From: Thomas Gummerer <t.gummerer@gmail.com> To: git@vger.kernel.org Cc: trast@inf.ethz.ch, mhagger@alum.mit.edu, gitster@pobox.com, pclouds@gmail.com, robin.rosenberg@dewire.com, t.gummerer@gmail.com Subject: [PATCH 02/22] read-cache: split index file version specific functionality Date: Sun, 7 Jul 2013 10:11:40 +0200 Message-ID: <1373184720-29767-3-git-send-email-t.gummerer@gmail.com> (raw) In-Reply-To: <1373184720-29767-1-git-send-email-t.gummerer@gmail.com> 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 <t.gummerer@gmail.com> --- cache.h | 5 +- read-cache.c | 130 +++++++++++++++++++++++++++++++++------------------ test-index-version.c | 2 +- 3 files changed, 90 insertions(+), 47 deletions(-) diff --git a/cache.h b/cache.h index c288678..7af853b 100644 --- a/cache.h +++ b/cache.h @@ -100,9 +100,12 @@ unsigned long git_deflate_bound(git_zstream *, unsigned long); */ #define CACHE_SIGNATURE 0x44495243 /* "DIRC" */ -struct cache_header { +struct cache_version_header { unsigned int hdr_signature; unsigned int hdr_version; +}; + +struct cache_header { unsigned int hdr_entries; }; diff --git a/read-cache.c b/read-cache.c index d5201f9..93947bf 100644 --- a/read-cache.c +++ b/read-cache.c @@ -1268,10 +1268,8 @@ 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_version_header *hdr, unsigned long size) { - git_SHA_CTX c; - unsigned char sha1[20]; int hdr_version; if (hdr->hdr_signature != htonl(CACHE_SIGNATURE)) @@ -1279,10 +1277,22 @@ 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_version_header) + + 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; } @@ -1424,47 +1434,19 @@ 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 cache_version_header *hdr; + struct cache_header *hdr_v2; 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; + hdr_v2 = (struct cache_header *)((char *)mmap + sizeof(*hdr)); istate->version = ntohl(hdr->hdr_version); - istate->cache_nr = ntohl(hdr->hdr_entries); + istate->cache_nr = ntohl(hdr_v2->hdr_entries); istate->cache_alloc = alloc_nr(istate->cache_nr); istate->cache = xcalloc(istate->cache_alloc, sizeof(*istate->cache)); istate->initialized = 1; @@ -1474,7 +1456,7 @@ int read_index_from(struct index_state *istate, const char *path) else previous_name = NULL; - src_offset = sizeof(*hdr); + src_offset = sizeof(*hdr) + sizeof(*hdr_v2); for (i = 0; i < istate->cache_nr; i++) { struct ondisk_cache_entry *disk_ce; struct cache_entry *ce; @@ -1487,8 +1469,6 @@ 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, @@ -1508,6 +1488,58 @@ 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_version_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; @@ -1771,10 +1803,11 @@ 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; + struct cache_version_header hdr; + struct cache_header hdr_v2; int i, err, removed, extended, hdr_version; struct cache_entry **cache = istate->cache; int entries = istate->cache_nr; @@ -1804,11 +1837,13 @@ int write_index(struct index_state *istate, int newfd) hdr.hdr_signature = htonl(CACHE_SIGNATURE); hdr.hdr_version = htonl(hdr_version); - hdr.hdr_entries = htonl(entries - removed); + hdr_v2.hdr_entries = htonl(entries - removed); git_SHA1_Init(&c); if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0) return -1; + if (ce_write(&c, newfd, &hdr_v2, sizeof(hdr_v2)) < 0) + return -1; previous_name = (hdr_version == 4) ? &previous_name_buf : NULL; for (i = 0; i < entries; i++) { @@ -1854,6 +1889,11 @@ 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 diff --git a/test-index-version.c b/test-index-version.c index 05d4699..4c0386f 100644 --- a/test-index-version.c +++ b/test-index-version.c @@ -2,7 +2,7 @@ int main(int argc, char **argv) { - struct cache_header hdr; + struct cache_version_header hdr; int version; memset(&hdr,0,sizeof(hdr)); -- 1.8.3.453.g1dfc63d
