set expires headers to avoid cache

include/ngx_http_push_stream_module.h

@@ -349,4 +349,19 @@ static const ngx_str_t  NGX_HTTP_PUSH_STREAM_ALLOWED_HEADERS = ngx_string("If-Mo
 
 #define NGX_HTTP_PUSH_STREAM_TIME_FMT_LEN   30 //sizeof("Mon, 28 Sep 1970 06:00:00 GMT")
 
+
+/**
+ * borrowed from Nginx core files
+ */
+typedef enum {
+    NGX_HTTP_PUSH_STREAM_EXPIRES_OFF,
+    NGX_HTTP_PUSH_STREAM_EXPIRES_EPOCH,
+    NGX_HTTP_PUSH_STREAM_EXPIRES_MAX,
+    NGX_HTTP_PUSH_STREAM_EXPIRES_ACCESS,
+    NGX_HTTP_PUSH_STREAM_EXPIRES_MODIFIED,
+    NGX_HTTP_PUSH_STREAM_EXPIRES_DAILY,
+    NGX_HTTP_PUSH_STREAM_EXPIRES_UNSET
+} ngx_http_push_stream_expires_t;
+
+
 #endif /* NGX_HTTP_PUSH_STREAM_MODULE_H_ */

include/ngx_http_push_stream_module_utils.h

@@ -292,4 +292,7 @@ static ngx_str_t *          ngx_http_push_stream_get_formatted_hostname(ngx_pool
 uint64_t                    ngx_http_push_stream_htonll(uint64_t value);
 uint64_t                    ngx_http_push_stream_ntohll(uint64_t value);
 
+static ngx_int_t            ngx_http_push_stream_set_expires(ngx_http_request_t *r, ngx_http_push_stream_expires_t expires, time_t expires_time);
+
+
 #endif /* NGX_HTTP_PUSH_STREAM_MODULE_UTILS_H_ */

misc/spec/mix/channel_statistics_spec.rb

@@ -633,4 +633,19 @@ describe "Channel Statistics" do
       end
     end
   end
+
+  it "should not cache the response" do
+    channel = 'ch_test_not_cache_the_response'
+
+    nginx_run_server(config) do |conf|
+      EventMachine.run do
+        pub_1 = EventMachine::HttpRequest.new(nginx_address + '/channels-stats?id=' + channel.to_s).get :head => headers
+        pub_1.callback do
+          pub_1.response_header["EXPIRES"].should eql("Thu, 01 Jan 1970 00:00:01 GMT")
+          pub_1.response_header["CACHE_CONTROL"].should eql("no-cache, no-store, must-revalidate")
+          EventMachine.stop
+        end
+      end
+    end
+  end
 end

misc/spec/publisher/properties_spec.rb

@@ -388,6 +388,21 @@ describe "Publisher Properties" do
         end
       end
     end
+
+    it "should not cache the response" do
+      channel = 'ch_test_not_cache_the_response'
+
+      nginx_run_server(config) do |conf|
+        EventMachine.run do
+          pub_1 = EventMachine::HttpRequest.new(nginx_address + '/pub?id=' + channel.to_s).get :head => headers
+          pub_1.callback do
+            pub_1.response_header["EXPIRES"].should eql("Thu, 01 Jan 1970 00:00:01 GMT")
+            pub_1.response_header["CACHE_CONTROL"].should eql("no-cache, no-store, must-revalidate")
+            EventMachine.stop
+          end
+        end
+      end
+    end
   end
 
   context "when is on normal mode" do

misc/spec/subscriber/long_polling_spec.rb

@@ -407,6 +407,21 @@ describe "Subscriber Properties" do
         end
       end
     end
+
+    it "should not cache the response" do
+      channel = 'ch_test_not_cache_the_response'
+
+      nginx_run_server(config.merge(:longpolling_connection_ttl => '1s')) do |conf|
+        EventMachine.run do
+          sub_1 = EventMachine::HttpRequest.new(nginx_address + '/sub/' + channel.to_s).get :head => headers
+          sub_1.callback do
+            sub_1.response_header["EXPIRES"].should eql("Thu, 01 Jan 1970 00:00:01 GMT")
+            sub_1.response_header["CACHE_CONTROL"].should eql("no-cache, no-store, must-revalidate")
+            EventMachine.stop
+          end
+        end
+      end
+    end
   end
 
