[PATCH 15/22] replace cache_name_pos

From

CLChuck Lever <cel@netapp.com>

Date

Sep 12, 2005, 14:56 UTC

Message-ID

<20050912145616.28120.30912.stgit@dexter.citi.umich.edu>

In-Reply-To

<20050912145543.28120.7086.stgit@dexter.citi.umich.edu>

Signed-off-by: Chuck Lever <cel@netapp.com>
---

 cache.h      |   13 +++++++++++++
 read-cache.c |   44 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+), 0 deletions(-)

diff --git a/cache.h b/cache.h
--- a/cache.h
+++ b/cache.h
@@ -160,6 +160,8 @@ extern int read_cache(void);
 extern int read_cache_unmerged(void);
 extern int write_cache(int newfd);
 extern int cache_name_pos(const char *name, int namelen);
+extern int cache_find_name(const char *name, int namelen, struct cache_cursor *cc);
+
 #define ADD_CACHE_OK_TO_ADD 1		/* Ok to add */
 #define ADD_CACHE_OK_TO_REPLACE 2	/* Ok to replace file/directory */
 #define ADD_CACHE_SKIP_DFCHECK 4	/* Ok to skip DF conflict checks */
@@ -350,6 +352,17 @@ static inline int walk_cache(cache_itera
 	return 0;
 }
 
+static inline int cache_find_entry(const char *name, int namelen, struct cache_entry **ce)
+{
+	struct cache_cursor cc;
+	int result;
+
+	result = cache_find_name(name, namelen, &cc);
+	if (ce)
+		*ce = active_cache[cc.pos];
+	return result;
+}
+
 struct checkout {
 	const char *base_dir;
 	int base_dir_len;
diff --git a/read-cache.c b/read-cache.c
--- a/read-cache.c
+++ b/read-cache.c
@@ -144,6 +144,50 @@ int cache_name_pos(const char *name, int
 	return -first-1;
 }
 
+/*
+ * Given a name, find the first cache entry that matches.  Returning 1
+ * means the cursor points to the cache entry with a matching name.
+ * Returning 0 means the name wasn't found, but the cursor points to an
+ * appropriate insertion point.
+ */
+int cache_find_name(const char *name, int namelen, struct cache_cursor *cc)
+{
+	int first, last;
+
+	/*
+	 * Look for the right name
+	 */
+	cc->pos = first = 0;
+	last = active_nr;
+	while (last > first) {
+		struct cache_entry *ce;
+		int cmp;
+		cc->pos = (last + first) >> 1;
+		ce = active_cache[cc->pos];
+		cmp = cache_name_compare(name, namelen, ce->name, ntohs(ce->ce_flags));
+		if (!cmp) {
+			/* found it */
+			return 1;
+		}
+		if (cmp < 0) {
+			/* next: search [first, cc->pos] */
+			last = cc->pos;
+			continue;
+		}
+		/* next: search [cc->pos + 1, last] */
+		first = cc->pos + 1;
+	}
+
+	/*
+	 * Name not found, so return an insertion point.
+	 *
+	 * On return, callers insert *before* the insertion point,
+	 * not after it, to maintain proper list order.
+	 */
+	cc->pos = first;
+	return 0;
+}
+
 /* Remove entry, return true if there are more entries to go.. */
 int remove_cache_entry_at(int pos)
 {