Bug 1542172 - Firefox freezes when inspecting large POST data. r=Honza

Truncate the Request Payload if it exceeds the `devtools.netmonitor.requestBodyLimit` pref and show `Request has been truncated` error in the Params Tab

Differential Revision: https://phabricator.services.mozilla.com/D27898

--HG--
extra : moz-landing-system : lando

devtools/client/locales/en-US/netmonitor.properties

@@ -141,6 +141,11 @@ jsonpScopeName=JSONP → callback %S()
 # the truncation limit and thus was truncated.
 responseTruncated=Response has been truncated
 
+# LOCALIZATION NOTE (requestTruncated): This is the text displayed
+# in the params tab of the network details pane when the request is over
+# the truncation limit and thus was truncated.
+requestTruncated=Request has been truncated
+
 # LOCALIZATION NOTE (responsePreview): This is the text displayed
 # in the response tab of the network details pane for an HTML preview.
 responsePreview=Preview

devtools/client/netmonitor/src/assets/styles/NetworkDetailsPanel.css

@@ -327,6 +327,15 @@
     margin-left: 4px;
 }
 
+/* Params tabpanel */
+
+.network-monitor .request-error-header {
+  margin: 0;
+  padding: 3px 8px;
+  background-color: var(--theme-highlight-red);
+  color: var(--theme-selection-color);
+}
+
 /* Response tabpanel */
 
 .network-monitor .response-error-header {

devtools/client/netmonitor/src/components/ParamsPanel.js

@@ -7,6 +7,7 @@
 const { Component, createFactory } = require("devtools/client/shared/vendor/react");
 const dom = require("devtools/client/shared/vendor/react-dom-factories");
 const PropTypes = require("devtools/client/shared/vendor/react-prop-types");
+const Services = require("Services");
 const { connect } = require("devtools/client/shared/redux/visibility-handler-connect");
 const { L10N } = require("../utils/l10n");
 const {
@@ -30,6 +31,7 @@ const PARAMS_FILTER_TEXT = L10N.getStr("paramsFilterText");
 const PARAMS_FORM_DATA = L10N.getStr("paramsFormData");
 const PARAMS_POST_PAYLOAD = L10N.getStr("paramsPostPayload");
 const PARAMS_QUERY_STRING = L10N.getStr("paramsQueryString");
+const REQUEST_TRUNCATED = L10N.getStr("requestTruncated");
 const SECTION_NAMES = [
   JSON_SCOPE_NAME,
   PARAMS_FORM_DATA,
@@ -115,7 +117,7 @@ class ParamsPanel extends Component {
     }
 
     const object = {};
-    let json;
+    let json, error;
 
     // Query String section
     if (query) {
@@ -129,16 +131,27 @@ class ParamsPanel extends Component {
     }
 
     // Request payload section
+
+    const limit = Services.prefs.getIntPref("devtools.netmonitor.requestBodyLimit");
+    // Check if the request post data has been truncated, in which case no parse should
+    // be attempted.
+    if (postData && limit <= postData.length) {
+      error = REQUEST_TRUNCATED;
+    }
+
     if (formDataSections && formDataSections.length === 0 && postData) {
+      if (!error) {
         try {
           json = JSON.parse(postData);
-      } catch (error) {
+        } catch (err) {
           // Continue regardless of parsing error
         }
 
         if (json) {
           object[JSON_SCOPE_NAME] = sortObjectKeys(json);
         }
+      }
+
       object[PARAMS_POST_PAYLOAD] = {
         EDITOR_CONFIG: {
           text: postData,
@@ -151,6 +164,9 @@ class ParamsPanel extends Component {
 
     return (
       div({ className: "panel-container" },
+        error && div({ className: "request-error-header", title: error },
+          error
+        ),
         PropertiesView({
           object,
           filterPlaceHolder: PARAMS_FILTER_TEXT,

devtools/client/netmonitor/test/browser.ini

@@ -213,6 +213,7 @@ skip-if = true # Bug 1373558
 skip-if = true # TODO: fix the test
 [browser_net_timing-division.js]
 [browser_net_tracking-resources.js]
+[browser_net_truncate-post-data.js]
 [browser_net_truncate.js]
 [browser_net_view-source-debugger.js]
 [browser_net_waterfall-click.js]

