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authorLinus Torvalds <torvalds@linux-foundation.org>2008-01-15 00:03:17 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2008-01-21 20:44:31 (GMT)
commit7a51ed66f653c248993b3c4a61932e47933d835e (patch)
treeeb40e8e3b00979deee24e0a03a32b5f25d1f275e /read-cache.c
parentce33288ea6b81a2f4f5aecd72177bcc8174562ae (diff)
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Make on-disk index representation separate from in-core one
This converts the index explicitly on read and write to its on-disk format, allowing the in-core format to contain more flags, and be simpler. In particular, the in-core format is now host-endian (as opposed to the on-disk one that is network endian in order to be able to be shared across machines) and as a result we can dispense with all the htonl/ntohl on accesses to the cache_entry fields. This will make it easier to make use of various temporary flags that do not exist in the on-disk format. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'read-cache.c')
-rw-r--r--read-cache.c200
1 files changed, 118 insertions, 82 deletions
diff --git a/read-cache.c b/read-cache.c
index 7db5588..82a6238 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -30,20 +30,16 @@ struct index_state the_index;
*/
void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
{
- ce->ce_ctime.sec = htonl(st->st_ctime);
- ce->ce_mtime.sec = htonl(st->st_mtime);
-#ifdef USE_NSEC
- ce->ce_ctime.nsec = htonl(st->st_ctim.tv_nsec);
- ce->ce_mtime.nsec = htonl(st->st_mtim.tv_nsec);
-#endif
- ce->ce_dev = htonl(st->st_dev);
- ce->ce_ino = htonl(st->st_ino);
- ce->ce_uid = htonl(st->st_uid);
- ce->ce_gid = htonl(st->st_gid);
- ce->ce_size = htonl(st->st_size);
+ ce->ce_ctime = st->st_ctime;
+ ce->ce_mtime = st->st_mtime;
+ ce->ce_dev = st->st_dev;
+ ce->ce_ino = st->st_ino;
+ ce->ce_uid = st->st_uid;
+ ce->ce_gid = st->st_gid;
+ ce->ce_size = st->st_size;
if (assume_unchanged)
- ce->ce_flags |= htons(CE_VALID);
+ ce->ce_flags |= CE_VALID;
}
static int ce_compare_data(struct cache_entry *ce, struct stat *st)
@@ -116,7 +112,7 @@ static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st)
return DATA_CHANGED;
break;
case S_IFDIR:
- if (S_ISGITLINK(ntohl(ce->ce_mode)))
+ if (S_ISGITLINK(ce->ce_mode))
return 0;
default:
return TYPE_CHANGED;
@@ -128,14 +124,17 @@ static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
{
unsigned int changed = 0;
- switch (ntohl(ce->ce_mode) & S_IFMT) {
+ if (ce->ce_flags & CE_REMOVE)
+ return MODE_CHANGED | DATA_CHANGED | TYPE_CHANGED;
+
+ switch (ce->ce_mode & S_IFMT) {
case S_IFREG:
changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0;
/* We consider only the owner x bit to be relevant for
* "mode changes"
*/
if (trust_executable_bit &&
- (0100 & (ntohl(ce->ce_mode) ^ st->st_mode)))
+ (0100 & (ce->ce_mode ^ st->st_mode)))
changed |= MODE_CHANGED;
break;
case S_IFLNK:
@@ -149,32 +148,18 @@ static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
else if (ce_compare_gitlink(ce))
changed |= DATA_CHANGED;
return changed;
- case 0: /* Special case: unmerged file in index */
- return MODE_CHANGED | DATA_CHANGED | TYPE_CHANGED;
default:
- die("internal error: ce_mode is %o", ntohl(ce->ce_mode));
+ die("internal error: ce_mode is %o", ce->ce_mode);
}
- if (ce->ce_mtime.sec != htonl(st->st_mtime))
- changed |= MTIME_CHANGED;
- if (ce->ce_ctime.sec != htonl(st->st_ctime))
- changed |= CTIME_CHANGED;
-
-#ifdef USE_NSEC
- /*
- * nsec seems unreliable - not all filesystems support it, so
- * as long as it is in the inode cache you get right nsec
- * but after it gets flushed, you get zero nsec.
