[core] inet_ntop_cache now 4-element cache

(round-robin replacement; fixes what was effectively a 1-element cache)

src/base.h

@@ -425,19 +425,6 @@ typedef struct {
 } connections;
 
 
-#ifdef HAVE_IPV6
-typedef struct {
-	int family;
-	union {
-		struct in6_addr ipv6;
-		struct in_addr  ipv4;
-	} addr;
-	char b2[INET6_ADDRSTRLEN + 1];
-	time_t ts;
-} inet_ntop_cache_type;
-#endif
-
-
 typedef struct {
 	buffer *uri;
 	time_t mtime;
@@ -564,9 +551,6 @@ typedef struct server {
 	buffer *cond_check_buf;
 
 	/* caches */
-#ifdef HAVE_IPV6
-	inet_ntop_cache_type inet_ntop_cache[INET_NTOP_CACHE_MAX];
-#endif
 	mtime_cache_type mtime_cache[FILE_CACHE_MAX];
 
 	array *split_vals;

src/inet_ntop_cache.c

@@ -87,15 +87,28 @@ int sock_addr_inet_ntop_append_buffer(buffer *b, const sock_addr *addr)
 
 const char * inet_ntop_cache_get_ip(server *srv, sock_addr *addr) {
 #ifdef HAVE_IPV6
-	size_t ndx = 0, i;
+	typedef struct {
+		int family;
+		union {
+			struct in6_addr ipv6;
+			struct in_addr  ipv4;
+		} addr;
+		char b2[INET6_ADDRSTRLEN + 1];
+	} inet_ntop_cache_type;
+	#define INET_NTOP_CACHE_MAX 4
+	static inet_ntop_cache_type inet_ntop_cache[INET_NTOP_CACHE_MAX];
+	static int ndx;
+
+	int i;
+	UNUSED(srv);
 	for (i = 0; i < INET_NTOP_CACHE_MAX; i++) {
-		if (srv->inet_ntop_cache[i].ts != 0 && srv->inet_ntop_cache[i].family == addr->plain.sa_family) {
-			if (srv->inet_ntop_cache[i].family == AF_INET6 &&
-			    0 == memcmp(srv->inet_ntop_cache[i].addr.ipv6.s6_addr, addr->ipv6.sin6_addr.s6_addr, 16)) {
+		if (inet_ntop_cache[i].family == addr->plain.sa_family) {
+			if (inet_ntop_cache[i].family == AF_INET6 &&
+			    0 == memcmp(inet_ntop_cache[i].addr.ipv6.s6_addr, addr->ipv6.sin6_addr.s6_addr, 16)) {
 				/* IPv6 found in cache */
 				break;
-			} else if (srv->inet_ntop_cache[i].family == AF_INET &&
-				   srv->inet_ntop_cache[i].addr.ipv4.s_addr == addr->ipv4.sin_addr.s_addr) {
+			} else if (inet_ntop_cache[i].family == AF_INET &&
+				   inet_ntop_cache[i].addr.ipv4.s_addr == addr->ipv4.sin_addr.s_addr) {
 				/* IPv4 found in cache */
 				break;
 
@@ -107,29 +120,26 @@ const char * inet_ntop_cache_get_ip(server *srv, sock_addr *addr) {
 		/* not found in cache */
 		const char *s;
 
-		/* TODO: ndx is never modified above;
-		 * inet_ntop_cache is effectively a 1-element cache */
-
 		i = ndx;
+		if (++ndx >= INET_NTOP_CACHE_MAX) ndx = 0;
 		s =
 		inet_ntop(addr->plain.sa_family,
 			  addr->plain.sa_family == AF_INET6 ?
 			  (const void *) &(addr->ipv6.sin6_addr) :
 			  (const void *) &(addr->ipv4.sin_addr),
-			  srv->inet_ntop_cache[i].b2, INET6_ADDRSTRLEN);
+			  inet_ntop_cache[i].b2, INET6_ADDRSTRLEN);
 		if (NULL == s) return "";
 
-		srv->inet_ntop_cache[i].ts = srv->cur_ts;
-		srv->inet_ntop_cache[i].family = addr->plain.sa_family;
+		inet_ntop_cache[i].family = addr->plain.sa_family;
 
-		if (srv->inet_ntop_cache[i].family == AF_INET) {
-			srv->inet_ntop_cache[i].addr.ipv4.s_addr = addr->ipv4.sin_addr.s_addr;
-		} else if (srv->inet_ntop_cache[i].family == AF_INET6) {
-			memcpy(srv->inet_ntop_cache[i].addr.ipv6.s6_addr, addr->ipv6.sin6_addr.s6_addr, 16);
+		if (inet_ntop_cache[i].family == AF_INET) {
+			inet_ntop_cache[i].addr.ipv4.s_addr = addr->ipv4.sin_addr.s_addr;
+		} else if (inet_ntop_cache[i].family == AF_INET6) {
+			memcpy(inet_ntop_cache[i].addr.ipv6.s6_addr, addr->ipv6.sin6_addr.s6_addr, 16);
 		}
 	}
 
-	return srv->inet_ntop_cache[i].b2;
+	return inet_ntop_cache[i].b2;
 #else
 	UNUSED(srv);
 	return inet_ntoa(addr->ipv4.sin_addr);

src/settings.h

@@ -12,7 +12,6 @@
 
 #define BV(x) (1 << x)
 
-#define INET_NTOP_CACHE_MAX 4
 #define FILE_CACHE_MAX      16
 
 /**