devtools/client/netmonitor/test/browser_net_truncate-post-data.js

@@ -0,0 +1,54 @@
+/* Any copyright is dedicated to the Public Domain.
+  http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+/**
+  * Bug 1542172 -
+  * Verifies that requests with large post data are truncated and error is displayed.
+*/
+add_task(async function() {
+  const { monitor, tab } = await initNetMonitor(POST_JSON_URL);
+
+  info("Starting test... ");
+
+  const { L10N } = require("devtools/client/netmonitor/src/utils/l10n");
+
+  const { document, store, windowRequire } = monitor.panelWin;
+  const Actions = windowRequire("devtools/client/netmonitor/src/actions/index");
+  store.dispatch(Actions.batchEnable(false));
+
+  requestLongerTimeout(2);
+
+  info("Perform requests");
+  await performRequestsAndWait();
+
+  await waitUntil(() => document.querySelector(".request-list-item"));
+  const item = document.querySelectorAll(".request-list-item")[0];
+  await waitUntil(() => item.querySelector(".requests-list-type").title);
+
+  wait = waitForDOM(document, "#params-panel .tree-section", 1);
+  store.dispatch(Actions.toggleNetworkDetails());
+  EventUtils.sendMouseEvent({ type: "click" }, document.querySelector("#params-tab"));
+  await wait;
+
+  const tabpanel = document.querySelector("#params-panel");
+  is(tabpanel.querySelector(".request-error-header") === null, false,
+    "The request error header doesn't have the intended visibility.");
+  is(tabpanel.querySelector(".request-error-header").textContent,
+    "Request has been truncated", "The error message shown is incorrect");
+  const jsonView = tabpanel.querySelector(".tree-section .treeLabel") || {};
+  is(jsonView.textContent === L10N.getStr("jsonScopeName"), false,
+    "The params json view doesn't have the intended visibility.");
+  is(tabpanel.querySelector("pre") === null, false,
+    "The Request Payload has the intended visibility.");
+
+  return teardown(monitor);
+  async function performRequestsAndWait() {
+    const wait = waitForNetworkEvents(monitor, 1);
+    await ContentTask.spawn(tab.linkedBrowser, {}, async function() {
+      content.wrappedJSObject.performLargePostDataRequest();
+    });
+    await wait;
+  }
+});

devtools/client/netmonitor/test/html_post-json-test-page.html

@@ -15,7 +15,7 @@
     <p>POST raw test</p>
 
     <script type="text/javascript">
-      /* exported performRequests */
+      /* exported performRequests performLargePostDataRequest */
       "use strict";
 
       function post(address, message, callback) {
@@ -36,6 +36,14 @@
           // Done.
         });
       }
+
+      function performLargePostDataRequest() {
+        const limit = 1048576;
+        const data = "x".repeat(2 * limit);
+        post("sjs_simple-test-server.sjs", JSON.stringify(data), function() {
+          // Done.
+        });
+      }
     </script>
   </body>
 

devtools/server/actors/network-event.js

@@ -356,7 +356,7 @@ const NetworkEventActor = protocol.ActorClassWithSpec(networkEventSpec, {
     // bug 1462561 - Use "json" type and manually manage/marshall actors to woraround
     // protocol.js performance issue
     this.manage(postData.text);
-    const dataSize = postData.text.str.length;
+    const dataSize = postData.size;
     postData.text = postData.text.form();
 
     this.emit("network-event-update:post-data", "requestPostData", {

devtools/server/actors/network-monitor/network-observer.js

@@ -395,7 +395,15 @@ NetworkObserver.prototype = {
       case gActivityDistributor.ACTIVITY_SUBTYPE_REQUEST_BODY_SENT:
         this._onRequestBodySent(httpActivity);
         if (httpActivity.sentBody !== null) {
-          httpActivity.owner.addRequestPostData({ text: httpActivity.sentBody });
+          const limit = Services.prefs.getIntPref("devtools.netmonitor.requestBodyLimit");
+          const size = httpActivity.sentBody.length;
+          if (size > limit && limit > 0) {
+            httpActivity.sentBody = httpActivity.sentBody.substr(0, limit);
+          }
+          httpActivity.owner.addRequestPostData({
+            text: httpActivity.sentBody,
+            size: size,
+          });
           httpActivity.sentBody = null;
         }
         break;

devtools/shared/preferences/devtools-shared.js

@@ -38,11 +38,12 @@ pref("devtools.debugger.remote-websocket", false);
 // Force debugger server binding on the loopback interface
 pref("devtools.debugger.force-local", true);
 
-// Limit for intercepted response bodies (1 MB)
+// Limit for intercepted request and response bodies (1 MB)
 // Possible values:
 // 0 => the response body has no limit
 // n => represents max number of bytes stored
 pref("devtools.netmonitor.responseBodyLimit", 1048576);
+pref("devtools.netmonitor.requestBodyLimit", 1048576);
 
 // DevTools default color unit
 pref("devtools.defaultColorUnit", "authored");