Changes with nginx 0.8.46 19 Jul 2010v0.8.46

    *) Change: now the "proxy_no_cache", "fastcgi_no_cache",
       "uwsgi_no_cache", and "sсgi_no_cache" directives affect on a cached
       response saving only.

    *) Feature: the "proxy_cache_bypass", "fastcgi_cache_bypass",
       "uwsgi_cache_bypass", and "sсgi_cache_bypass" directives.

    *) Bugfix: nginx did not free memory in cache keys zones if there was
       an error during working with backend: the memory was freed only
       after inactivity time or on memory low condition.

14 files changed, 336 insertions, 61 deletions

diff --git a/CHANGES b/CHANGES
index c07989efa..915a23052 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,4 +1,18 @@
 
+Changes with nginx 0.8.46                                        19 Jul 2010
+
+    *) Change: now the "proxy_no_cache", "fastcgi_no_cache", 
+       "uwsgi_no_cache", and "sсgi_no_cache" directives affect on a cached 
+       response saving only.
+
+    *) Feature: the "proxy_cache_bypass", "fastcgi_cache_bypass", 
+       "uwsgi_cache_bypass", and "sсgi_cache_bypass" directives.
+
+    *) Bugfix: nginx did not free memory in cache keys zones if there was 
+       an error during working with backend: the memory was freed only 
+       after inactivity time or on memory low condition.
+
+
 Changes with nginx 0.8.45                                        13 Jul 2010
 
     *) Feature: ngx_http_xslt_filter improvements.
diff --git a/CHANGES.ru b/CHANGES.ru
index 22c9efad9..66c54a3af 100644
--- a/CHANGES.ru
+++ b/CHANGES.ru
@@ -1,4 +1,18 @@
 
+Изменения в nginx 0.8.46                                          19.07.2010
+
+    *) Изменение: директивы proxy_no_cache, fastcgi_no_cache, 
+       uwsgi_no_cache и sсgi_no_cache теперь влияют только на сохранение 
+       закэшированного ответа.
+
+    *) Добавление: директивы proxy_cache_bypass, fastcgi_cache_bypass, 
+       uwsgi_cache_bypass и sсgi_cache_bypass.
+
+    *) Исправление: nginx не освобождал память в keys_zone кэшей в случае 
+       ошибки работы с бэкендом: память освобождалась только по истечении 
+       времени неактивности или при недостатке памяти.
+
+
 Изменения в nginx 0.8.45                                          13.07.2010
 
     *) Добавление: улучшения в модуле ngx_http_xslt_filter.
diff --git a/src/core/nginx.h b/src/core/nginx.h
index e9247e94b..64f7b18a5 100644
--- a/src/core/nginx.h
+++ b/src/core/nginx.h
@@ -8,8 +8,8 @@
 #define _NGINX_H_INCLUDED_
 
 
-#define nginx_version         8045
-#define NGINX_VERSION      "0.8.45"
+#define nginx_version         8046
+#define NGINX_VERSION      "0.8.46"
 #define NGINX_VER          "nginx/" NGINX_VERSION
 
 #define NGINX_VAR          "NGINX"
diff --git a/src/http/modules/ngx_http_fastcgi_module.c b/src/http/modules/ngx_http_fastcgi_module.c
index 16d2bf8a0..4731f784f 100644
--- a/src/http/modules/ngx_http_fastcgi_module.c
+++ b/src/http/modules/ngx_http_fastcgi_module.c
@@ -330,9 +330,16 @@ static ngx_command_t  ngx_http_fastcgi_commands[] = {
       0,
       &ngx_http_fastcgi_module },
 
+    { ngx_string("fastcgi_cache_bypass"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE,
+      ngx_http_set_predicate_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_fastcgi_loc_conf_t, upstream.cache_bypass),
+      NULL },
+
     { ngx_string("fastcgi_no_cache"),
       NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE,
-      ngx_http_no_cache_set_slot,
+      ngx_http_set_predicate_slot,
       NGX_HTTP_LOC_CONF_OFFSET,
       offsetof(ngx_http_fastcgi_loc_conf_t, upstream.no_cache),
       NULL },
@@ -1985,6 +1992,7 @@ ngx_http_fastcgi_create_loc_conf(ngx_conf_t *cf)
 #if (NGX_HTTP_CACHE)
     conf->upstream.cache = NGX_CONF_UNSET_PTR;
     conf->upstream.cache_min_uses = NGX_CONF_UNSET_UINT;
+    conf->upstream.cache_bypass = NGX_CONF_UNSET_PTR;
     conf->upstream.no_cache = NGX_CONF_UNSET_PTR;
     conf->upstream.cache_valid = NGX_CONF_UNSET_PTR;
 #endif
@@ -2208,9 +2216,18 @@ ngx_http_fastcgi_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child)
 
     conf->upstream.cache_methods |= NGX_HTTP_GET|NGX_HTTP_HEAD;
 
