[PATCH 02/16] Introduce CE_NO_CHECKOUT bit

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

This bit is the basis of narrow checkout. If this bit is on, the entry
is outside narrow checkout and therefore should be ignored (similar
to CE_VALID)

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 cache.h      |   10 +++++++++-
 read-cache.c |    6 +++---
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/cache.h b/cache.h
index 1e572e4..2b2c90f 100644
--- a/cache.h
+++ b/cache.h
@@ -170,10 +170,11 @@ struct cache_entry {
 /*
  * Extended on-disk flags
  */
+#define CE_NO_CHECKOUT 0x40000000
 /* CE_EXTENDED2 is for future extension */
 #define CE_EXTENDED2 0x80000000
 
-#define CE_EXTENDED_FLAGS (0)
+#define CE_EXTENDED_FLAGS (CE_NO_CHECKOUT)
 
 /*
  * Safeguard to avoid saving wrong flags:
@@ -185,6 +186,9 @@ struct cache_entry {
 #error "CE_EXTENDED_FLAGS out of range"
 #endif
 
+/* "Assume unchanged" mask */
+#define CE_VALID_MASK (CE_VALID | CE_NO_CHECKOUT)
+
 /*
  * Copy the sha1 and stat state of a cache entry from one to
  * another. But we never change the name, or the hash state!
@@ -222,6 +226,10 @@ static inline size_t ce_namelen(const struct cache_entry *ce)
 			    ondisk_cache_entry_size(ce_namelen(ce)))
 #define ce_stage(ce) ((CE_STAGEMASK & (ce)->ce_flags) >> CE_STAGESHIFT)
 #define ce_uptodate(ce) ((ce)->ce_flags & CE_UPTODATE)
+#define ce_no_checkout(ce) ((ce)->ce_flags & CE_NO_CHECKOUT)
+#define ce_checkout(ce) (!ce_no_checkout(ce))
+#define ce_mark_no_checkout(ce) ((ce)->ce_flags |= CE_NO_CHECKOUT)
+#define ce_mark_checkout(ce) ((ce)->ce_flags &= ~CE_NO_CHECKOUT)
 #define ce_mark_uptodate(ce) ((ce)->ce_flags |= CE_UPTODATE)
 
 #define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
diff --git a/read-cache.c b/read-cache.c
index 667c36b..e965a4c 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -254,7 +254,7 @@ int ie_match_stat(const 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 & CE_VALID))
+	if (!ignore_valid && (ce->ce_flags & CE_VALID_MASK))
 		return 0;
 
 	changed = ce_match_stat_basic(ce, st);
@@ -962,10 +962,10 @@ static struct cache_entry *refresh_cache_ent(struct index_state *istate,
 		return ce;
 
 	/*
-	 * CE_VALID means the user promised us that the change to
+	 * CE_VALID_MASK means the user promised us that the change to
 	 * the work tree does not matter and told us not to worry.
 	 */
-	if (!ignore_valid && (ce->ce_flags & CE_VALID)) {
+	if (!ignore_valid && (ce->ce_flags & CE_VALID_MASK)) {
 		ce_mark_uptodate(ce);
 		return ce;
 	}
-- 
1.6.0.96.g2fad1.dirty