- */
- if (ce->ce_mtime.nsec != htonl(st->st_mtim.tv_nsec))
+ if (ce->ce_mtime != (unsigned int) st->st_mtime)
changed |= MTIME_CHANGED;
- if (ce->ce_ctime.nsec != htonl(st->st_ctim.tv_nsec))
+ if (ce->ce_ctime != (unsigned int) st->st_ctime)
changed |= CTIME_CHANGED;
-#endif
- if (ce->ce_uid != htonl(st->st_uid) ||
- ce->ce_gid != htonl(st->st_gid))
+ if (ce->ce_uid != (unsigned int) st->st_uid ||
+ ce->ce_gid != (unsigned int) st->st_gid)
changed |= OWNER_CHANGED;
- if (ce->ce_ino != htonl(st->st_ino))
+ if (ce->ce_ino != (unsigned int) st->st_ino)
changed |= INODE_CHANGED;
#ifdef USE_STDEV
@@ -183,11 +168,11 @@ static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
* clients will have different views of what "device"
* the filesystem is on
*/
- if (ce->ce_dev != htonl(st->st_dev))
+ if (ce->ce_dev != (unsigned int) st->st_dev)
changed |= INODE_CHANGED;
#endif
- if (ce->ce_size != htonl(st->st_size))
+ if (ce->ce_size != (unsigned int) st->st_size)
changed |= DATA_CHANGED;
return changed;
@@ -205,7 +190,7 @@ int ie_match_stat(struct index_state *istate,
* If it's marked as always valid in the index, it's
* valid whatever the checked-out copy says.
*/
- if (!ignore_valid && (ce->ce_flags & htons(CE_VALID)))
+ if (!ignore_valid && (ce->ce_flags & CE_VALID))
return 0;
changed = ce_match_stat_basic(ce, st);
@@ -228,7 +213,7 @@ int ie_match_stat(struct index_state *istate,
*/
if (!changed &&
istate->timestamp &&
- istate->timestamp <= ntohl(ce->ce_mtime.sec)) {
+ istate->timestamp <= ce->ce_mtime) {
if (assume_racy_is_modified)
changed |= DATA_CHANGED;
else
@@ -257,7 +242,7 @@ int ie_modified(struct index_state *istate,
* the length field is zero. For other cases the ce_size
* should match the SHA1 recorded in the index entry.
*/
- if ((changed & DATA_CHANGED) && ce->ce_size != htonl(0))
+ if ((changed & DATA_CHANGED) && ce->ce_size != 0)
return changed;
changed_fs = ce_modified_check_fs(ce, st);
@@ -320,7 +305,7 @@ int index_name_pos(struct index_state *istate, const char *name, int namelen)
while (last > first) {
int next = (last + first) >> 1;
struct cache_entry *ce = istate->cache[next];
- int cmp = cache_name_compare(name, namelen, ce->name, ntohs(ce->ce_flags));
+ int cmp = cache_name_compare(name, namelen, ce->name, ce->ce_flags);
if (!cmp)
return next;
if (cmp < 0) {
@@ -405,7 +390,7 @@ int add_file_to_index(struct index_state *istate, const char *path, int verbose)
size = cache_entry_size(namelen);
ce = xcalloc(1, size);
memcpy(ce->name, path, namelen);
- ce->ce_flags = htons(namelen);
+ ce->ce_flags = namelen;
fill_stat_cache_info(ce, &st);
if (trust_executable_bit && has_symlinks)
@@ -583,7 +568,7 @@ static int has_file_name(struct index_state *istate,
continue;
if (p->name[len] != '/')
continue;
- if (!ce_stage(p) && !p->ce_mode)
+ if (p->ce_flags & CE_REMOVE)
continue;
retval = -1;
if (!ok_to_replace)
@@ -616,7 +601,7 @@ static int has_dir_name(struct index_state *istate,
}
len = slash - name;
- pos = index_name_pos(istate, name, ntohs(create_ce_flags(len, stage)));
+ pos = index_name_pos(istate, name, create_ce_flags(len, stage));
if (pos >= 0) {
/*
* Found one, but not so fast. This could
@@ -679,7 +664,7 @@ static int check_file_directory_conflict(struct index_state *istate,
/*
* When ce is an "I am going away" entry, we allow it to be added
*/
- if (!ce_stage(ce) && !ce->ce_mode)
+ if (ce->ce_flags & CE_REMOVE)
return 0;
/*
@@ -704,7 +689,7 @@ static int add_index_entry_with_check(struct index_state *istate, struct cache_e
int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK;
cache_tree_invalidate_path(istate->cache_tree, ce->name);
- pos = index_name_pos(istate, ce->name, ntohs(ce->ce_flags));
+ pos = index_name_pos(istate, ce->name, ce->ce_flags);
/* existing match? Just replace it. */
if (pos >= 0) {
@@ -736,7 +721,7 @@ static int add_index_entry_with_check(struct index_state *istate, struct cache_e
if (!ok_to_replace)
return error("'%s' appears as both a file and as a directory",
ce->name);
- pos = index_name_pos(istate, ce->name, ntohs(ce->ce_flags));
+ pos = index_name_pos(istate, ce->name, ce->ce_flags);
pos = -pos-1;
}
return pos + 1;
@@ -810,7 +795,7 @@ static struct cache_entry *refresh_cache_ent(struct index_state *istate,
* valid again, under "assume unchanged" mode.