+    ngx_conf_merge_ptr_value(conf->upstream.cache_bypass,
+                             prev->upstream.cache_bypass, NULL);
+
     ngx_conf_merge_ptr_value(conf->upstream.no_cache,
                              prev->upstream.no_cache, NULL);
 
+    if (conf->upstream.no_cache && conf->upstream.cache_bypass == NULL) {
+        ngx_log_error(NGX_LOG_WARN, cf->log, 0,
+             "\"fastcgi_no_cache\" functionality has been changed in 0.8.46, "
+             "now it should be used together with \"fastcgi_cache_bypass\"");
+    }
+
     ngx_conf_merge_ptr_value(conf->upstream.cache_valid,
                              prev->upstream.cache_valid, NULL);
 
diff --git a/src/http/modules/ngx_http_proxy_module.c b/src/http/modules/ngx_http_proxy_module.c
index fcae88e12..b067d60c6 100644
--- a/src/http/modules/ngx_http_proxy_module.c
+++ b/src/http/modules/ngx_http_proxy_module.c
@@ -339,9 +339,16 @@ static ngx_command_t  ngx_http_proxy_commands[] = {
       0,
       &ngx_http_proxy_module },
 
+    { ngx_string("proxy_cache_bypass"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE,
+      ngx_http_set_predicate_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_proxy_loc_conf_t, upstream.cache_bypass),
+      NULL },
+
     { ngx_string("proxy_no_cache"),
       NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE,
-      ngx_http_no_cache_set_slot,
+      ngx_http_set_predicate_slot,
       NGX_HTTP_LOC_CONF_OFFSET,
       offsetof(ngx_http_proxy_loc_conf_t, upstream.no_cache),
       NULL },
@@ -1678,6 +1685,7 @@ ngx_http_proxy_create_loc_conf(ngx_conf_t *cf)
 #if (NGX_HTTP_CACHE)
     conf->upstream.cache = NGX_CONF_UNSET_PTR;
     conf->upstream.cache_min_uses = NGX_CONF_UNSET_UINT;
+    conf->upstream.cache_bypass = NGX_CONF_UNSET_PTR;
     conf->upstream.no_cache = NGX_CONF_UNSET_PTR;
     conf->upstream.cache_valid = NGX_CONF_UNSET_PTR;
 #endif
@@ -1902,9 +1910,18 @@ ngx_http_proxy_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child)
                                          |NGX_HTTP_UPSTREAM_FT_OFF;
     }
 
+    ngx_conf_merge_ptr_value(conf->upstream.cache_bypass,
+                             prev->upstream.cache_bypass, NULL);
+
     ngx_conf_merge_ptr_value(conf->upstream.no_cache,
                              prev->upstream.no_cache, NULL);
 
+    if (conf->upstream.no_cache && conf->upstream.cache_bypass == NULL) {
+        ngx_log_error(NGX_LOG_WARN, cf->log, 0,
+             "\"proxy_no_cache\" functionality has been changed in 0.8.46, "
+             "now it should be used together with \"proxy_cache_bypass\"");
+    }
+
     ngx_conf_merge_ptr_value(conf->upstream.cache_valid,
                              prev->upstream.cache_valid, NULL);
 
diff --git a/src/http/modules/ngx_http_scgi_module.c b/src/http/modules/ngx_http_scgi_module.c
index c6d848e4b..9f89650b8 100644
--- a/src/http/modules/ngx_http_scgi_module.c
+++ b/src/http/modules/ngx_http_scgi_module.c
@@ -196,9 +196,16 @@ static ngx_command_t ngx_http_scgi_commands[] = {
       0,
       &ngx_http_scgi_module },
 
