bugfix: HEAD and conditional GET requests would still fall back to content handler execution (leading to backend accesses) even in case of a cache hit. thanks Wang Lichao for reporting this issue.

Author: agentzh

src/ngx_http_srcache_fetch.c

@@ -154,10 +154,16 @@ ngx_http_srcache_access_handler(ngx_http_request_t *r)
 
                 dd("srcache fetch header returned %d", (int) rc);
 
-                if (rc == NGX_ERROR || rc > NGX_OK || r->header_only) {
+                if (rc == NGX_ERROR || rc > NGX_OK) {
                     return rc;
                 }
 
+#if 1
+                if (r->header_only) {
+                    return NGX_HTTP_OK;
+                }
+#endif
+
                 if (!r->filter_finalize) {
                     rc = ngx_http_srcache_next_body_filter(r,
                             ctx->body_from_cache);

t/conditional-get.t

@@ -76,7 +76,7 @@ hello
 
         default_type text/css;
 
-        echo world;
+        proxy_pass http://agentzh.org:12345/;
     }
 
     location /memc {
@@ -107,7 +107,7 @@ hello
 
         default_type text/css;
 
-        echo world;
+        proxy_pass http://agentzh.org:12345/;
     }
 
     location /memc {
@@ -125,6 +125,11 @@ If-Modified-Since: Thu, 10 May 2012 07:50:59 GMT
 !Content-Type
 !Content-Length
 Last-Modified: Thu, 10 May 2012 07:50:59 GMT
+--- stap2
+F(ngx_http_core_content_phase) {
+    printf("r content handler: %s\n", usymname($r->content_handler))
+}
+
 --- error_code: 304
 --- response_body
 --- no_error_log
@@ -140,7 +145,7 @@ Last-Modified: Thu, 10 May 2012 07:50:59 GMT
 
         default_type text/css;
 
-        echo world;
+        proxy_pass http://agentzh.org:12345/;
     }
 
     location /memc {
@@ -174,7 +179,7 @@ hello
 
         default_type text/css;
 
-        echo world;
+        proxy_pass http://agentzh.org:12345/;
     }
 
     location /memc {
@@ -208,7 +213,7 @@ Last-Modified: Thu, 10 May 2012 07:50:59 GMT
 
         default_type text/css;
 
-        echo world;
+        proxy_pass http://agentzh.org:12345/;
     }
 
     location /memc {
@@ -241,7 +246,7 @@ Content-Length: 182
 
         default_type text/css;
 
-        echo world;
+        proxy_pass http://agentzh.org:12345/;
     }
 
     location /memc {
@@ -274,7 +279,7 @@ hello
 
         default_type text/css;
 
-        echo world;
+        proxy_pass http://agentzh.org:12345/;
     }
 
     location /memc {

t/methods.t

@@ -65,7 +65,7 @@ hello
         srcache_fetch GET /memc $uri;
         srcache_store PUT /memc $uri;
 
-        echo world;
+        proxy_pass http://agentzh.org:12345/;
     }
 
     location /memc {
@@ -121,7 +121,7 @@ world
         srcache_store PUT /memc $uri;
         srcache_methods POST;
 
-        echo world;
+        proxy_pass http://agentzh.org:12345/;
     }
 
     location /memc {
@@ -150,7 +150,7 @@ hello
         srcache_store PUT /memc $uri;
         srcache_methods POST PUT;
 
-        echo world;
+        proxy_pass http://agentzh.org:12345/;
     }
 
     location /memc {
@@ -178,7 +178,7 @@ hello
         srcache_store PUT /memc $uri;
         srcache_methods POST;
 
-        echo world;
+        proxy_pass http://agentzh.org:12345/;
     }
 
     location /memc {
@@ -320,7 +320,7 @@ hello
         srcache_fetch GET /memc $uri;
         srcache_store PUT /memc $uri;
 
-        echo world;
+        proxy_pass http://agentzh.org:12345/;
     }
 
     location /memc {