*/
if (ignore_valid && assume_unchanged &&
- !(ce->ce_flags & htons(CE_VALID)))
+ !(ce->ce_flags & CE_VALID))
; /* mark this one VALID again */
else
return ce;
@@ -826,7 +811,6 @@ static struct cache_entry *refresh_cache_ent(struct index_state *istate,
updated = xmalloc(size);
memcpy(updated, ce, size);
fill_stat_cache_info(updated, &st);
-
/*
* If ignore_valid is not set, we should leave CE_VALID bit
* alone. Otherwise, paths marked with --no-assume-unchanged
@@ -834,8 +818,8 @@ static struct cache_entry *refresh_cache_ent(struct index_state *istate,
* automatically, which is not really what we want.
*/
if (!ignore_valid && assume_unchanged &&
- !(ce->ce_flags & htons(CE_VALID)))
- updated->ce_flags &= ~htons(CE_VALID);
+ !(ce->ce_flags & CE_VALID))
+ updated->ce_flags &= ~CE_VALID;
return updated;
}
@@ -880,7 +864,7 @@ int refresh_index(struct index_state *istate, unsigned int flags, const char **p
/* If we are doing --really-refresh that
* means the index is not valid anymore.
*/
- ce->ce_flags &= ~htons(CE_VALID);
+ ce->ce_flags &= ~CE_VALID;
istate->cache_changed = 1;
}
if (quiet)
@@ -942,16 +926,34 @@ int read_index(struct index_state *istate)
return read_index_from(istate, get_index_file());
}
+static void convert_from_disk(struct ondisk_cache_entry *ondisk, struct cache_entry *ce)
+{
+ ce->ce_ctime = ntohl(ondisk->ctime.sec);
+ ce->ce_mtime = ntohl(ondisk->mtime.sec);
+ ce->ce_dev = ntohl(ondisk->dev);
+ ce->ce_ino = ntohl(ondisk->ino);
+ ce->ce_mode = ntohl(ondisk->mode);
+ ce->ce_uid = ntohl(ondisk->uid);
+ ce->ce_gid = ntohl(ondisk->gid);
+ ce->ce_size = ntohl(ondisk->size);
+ /* On-disk flags are just 16 bits */
+ ce->ce_flags = ntohs(ondisk->flags);
+ hashcpy(ce->sha1, ondisk->sha1);
+ memcpy(ce->name, ondisk->name, ce_namelen(ce)+1);
+}
+
/* remember to discard_cache() before reading a different cache! */
int read_index_from(struct index_state *istate, const char *path)
{
int fd, i;
struct stat st;
- unsigned long offset;
+ unsigned long src_offset, dst_offset;
struct cache_header *hdr;
+ void *mmap;
+ size_t mmap_size;
errno = EBUSY;
- if (istate->mmap)
+ if (istate->alloc)
return istate->cache_nr;
errno = ENOENT;
@@ -967,31 +969,47 @@ int read_index_from(struct index_state *istate, const char *path)
die("cannot stat the open index (%s)", strerror(errno));
errno = EINVAL;
- istate->mmap_size = xsize_t(st.st_size);
- if (istate->mmap_size < sizeof(struct cache_header) + 20)
+ mmap_size = xsize_t(st.st_size);
+ if (mmap_size < sizeof(struct cache_header) + 20)
die("index file smaller than expected");
- istate->mmap = xmmap(NULL, istate->mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
+ mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
close(fd);
+ if (mmap == MAP_FAILED)
+ die("unable to map index file");
- hdr = istate->mmap;
- if (verify_hdr(hdr, istate->mmap_size) < 0)
+ hdr = mmap;
+ if (verify_hdr(hdr, mmap_size) < 0)
goto unmap;
istate->cache_nr = ntohl(hdr->hdr_entries);
istate->cache_alloc = alloc_nr(istate->cache_nr);
istate->cache = xcalloc(istate->cache_alloc, sizeof(struct cache_entry *));
- offset = sizeof(*hdr);
+ /*
+ * The disk format is actually larger than the in-memory format,
+ * due to space for nsec etc, so even though the in-memory one
+ * has room for a few more flags, we can allocate using the same
+ * index size
+ */
+ istate->alloc = xmalloc(mmap_size);
+
+ src_offset = sizeof(*hdr);
+ dst_offset = 0;
for (i = 0; i < istate->cache_nr; i++) {
+ struct ondisk_cache_entry *disk_ce;
struct cache_entry *ce;
- ce = (struct cache_entry *)((char *)(istate->mmap) + offset);
- offset = offset + ce_size(ce);
+ disk_ce = (struct ondisk_cache_entry *)((char *)mmap + src_offset);
+ ce = (struct cache_entry *)((char *)istate->alloc + dst_offset);
+ convert_from_disk(disk_ce, ce);
istate->cache[i] = ce;
+
+ src_offset += ondisk_ce_size(ce);
+ dst_offset += ce_size(ce);
}
istate->timestamp = st.st_mtime;
- while (offset <= istate->mmap_size - 20 - 8) {
+ while (src_offset <= mmap_size - 20 - 8) {
/* After an array of active_nr index entries,
* there can be arbitrary number of extended
* sections, each of which is prefixed with
@@ -999,40 +1017,36 @@ int read_index_from(struct index_state *istate, const char *path)
* in 4-byte network byte order.