+    { ngx_string("scgi_cache_bypass"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE,
+      ngx_http_set_predicate_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_scgi_loc_conf_t, upstream.cache_bypass),
+      NULL },
+
     { ngx_string("scgi_no_cache"),
       NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE,
-      ngx_http_no_cache_set_slot,
+      ngx_http_set_predicate_slot,
       NGX_HTTP_LOC_CONF_OFFSET,
       offsetof(ngx_http_scgi_loc_conf_t, upstream.no_cache),
       NULL },
@@ -1015,6 +1022,8 @@ ngx_http_scgi_create_loc_conf(ngx_conf_t *cf)
 #if (NGX_HTTP_CACHE)
     conf->upstream.cache = NGX_CONF_UNSET_PTR;
     conf->upstream.cache_min_uses = NGX_CONF_UNSET_UINT;
+    conf->upstream.cache_bypass = NGX_CONF_UNSET_PTR;
+    conf->upstream.no_cache = NGX_CONF_UNSET_PTR;
     conf->upstream.cache_valid = NGX_CONF_UNSET_PTR;
 #endif
 
@@ -1233,6 +1242,9 @@ ngx_http_scgi_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child)
 
     conf->upstream.cache_methods |= NGX_HTTP_GET|NGX_HTTP_HEAD;
 
+    ngx_conf_merge_ptr_value(conf->upstream.cache_bypass,
+                             prev->upstream.cache_bypass, NULL);
+
     ngx_conf_merge_ptr_value(conf->upstream.no_cache,
                              prev->upstream.no_cache, NULL);
 
diff --git a/src/http/modules/ngx_http_uwsgi_module.c b/src/http/modules/ngx_http_uwsgi_module.c
index 466d34be0..f27a3dc76 100644
--- a/src/http/modules/ngx_http_uwsgi_module.c
+++ b/src/http/modules/ngx_http_uwsgi_module.c
@@ -223,9 +223,16 @@ static ngx_command_t ngx_http_uwsgi_commands[] = {
       0,
       &ngx_http_uwsgi_module },
 
+    { ngx_string("uwsgi_cache_bypass"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE,
+      ngx_http_set_predicate_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_uwsgi_loc_conf_t, upstream.cache_bypass),
+      NULL },
+
     { ngx_string("uwsgi_no_cache"),
       NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE,
-      ngx_http_no_cache_set_slot,
+      ngx_http_set_predicate_slot,
       NGX_HTTP_LOC_CONF_OFFSET,
       offsetof(ngx_http_uwsgi_loc_conf_t, upstream.no_cache),
       NULL },
@@ -1068,6 +1075,8 @@ ngx_http_uwsgi_create_loc_conf(ngx_conf_t *cf)
 #if (NGX_HTTP_CACHE)
     conf->upstream.cache = NGX_CONF_UNSET_PTR;
     conf->upstream.cache_min_uses = NGX_CONF_UNSET_UINT;
+    conf->upstream.cache_bypass = NGX_CONF_UNSET_PTR;
+    conf->upstream.no_cache = NGX_CONF_UNSET_PTR;
     conf->upstream.cache_valid = NGX_CONF_UNSET_PTR;
 #endif
 
@@ -1286,6 +1295,9 @@ ngx_http_uwsgi_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child)
 
     conf->upstream.cache_methods |= NGX_HTTP_GET|NGX_HTTP_HEAD;
 
+    ngx_conf_merge_ptr_value(conf->upstream.cache_bypass,
+                             prev->upstream.cache_bypass, NULL);
+
     ngx_conf_merge_ptr_value(conf->upstream.no_cache,
                              prev->upstream.no_cache, NULL);
 
diff --git a/src/http/modules/perl/nginx.pm b/src/http/modules/perl/nginx.pm
index f8527658f..c720a23e8 100644
--- a/src/http/modules/perl/nginx.pm
+++ b/src/http/modules/perl/nginx.pm
@@ -48,7 +48,7 @@ our @EXPORT = qw(
     HTTP_INSUFFICIENT_STORAGE
 );
 
-our $VERSION = '0.8.45';
+our $VERSION = '0.8.46';
 
 require XSLoader;
 XSLoader::load('nginx', $VERSION);
diff --git a/src/http/ngx_http_cache.h b/src/http/ngx_http_cache.h
index 8f0032921..36b14b26e 100644
--- a/src/http/ngx_http_cache.h
+++ b/src/http/ngx_http_cache.h
@@ -14,11 +14,12 @@
 
