Use helper function for copying index entry information

[git.git] / cache.h

diff --git a/cache.h b/cache.h
index e1000bccb2470ad66038aabbf57b0af96e506f11..fa5a9e523eda0f075a4e36fcf3b4c0760e54f583 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -110,7 +110,6 @@ struct ondisk_cache_entry {
 };
 
 struct cache_entry {
-       struct cache_entry *next;
        unsigned int ce_ctime;
        unsigned int ce_mtime;
        unsigned int ce_dev;
@@ -121,6 +120,7 @@ struct cache_entry {
        unsigned int ce_size;
        unsigned int ce_flags;
        unsigned char sha1[20];
+       struct cache_entry *next;
        char name[FLEX_ARRAY]; /* more */
 };
 
@@ -133,7 +133,39 @@ struct cache_entry {
 #define CE_UPDATE    (0x10000)
 #define CE_REMOVE    (0x20000)
 #define CE_UPTODATE  (0x40000)
-#define CE_UNHASHED  (0x80000)
+
+#define CE_HASHED    (0x100000)
+#define CE_UNHASHED  (0x200000)
+
+/*
+ * Copy the sha1 and stat state of a cache entry from one to
+ * another. But we never change the name, or the hash state!
+ */
+#define CE_STATE_MASK (CE_HASHED | CE_UNHASHED)
+static inline void copy_cache_entry(struct cache_entry *dst, struct cache_entry *src)
+{
+       unsigned int state = dst->ce_flags & CE_STATE_MASK;
+
+       /* Don't copy hash chain and name */
+       memcpy(dst, src, offsetof(struct cache_entry, next));
+
+       /* Restore the hash state */
+       dst->ce_flags = (dst->ce_flags & ~CE_STATE_MASK) | state;
+}
+
+/*
+ * We don't actually *remove* it, we can just mark it invalid so that
+ * we won't find it in lookups.
+ *
+ * Not only would we have to search the lists (simple enough), but
+ * we'd also have to rehash other hash buckets in case this makes the
+ * hash bucket empty (common). So it's much better to just mark
+ * it.
+ */
+static inline void remove_index_entry(struct cache_entry *ce)
+{
+       ce->ce_flags |= CE_UNHASHED;
+}
 
 static inline unsigned create_ce_flags(size_t len, unsigned stage)
 {