*/
unsigned long extsize;
- memcpy(&extsize, (char *)(istate->mmap) + offset + 4, 4);
+ memcpy(&extsize, (char *)mmap + src_offset + 4, 4);
extsize = ntohl(extsize);
if (read_index_extension(istate,
- ((const char *) (istate->mmap)) + offset,
- (char *) (istate->mmap) + offset + 8,
+ (const char *) mmap + src_offset,
+ (char *) mmap + src_offset + 8,
extsize) < 0)
goto unmap;
- offset += 8;
- offset += extsize;
+ src_offset += 8;
+ src_offset += extsize;
}
+ munmap(mmap, mmap_size);
return istate->cache_nr;
unmap:
- munmap(istate->mmap, istate->mmap_size);
+ munmap(mmap, mmap_size);
errno = EINVAL;
die("index file corrupt");
}
int discard_index(struct index_state *istate)
{
- int ret;
-
istate->cache_nr = 0;
istate->cache_changed = 0;
istate->timestamp = 0;
cache_tree_free(&(istate->cache_tree));
- if (istate->mmap == NULL)
- return 0;
- ret = munmap(istate->mmap, istate->mmap_size);
- istate->mmap = NULL;
- istate->mmap_size = 0;
+ free(istate->alloc);
+ istate->alloc = NULL;
/* no need to throw away allocated active_cache */
- return ret;
+ return 0;
}
#define WRITE_BUFFER_SIZE 8192
@@ -1144,10 +1158,32 @@ static void ce_smudge_racily_clean_entry(struct cache_entry *ce)
* file, and never calls us, so the cached size information
* for "frotz" stays 6 which does not match the filesystem.
*/
- ce->ce_size = htonl(0);
+ ce->ce_size = 0;
}
}
+static int ce_write_entry(SHA_CTX *c, int fd, struct cache_entry *ce)
+{
+ int size = ondisk_ce_size(ce);
+ struct ondisk_cache_entry *ondisk = xcalloc(1, size);
+
+ ondisk->ctime.sec = htonl(ce->ce_ctime);
+ ondisk->ctime.nsec = 0;
+ ondisk->mtime.sec = htonl(ce->ce_mtime);
+ ondisk->mtime.nsec = 0;
+ ondisk->dev = htonl(ce->ce_dev);
+ ondisk->ino = htonl(ce->ce_ino);
+ ondisk->mode = htonl(ce->ce_mode);
+ ondisk->uid = htonl(ce->ce_uid);
+ ondisk->gid = htonl(ce->ce_gid);
+ ondisk->size = htonl(ce->ce_size);
+ hashcpy(ondisk->sha1, ce->sha1);
+ ondisk->flags = htons(ce->ce_flags);
+ memcpy(ondisk->name, ce->name, ce_namelen(ce));
+
+ return ce_write(c, fd, ondisk, size);
+}
+
int write_index(struct index_state *istate, int newfd)
{
SHA_CTX c;
@@ -1157,7 +1193,7 @@ int write_index(struct index_state *istate, int newfd)
int entries = istate->cache_nr;
for (i = removed = 0; i < entries; i++)
- if (!cache[i]->ce_mode)
+ if (cache[i]->ce_flags & CE_REMOVE)
removed++;
hdr.hdr_signature = htonl(CACHE_SIGNATURE);
@@ -1170,12 +1206,12 @@ int write_index(struct index_state *istate, int newfd)
for (i = 0; i < entries; i++) {
struct cache_entry *ce = cache[i];
- if (!ce->ce_mode)
+ if (ce->ce_flags & CE_REMOVE)
continue;
if (istate->timestamp &&
- istate->timestamp <= ntohl(ce->ce_mtime.sec))
+ istate->timestamp <= ce->ce_mtime)
ce_smudge_racily_clean_entry(ce);
- if (ce_write(&c, newfd, ce, ce_size(ce)) < 0)
+ if (ce_write_entry(&c, newfd, ce) < 0)
return -1;
}