 
 #define NGX_HTTP_CACHE_MISS          1
-#define NGX_HTTP_CACHE_EXPIRED       2
-#define NGX_HTTP_CACHE_STALE         3
-#define NGX_HTTP_CACHE_UPDATING      4
-#define NGX_HTTP_CACHE_HIT           5
-#define NGX_HTTP_CACHE_SCARCE        6
+#define NGX_HTTP_CACHE_BYPASS        2
+#define NGX_HTTP_CACHE_EXPIRED       3
+#define NGX_HTTP_CACHE_STALE         4
+#define NGX_HTTP_CACHE_UPDATING      5
+#define NGX_HTTP_CACHE_HIT           6
+#define NGX_HTTP_CACHE_SCARCE        7
 
 #define NGX_HTTP_CACHE_KEY_LEN       16
 
@@ -121,6 +122,8 @@ struct ngx_http_file_cache_s {
 };
 
 
+ngx_int_t ngx_http_file_cache_new(ngx_http_request_t *r);
+ngx_int_t ngx_http_file_cache_create(ngx_http_request_t *r);
 void ngx_http_file_cache_create_key(ngx_http_request_t *r);
 ngx_int_t ngx_http_file_cache_open(ngx_http_request_t *r);
 void ngx_http_file_cache_set_header(ngx_http_request_t *r, u_char *buf);
@@ -134,10 +137,6 @@ char *ngx_http_file_cache_set_slot(ngx_conf_t *cf, ngx_command_t *cmd,
 char *ngx_http_file_cache_valid_set_slot(ngx_conf_t *cf, ngx_command_t *cmd,
     void *conf);
 
-ngx_int_t ngx_http_cache(ngx_http_request_t *r, ngx_array_t *no_cache);
-char *ngx_http_no_cache_set_slot(ngx_conf_t *cf, ngx_command_t *cmd,
-    void *conf);
-
 
 extern ngx_str_t  ngx_http_cache_status[];
 
diff --git a/src/http/ngx_http_file_cache.c b/src/http/ngx_http_file_cache.c
index 277475179..2fefe095b 100644
--- a/src/http/ngx_http_file_cache.c
+++ b/src/http/ngx_http_file_cache.c
@@ -19,6 +19,8 @@ static void ngx_http_cache_aio_event_handler(ngx_event_t *ev);
 #endif
 static ngx_int_t ngx_http_file_cache_exists(ngx_http_file_cache_t *cache,
     ngx_http_cache_t *c);
+static ngx_int_t ngx_http_file_cache_name(ngx_http_request_t *r,
+    ngx_path_t *path);
 static ngx_http_file_cache_node_t *
     ngx_http_file_cache_lookup(ngx_http_file_cache_t *cache, u_char *key);
 static void ngx_http_file_cache_rbtree_insert_value(ngx_rbtree_node_t *temp,
@@ -44,6 +46,7 @@ static ngx_int_t ngx_http_file_cache_delete_file(ngx_tree_ctx_t *ctx,
 
 ngx_str_t  ngx_http_cache_status[] = {
     ngx_string("MISS"),
+    ngx_string("BYPASS"),
     ngx_string("EXPIRED"),
     ngx_string("STALE"),
     ngx_string("UPDATING"),
@@ -142,6 +145,59 @@ ngx_http_file_cache_init(ngx_shm_zone_t *shm_zone, void *data)
 }
 
 
+ngx_int_t
+ngx_http_file_cache_new(ngx_http_request_t *r)
+{
+    ngx_http_cache_t  *c;
+
+    c = ngx_pcalloc(r->pool, sizeof(ngx_http_cache_t));
+    if (c == NULL) {
+        return NGX_ERROR;
+    }
+
+    if (ngx_array_init(&c->keys, r->pool, 4, sizeof(ngx_str_t)) != NGX_OK) {
+        return NGX_ERROR;
+    }
+
+    r->cache = c;
+    c->file.log = r->connection->log;
+
+    return NGX_OK;
+}
+
+
+ngx_int_t
+ngx_http_file_cache_create(ngx_http_request_t *r)
+{
+    ngx_http_cache_t       *c;
+    ngx_pool_cleanup_t     *cln;
+    ngx_http_file_cache_t  *cache;
+
+    ngx_http_file_cache_create_key(r);
+
+    c = r->cache;
+    cache = c->file_cache;
+
+    cln = ngx_pool_cleanup_add(r->pool, 0);
+    if (cln == NULL) {
+        return NGX_ERROR;
+    }
+
+    if (ngx_http_file_cache_exists(cache, c) == NGX_ERROR) {
+        return NGX_ERROR;
+    }
+
+    cln->handler = ngx_http_file_cache_cleanup;
+    cln->data = c;
+
+    if (ngx_http_file_cache_name(r, cache->path) != NGX_OK) {
+        return NGX_ERROR;
+    }
+
+    return NGX_OK;
+}
+
+
 void
 ngx_http_file_cache_create_key(ngx_http_request_t *r)
 {
@@ -180,10 +236,8 @@ ngx_http_file_cache_create_key(ngx_http_request_t *r)
 ngx_int_t
 ngx_http_file_cache_open(ngx_http_request_t *r)
 {
-    u_char                    *p;
     ngx_int_t                  rc, rv;
     ngx_uint_t                 cold, test;
-    ngx_path_t                *path;
     ngx_http_cache_t          *c;
     ngx_pool_cleanup_t        *cln;
     ngx_open_file_info_t       of;
@@ -249,27 +303,10 @@ ngx_http_file_cache_open(ngx_http_request_t *r)
         }
     }
 
