move request latency meter to StatisticsFilter

Author: Vladimir Kotal

opengrok-indexer/src/main/java/org/opengrok/indexer/web/Prefix.java

@@ -73,7 +73,13 @@ public enum Prefix {
     /** Related source file or directory not found/unavailable/ignored. */
     NOT_FOUND("/enoent"),
     /** Misc error occurred. */
-    ERROR("/error");
+    ERROR("/error"),
+    /** RESTful API */
+    REST_API("/api"),
+    /** Monitoring */
+    METRICS("/metrics"),
+    /** CSS and images */
+    STATIC("/default");
 
     private final String prefix;
     Prefix(String prefix) {

opengrok-web/src/main/java/org/opengrok/web/StatisticsFilter.java

@@ -60,6 +60,12 @@ public void init(FilterConfig fc) throws ServletException {
     @Override
     public void doFilter(ServletRequest sr, ServletResponse sr1, FilterChain fc)
             throws IOException, ServletException {
+        /*
+         * Add the request to the statistics. Be aware of the colliding call in
+         * {@code AuthorizationFilter#doFilter}.
+         */
+        requests.record(1);
+
         HttpServletRequest httpReq = (HttpServletRequest) sr;
 
         Instant start = Instant.now();
@@ -79,13 +85,7 @@ public void doFilter(ServletRequest sr, ServletResponse sr1, FilterChain fc)
             return;
         }
 
-        /*
-         * Add the request to the statistics. Be aware of the colliding call in
-         * {@code AuthorizationFilter#doFilter}.
-         */
-        requests.record(1);
-
-        Timer categoryTimer = Timer.builder("requests.latency.category").
+        Timer categoryTimer = Timer.builder("requests.latency").
                 tags("category", category).
                 register(Metrics.getRegistry());
         categoryTimer.record(duration);

opengrok-web/src/main/java/org/opengrok/web/WebappListener.java

@@ -57,19 +57,13 @@ public final class WebappListener
 
     private static final Logger LOGGER = LoggerFactory.getLogger(WebappListener.class);
 
-    private static final String TIMER_ATTR_NAME = WebappListener.class.getName() + ".request_start";
-    private Timer requestTimer;
-
     /**
      * {@inheritDoc}
      */
     @Override
     public void contextInitialized(final ServletContextEvent servletContextEvent) {
         ServletContext context = servletContextEvent.getServletContext();
         RuntimeEnvironment env = RuntimeEnvironment.getInstance();
-        requestTimer = Timer.builder("request.latency").
-                description("web application request latency").
-                register(Metrics.getRegistry());
 
         LOGGER.log(Level.INFO, "Starting webapp with version {0} ({1})",
                     new Object[]{Info.getVersion(), Info.getRevision()});
@@ -130,20 +124,14 @@ public void contextDestroyed(final ServletContextEvent servletContextEvent) {
      */
     @Override
     public void requestInitialized(ServletRequestEvent e) {
-        e.getServletRequest().setAttribute(TIMER_ATTR_NAME, Instant.now());
+        // pass
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void requestDestroyed(ServletRequestEvent e) {
-        Instant start = (Instant) e.getServletRequest().getAttribute(TIMER_ATTR_NAME);
-        if (start != null) {
-            Duration duration = Duration.between(start, Instant.now());
-            requestTimer.record(duration);
-        }
-
         PageConfig.cleanup(e.getServletRequest());
         SearchHelper sh = (SearchHelper) e.getServletRequest().getAttribute(SearchHelper.REQUEST_ATTR);
         if (sh != null) {