From: Thomas Gummerer <t.gummerer@gmail.com>
To: git@vger.kernel.org
Cc: trast@student.ethz.ch, mhagger@alum.mit.edu, gitster@pobox.com,
pcouds@gmail.com, robin.rosenberg@dewire.com,
Thomas Gummerer <t.gummerer@gmail.com>
Subject: [PATCH/RFC v2 02/16] Modify read functions to prepare for other index formats
Date: Sun, 5 Aug 2012 23:48:59 +0200 [thread overview]
Message-ID: <1344203353-2819-3-git-send-email-t.gummerer@gmail.com> (raw)
In-Reply-To: <1344203353-2819-1-git-send-email-t.gummerer@gmail.com>
Modify the read_index_from function, splitting it up into
one function that stays the same for every index format,
doing the basic operations such as verifying the header,
and a function which is specific for each index version,
which does the real reading of the index.
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
---
read-cache.c | 107 +++++++++++++++++++++++++++++++++++-----------------------
1 file changed, 64 insertions(+), 43 deletions(-)
diff --git a/read-cache.c b/read-cache.c
index 5d61d92..24b5e02 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -1259,10 +1259,8 @@ 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_version_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))
@@ -1270,6 +1268,14 @@ static int verify_hdr(struct cache_version_header *hdr, unsigned long size)
hdr_version = ntohl(hdr->hdr_version);
if (hdr_version < 2 || 4 < hdr_version)
return error("bad index version %d", hdr_version);
+ return 0;
+}
+
+static int verify_hdr_v2(struct cache_version_header *hdr, unsigned long size)
+{
+ git_SHA_CTX c;
+ unsigned char sha1[20];
+
git_SHA1_Init(&c);
git_SHA1_Update(&c, hdr, size - 20);
git_SHA1_Final(sha1, &c);
@@ -1415,50 +1421,15 @@ 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 void read_index_v2(struct index_state *istate, void *mmap, int mmap_size)
{
- int fd, i;
- struct stat st;
+ int i;
unsigned long src_offset;
struct cache_version_header *hdr;
struct cache_header_v2 *hdr_v2;
- void *mmap;
- size_t mmap_size;
struct strbuf previous_name_buf = STRBUF_INIT, *previous_name;
- 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_version_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;
- hdr_v2 = mmap + sizeof(*hdr);
- if (verify_hdr(hdr, mmap_size) < 0)
- goto unmap;
-
hdr_v2 = mmap + sizeof(*hdr);
istate->version = ntohl(hdr->hdr_version);
istate->cache_nr = ntohl(hdr_v2->hdr_entries);
@@ -1484,8 +1455,6 @@ 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,
@@ -1505,12 +1474,64 @@ int read_index_from(struct index_state *istate, const char *path)
src_offset += 8;
src_offset += extsize;
}
+ return;
+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_version_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");
+
+ hdr = mmap;
+ if (verify_hdr_version(hdr, mmap_size) < 0)
+ goto unmap;
+
+ if (verify_hdr_v2(hdr, 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);
+
+ close(fd);
munmap(mmap, mmap_size);
return istate->cache_nr;
unmap:
munmap(mmap, mmap_size);
- errno = EINVAL;
die("index file corrupt");
}
--
1.7.10.GIT
next prev parent reply other threads:[~2012-08-05 21:51 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-05 21:48 [PATCH/RFC v2 0/16] Introduce index file format version 5 Thomas Gummerer