-    path = cache->path;
-
-    c->file.name.len = path->name.len + 1 + path->len
-                       + 2 * NGX_HTTP_CACHE_KEY_LEN;
-
-    c->file.name.data = ngx_pnalloc(r->pool, c->file.name.len + 1);
-    if (c->file.name.data == NULL) {
+    if (ngx_http_file_cache_name(r, cache->path) != NGX_OK) {
         return NGX_ERROR;
     }
 
-    ngx_memcpy(c->file.name.data, path->name.data, path->name.len);
-
-    p = c->file.name.data + path->name.len + 1 + path->len;
-    p = ngx_hex_dump(p, c->key, NGX_HTTP_CACHE_KEY_LEN);
-    *p = '\0';
-
-    ngx_create_hashed_filename(path, c->file.name.data, c->file.name.len);
-
-    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, ngx_cycle->log, 0,
-                   "cache file: \"%s\"", c->file.name.data);
-
     if (!test) {
         return NGX_DECLINED;
     }
@@ -574,6 +611,37 @@ failed:
 }
 
 
+static ngx_int_t
+ngx_http_file_cache_name(ngx_http_request_t *r, ngx_path_t *path)
+{
+    u_char            *p;
+    ngx_http_cache_t  *c;
+
+    c = r->cache;
+
+    c->file.name.len = path->name.len + 1 + path->len
+                       + 2 * NGX_HTTP_CACHE_KEY_LEN;
+
+    c->file.name.data = ngx_pnalloc(r->pool, c->file.name.len + 1);
+    if (c->file.name.data == NULL) {
+        return NGX_ERROR;
+    }
+
+    ngx_memcpy(c->file.name.data, path->name.data, path->name.len);
+
+    p = c->file.name.data + path->name.len + 1 + path->len;
+    p = ngx_hex_dump(p, c->key, NGX_HTTP_CACHE_KEY_LEN);
+    *p = '\0';
+
+    ngx_create_hashed_filename(path, c->file.name.data, c->file.name.len);
+
+    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                   "cache file: \"%s\"", c->file.name.data);
+
+    return NGX_OK;
+}
+
+
 static ngx_http_file_cache_node_t *
 ngx_http_file_cache_lookup(ngx_http_file_cache_t *cache, u_char *key)
 {
@@ -835,8 +903,9 @@ ngx_http_cache_send(ngx_http_request_t *r)
 void
 ngx_http_file_cache_free(ngx_http_request_t *r, ngx_temp_file_t *tf)
 {
-    ngx_http_cache_t       *c;
-    ngx_http_file_cache_t  *cache;
+    ngx_http_cache_t            *c;
+    ngx_http_file_cache_t       *cache;
+    ngx_http_file_cache_node_t  *fcn;
 
     c = r->cache;
 
@@ -853,15 +922,21 @@ ngx_http_file_cache_free(ngx_http_request_t *r, ngx_temp_file_t *tf)
 
     ngx_shmtx_lock(&cache->shpool->mutex);
 
-    c->node->count--;
+    fcn = c->node;
+    fcn->count--;
+    fcn->updating = 0;
 
     if (c->error) {
-        c->node->valid_sec = c->valid_sec;
-        c->node->valid_msec = c->valid_msec;
-        c->node->error = c->error;
-    }
+        fcn->valid_sec = c->valid_sec;
+        fcn->valid_msec = c->valid_msec;
+        fcn->error = c->error;
 
