implemented builtin nginx variable $srcache_expire for automatic expiration time calculation; also added new directives srcache_max_expire and srcache_default_expire.

agentzh · agentzh · commit 62606a0e40c6 · 2011-10-02T22:31:11.000-07:00
diff --git a/src/ngx_http_srcache_filter_module.c b/src/ngx_http_srcache_filter_module.c
@@ -185,6 +185,22 @@ static ngx_command_t  ngx_http_srcache_commands[] = {
       offsetof(ngx_http_srcache_loc_conf_t, header_buf_size),
       NULL },
 
+    { ngx_string("srcache_max_expire"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF
+          |NGX_HTTP_LIF_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_sec_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_srcache_loc_conf_t, max_expire),
+      NULL },
+
+    { ngx_string("srcache_default_expire"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF
+          |NGX_HTTP_LIF_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_sec_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_srcache_loc_conf_t, default_expire),
+      NULL },
+
       ngx_null_command
 };
 
@@ -664,6 +680,9 @@ ngx_http_srcache_create_loc_conf(ngx_conf_t *cf)
     conf->store_no_store = NGX_CONF_UNSET;
     conf->store_no_cache = NGX_CONF_UNSET;
 
+    conf->max_expire = NGX_CONF_UNSET;
+    conf->default_expire = NGX_CONF_UNSET;
+
     conf->ignore_content_encoding = NGX_CONF_UNSET;
 
     conf->hide_headers = NGX_CONF_UNSET_PTR;
@@ -712,6 +731,9 @@ ngx_http_srcache_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child)
     ngx_conf_merge_value(conf->store_no_store, prev->store_no_store, 0);
     ngx_conf_merge_value(conf->store_no_cache, prev->store_no_cache, 0);
 
+    ngx_conf_merge_value(conf->max_expire, prev->max_expire, 0);
+    ngx_conf_merge_value(conf->default_expire, prev->default_expire, 60);
+
     ngx_conf_merge_value(conf->ignore_content_encoding,
             prev->ignore_content_encoding, 0);
 
diff --git a/src/ngx_http_srcache_filter_module.h b/src/ngx_http_srcache_filter_module.h
@@ -54,6 +54,8 @@ typedef struct {
     ngx_array_t                     *pass_headers;
 
     unsigned                         hide_content_type;
+    time_t                           max_expire;
+    time_t                           default_expire;
 
     unsigned              postponed_to_access_phase_end;
 } ngx_http_srcache_loc_conf_t;
diff --git a/src/ngx_http_srcache_util.c b/src/ngx_http_srcache_util.c
@@ -945,7 +945,8 @@ ngx_http_srcache_store_response_header(ngx_http_request_t *r,
         dd("header key: %.*s", (int) header[i].key.len, header[i].key.data);
 
         dd("header hash: %lu, hash lc: %lu", (unsigned long) header[i].hash,
-                (unsigned long) ngx_hash_key_lc(header[i].key.data, header[i].key.len));
+                (unsigned long) ngx_hash_key_lc(header[i].key.data,
+                header[i].key.len));
 
         if (ngx_hash_find(&conf->hide_headers_hash, header[i].hash,
                           header[i].lowcase_key, header[i].key.len))
diff --git a/src/ngx_http_srcache_var.c b/src/ngx_http_srcache_var.c
@@ -15,7 +15,7 @@ static ngx_http_variable_t ngx_http_srcache_variables[] = {
 
     { ngx_string("srcache_expire"), NULL,
       ngx_http_srcache_expire_variable, 0,
-      0, 0 },
+      NGX_HTTP_VAR_NOCACHEABLE, 0 },
 
     { ngx_null_string, NULL, NULL, 0, 0, 0 }
 };
@@ -25,27 +25,42 @@ static ngx_int_t
 ngx_http_srcache_expire_variable(ngx_http_request_t *r,
     ngx_http_variable_value_t *v, uintptr_t data)
 {
-    ngx_http_srcache_ctx_t      *ctx;
-    u_char                      *p;
+    ngx_http_srcache_ctx_t       *ctx;
+    u_char                       *p;
+    time_t                        expire;
+    ngx_http_srcache_loc_conf_t  *conf;
+
+    conf = ngx_http_get_module_loc_conf(r, ngx_http_srcache_filter_module);
 
     v->valid = 1;
-    v->no_cacheable = 0;
+    v->no_cacheable = 1;
     v->not_found = 0;
 
     ctx = ngx_http_get_module_ctx(r, ngx_http_srcache_filter_module);
 
-    if (ctx->valid_sec == 0) {
+    if (!ctx || !ctx->store_response) {
         v->not_found = 1;
         return NGX_OK;
     }
 
+    if (ctx->valid_sec == 0) {
+        expire = conf->default_expire;
+
+    } else {
+        expire = ctx->valid_sec - ngx_time();
+    }
+
+    if (conf->max_expire > 0 && expire > conf->max_expire) {
+        expire = conf->max_expire;
+    }
+
     p = ngx_palloc(r->pool, NGX_TIME_T_LEN);
     if (p == NULL) {
         return NGX_ERROR;
     }
 
     v->data = p;
-    p =  ngx_sprintf(p, "%T", ctx->valid_sec - ngx_time());
+    p =  ngx_sprintf(p, "%T", expire);
     v->len = p - v->data;
 
     return NGX_OK;
diff --git a/t/expire-var.t b/t/expire-var.t
