De-client tracing.TraceController interface

mojo/common/weak_interface_ptr_set.h

+// Copyright 2014 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.
+
+#include <vector>
+
+#include "base/memory/weak_ptr.h"
+#include "mojo/public/cpp/bindings/interface_ptr.h"
+
+namespace mojo {
+
+template <typename Interface>
+class WeakInterfacePtr;
+
+template <typename Interface>
+class WeakInterfacePtrSet {
+ public:
+  WeakInterfacePtrSet() {}
+  ~WeakInterfacePtrSet() { CloseAll(); }
+
+  void AddInterfacePtr(InterfacePtr<Interface> ptr) {
+    auto weak_interface_ptr = new WeakInterfacePtr<Interface>(ptr.Pass());
+    ptrs_.push_back(weak_interface_ptr->GetWeakPtr());
+    ClearNullInterfacePtrs();
+  }
+
+  template <typename FunctionType>
+  void ForAllPtrs(FunctionType function) {
+    for (const auto& it : ptrs_) {
+      if (it)
+        function(it->get());
+    }
+    ClearNullInterfacePtrs();
+  }
+
+  void CloseAll() {
+    for (const auto& it : ptrs_) {
+      if (it)
+        it->Close();
+    }
+    ptrs_.clear();
+  }
+
+ private:
+  using WPWIPI = base::WeakPtr<WeakInterfacePtr<Interface>>;
+
+  void ClearNullInterfacePtrs() {
+    ptrs_.erase(std::remove_if(ptrs_.begin(), ptrs_.end(), [](const WPWIPI& p) {
+      return p.get() == nullptr;
+    }), ptrs_.end());
+  }
+
+  std::vector<WPWIPI> ptrs_;
+};
+
+template <typename Interface>
+class WeakInterfacePtr : public ErrorHandler {
+ public:
+  explicit WeakInterfacePtr(InterfacePtr<Interface> ptr)
+      : ptr_(ptr.Pass()), weak_ptr_factory_(this) {
+    ptr_.set_error_handler(this);
+  }
+  ~WeakInterfacePtr() override {}
+
+  void Close() { ptr_.reset(); }
+
+  Interface* get() { return ptr_.get(); }
+
+  base::WeakPtr<WeakInterfacePtr> GetWeakPtr() {
+    return weak_ptr_factory_.GetWeakPtr();
+  }
+
+ private:
+  // ErrorHandler implementation
+  void OnConnectionError() override { delete this; }
+
+  InterfacePtr<Interface> ptr_;
+  base::WeakPtrFactory<WeakInterfacePtr> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(WeakInterfacePtr);
+};
+
+}  // namespace mojo