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[PATCH 08/12] Extract a struct stat_data from cache_entry

From
Michael Haggerty <mhagger@alum.mit.edu>
Date
Jun 11, 2013, 21:48 UTC
Message-ID
<1370987312-6761-9-git-send-email-mhagger@alum.mit.edu>
In-Reply-To
<1370987312-6761-1-git-send-email-mhagger@alum.mit.edu>

Add public functions fill_stat_data() and match_stat_data() to work with it. This infrastructure will later be used to check the validity of other types of file.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
---
I'm not too familiar with this part of the code, so please make sure
that I've put the dividing line at the right place.
 builtin/ls-files.c |  12 +++--
 cache.h            |  33 +++++++++---
 read-cache.c       | 151 +++++++++++++++++++++++++++++------------------------
 3 files changed, 116 insertions(+), 80 deletions(-)
diff --git a/builtin/ls-files.c b/builtin/ls-files.c
index 2202072..6a0730f 100644
--- a/builtin/ls-files.c
+++ b/builtin/ls-files.c
@@ -165,11 +165,13 @@ static void show_ce_entry(const char *tag, struct cache_entry *ce)
 	}
 	write_name(ce->name, ce_namelen(ce));
 	if (debug_mode) {
-		printf("  ctime: %d:%d\n", ce->ce_ctime.sec, ce->ce_ctime.nsec);
-		printf("  mtime: %d:%d\n", ce->ce_mtime.sec, ce->ce_mtime.nsec);
-		printf("  dev: %d\tino: %d\n", ce->ce_dev, ce->ce_ino);
-		printf("  uid: %d\tgid: %d\n", ce->ce_uid, ce->ce_gid);
-		printf("  size: %d\tflags: %x\n", ce->ce_size, ce->ce_flags);
+		struct stat_data *sd = &ce->ce_stat_data;
+
+		printf("  ctime: %d:%d\n", sd->sd_ctime.sec, sd->sd_ctime.nsec);
+		printf("  mtime: %d:%d\n", sd->sd_mtime.sec, sd->sd_mtime.nsec);
+		printf("  dev: %d\tino: %d\n", sd->sd_dev, sd->sd_ino);
+		printf("  uid: %d\tgid: %d\n", sd->sd_uid, sd->sd_gid);
+		printf("  size: %d\tflags: %x\n", sd->sd_size, ce->ce_flags);
 	}
 }
 
diff --git a/cache.h b/cache.h
index df532f8..207f849 100644
--- a/cache.h
+++ b/cache.h
@@ -119,15 +119,19 @@ struct cache_time {
 	unsigned int nsec;
 };
 
+struct stat_data {
+	struct cache_time sd_ctime;
+	struct cache_time sd_mtime;
+	unsigned int sd_dev;
+	unsigned int sd_ino;
+	unsigned int sd_uid;
+	unsigned int sd_gid;
+	unsigned int sd_size;
+};
+
 struct cache_entry {
-	struct cache_time ce_ctime;
-	struct cache_time ce_mtime;
-	unsigned int ce_dev;
-	unsigned int ce_ino;
+	struct stat_data ce_stat_data;
 	unsigned int ce_mode;
-	unsigned int ce_uid;
-	unsigned int ce_gid;
-	unsigned int ce_size;
 	unsigned int ce_flags;
 	unsigned int ce_namelen;
 	unsigned char sha1[20];
@@ -509,6 +513,21 @@ extern int limit_pathspec_to_literal(void);
 #define HASH_FORMAT_CHECK 2
 extern int index_fd(unsigned char *sha1, int fd, struct stat *st, enum object_type type, const char *path, unsigned flags);
 extern int index_path(unsigned char *sha1, const char *path, struct stat *st, unsigned flags);
+
+/*
+ * Record to sd the data from st that we use to check whether a file
+ * might have changed.
+ */
+extern void fill_stat_data(struct stat_data *sd, struct stat *st);
+
+/*
+ * Return 0 if st is consistent with a file not having been changed
+ * since sd was filled.  If there are differences, return a
+ * combination of MTIME_CHANGED, CTIME_CHANGED, OWNER_CHANGED,
+ * INODE_CHANGED, and DATA_CHANGED.
+ */
+extern int match_stat_data(struct stat_data *sd, struct stat *st);
+
 extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
 
