read_index_from(struct index_state *istate, const char *path) src_offset += consumed; } strbuf_release(&previous_name_buf); - istate->timestamp.sec = st.st_mtime; - istate->timestamp.nsec = ST_MTIME_NSEC(st); while (src_offset <= mmap_size - 20 - 8) { /* After an array of active_nr index entries, @@ -1509,6 +1486,58 @@ int read_index_from(struct index_state *istate, const char *path) src_offset += 8; src_offset += extsize; } + return 0; +unmap: + munmap(mmap, mmap_size); + die("index file corrupt"); +} + +/* remember to discard_cache() before reading a different cache! */ +int read_index_from(struct index_state *istate, const char *path) +{ + int fd; + struct stat st; + struct cache_header *hdr; + void *mmap; + size_t mmap_size; + + errno = EBUSY; + if (istate->initialized) + return istate->cache_nr; + + errno = ENOENT; + istate->timestamp.sec = 0; + istate->timestamp.nsec = 0; + fd = open(path, O_RDONLY); + if (fd < 0) { + if (errno == ENOENT) + return 0; + die_errno("index file open failed"); + } + + if (fstat(fd, &st)) + die_errno("cannot stat the open index"); + + errno = EINVAL; + mmap_size = xsize_t(st.st_size); + if (mmap_size < sizeof(struct cache_header) + 20) + die("index file smaller than expected"); + + mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); + close(fd); + if (mmap == MAP_FAILED) + die_errno("unable to map index file"); + + hdr = mmap; + if (verify_hdr_version(hdr, mmap_size) < 0) + goto unmap; + + if (verify_hdr(mmap, mmap_size) < 0) + goto unmap; + + read_index_v2(istate, mmap, mmap_size); + istate->timestamp.sec = st.st_mtime; + istate->timestamp.nsec = ST_MTIME_NSEC(st); munmap(mmap, mmap_size); return istate->cache_nr; @@ -1772,7 +1801,7 @@ void update_index_if_able(struct index_state *istate, struct lock_file *lockfile rollback_lock_file(lockfile); } -int write_index(struct index_state *istate, int newfd) +static int write_index_v2(struct index_state *istate, int newfd) { git_SHA_CTX c; struct cache_header hdr; @@ -1864,6 +1893,11 @@ int write_index(struct index_state *istate, int newfd) return 0; } +int write_index(struct index_state *istate, int newfd) +{ + return write_index_v2(istate, newfd); +} + /* * Read the index file that is potentially unmerged into given * index_state, dropping any unmerged entries. Returns true if -- 1.8.4.2