feature: added new nginx variable $srcache_fetch_status which takes one of three values, "BYASS", "MISS", and "HIT". thanks Feibo Li for the patch.

agentzh · agentzh · commit ccf190d4a1a7 · 2012-06-26T18:06:58.000+08:00
diff --git a/README.markdown b/README.markdown
@@ -1,3 +1,8 @@
+<!---
+Don't edit this file manually! Instead you should generate it by using:
+    wiki2markdown.pl doc/HttpSRCacheModule.wiki
+-->
+
 Name
 ====
 
diff --git a/src/ngx_http_srcache_fetch.c b/src/ngx_http_srcache_fetch.c
@@ -374,6 +374,7 @@ ngx_http_srcache_fetch_subrequest(ngx_http_request_t *r,
     ngx_http_set_ctx(sr, sr_ctx, ngx_http_srcache_filter_module);
 
     ctx->fetch_sr = sr;
+    ctx->issued_fetch_subrequest = 1;
 
     return NGX_OK;
 }
diff --git a/src/ngx_http_srcache_filter_module.c b/src/ngx_http_srcache_filter_module.c
@@ -517,11 +517,12 @@ ngx_http_srcache_post_config(ngx_conf_t *cf)
     ngx_http_handler_pt             *h;
     ngx_http_core_main_conf_t       *cmcf;
 
+    rc = ngx_http_srcache_add_variables(cf);
+    if (rc != NGX_OK) {
+        return rc;
+    }
+
     if (ngx_http_srcache_used) {
-        rc = ngx_http_srcache_add_variables(cf);
-        if (rc != NGX_OK) {
-            return rc;
-        }
 
         dd("using ngx-srcache");
 
diff --git a/src/ngx_http_srcache_filter_module.h b/src/ngx_http_srcache_filter_module.h
@@ -7,6 +7,13 @@
 #include <nginx.h>
 
 
+enum {
+    NGX_HTTP_SRCACHE_FETCH_BYPASS = 0,
+    NGX_HTTP_SRCACHE_FETCH_MISS   = 1,
+    NGX_HTTP_SRCACHE_FETCH_HIT    = 2
+};
+
+
 extern ngx_module_t  ngx_http_srcache_filter_module;
 
 
@@ -107,6 +114,7 @@ struct ngx_http_srcache_ctx_s {
     unsigned        parsing_cached_headers:1;
     unsigned        store_response:1;
     unsigned        store_skip:1;
+    unsigned        issued_fetch_subrequest:1;
 };
 
 
diff --git a/src/ngx_http_srcache_var.c b/src/ngx_http_srcache_var.c
@@ -9,6 +9,15 @@
 
 static ngx_int_t ngx_http_srcache_expire_variable(ngx_http_request_t *r,
     ngx_http_variable_value_t *v, uintptr_t data);
+static ngx_int_t ngx_http_srcache_fetch_status_variable(ngx_http_request_t *r,
+    ngx_http_variable_value_t *v, uintptr_t data);
+
+
+static ngx_str_t  ngx_http_srcache_fetch_status[] = {
+    ngx_string("BYPASS"),
+    ngx_string("MISS"),
+    ngx_string("HIT")
+};
 
 
 static ngx_http_variable_t ngx_http_srcache_variables[] = {
@@ -17,6 +26,10 @@ static ngx_http_variable_t ngx_http_srcache_variables[] = {
       ngx_http_srcache_expire_variable, 0,
       NGX_HTTP_VAR_NOCACHEABLE, 0 },
 
+    { ngx_string("srcache_fetch_status"), NULL,
+      ngx_http_srcache_fetch_status_variable, 0,
+      NGX_HTTP_VAR_NOCACHEABLE, 0 },
+
     { ngx_null_string, NULL, NULL, 0, 0, 0 }
 };
 
@@ -67,6 +80,39 @@ ngx_http_srcache_expire_variable(ngx_http_request_t *r,
 }
 
 
+static ngx_int_t
+ngx_http_srcache_fetch_status_variable(ngx_http_request_t *r,
+    ngx_http_variable_value_t *v, uintptr_t data)
+{
+    ngx_uint_t                    status;
+    ngx_http_srcache_ctx_t       *ctx;
+
+    ctx = ngx_http_get_module_ctx(r, ngx_http_srcache_filter_module);
+
+    if (ctx == NULL) {
+        status = NGX_HTTP_SRCACHE_FETCH_BYPASS;
+
+    } else if (ctx->from_cache) {
+        status = NGX_HTTP_SRCACHE_FETCH_HIT;
+
+    } else if (ctx->issued_fetch_subrequest) {
+        status = NGX_HTTP_SRCACHE_FETCH_MISS;
+
+    } else {
+        status = NGX_HTTP_SRCACHE_FETCH_BYPASS;
+    }
+
+    v->valid = 1;
+    v->no_cacheable = 1;
+    v->not_found = 0;
+
+    v->len = ngx_http_srcache_fetch_status[status].len;
+    v->data = ngx_http_srcache_fetch_status[status].data;
+
+    return NGX_OK;
+}
+
+
 ngx_int_t
 ngx_http_srcache_add_variables(ngx_conf_t *cf)
 {
diff --git a/t/fetch-header.t b/t/fetch-header.t
@@ -5,7 +5,7 @@ use Test::Nginx::Socket;
 