 #define REFRESH_REALLY		0x0001	/* ignore_valid */
diff --git a/read-cache.c b/read-cache.c
index 04ed561..4c4328e 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -67,6 +67,61 @@ void rename_index_entry_at(struct index_state *istate, int nr, const char *new_n
 	add_index_entry(istate, new, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
 }
 
+void fill_stat_data(struct stat_data *sd, struct stat *st)
+{
+	sd->sd_ctime.sec = (unsigned int)st->st_ctime;
+	sd->sd_mtime.sec = (unsigned int)st->st_mtime;
+	sd->sd_ctime.nsec = ST_CTIME_NSEC(*st);
+	sd->sd_mtime.nsec = ST_MTIME_NSEC(*st);
+	sd->sd_dev = st->st_dev;
+	sd->sd_ino = st->st_ino;
+	sd->sd_uid = st->st_uid;
+	sd->sd_gid = st->st_gid;
+	sd->sd_size = st->st_size;
+}
+
+int match_stat_data(struct stat_data *sd, struct stat *st)
+{
+	int changed = 0;
+
+	if (sd->sd_mtime.sec != (unsigned int)st->st_mtime)
+		changed |= MTIME_CHANGED;
+	if (trust_ctime && check_stat &&
+	    sd->sd_ctime.sec != (unsigned int)st->st_ctime)
+		changed |= CTIME_CHANGED;
+
+#ifdef USE_NSEC
+	if (check_stat && sd->sd_mtime.nsec != ST_MTIME_NSEC(*st))
+		changed |= MTIME_CHANGED;
+	if (trust_ctime && check_stat &&
+	    sd->sd_ctime.nsec != ST_CTIME_NSEC(*st))
+		changed |= CTIME_CHANGED;
+#endif
+
+	if (check_stat) {
+		if (sd->sd_uid != (unsigned int) st->st_uid ||
+			sd->sd_gid != (unsigned int) st->st_gid)
+			changed |= OWNER_CHANGED;
+		if (sd->sd_ino != (unsigned int) st->st_ino)
+			changed |= INODE_CHANGED;
+	}
+
+#ifdef USE_STDEV
+	/*
+	 * st_dev breaks on network filesystems where different
+	 * clients will have different views of what "device"
+	 * the filesystem is on
+	 */
+	if (check_stat && sd->sd_dev != (unsigned int) st->st_dev)
+			changed |= INODE_CHANGED;
+#endif
+
+	if (sd->sd_size != (unsigned int) st->st_size)
+		changed |= DATA_CHANGED;
+
+	return changed;
+}
+
 /*
  * This only updates the "non-critical" parts of the directory
  * cache, ie the parts that aren't tracked by GIT, and only used
@@ -74,15 +129,7 @@ void rename_index_entry_at(struct index_state *istate, int nr, const char *new_n
  */
 void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
 {
-	ce->ce_ctime.sec = (unsigned int)st->st_ctime;
-	ce->ce_mtime.sec = (unsigned int)st->st_mtime;
-	ce->ce_ctime.nsec = ST_CTIME_NSEC(*st);
-	ce->ce_mtime.nsec = ST_MTIME_NSEC(*st);
-	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;
+	fill_stat_data(&ce->ce_stat_data, st);
 
 	if (assume_unchanged)
 		ce->ce_flags |= CE_VALID;
@@ -195,43 +242,11 @@ static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
 	default:
 		die("internal error: ce_mode is %o", ce->ce_mode);
 	}
-	if (ce->ce_mtime.sec != (unsigned int)st->st_mtime)
-		changed |= MTIME_CHANGED;
-	if (trust_ctime && check_stat &&
-	    ce->ce_ctime.sec != (unsigned int)st->st_ctime)
-		changed |= CTIME_CHANGED;
 
-#ifdef USE_NSEC
-	if (check_stat && ce->ce_mtime.nsec != ST_MTIME_NSEC(*st))
-		changed |= MTIME_CHANGED;
-	if (trust_ctime && check_stat &&
-	    ce->ce_ctime.nsec != ST_CTIME_NSEC(*st))
-		changed |= CTIME_CHANGED;
-#endif
-
-	if (check_stat) {
-		if (ce->ce_uid != (unsigned int) st->st_uid ||
-			ce->ce_gid != (unsigned int) st->st_gid)
-			changed |= OWNER_CHANGED;
-		if (ce->ce_ino != (unsigned int) st->st_ino)
-			changed |= INODE_CHANGED;
-	}
-
-#ifdef USE_STDEV
-	/*
-	 * st_dev breaks on network filesystems where different
-	 * clients will have different views of what "device"
-	 * the filesystem is on
-	 */
-	if (check_stat && ce->ce_dev != (unsigned int) st->st_dev)
-			changed |= INODE_CHANGED;
-#endif
-
-	if (ce->ce_size != (unsigned int) st->st_size)
-		changed |= DATA_CHANGED;
+	changed |= match_stat_data(&ce->ce_stat_data, st);
 