-    c->node->updating = 0;
+    } else if (fcn->valid_msec == 0 && fcn->count == 0) {
+        ngx_queue_remove(&fcn->queue);
+        ngx_rbtree_delete(&cache->sh->rbtree, &fcn->node);
+        ngx_slab_free_locked(cache->shpool, fcn);
+        c->node = NULL;
+    }
 
     ngx_shmtx_unlock(&cache->shpool->mutex);
 
@@ -1104,9 +1179,7 @@ ngx_http_file_cache_delete(ngx_http_file_cache_t *cache, ngx_queue_t *q,
     *p = '\0';
 
     ngx_queue_remove(q);
-
     ngx_rbtree_delete(&cache->sh->rbtree, &fcn->node);
-
     ngx_slab_free_locked(cache->shpool, fcn);
 
     ngx_shmtx_unlock(&cache->shpool->mutex);
diff --git a/src/http/ngx_http_script.c b/src/http/ngx_http_script.c
index 1f4288969..1474f3245 100644
--- a/src/http/ngx_http_script.c
+++ b/src/http/ngx_http_script.c
@@ -211,6 +211,76 @@ ngx_http_compile_complex_value(ngx_http_compile_complex_value_t *ccv)
 }
 
 
+ngx_int_t
+ngx_http_test_predicates(ngx_http_request_t *r, ngx_array_t *predicates)
+{
+    ngx_str_t                  val;
+    ngx_uint_t                 i;
+    ngx_http_complex_value_t  *cv;
+
+    if (predicates == NULL) {
+        return NGX_OK;
+    }
+
+    cv = predicates->elts;
+
+    for (i = 0; i < predicates->nelts; i++) {
+        if (ngx_http_complex_value(r, &cv[i], &val) != NGX_OK) {
+            return NGX_ERROR;
+        }
+
+        if (val.len && val.data[0] != '0') {
+            return NGX_DECLINED;
+        }
+    }
+
+    return NGX_OK;
+}
+
+
+char *
+ngx_http_set_predicate_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
+{
+    char  *p = conf;
+
+    ngx_str_t                          *value;
+    ngx_uint_t                          i;
+    ngx_array_t                       **a;
+    ngx_http_complex_value_t           *cv;
+    ngx_http_compile_complex_value_t    ccv;
+
+    a = (ngx_array_t **) (p + cmd->offset);
+
+    if (*a == NGX_CONF_UNSET_PTR) {
+        *a = ngx_array_create(cf->pool, 1, sizeof(ngx_http_complex_value_t));
+        if (*a == NULL) {
+            return NGX_CONF_ERROR;
+        }
+    }
+
+    value = cf->args->elts;
+
+    for (i = 1; i < cf->args->nelts; i++) {
+        cv = ngx_array_push(*a);
+        if (cv == NULL) {
+            return NGX_CONF_ERROR;
+        }
+
+        ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t));
+
+        ccv.cf = cf;
+        ccv.value = &value[i];
+        ccv.complex_value = cv;
+
+        if (ngx_http_compile_complex_value(&ccv) != NGX_OK) {
+            return NGX_CONF_ERROR;
+        }
+    }
+
+    return NGX_CONF_OK;
+}
+
+
 ngx_uint_t
 ngx_http_script_variables_count(ngx_str_t *value)
 {
diff --git a/src/http/ngx_http_script.h b/src/http/ngx_http_script.h
index f7943d37c..d741ceabb 100644
--- a/src/http/ngx_http_script.h
+++ b/src/http/ngx_http_script.h
@@ -208,6 +208,11 @@ ngx_int_t ngx_http_complex_value(ngx_http_request_t *r,
     ngx_http_complex_value_t *val, ngx_str_t *value);
 ngx_int_t ngx_http_compile_complex_value(ngx_http_compile_complex_value_t *ccv);
 