next prev parent reply other threads:[~2013-07-07 8:12 UTC|newest] Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top 2013-07-07 8:11 [PATCH 00/22] Index v5 Thomas Gummerer 2013-07-07 8:11 ` [PATCH 01/22] t2104: Don't fail for index versions other than [23] Thomas Gummerer 2013-07-07 8:11 ` Thomas Gummerer [this message] 2013-07-07 8:11 ` [PATCH 03/22] read-cache: move index v2 specific functions to their own file Thomas Gummerer 2013-07-07 8:11 ` [PATCH 04/22] read-cache: Re-read index if index file changed Thomas Gummerer 2013-07-07 8:11 ` [PATCH 05/22] read-cache: add index reading api Thomas Gummerer 2013-07-08 2:01 ` Duy Nguyen 2013-07-08 11:40 ` Thomas Gummerer 2013-07-08 2:19 ` Duy Nguyen 2013-07-08 11:20 ` Thomas Gummerer 2013-07-08 12:45 ` Duy Nguyen 2013-07-08 13:37 ` Thomas Gummerer 2013-07-08 20:54 ` [PATCH 5.5/22] Add documentation for the index api Thomas Gummerer 2013-07-09 15:42 ` Duy Nguyen 2013-07-09 20:10 ` Thomas Gummerer 2013-07-10 5:28 ` Duy Nguyen 2013-07-11 11:30 ` Thomas Gummerer 2013-07-11 11:42 ` Duy Nguyen 2013-07-11 12:27 ` Duy Nguyen 2013-07-08 16:36 ` [PATCH 05/22] read-cache: add index reading api Junio C Hamano 2013-07-08 20:10 ` Thomas Gummerer 2013-07-08 23:09 ` Junio C Hamano 2013-07-09 20:13 ` Thomas Gummerer 2013-07-07 8:11 ` [PATCH 06/22] make sure partially read index is not changed Thomas Gummerer 2013-07-08 16:31 ` Junio C Hamano 2013-07-08 18:33 ` Thomas Gummerer 2013-07-07 8:11 ` [PATCH 07/22] dir.c: use index api Thomas Gummerer 2013-07-07 8:11 ` [PATCH 08/22] tree.c: " Thomas Gummerer 2013-07-07 8:11 ` [PATCH 09/22] name-hash.c: " Thomas Gummerer 2013-07-07 8:11 ` [PATCH 10/22] grep.c: Use " Thomas Gummerer 2013-07-07 8:11 ` [PATCH 11/22] ls-files.c: use the " Thomas Gummerer 2013-07-07 8:11 ` [PATCH 12/22] read-cache: make read_blob_data_from_index use " Thomas Gummerer 2013-07-07 8:11 ` [PATCH 13/22] documentation: add documentation of the index-v5 file format Thomas Gummerer 2013-07-11 10:39 ` Duy Nguyen 2013-07-11 11:39 ` Thomas Gummerer 2013-07-11 11:47 ` Duy Nguyen 2013-07-11 12:26 ` Thomas Gummerer 2013-07-11 12:50 ` Duy Nguyen 2013-07-07 8:11 ` [PATCH 14/22] read-cache: make in-memory format aware of stat_crc Thomas Gummerer 2013-07-07 8:11 ` [PATCH 15/22] read-cache: read index-v5 Thomas Gummerer 2013-07-07 20:18 ` Eric Sunshine 2013-07-08 11:40 ` Thomas Gummerer 2013-07-07 8:11 ` [PATCH 16/22] read-cache: read resolve-undo data Thomas Gummerer 2013-07-07 8:11 ` [PATCH 17/22] read-cache: read cache-tree in index-v5 Thomas Gummerer 2013-07-07 20:41 ` Eric Sunshine 2013-07-07 8:11 ` [PATCH 18/22] read-cache: write index-v5 Thomas Gummerer 2013-07-07 20:43 ` Eric Sunshine 2013-07-07 8:11 ` [PATCH 19/22] read-cache: write index-v5 cache-tree data Thomas Gummerer 2013-07-07 8:11 ` [PATCH 20/22] read-cache: write resolve-undo data for index-v5 Thomas Gummerer 2013-07-07 8:11 ` [PATCH 21/22] update-index.c: rewrite index when index-version is given Thomas Gummerer 2013-07-07 8:12 ` [PATCH 22/22] p0003-index.sh: add perf test for the index formats Thomas Gummerer
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