If an entry is "watched", git lets an external program decide if the
entry is modified or not. It's more like --assume-unchanged, but
designed to be controlled by machine.
We are running out of on-disk ce_flags, so instead of extending
on-disk entry format again, "watched" flags are in-core only and
stored as extension instead.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclo...@gmail.com>
---
cache.h | 2 ++
read-cache.c | 41 ++++++++++++++++++++++++++++++++++++++++-
2 files changed, 42 insertions(+), 1 deletion(-)
diff --git a/cache.h b/cache.h
index a09d622..069dce7 100644
--- a/cache.h
+++ b/cache.h
@@ -168,6 +168,8 @@ struct cache_entry {
/* used to temporarily mark paths matched by pathspecs */
#define CE_MATCHED (1 << 26)
+#define CE_WATCHED (1 << 27)
+
/*
* Extended on-disk flags
*/
diff --git a/read-cache.c b/read-cache.c
index fe1d153..6f21e3f 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -33,6 +33,7 @@ static struct cache_entry *refresh_cache_entry(struct
cache_entry *ce, int reall
#define CACHE_EXT(s) ( (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]) )
#define CACHE_EXT_TREE 0x54524545 /* "TREE" */
#define CACHE_EXT_RESOLVE_UNDO 0x52455543 /* "REUC" */
+#define CACHE_EXT_WATCH 0x57415443 /* "WATC" */
struct index_state the_index;
@@ -1293,6 +1294,19 @@ static int verify_hdr(struct cache_header *hdr,
return 0;
}
+static void read_watch_extension(struct index_state *istate, uint8_t *data,
+ unsigned long sz)
+{
+ int i;
+ if ((istate->cache_nr + 7) / 8 != sz) {
+ error("invalid 'WATC' extension");
+ return;
+ }
+ for (i = 0; i < istate->cache_nr; i++)
+ if (data[i / 8] & (1 << (i % 8)))
+ istate->cache[i]->ce_flags |= CE_WATCHED;
+}
+
static int read_index_extension(struct index_state *istate,
const char *ext, void *data, unsigned long sz)
{
@@ -1303,6 +1317,9 @@ static int read_index_extension(struct index_state
*istate,
case CACHE_EXT_RESOLVE_UNDO:
istate->resolve_undo = resolve_undo_read(data, sz);
break;
+ case CACHE_EXT_WATCH:
+ read_watch_extension(istate, data, sz);
+ break;
default:
if (*ext < 'A' || 'Z' < *ext)
return error("index uses %.4s extension, which we do
not understand",
@@ -1781,7 +1798,7 @@ int write_index(struct index_state *istate, int newfd)
{
git_SHA_CTX c;
struct cache_header hdr;
- int i, err, removed, extended, hdr_version;
+ int i, err, removed, extended, hdr_version, has_watches = 0;
struct cache_entry **cache = istate->cache;
int entries = istate->cache_nr;
struct stat st;
@@ -1790,6 +1807,8 @@ int write_index(struct index_state *istate, int newfd)
for (i = removed = extended = 0; i < entries; i++) {
if (cache[i]->ce_flags & CE_REMOVE)
removed++;
+ else if (cache[i]->ce_flags & CE_WATCHED)
+ has_watches++;
/* reduce extended entries if possible */
cache[i]->ce_flags &= ~CE_EXTENDED;
@@ -1861,6 +1880,26 @@ int write_index(struct index_state *istate, int newfd)
if (err)
return -1;
}
+ if (has_watches) {
+ int id, sz = (entries - removed + 7) / 8;
+ uint8_t *data = xmalloc(sz);
+ memset(data, 0, sz);
+ for (i = 0, id = 0; i < entries && has_watches; i++) {
+ struct cache_entry *ce = cache[i];
+ if (ce->ce_flags & CE_REMOVE)
+ continue;
+ if (ce->ce_flags & CE_WATCHED) {
+ data[id / 8] |= 1 << (id % 8);
+ has_watches--;
+ }
+ id++;
+ }
+ err = write_index_ext_header(&c, newfd, CACHE_EXT_WATCH, sz) < 0
+ || ce_write(&c, newfd, data, sz) < 0;
+ free(data);
+ if (err)
+ return -1;
+ }
if (ce_flush(&c, newfd) || fstat(newfd, &st))
return -1;
--
1.8.5.1.208.g05b12ea
--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