+ngx_int_t ngx_http_test_predicates(ngx_http_request_t *r,
+    ngx_array_t *predicates);
+char *ngx_http_set_predicate_slot(ngx_conf_t *cf, ngx_command_t *cmd,
+    void *conf);
+
 ngx_uint_t ngx_http_script_variables_count(ngx_str_t *value);
 ngx_int_t ngx_http_script_compile(ngx_http_script_compile_t *sc);
 u_char *ngx_http_script_run(ngx_http_request_t *r, ngx_str_t *value,
diff --git a/src/http/ngx_http_upstream.c b/src/http/ngx_http_upstream.c
index 44b8b947c..8ee5aeabd 100644
--- a/src/http/ngx_http_upstream.c
+++ b/src/http/ngx_http_upstream.c
@@ -633,11 +633,17 @@ ngx_http_upstream_cache(ngx_http_request_t *r, ngx_http_upstream_t *u)
 
     if (c == NULL) {
 
-        if (u->conf->no_cache) {
-            rc = ngx_http_cache(r, u->conf->no_cache);
-            if (rc != NGX_OK) {
-                return rc;
-            }
+        switch (ngx_http_test_predicates(r, u->conf->cache_bypass)) {
+
+        case NGX_ERROR:
+            return NGX_ERROR;
+
+        case NGX_DECLINED:
+            u->cache_status = NGX_HTTP_CACHE_BYPASS;
+            return NGX_DECLINED;
+
+        default: /* NGX_OK */
+            break;
         }
 
         if (!(r->method & u->conf->cache_methods)) {
@@ -648,18 +654,10 @@ ngx_http_upstream_cache(ngx_http_request_t *r, ngx_http_upstream_t *u)
             u->method = ngx_http_core_get_method;
         }
 
-        c = ngx_pcalloc(r->pool, sizeof(ngx_http_cache_t));
-        if (c == NULL) {
-            return NGX_ERROR;
-        }
-
-        if (ngx_array_init(&c->keys, r->pool, 4, sizeof(ngx_str_t)) != NGX_OK) {
+        if (ngx_http_file_cache_new(r) != NGX_OK) {
             return NGX_ERROR;
         }
 
-        r->cache = c;
-        c->file.log = r->connection->log;
-
         if (u->create_key(r) != NGX_OK) {
             return NGX_ERROR;
         }
@@ -670,6 +668,8 @@ ngx_http_upstream_cache(ngx_http_request_t *r, ngx_http_upstream_t *u)
 
         u->cacheable = 1;
 
+        c = r->cache;
+
         c->min_uses = u->conf->cache_min_uses;
         c->body_start = u->conf->buffer_size;
         c->file_cache = u->conf->cache->data;
@@ -2098,6 +2098,47 @@ ngx_http_upstream_send_response(ngx_http_request_t *r, ngx_http_upstream_t *u)
         r->cache->file.fd = NGX_INVALID_FILE;
     }
 
+    switch (ngx_http_test_predicates(r, u->conf->no_cache)) {
+
+    case NGX_ERROR:
+        ngx_http_upstream_finalize_request(r, u, 0);
+        return;
+
+    case NGX_DECLINED:
+        u->cacheable = 0;
+        break;
+
+    default: /* NGX_OK */
+
+        if (u->cache_status == NGX_HTTP_CACHE_BYPASS) {
+
+            if (ngx_http_file_cache_new(r) != NGX_OK) {
+                ngx_http_upstream_finalize_request(r, u, 0);
+                return;
+            }
+
+            if (u->create_key(r) != NGX_OK) {
+                ngx_http_upstream_finalize_request(r, u, 0);
+                return;
+            }
+
+            /* TODO: add keys */
+
+            r->cache->min_uses = u->conf->cache_min_uses;
+            r->cache->body_start = u->conf->buffer_size;
+            r->cache->file_cache = u->conf->cache->data;
+
+            if (ngx_http_file_cache_create(r) != NGX_OK) {
+                ngx_http_upstream_finalize_request(r, u, 0);
+                return;
+            }
+
+            u->cacheable = 1;
+        }
+
+        break;
+    }
+
     if (u->cacheable) {
         time_t  now, valid;
 
diff --git a/src/http/ngx_http_upstream.h b/src/http/ngx_http_upstream.h
index bcdfc5fdd..ef460a488 100644
--- a/src/http/ngx_http_upstream.h
+++ b/src/http/ngx_http_upstream.h
@@ -163,7 +163,8 @@ typedef struct {
     ngx_uint_t                       cache_methods;
 
     ngx_array_t                     *cache_valid;
-    ngx_array_t                     *no_cache; /* ngx_http_complex_value_t */
+    ngx_array_t                     *cache_bypass;
+    ngx_array_t                     *no_cache;
 #endif
 
     ngx_array_t                     *store_lengths;