2012-08-05 21:48 ` [PATCH/RFC v2 01/16] Modify cache_header to prepare for other index formats Thomas Gummerer
2012-08-06 1:17 ` Junio C Hamano
2012-08-07 12:41 ` Thomas Gummerer
2012-08-07 15:45 ` Junio C Hamano
2012-08-05 21:48 ` Thomas Gummerer [this message]
2012-08-05 21:49 ` [PATCH/RFC v2 03/16] Modify match_stat_basic " Thomas Gummerer
2012-08-05 21:49 ` [PATCH/RFC v2 04/16] Modify write functions " Thomas Gummerer
2012-08-06 1:34 ` Junio C Hamano
2012-08-07 12:50 ` Thomas Gummerer
2012-08-05 21:49 ` [PATCH/RFC v2 05/16] t2104: Don't fail for index versions other than [23] Thomas Gummerer
2012-08-06 1:36 ` Junio C Hamano
2012-08-05 21:49 ` [PATCH/RFC v2 06/16] t3700: sleep for 1 second, to avoid interfering with the racy code Thomas Gummerer
2012-08-06 1:43 ` Junio C Hamano
2012-08-07 16:59 ` Thomas Gummerer
2012-08-08 20:16 ` Junio C Hamano
2012-08-08 20:57 ` Junio C Hamano
2012-08-09 13:19 ` Thomas Gummerer
2012-08-09 16:51 ` Junio C Hamano
2012-08-09 22:51 ` Thomas Gummerer
2012-08-05 21:49 ` [PATCH/RFC v2 07/16] Add documentation of the index-v5 file format Thomas Gummerer
2012-08-05 21:49 ` [PATCH/RFC v2 08/16] Make in-memory format aware of stat_crc Thomas Gummerer
2012-08-06 1:46 ` Junio C Hamano
2012-08-07 19:02 ` Thomas Gummerer
2012-08-05 21:49 ` [PATCH/RFC v2 09/16] Read index-v5 Thomas Gummerer
2012-08-06 5:17 ` Junio C Hamano
2012-08-08 7:41 ` Thomas Gummerer
2012-08-08 16:49 ` Junio C Hamano
2012-08-08 20:44 ` Thomas Gummerer
2012-08-08 21:50 ` Junio C Hamano
2012-08-05 21:49 ` [PATCH/RFC v2 10/16] Read resolve-undo data Thomas Gummerer
2012-08-06 1:51 ` Junio C Hamano
2012-08-07 19:17 ` Thomas Gummerer
2012-08-05 21:49 ` [PATCH/RFC v2 11/16] Read cache-tree in index-v5 Thomas Gummerer
2012-08-05 21:49 ` [PATCH/RFC v2 12/16] Write index-v5 Thomas Gummerer
2012-08-05 21:49 ` [PATCH/RFC v2 13/16] Write index-v5 cache-tree data Thomas Gummerer
2012-08-05 21:49 ` [PATCH/RFC v2 14/16] Write resolve-undo data for index-v5 Thomas Gummerer
2012-08-05 21:49 ` [PATCH/RFC v2 15/16] update-index.c: add a force-rewrite option Thomas Gummerer
2012-08-06 1:58 ` Junio C Hamano
2012-08-08 7:31 ` Thomas Gummerer
2012-08-05 21:49 ` [PATCH/RFC v2 16/16] p0002-index.sh: add perf test for the index formats Thomas Gummerer
2012-08-06 14:35 ` [PATCH/RFC v2 0/16] Introduce index file format version 5 Nguyễn Thái Ngọc Duy
2012-08-06 14:35 ` [PATCH 1/2] Move index v2 specific code out of read-cache Nguyễn Thái Ngọc Duy
2012-08-06 14:36 ` [PATCH 2/2] Add index-v5 Nguyễn Thái Ngọc Duy
2012-08-07 21:52 ` Robin Rosenberg
2012-08-08 10:54 ` Thomas Gummerer
2012-08-06 15:51 ` [PATCH/RFC v2 0/16] Introduce index file format version 5 Junio C Hamano
2012-08-06 16:06 ` Thomas Gummerer
2012-08-06 17:46 ` Junio C Hamano
2012-08-07 12:16 ` Nguyen Thai Ngoc Duy
2012-08-08 1:38 ` Junio C Hamano
2012-08-08 13:54 ` Nguyen Thai Ngoc Duy
2012-08-08 16:31 ` Junio C Hamano
2012-08-09 2:28 ` Nguyen Thai Ngoc Duy
2012-08-07 22:31 ` Thomas Rast
2012-08-07 23:26 ` Junio C Hamano
2012-08-08 9:07 ` Thomas Rast
2012-08-08 22:47 ` Junio C Hamano
2012-08-08 10:30 ` Nguyen Thai Ngoc Duy
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