   context "when using subscriber push mode config" do

misc/spec/subscriber/polling_spec.rb

@@ -340,6 +340,21 @@ describe "Subscriber Properties" do
       end
 
     end
+
+    it "should not cache the response" do
+      channel = 'ch_test_not_cache_the_response'
+
+      nginx_run_server(config) do |conf|
+        EventMachine.run do
+          sub_1 = EventMachine::HttpRequest.new(nginx_address + '/sub/' + channel.to_s).get :head => headers
+          sub_1.callback do
+            sub_1.response_header["EXPIRES"].should eql("Thu, 01 Jan 1970 00:00:01 GMT")
+            sub_1.response_header["CACHE_CONTROL"].should eql("no-cache, no-store, must-revalidate")
+            EventMachine.stop
+          end
+        end
+      end
+    end
   end
 
   context "when using subscriber push mode config" do

misc/spec/subscriber/properties_spec.rb

@@ -907,4 +907,19 @@ describe "Subscriber Properties" do
       end
     end
   end
+
+  it "should not cache the response" do
+    channel = 'ch_test_not_cache_the_response'
+
+    nginx_run_server(config.merge(:subscriber_connection_ttl => '1s')) do |conf|
+      EventMachine.run do
+        sub_1 = EventMachine::HttpRequest.new(nginx_address + '/sub/' + channel.to_s).get :head => headers
+        sub_1.callback do
+          sub_1.response_header["EXPIRES"].should eql("Thu, 01 Jan 1970 00:00:01 GMT")
+          sub_1.response_header["CACHE_CONTROL"].should eql("no-cache, no-store, must-revalidate")
+          EventMachine.stop
+        end
+      end
+    end
+  end
 end

misc/spec/subscriber/websocket_spec.rb

@@ -394,4 +394,19 @@ describe "Subscriber WebSocket" do
       end
     end
   end
+
+  it "should not cache the response" do
+    channel = 'ch_test_not_cache_the_response'
+
+    request = "GET /ws/#{channel}.b1 HTTP/1.0\r\nConnection: Upgrade\r\nSec-WebSocket-Key: /mQoZf6pRiv8+6o72GncLQ==\r\nUpgrade: websocket\r\nSec-WebSocket-Version: 8\r\n"
+
+    nginx_run_server(config) do |conf|
+      socket = open_socket(nginx_host, nginx_port)
+      socket.print("#{request}\r\n")
+      headers, body = read_response_on_socket(socket)
+
+      headers.should include("Expires: Thu, 01 Jan 1970 00:00:01 GMT\r\n")
+      headers.should include("Cache-Control: no-cache, no-store, must-revalidate\r\n")
+    end
+  end
 end

src/ngx_http_push_stream_module_publisher.c

@@ -36,6 +36,7 @@ ngx_http_push_stream_publisher_handler(ngx_http_request_t *r)
     ngx_http_push_stream_loc_conf_t    *cf = ngx_http_get_module_loc_conf(r, ngx_http_push_stream_module);
 
     r->keepalive = cf->keepalive;
+    ngx_http_push_stream_set_expires(r, NGX_HTTP_PUSH_STREAM_EXPIRES_EPOCH, 0);
 
     if (cf->allowed_origins.len > 0) {
         ngx_http_push_stream_add_response_header(r, &NGX_HTTP_PUSH_STREAM_HEADER_ACCESS_CONTROL_ALLOW_ORIGIN, &cf->allowed_origins);
@@ -216,6 +217,7 @@ ngx_http_push_stream_channels_statistics_handler(ngx_http_request_t *r)
     ngx_http_push_stream_loc_conf_t    *cf = ngx_http_get_module_loc_conf(r, ngx_http_push_stream_module);
 
     r->keepalive = cf->keepalive;
+    ngx_http_push_stream_set_expires(r, NGX_HTTP_PUSH_STREAM_EXPIRES_EPOCH, 0);
 
     // only accept GET method
     if (!(r->method & NGX_HTTP_GET)) {

src/ngx_http_push_stream_module_subscriber.c

@@ -63,6 +63,8 @@ ngx_http_push_stream_subscriber_handler(ngx_http_request_t *r)
         return ngx_http_push_stream_send_only_header_response(r, NGX_HTTP_OK, NULL);
     }
 
+    ngx_http_push_stream_set_expires(r, NGX_HTTP_PUSH_STREAM_EXPIRES_EPOCH, 0);
+
     // only accept GET method
     if (!(r->method & NGX_HTTP_GET)) {
         ngx_http_push_stream_add_response_header(r, &NGX_HTTP_PUSH_STREAM_HEADER_ALLOW, &NGX_HTTP_PUSH_STREAM_ALLOW_GET);