 	/* Racily smudged entry? */
-	if (!ce->ce_size) {
+	if (!ce->ce_stat_data.sd_size) {
 		if (!is_empty_blob_sha1(ce->sha1))
 			changed |= DATA_CHANGED;
 	}
@@ -245,11 +260,11 @@ static int is_racy_timestamp(const struct index_state *istate, struct cache_entr
 		istate->timestamp.sec &&
 #ifdef USE_NSEC
 		 /* nanosecond timestamped files can also be racy! */
-		(istate->timestamp.sec < ce->ce_mtime.sec ||
-		 (istate->timestamp.sec == ce->ce_mtime.sec &&
-		  istate->timestamp.nsec <= ce->ce_mtime.nsec))
+		(istate->timestamp.sec < ce->ce_stat_data.sd_mtime.sec ||
+		 (istate->timestamp.sec == ce->ce_stat_data.sd_mtime.sec &&
+		  istate->timestamp.nsec <= ce->ce_stat_data.sd_mtime.nsec))
 #else
-		istate->timestamp.sec <= ce->ce_mtime.sec
+		istate->timestamp.sec <= ce->ce_stat_data.sd_mtime.sec
 #endif
 		 );
 }
@@ -340,7 +355,7 @@ int ie_modified(const struct index_state *istate,
 	 * then we know it is.
 	 */
 	if ((changed & DATA_CHANGED) &&
-	    (S_ISGITLINK(ce->ce_mode) || ce->ce_size != 0))
+	    (S_ISGITLINK(ce->ce_mode) || ce->ce_stat_data.sd_size != 0))
 		return changed;
 
 	changed_fs = ce_modified_check_fs(ce, st);
@@ -1322,16 +1337,16 @@ static struct cache_entry *cache_entry_from_ondisk(struct ondisk_cache_entry *on
 {
 	struct cache_entry *ce = xmalloc(cache_entry_size(len));
 
-	ce->ce_ctime.sec = ntoh_l(ondisk->ctime.sec);
-	ce->ce_mtime.sec = ntoh_l(ondisk->mtime.sec);
-	ce->ce_ctime.nsec = ntoh_l(ondisk->ctime.nsec);
-	ce->ce_mtime.nsec = ntoh_l(ondisk->mtime.nsec);
-	ce->ce_dev   = ntoh_l(ondisk->dev);
-	ce->ce_ino   = ntoh_l(ondisk->ino);
+	ce->ce_stat_data.sd_ctime.sec = ntoh_l(ondisk->ctime.sec);
+	ce->ce_stat_data.sd_mtime.sec = ntoh_l(ondisk->mtime.sec);
+	ce->ce_stat_data.sd_ctime.nsec = ntoh_l(ondisk->ctime.nsec);
+	ce->ce_stat_data.sd_mtime.nsec = ntoh_l(ondisk->mtime.nsec);
+	ce->ce_stat_data.sd_dev   = ntoh_l(ondisk->dev);
+	ce->ce_stat_data.sd_ino   = ntoh_l(ondisk->ino);
 	ce->ce_mode  = ntoh_l(ondisk->mode);
-	ce->ce_uid   = ntoh_l(ondisk->uid);
-	ce->ce_gid   = ntoh_l(ondisk->gid);
-	ce->ce_size  = ntoh_l(ondisk->size);
+	ce->ce_stat_data.sd_uid   = ntoh_l(ondisk->uid);
+	ce->ce_stat_data.sd_gid   = ntoh_l(ondisk->gid);
+	ce->ce_stat_data.sd_size  = ntoh_l(ondisk->size);
 	ce->ce_flags = flags & ~CE_NAMEMASK;
 	ce->ce_namelen = len;
 	hashcpy(ce->sha1, ondisk->sha1);
@@ -1608,7 +1623,7 @@ static void ce_smudge_racily_clean_entry(struct cache_entry *ce)
 	 * The only thing we care about in this function is to smudge the
 	 * falsely clean entry due to touch-update-touch race, so we leave
 	 * everything else as they are.  We are called for entries whose
-	 * ce_mtime match the index file mtime.
+	 * ce_stat_data.sd_mtime match the index file mtime.
 	 *
 	 * Note that this actually does not do much for gitlinks, for
 	 * which ce_match_stat_basic() always goes to the actual
@@ -1647,7 +1662,7 @@ 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 = 0;
+		ce->ce_stat_data.sd_size = 0;
 	}
 }
 
