[inspector] deduplicate stack frames

src/inspector/v8-debugger.h

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_INSPECTOR_V8DEBUGGER_H_
 #define V8_INSPECTOR_V8DEBUGGER_H_
 
 #include <list>
 #include <vector>
 
 #include "src/base/macros.h"
 #include "src/debug/debug-interface.h"
 #include "src/inspector/java-script-call-frame.h"
 #include "src/inspector/protocol/Debugger.h"
 #include "src/inspector/protocol/Forward.h"
 #include "src/inspector/protocol/Runtime.h"
 #include "src/inspector/v8-debugger-script.h"
 #include "src/inspector/wasm-translation.h"
 
 #include "include/v8-inspector.h"
 
 namespace v8_inspector {
 
 class AsyncStackTrace;
 struct ScriptBreakpoint;
+class StackFrame;
 class V8Debugger;
 class V8DebuggerAgentImpl;
 class V8InspectorImpl;
 class V8StackTraceImpl;
 
 using protocol::Response;
 using ScheduleStepIntoAsyncCallback =
     protocol::Debugger::Backend::ScheduleStepIntoAsyncCallback;
 
 class V8Debugger : public v8::debug::DebugDelegate {
@@ skipping 42 matching lines @@
 
   bool isPaused() const { return m_runningNestedMessageLoop; }
   v8::Local<v8::Context> pausedContext() { return m_pausedContext; }
 
   int maxAsyncCallChainDepth() { return m_maxAsyncCallStackDepth; }
   void setAsyncCallStackDepth(V8DebuggerAgentImpl*, int);
 
   std::shared_ptr<AsyncStackTrace> currentAsyncParent();
   std::shared_ptr<AsyncStackTrace> currentAsyncCreation();
 
+  std::shared_ptr<StackFrame> lookupFrame(int frameId);
+  void storeFrame(int frameId, std::shared_ptr<StackFrame> frame);
+
   std::unique_ptr<V8StackTraceImpl> createStackTrace(v8::Local<v8::StackTrace>);
   std::unique_ptr<V8StackTraceImpl> captureStackTrace(bool fullStack);
 
   v8::MaybeLocal<v8::Array> internalProperties(v8::Local<v8::Context>,
                                                v8::Local<v8::Value>);
 
   void asyncTaskScheduled(const StringView& taskName, void* task,
                           bool recurring);
   void asyncTaskCanceled(void* task);
   void asyncTaskStarted(void* task);
@@ skipping 96 matching lines @@
   std::vector<void*> m_currentTasks;
   std::vector<std::shared_ptr<AsyncStackTrace>> m_currentAsyncParent;
   std::vector<std::shared_ptr<AsyncStackTrace>> m_currentAsyncCreation;
 
   void collectOldAsyncStacksIfNeeded();
   void removeOldAsyncTasks(AsyncTaskToStackTrace& map);
   int m_asyncStacksCount = 0;
   // V8Debugger owns all the async stacks, while most of the other references
   // are weak, which allows to collect some stacks when there are too many.
   std::list<std::shared_ptr<AsyncStackTrace>> m_allAsyncStacks;
+  std::map<int, std::weak_ptr<StackFrame>> m_framesCache;
 
   protocol::HashMap<V8DebuggerAgentImpl*, int> m_maxAsyncCallStackDepthMap;
   void* m_taskWithScheduledBreak = nullptr;
 
   std::unique_ptr<ScheduleStepIntoAsyncCallback> m_stepIntoAsyncCallback;
   bool m_breakRequested = false;
 
   v8::debug::ExceptionBreakState m_pauseOnExceptionsState;
 
   WasmTranslation m_wasmTranslation;
 
   DISALLOW_COPY_AND_ASSIGN(V8Debugger);
 };
 
 }  // namespace v8_inspector
 
 #endif  // V8_INSPECTOR_V8DEBUGGER_H_