move "Expires" header code to a separate function

src/http/modules/ngx_http_headers_filter_module.c

@@ -43,6 +43,8 @@ typedef struct {
 #define NGX_HTTP_EXPIRES_MAX     -2147483644
 
 
+static ngx_int_t ngx_http_set_expires(ngx_http_request_t *r,
+    ngx_http_headers_conf_t *conf);
 static ngx_int_t ngx_http_add_cache_control(ngx_http_request_t *r,
     ngx_http_header_val_t *hv, ngx_str_t *value);
 static ngx_int_t ngx_http_set_last_modified(ngx_http_request_t *r,
@@ -129,14 +131,15 @@ static ngx_http_output_header_filter_pt  ngx_http_next_header_filter;
 static ngx_int_t
 ngx_http_headers_filter(ngx_http_request_t *r)
 {
-    size_t                    len;
     ngx_str_t                 value;
     ngx_uint_t                i;
-    ngx_table_elt_t          *expires, *cc, **ccp;
     ngx_http_header_val_t    *h;
     ngx_http_headers_conf_t  *conf;
 
-    if (r != r->main
+    conf = ngx_http_get_module_loc_conf(r, ngx_http_headers_filter_module);
+
+    if ((conf->expires == NGX_HTTP_EXPIRES_OFF && conf->headers == NULL)
+        || r != r->main
         || (r->headers_out.status != NGX_HTTP_OK
             && r->headers_out.status != NGX_HTTP_NO_CONTENT
             && r->headers_out.status != NGX_HTTP_MOVED_PERMANENTLY
@@ -146,9 +149,44 @@ ngx_http_headers_filter(ngx_http_request_t *r)
         return ngx_http_next_header_filter(r);
     }
 
-    conf = ngx_http_get_module_loc_conf(r, ngx_http_headers_filter_module);
-
     if (conf->expires != NGX_HTTP_EXPIRES_OFF) {
+        if (ngx_http_set_expires(r, conf) != NGX_OK) {
+            return NGX_ERROR;
+        }
+    }
+
+    if (conf->headers) {
+        h = conf->headers->elts;
+        for (i = 0; i < conf->headers->nelts; i++) {
+
+            if (h[i].lengths == NULL) {
+                value = h[i].value.value;
+
+            } else {
+                if (ngx_http_script_run(r, &value, h[i].lengths->elts, 0,
+                                        h[i].values->elts)
+                    == NULL)
+                {
+                    return NGX_ERROR;
+                }
+            }
+
+            if (h[i].handler(r, &h[i], &value) != NGX_OK) {
+                return NGX_ERROR;
+            }
+        }
+    }
+
+    return ngx_http_next_header_filter(r);
+}
+
+
+static ngx_int_t
+ngx_http_set_expires(ngx_http_request_t *r, ngx_http_headers_conf_t *conf)
+{
+    size_t            len;
+    ngx_uint_t        i;
+    ngx_table_elt_t  *expires, *cc, **ccp;
 
     expires = r->headers_out.expires;
 
@@ -210,14 +248,19 @@ ngx_http_headers_filter(ngx_http_request_t *r)
         cc->value.len = sizeof("no-cache") - 1;
         cc->value.data = (u_char *) "no-cache";
 
-        } else if (conf->expires == NGX_HTTP_EXPIRES_MAX) {
+        return NGX_OK;
+    }
+
+    if (conf->expires == NGX_HTTP_EXPIRES_MAX) {
         expires->value.data = (u_char *) "Thu, 31 Dec 2037 23:55:55 GMT";
 
         /* 10 years */
         cc->value.len = sizeof("max-age=315360000") - 1;
         cc->value.data = (u_char *) "max-age=315360000";
 
-        } else {
+        return NGX_OK;
+    }
+
     expires->value.data = ngx_palloc(r->pool, len);
     if (expires->value.data == NULL) {
         return NGX_ERROR;
@@ -230,51 +273,28 @@ ngx_http_headers_filter(ngx_http_request_t *r)
         cc->value.len = sizeof("max-age=0") - 1;
         cc->value.data = (u_char *) "max-age=0";
 
-            } else {
+        return NGX_OK;
+    }
+
     ngx_http_time(expires->value.data, ngx_time() + conf->expires);
 
     if (conf->expires < 0) {
         cc->value.len = sizeof("no-cache") - 1;
         cc->value.data = (u_char *) "no-cache";
 
-                } else {
+        return NGX_OK;
-                    cc->value.data = ngx_palloc(r->pool, sizeof("max-age=")
+    }
-                                                         + NGX_TIME_T_LEN + 1);
+
+    cc->value.data = ngx_palloc(r->pool,
+                                sizeof("max-age=") + NGX_TIME_T_LEN + 1);
     if (cc->value.data == NULL) {
         return NGX_ERROR;
     }
 
-                    cc->value.len = ngx_sprintf(cc->value.data, "max-age=%T",
+    cc->value.len = ngx_sprintf(cc->value.data, "max-age=%T", conf->expires)
-                                                conf->expires)
                     - cc->value.data;
-                }
-            }
-        }
-    }
 
-    if (conf->headers) {
+    return NGX_OK;
-        h = conf->headers->elts;
-        for (i = 0; i < conf->headers->nelts; i++) {
-
-            if (h[i].lengths == NULL) {
-                value = h[i].value.value;
-
-            } else {
-                if (ngx_http_script_run(r, &value, h[i].lengths->elts, 0,
-                                        h[i].values->elts)
-                    == NULL)
-                {
-                    return NGX_ERROR;
-                }
-            }
-
-            if (h[i].handler(r, &h[i], &value) != NGX_OK) {
-                return NGX_ERROR;
-            }
-        }
-    }
-
-    return ngx_http_next_header_filter(r);
 }
 
 
@@ -382,8 +402,6 @@ ngx_http_headers_create_conf(ngx_conf_t *cf)
     /*
      * set by ngx_pcalloc():
      *
-     *     conf->cache_control.len = 0;
-     *     conf->cache_control.data = NULL;
      *     conf->headers = NULL;
      */