Seculative resource prefetching for URLs CL.

chrome/browser/resources/predictors/resource_prefetch_predictor.js

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * Requests the database from the backend.
+ */
+function requestResourcePrefetchPredictorDb() {
+  chrome.send('requestResourcePrefetchPredictorDb');
+}
+
+/**
+ * Callback from backend with the database contents. Sets up some globals and
+ * calls to create the UI.
+ * @param {Dictionary} database Information about ResourcePrefetchPredictor
+ *     including the database as a flattened list, a boolean indicating if the
+ *     system is enabled.
+ */
+function updateResourcePrefetchPredictorDb(database) {
+  updateResourcePrefetchPredictorDbView(database);
+}
+
+/**
+ * Truncates the string to keep the database readable.
+ * @param {String} str The string to truncate.
+ * @return {String} The truncated string.
+ */
+function truncateString(str) {
+  return str.length < 100 ? str : str.substring(0, 99);
+}
+
+/**
+ * Updates the table from the database.
+ * @param {Dictionary} database Information about ResourcePrefetchPredictor
+ *     including the database as a flattened list, a boolean indicating if the
+ *     system is enabled and the current hit weight.
+ */
+function updateResourcePrefetchPredictorDbView(database) {
+  if (!database.enabled) {
+    $('resource_prefetch_predictor_enabled').style.display = 'none';
+    $('resource_prefetch_predictor_disabled').style.display = 'block';
+    return;
+  } else {
+    $('resource_prefetch_predictor_enabled').style.display = 'block';
+    $('resource_prefetch_predictor_disabled').style.display = 'none';
+  }
+
+  if (database.db) {
+    if (database.db.length > 0) {
+      $('resource_prefetch_predictor_db').style.display = 'block';
+      $('empty_resource_prefetch_predictor_db').style.display = 'none';
+    } else {
+      $('resource_prefetch_predictor_db').style.display = 'none';
+      $('empty_resource_prefetch_predictor_db').style.display = 'block';
+    }
+
+    var dbSection = $('resource_prefetch_predictor_db_body');
+    dbSection.textContent = '';
+    for (var i = 0; i < database.db.length; ++i) {
+      var main = database.db[i];
+
+      for (var j = 0; j < main.resources.length; ++j) {
+        var resource = main.resources[j];
+        var row = document.createElement('tr');
+
+        if (j == 0) {
+          var t = document.createElement('td');
+          t.rowSpan = main.resources.length;
+          t.textContent = truncateString(main.main_frame_url);
+          t.className = 'last';
+          row.appendChild(t);
+        }
+
+        if (j == main.resources.length - 1)
+          row.className = 'last';
+
+        row.appendChild(document.createElement('td')).textContent =
+            truncateString(resource.resource_url);
+        row.appendChild(document.createElement('td')).textContent =
+            resource.resource_type;
+        row.appendChild(document.createElement('td')).textContent =
+            resource.number_of_hits;
+        row.appendChild(document.createElement('td')).textContent =
+            resource.number_of_misses;
+        row.appendChild(document.createElement('td')).textContent =
+            resource.consecutive_misses;
+        row.appendChild(document.createElement('td')).textContent =
+            resource.position;
+        row.appendChild(document.createElement('td')).textContent =
+            resource.score;
+        dbSection.appendChild(row);
+      }
+    }
+  }
+}
+
+document.addEventListener('DOMContentLoaded',
+                          requestResourcePrefetchPredictorDb);