 #repeat_each(2);
 
-plan tests => repeat_each() * (4 * blocks() + 1);
+plan tests => repeat_each() * (5 * blocks() + 1);
 
 $ENV{TEST_NGINX_MEMCACHED_PORT} ||= 11211;
 
@@ -21,10 +21,12 @@ __DATA__
     location /flush {
         set $memc_cmd 'flush_all';
         memc_pass 127.0.0.1:$TEST_NGINX_MEMCACHED_PORT;
+        add_header X-Fetch-Status $srcache_fetch_status;
     }
 --- response_headers
 Content-Type: text/plain
 Content-Length: 4
+X-Fetch-Status: BYPASS
 --- request
 GET /flush
 --- response_body eval: "OK\r\n"
@@ -40,6 +42,7 @@ GET /flush
 --- response_headers
 Content-Type: text/plain
 Content-Length: 8
+!X-Fetch-Status
 --- request eval
 "PUT /memc
 HTTP/1.1 200 OK\r
@@ -61,6 +64,7 @@ hello
         srcache_store PUT /memc $uri;
 
         echo world;
+        add_header X-Fetch-Status $srcache_fetch_status;
     }
 
     location /memc {
@@ -76,6 +80,7 @@ GET /foo
 Content-Type: foo/bar
 Content-Length: 5
 Foo: Bar
+X-Fetch-Status: HIT
 --- response_body chop
 hello
 
@@ -90,6 +95,7 @@ hello
 --- response_headers
 Content-Type: text/plain
 Content-Length: 8
+!X-Fetch-Status
 --- request eval
 "PUT /memc
 HTTP 200 OK\r
@@ -111,6 +117,7 @@ hello
         srcache_store PUT /memc $uri;
 
         echo world;
+        add_header X-Fetch-Status $srcache_fetch_status;
     }
 
     location /memc {
@@ -125,6 +132,7 @@ GET /foo
 --- response_headers
 Content-Type: text/css
 Content-Length: 
+X-Fetch-Status: MISS
 --- response_body
 world
 
@@ -139,6 +147,7 @@ world
 --- response_headers
 Content-Type: text/plain
 Content-Length: 8
+!X-Fetch-Status
 --- request eval
 "PUT /memc
 HTTP/1.1 200"
@@ -155,6 +164,7 @@ HTTP/1.1 200"
         srcache_store PUT /memc $uri;
 
         echo world;
+        add_header X-Fetch-Status $srcache_fetch_status;
     }
 
     location /memc {
@@ -169,6 +179,7 @@ GET /foo
 --- response_headers
 Content-Type: text/css
 Content-Length: 
+X-Fetch-Status: MISS
 --- response_body
 world
 
@@ -183,6 +194,7 @@ world
 --- response_headers
 Content-Type: text/plain
 Content-Length: 8
+!X-Fetch-Status
 --- request eval
 "PUT /memc
 HTTP/1.1 200 OK\r
@@ -198,6 +210,7 @@ Content-Ty"
         default_type text/css;
         srcache_fetch GET /memc $uri;
         srcache_store PUT /memc $uri;
+        add_header X-Fetch-Status $srcache_fetch_status;
 
         echo world;
     }
@@ -214,6 +227,7 @@ GET /foo
 --- response_headers
 Content-Type: text/css
 Content-Length: 
+X-Fetch-Status: MISS
 --- response_body
 world
 
diff --git a/t/fetch-skip.t b/t/fetch-skip.t
diff --git a/t/main-req.t b/t/main-req.t

-Original file line number
+Diff line change
@@ @@ -1,3 +1,8 @@ @@
 +<!---
 +Don't edit this file manually! Instead you should generate it by using:
 +    wiki2markdown.pl doc/HttpSRCacheModule.wiki
 +-->
++
 Name
 ====
Original file line number	Diff line number	Diff line change
`@@ -374,6 +374,7 @@ ngx_http_srcache_fetch_subrequest(ngx_http_request_t *r,`
`374`	`374`	`ngx_http_set_ctx(sr, sr_ctx, ngx_http_srcache_filter_module);`
`375`	`375`
`376`	`376`	`ctx->fetch_sr = sr;`
	`377`	`+ ctx->issued_fetch_subrequest = 1;`
`377`	`378`
`378`	`379`	`return NGX_OK;`
`379`	`380`	`}`