src/ngx_http_push_stream_module_utils.c

@@ -1704,3 +1704,119 @@ ngx_http_push_stream_unescape_uri(ngx_str_t *value)
         }
     }
 }
+
+
+/**
+ * borrowed from Nginx core files
+ */
+static ngx_int_t
+ngx_http_push_stream_set_expires(ngx_http_request_t *r, ngx_http_push_stream_expires_t expires, time_t expires_time)
+{
+    size_t            len;
+    time_t            now, expires_header_time, max_age;
+    ngx_uint_t        i;
+    ngx_table_elt_t  *expires_header, *cc, **ccp;
+
+    expires_header = r->headers_out.expires;
+
+    if (expires_header == NULL) {
+
+        expires_header = ngx_list_push(&r->headers_out.headers);
+        if (expires_header == NULL) {
+            return NGX_ERROR;
+        }
+
+        r->headers_out.expires = expires_header;
+
+        expires_header->hash = 1;
+        ngx_str_set(&expires_header->key, "Expires");
+    }
+
+    len = sizeof("Mon, 28 Sep 1970 06:00:00 GMT");
+    expires_header->value.len = len - 1;
+
+    ccp = r->headers_out.cache_control.elts;
+
+    if (ccp == NULL) {
+
+        if (ngx_array_init(&r->headers_out.cache_control, r->pool, 1, sizeof(ngx_table_elt_t *)) != NGX_OK) {
+            return NGX_ERROR;
+        }
+
+        ccp = ngx_array_push(&r->headers_out.cache_control);
+        if (ccp == NULL) {
+            return NGX_ERROR;
+        }
+
+        cc = ngx_list_push(&r->headers_out.headers);
+        if (cc == NULL) {
+            return NGX_ERROR;
+        }
+
+        cc->hash = 1;
+        ngx_str_set(&cc->key, "Cache-Control");
+        *ccp = cc;
+
+    } else {
+        for (i = 1; i < r->headers_out.cache_control.nelts; i++) {
+            ccp[i]->hash = 0;
+        }
+
+        cc = ccp[0];
+    }
+
+    if (expires == NGX_HTTP_PUSH_STREAM_EXPIRES_EPOCH) {
+        expires_header->value.data = (u_char *) "Thu, 01 Jan 1970 00:00:01 GMT";
+        ngx_str_set(&cc->value, "no-cache, no-store, must-revalidate");
+        return NGX_OK;
+    }
+
+    if (expires == NGX_HTTP_PUSH_STREAM_EXPIRES_MAX) {
+        expires_header->value.data = (u_char *) "Thu, 31 Dec 2037 23:55:55 GMT";
+        /* 10 years */
+        ngx_str_set(&cc->value, "max-age=315360000");
+        return NGX_OK;
+    }
+
+    expires_header->value.data = ngx_pnalloc(r->pool, len);
+    if (expires_header->value.data == NULL) {
+        return NGX_ERROR;
+    }
+
+    if (expires_time == 0 && expires != NGX_HTTP_PUSH_STREAM_EXPIRES_DAILY) {
+        ngx_memcpy(expires_header->value.data, ngx_cached_http_time.data, ngx_cached_http_time.len + 1);
+        ngx_str_set(&cc->value, "max-age=0");
+        return NGX_OK;
+    }
+
+    now = ngx_time();
+
+    if (expires == NGX_HTTP_PUSH_STREAM_EXPIRES_DAILY) {
+        expires_header_time = ngx_next_time(expires_time);
+        max_age = expires_header_time - now;
+
+    } else if (expires == NGX_HTTP_PUSH_STREAM_EXPIRES_ACCESS || r->headers_out.last_modified_time == -1) {
+        expires_header_time = now + expires_time;
+        max_age = expires_time;
+
+    } else {
+        expires_header_time = r->headers_out.last_modified_time + expires_time;
+        max_age = expires_header_time - now;
+    }
+
+    ngx_http_time(expires_header->value.data, expires_header_time);
+
+    if (expires_time < 0 || max_age < 0) {
+        ngx_str_set(&cc->value, "no-cache, no-store, must-revalidate");
+        return NGX_OK;
+    }
+
+    cc->value.data = ngx_pnalloc(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", max_age) - cc->value.data;
+
+    return NGX_OK;
+}

src/ngx_http_push_stream_module_websocket.c

@@ -52,6 +52,8 @@ ngx_http_push_stream_websocket_handler(ngx_http_request_t *r)
         return ngx_http_push_stream_send_only_header_response(r, NGX_HTTP_NOT_ALLOWED, NULL);
     }
 
+    ngx_http_push_stream_set_expires(r, NGX_HTTP_PUSH_STREAM_EXPIRES_EPOCH, 0);
+
     upgrade_header = ngx_http_push_stream_get_header(r, &NGX_HTTP_PUSH_STREAM_HEADER_UPGRADE);
     connection_header = ngx_http_push_stream_get_header(r, &NGX_HTTP_PUSH_STREAM_HEADER_CONNECTION);
     sec_key_header = ngx_http_push_stream_get_header(r, &NGX_HTTP_PUSH_STREAM_HEADER_SEC_WEBSOCKET_KEY);