@@ -1657,16 +1672,16 @@ static char *copy_cache_entry_to_ondisk(struct ondisk_cache_entry *ondisk,
 {
 	short flags;
 
-	ondisk->ctime.sec = htonl(ce->ce_ctime.sec);
-	ondisk->mtime.sec = htonl(ce->ce_mtime.sec);
-	ondisk->ctime.nsec = htonl(ce->ce_ctime.nsec);
-	ondisk->mtime.nsec = htonl(ce->ce_mtime.nsec);
-	ondisk->dev  = htonl(ce->ce_dev);
-	ondisk->ino  = htonl(ce->ce_ino);
+	ondisk->ctime.sec = htonl(ce->ce_stat_data.sd_ctime.sec);
+	ondisk->mtime.sec = htonl(ce->ce_stat_data.sd_mtime.sec);
+	ondisk->ctime.nsec = htonl(ce->ce_stat_data.sd_ctime.nsec);
+	ondisk->mtime.nsec = htonl(ce->ce_stat_data.sd_mtime.nsec);
+	ondisk->dev  = htonl(ce->ce_stat_data.sd_dev);
+	ondisk->ino  = htonl(ce->ce_stat_data.sd_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);
+	ondisk->uid  = htonl(ce->ce_stat_data.sd_uid);
+	ondisk->gid  = htonl(ce->ce_stat_data.sd_gid);
+	ondisk->size = htonl(ce->ce_stat_data.sd_size);
 	hashcpy(ondisk->sha1, ce->sha1);
 
 	flags = ce->ce_flags;

-- 
1.8.3
Previous: Michael HaggertyNext: Michael Haggerty
Message 12 of 22 in “Fix some reference-related races”
  1. 00/12 Fix some reference-related racesMichael Haggerty, Jun 11, 2013
  2. 01/12 repack_without_ref(): split list curation and entry writingMichael Haggerty, Jun 11, 2013
  3. Jeff KingJun 12, 2013
  4. Michael HaggertyJun 12, 2013
  5. 02/12 pack_refs(): split creation of packed refs and entry writingMichael Haggerty, Jun 11, 2013
  6. 03/12 refs: wrap the packed refs cache in a level of indirectionMichael Haggerty, Jun 11, 2013
  7. 04/12 refs: implement simple transactions for the packed-refs fileMichael Haggerty, Jun 11, 2013
  8. Jeff KingJun 12, 2013
  9. 05/12 refs: manage lifetime of packed refs cache via reference countingMichael Haggerty, Jun 11, 2013
  10. 06/12 do_for_each_entry(): increment the packed refs cache refcountMichael Haggerty, Jun 11, 2013
  11. 07/12 packed_ref_cache: increment refcount when lockedMichael Haggerty, Jun 11, 2013
  12. 08/12 Extract a struct stat_data from cache_entryMichael Haggerty, Jun 11, 2013
  13. 09/12 add a stat_validity structMichael Haggerty, Jun 11, 2013
  14. 10/12 get_packed_ref_cache: reload packed-refs file when it changesMichael Haggerty, Jun 11, 2013
  15. 11/12 for_each_ref: load all loose refs before packed refsMichael Haggerty, Jun 11, 2013
  16. 12/12 refs: do not invalidate the packed-refs cache unnecessarilyMichael Haggerty, Jun 11, 2013
  17. Jeff KingJun 12, 2013
  18. Jeff KingJun 12, 2013
  19. Ramsay JonesJun 15, 2013
  20. Michael HaggertyJun 16, 2013
  21. Ramsay JonesJun 18, 2013
  22. Michael HaggertyJun 19, 2013

Read the whole thread, see it on lore, or plain text.

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