DevTools: carefully cleanup script UISourceCodes

third_party/WebKit/Source/devtools/front_end/sdk/DebuggerModel.js

Index: third_party/WebKit/Source/devtools/front_end/sdk/DebuggerModel.js
diff --git a/third_party/WebKit/Source/devtools/front_end/sdk/DebuggerModel.js b/third_party/WebKit/Source/devtools/front_end/sdk/DebuggerModel.js
index 657d96b6bdd6a58aa2b452f7f7bababdbb69889b..de8325dce00f3b77a455d466fe60c09674335d3c 100644
--- a/third_party/WebKit/Source/devtools/front_end/sdk/DebuggerModel.js
+++ b/third_party/WebKit/Source/devtools/front_end/sdk/DebuggerModel.js
@@ -49,8 +49,8 @@ SDK.DebuggerModel = class extends SDK.SDKModel {
 
     /** @type {?SDK.DebuggerPausedDetails} */
     this._debuggerPausedDetails = null;
-    /** @type {!Object.<string, !SDK.Script>} */
-    this._scripts = {};
+    /** @type {!Map<string, !SDK.Script>} */
+    this._scripts = new Map();

[dgozman, 2017/04/05 18:22:55]

Is it as performant? We have a lot of scripts!

[lushnikov, 2017/04/06 03:32:35]

According to 
https://docs.google.com/spreadsheets/d/1lQTC4ZG3XY33Gdw7Ibla30fz3HQHqWZ87DQjH...

Map is more performant for storing rather then for querying. And this is the
case we have!

     /** @type {!Map.<string, !Array.<!SDK.Script>>} */
     this._scriptsBySourceURL = new Map();
     /** @type {!Array.<!SDK.Script>} */
@@ -345,17 +345,17 @@ SDK.DebuggerModel = class extends SDK.SDKModel {
       this._sourceMapManager.detachSourceMap(scriptWithSourceMap);
     this._sourceMapIdToScript.clear();
 
-    this._scripts = {};
+    this._scripts.clear();
     this._scriptsBySourceURL.clear();
     this._stringMap.clear();
     this._discardableScripts = [];
   }
 
   /**
-   * @return {!Object.<string, !SDK.Script>}
+   * @return {!Array<!SDK.Script>}
    */
-  get scripts() {
-    return this._scripts;
+  scripts() {
+    return Array.from(this._scripts.values());

[dgozman, 2017/04/05 18:22:55]

Is this method performance-critical? Does it make sense to return an iterator or
map itself?

[lushnikov, 2017/04/06 03:32:35]

No, it's used by blackbox model only

   }
 
   /**
@@ -363,7 +363,7 @@ SDK.DebuggerModel = class extends SDK.SDKModel {
    * @return {?SDK.Script}
    */
   scriptForId(scriptId) {
-    return this._scripts[scriptId] || null;
+    return this._scripts.get(scriptId) || null;
   }
 
   /**
@@ -381,7 +381,8 @@ SDK.DebuggerModel = class extends SDK.SDKModel {
    * @param {function(?Protocol.Error, !Protocol.Runtime.ExceptionDetails=)} callback
    */
   setScriptSource(scriptId, newSource, callback) {
-    this._scripts[scriptId].editSource(newSource, this._didEditScriptSource.bind(this, scriptId, newSource, callback));
+    this._scripts.get(scriptId).editSource(
+        newSource, this._didEditScriptSource.bind(this, scriptId, newSource, callback));
   }
 
   /**
@@ -567,13 +568,19 @@ SDK.DebuggerModel = class extends SDK.SDKModel {
         this._sourceMapManager.detachSourceMap(script);
       }
     }
+    var affectedScripts = [];
+    for (var script of this._scripts.values()) {
+      if (script.executionContextId === executionContext.id)
+        affectedScripts.push(script);
+    }
+    this.dispatchEventToListeners(SDK.DebuggerModel.Events.ExecutionContextDestroyed, affectedScripts);
   }
 
   /**
    * @param {!SDK.Script} script
    */
   _registerScript(script) {
-    this._scripts[script.scriptId] = script;
+    this._scripts.set(script.scriptId, script);
     if (script.isAnonymousScript())
       return;
 
@@ -590,7 +597,7 @@ SDK.DebuggerModel = class extends SDK.SDKModel {
    */
   _unregisterScript(script) {
     console.assert(script.isAnonymousScript());
-    delete this._scripts[script.scriptId];
+    this._scripts.delete(script.scriptId);
   }
 
   _collectDiscardedScripts() {
@@ -918,6 +925,7 @@ SDK.DebuggerModel.Events = {
   DebuggerWasDisabled: Symbol('DebuggerWasDisabled'),
   DebuggerPaused: Symbol('DebuggerPaused'),
   DebuggerResumed: Symbol('DebuggerResumed'),
+  ExecutionContextDestroyed: Symbol('ExecutionContextDestroyed'),

[dgozman, 2017/04/05 18:22:55]

DiscardedScriptSources, and merge with DiscardedAnonymousScriptSource

[lushnikov, 2017/04/06 03:32:35]

As discussed offline, i'm started to listen to
RuntimeModel.ExecutionContextDestroyed in NetworkPanel

   ParsedScriptSource: Symbol('ParsedScriptSource'),
   FailedToParseScriptSource: Symbol('FailedToParseScriptSource'),
   DiscardedAnonymousScriptSource: Symbol('DiscardedAnonymousScriptSource'),