import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

devtools/client/shared/test/leakhunt.js

@@ -0,0 +1,165 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Memory leak hunter. Walks a tree of objects looking for DOM nodes.
+ * Usage:
+ * leakHunt({
+ *   thing: thing,
+ *   otherthing: otherthing
+ * });
+ */
+function leakHunt(root) {
+  let path = [];
+  let seen = [];
+
+  try {
+    let output = leakHunt.inner(root, path, seen);
+    output.forEach(function (line) {
+      dump(line + "\n");
+    });
+  } catch (ex) {
+    dump(ex + "\n");
+  }
+}
+
+leakHunt.inner = function (root, path, seen) {
+  let prefix = new Array(path.length).join("  ");
+
+  let reply = [];
+  function log(msg) {
+    reply.push(msg);
+  }
+
+  let direct;
+  try {
+    direct = Object.keys(root);
+  } catch (ex) {
+    log(prefix + "  Error enumerating: " + ex);
+    return reply;
+  }
+
+  try {
+    let index = 0;
+    for (let data of root) {
+      let prop = "" + index;
+      leakHunt.digProperty(prop, data, path, seen, direct, log);
+      index++;
+    }
+  } catch (ex) {
+    /* Ignore things that are not enumerable */
+  }
+
+  for (let prop in root) {
+    let data;
+    try {
+      data = root[prop];
+    } catch (ex) {
+      log(prefix + "  " + prop + " = Error: " + ex.toString().substring(0, 30));
+      continue;
+    }
+
+    leakHunt.digProperty(prop, data, path, seen, direct, log);
+  }
+
+  return reply;
+};
+
+leakHunt.hide = [ /^string$/, /^number$/, /^boolean$/, /^null/, /^undefined/ ];
+
+leakHunt.noRecurse = [
+  /^string$/, /^number$/, /^boolean$/, /^null/, /^undefined/,
+  /^Window$/, /^Document$/,
+  /^XULDocument$/, /^XULElement$/,
+  /^DOMWindow$/, /^HTMLDocument$/, /^HTML.*Element$/, /^ChromeWindow$/
+];
+
+leakHunt.digProperty = function (prop, data, path, seen, direct, log) {
+  let newPath = path.slice();
+  newPath.push(prop);
+  let prefix = new Array(newPath.length).join("  ");
+
+  let recurse = true;
+  let message = leakHunt.getType(data);
+
+  if (leakHunt.matchesAnyPattern(message, leakHunt.hide)) {
+    return;
+  }
+
+  if (message === "function" && direct.indexOf(prop) == -1) {
+    return;
+  }
+
+  if (message === "string") {
+    let extra = data.length > 10 ? data.substring(0, 9) + "_" : data;
+    message += ' "' + extra.replace(/\n/g, "|") + '"';
+    recurse = false;
+  } else if (leakHunt.matchesAnyPattern(message, leakHunt.noRecurse)) {
+    message += " (no recurse)";
+    recurse = false;
+  } else if (seen.indexOf(data) !== -1) {
+    message += " (already seen)";
+    recurse = false;
+  }
+
+  if (recurse) {
+    seen.push(data);
+    let lines = leakHunt.inner(data, newPath, seen);
+    if (lines.length == 0) {
+      if (message !== "function") {
+        log(prefix + prop + " = " + message + " { }");
+      }
+    } else {
+      log(prefix + prop + " = " + message + " {");
+      lines.forEach(function (line) {
+        log(line);
+      });
+      log(prefix + "}");
+    }
+  } else {
+    log(prefix + prop + " = " + message);
+  }
+};
+
+leakHunt.matchesAnyPattern = function (str, patterns) {
+  let match = false;
+  patterns.forEach(function (pattern) {
+    if (str.match(pattern)) {
+      match = true;
+    }
+  });
+  return match;
+};
+
+leakHunt.getType = function (data) {
+  if (data === null) {
+    return "null";
+  }
+  if (data === undefined) {
+    return "undefined";
+  }
+
+  let type = typeof data;
+  if (type === "object" || type === "Object") {
+    type = leakHunt.getCtorName(data);
+  }
+
+  return type;
+};
+
+leakHunt.getCtorName = function (obj) {
+  try {
+    if (obj.constructor && obj.constructor.name) {
+      return obj.constructor.name;
+    }
+  } catch (ex) {
+    return "UnknownObject";
+  }
+
+  // If that fails, use Objects toString which sometimes gives something
+  // better than 'Object', and at least defaults to Object if nothing better
+  return Object.prototype.toString.call(obj).slice(8, -1);
+};