Re: [tarantool-patches] Re: [PATCH v1 1/1] xlog: fix out of static memory on metadata load

[Kirill Shcherbatov <kshcherbatov@tarantool.org>]

> Too much of code duplication. Please add a helper for key matching.
Hi! ok.

===========================================

 src/box/xlog.c | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/src/box/xlog.c b/src/box/xlog.c
index 5ed11fc..c870d9d 100644
--- a/src/box/xlog.c
+++ b/src/box/xlog.c
@@ -183,6 +183,13 @@ parse_vclock(const char *val, const char *val_end, struct vclock *vclock)
 	return 0;
 }
 
+static inline bool
+xlog_meta_key_cmp(const char *key, uint32_t key_len, const char *str,
+		  uint32_t str_len)
+{
+	return key_len != str_len || memcmp(key, str, key_len);
+}
+
 /**
  * Parse xlog meta from buffer, update buffer read
  * position in case of success
@@ -261,8 +268,11 @@ xlog_meta_parse(struct xlog_meta *meta, const char **data,
 		assert(val <= val_end);
 		pos = eol + 1;
 
-		if (memcmp(key, INSTANCE_UUID_KEY, key_end - key) == 0 ||
-		    memcmp(key, INSTANCE_UUID_KEY_V12, key_end - key) == 0) {
+		size_t len = key_end - key;
+		if (xlog_meta_key_cmp(key, len, INSTANCE_UUID_KEY,
+				      strlen(INSTANCE_UUID_KEY)) == 0 ||
+		    xlog_meta_key_cmp(key, len, INSTANCE_UUID_KEY_V12,
+					  strlen(INSTANCE_UUID_KEY_V12)) == 0) {
 			/*
 			 * Instance: <uuid>
 			 */
@@ -277,19 +287,22 @@ xlog_meta_parse(struct xlog_meta *meta, const char **data,
 				diag_set(XlogError, "can't parse instance UUID");
 				return -1;
 			}
-		} else if (memcmp(key, VCLOCK_KEY, key_end - key) == 0){
+		} else if (xlog_meta_key_cmp(key, len, VCLOCK_KEY,
+					     strlen(VCLOCK_KEY)) == 0) {
 			/*
 			 * VClock: <vclock>
 			 */
 			if (parse_vclock(val, val_end, &meta->vclock) != 0)
 				return -1;
-		} else if (memcmp(key, PREV_VCLOCK_KEY, key_end - key) == 0) {
+		} else if (xlog_meta_key_cmp(key, len, PREV_VCLOCK_KEY,
+					     strlen(PREV_VCLOCK_KEY)) == 0) {
 			/*
 			 * PrevVClock: <vclock>
 			 */
 			if (parse_vclock(val, val_end, &meta->prev_vclock) != 0)
 				return -1;
-		} else if (memcmp(key, VERSION_KEY, key_end - key) == 0) {
+		} else if (xlog_meta_key_cmp(key, len, VERSION_KEY,
+					     strlen(VERSION_KEY)) == 0) {
 			/* Ignore Version: for now */
 		} else {
 			/*
-- 
2.7.4