[PATCH] teach update-index --refresh about --data-unchanged
When a repository has been copied with rsync, or cloned using a volume manager, the index can be incorrect even though the data is unchanged. This new flag tells update-index --refresh that it is not necessary to reread the data contents. Without this flag, everything works, but it is much slower due to the need to read all files.
Signed-off-by: Pete Wyckoff <pw@padd.com>
---
Documentation/git-update-index.txt | 9 +++++++++
builtin/update-index.c | 6 +++++-
cache.h | 9 ++++++---
read-cache.c | 16 ++++++++++------
4 files changed, 30 insertions(+), 10 deletions(-)
diff --git a/Documentation/git-update-index.txt b/Documentation/git-update-index.txt
index 765d4b3..69aaaee 100644
--- a/Documentation/git-update-index.txt
+++ b/Documentation/git-update-index.txt
@@ -14,6 +14,7 @@ SYNOPSIS
[--refresh] [-q] [--unmerged] [--ignore-missing]
[--cacheinfo <mode> <object> <file>]\*
[--chmod=(+|-)x]
+ [--data-unchanged]
[--assume-unchanged | --no-assume-unchanged]
[--skip-worktree | --no-skip-worktree]
[--ignore-submodules]
@@ -65,6 +66,14 @@ OPTIONS
behavior is to error out. This option makes 'git update-index'
continue anyway.
+--data-unchanged::
+ When refreshing the cache, do not re-read all data
+ files to verify that they are unchanged. This flag
+ attests that even though the index may be invalid, file content
+ has not been changed. This situation can happen when
+ a repository is copied with `rsync` or with a volume manager
+ clone command.
+
--ignore-missing::
Ignores missing files during a --refresh
diff --git a/builtin/update-index.c b/builtin/update-index.c
index 3ab214d..dc609cc 100644
--- a/builtin/update-index.c
+++ b/builtin/update-index.c
@@ -398,7 +398,7 @@ static void read_index_info(int line_termination)
}
static const char update_index_usage[] =
-"git update-index [-q] [--add] [--replace] [--remove] [--unmerged] [--refresh] [--really-refresh] [--cacheinfo] [--chmod=(+|-)x] [--assume-unchanged] [--skip-worktree|--no-skip-worktree] [--info-only] [--force-remove] [--stdin] [--index-info] [--unresolve] [--again | -g] [--ignore-missing] [-z] [--verbose] [--] <file>...";
+"git update-index [-q] [--add] [--replace] [--remove] [--unmerged] [--data-unchanged] [--refresh] [--really-refresh] [--cacheinfo] [--chmod=(+|-)x] [--assume-unchanged] [--skip-worktree|--no-skip-worktree] [--info-only] [--force-remove] [--stdin] [--index-info] [--unresolve] [--again | -g] [--ignore-missing] [-z] [--verbose] [--] <file>...";
static unsigned char head_sha1[20];
static unsigned char merge_head_sha1[20];
@@ -635,6 +635,10 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
refresh_flags |= REFRESH_UNMERGED;
continue;
}
+ if (!strcmp(path, "--data-unchanged")) {
+ refresh_flags |= REFRESH_DATA_UNCHANGED;
+ continue;
+ }
if (!strcmp(path, "--refresh")) {
setup_work_tree();
has_errors |= refresh_cache(refresh_flags);
diff --git a/cache.h b/cache.h
index 1e690d1..b2e692c 100644
--- a/cache.h
+++ b/cache.h
@@ -485,11 +485,13 @@ extern int ce_same_name(struct cache_entry *a, struct cache_entry *b);
extern int index_name_is_other(const struct index_state *, const char *, int);
/* do stat comparison even if CE_VALID is true */
-#define CE_MATCH_IGNORE_VALID 01
+#define CE_MATCH_IGNORE_VALID 0x1
/* do not check the contents but report dirty on racily-clean entries */
-#define CE_MATCH_RACY_IS_DIRTY 02
+#define CE_MATCH_RACY_IS_DIRTY 0x2
/* do stat comparison even if CE_SKIP_WORKTREE is true */
-#define CE_MATCH_IGNORE_SKIP_WORKTREE 04
+#define CE_MATCH_IGNORE_SKIP_WORKTREE 0x4
+/* trust that the contents of files have not been modified */
+#define CE_MATCH_DATA_UNCHANGED 0x8
extern int ie_match_stat(const struct index_state *, struct cache_entry *, struct stat *, unsigned int);
extern int ie_modified(const struct index_state *, struct cache_entry *, struct stat *, unsigned int);
@@ -504,6 +506,7 @@ extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
#define REFRESH_IGNORE_MISSING 0x0008 /* ignore non-existent */
#define REFRESH_IGNORE_SUBMODULES 0x0010 /* ignore submodules */
#define REFRESH_IN_PORCELAIN 0x0020 /* user friendly output, not "needs update" */
+#define REFRESH_DATA_UNCHANGED 0x0040 /* no need to read all files, trust unmodified */
extern int refresh_index(struct index_state *, unsigned int flags, const char **pathspec, char *seen, char *header_msg);
struct lock_file {
diff --git a/read-cache.c b/read-cache.c
index 1f42473..26d5d5f 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -137,12 +137,14 @@ static int ce_compare_gitlink(struct cache_entry *ce)
return hashcmp(sha1, ce->sha1);
}
-static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st)
+static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st,
+ int options)
{
switch (st->st_mode & S_IFMT) {
case S_IFREG:
- if (ce_compare_data(ce, st))
- return DATA_CHANGED;
+ if (!(options & CE_MATCH_DATA_UNCHANGED))
+ if (ce_compare_data(ce, st))
+ return DATA_CHANGED;
break;
case S_IFLNK:
if (ce_compare_link(ce, xsize_t(st->st_size)))
@@ -304,7 +306,7 @@ int ie_match_stat(const struct index_state *istate,
if (assume_racy_is_modified)
changed |= DATA_CHANGED;
else
- changed |= ce_modified_check_fs(ce, st);
+ changed |= ce_modified_check_fs(ce, st, 0);
}
return changed;
@@ -343,7 +345,7 @@ int ie_modified(const struct index_state *istate,
(S_ISGITLINK(ce->ce_mode) || ce->ce_size != 0))
return changed;
- changed_fs = ce_modified_check_fs(ce, st);
+ changed_fs = ce_modified_check_fs(ce, st, options);
if (changed_fs)
return changed | changed_fs;
return 0;
@@ -1108,6 +1110,8 @@ int refresh_index(struct index_state *istate, unsigned int flags, const char **p
needs_update_fmt = (in_porcelain ? "M\t%s\n" : "%s: needs update\n");
needs_merge_fmt = (in_porcelain ? "U\t%s\n" : "%s: needs merge\n");
+ if (flags & REFRESH_DATA_UNCHANGED)
+ options |= CE_MATCH_DATA_UNCHANGED;
for (i = 0; i < istate->cache_nr; i++) {
struct cache_entry *ce, *new;
int cache_errno = 0;
@@ -1481,7 +1485,7 @@ static void ce_smudge_racily_clean_entry(struct cache_entry *ce)
return;
if (ce_match_stat_basic(ce, &st))
return;
- if (ce_modified_check_fs(ce, &st)) {
+ if (ce_modified_check_fs(ce, &st, 0)) {
/* This is "racily clean"; smudge it. Note that this
* is a tricky code. At first glance, it may appear
* that it can break with this sequence:
--
1.7.2.3
