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// Copyright 2016 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.
#ifndef MOJO_PUBLIC_CPP_BINDINGS_STRONG_ASSOCIATED_BINDING_H_
#define MOJO_PUBLIC_CPP_BINDINGS_STRONG_ASSOCIATED_BINDING_H_
#include <memory>
#include <string>
#include <utility>
#include "base/bind.h"
#include "base/callback.h"
#include "base/logging.h"
#include "base/macros.h"
#include "base/memory/weak_ptr.h"
#include "mojo/public/cpp/bindings/associated_binding.h"
#include "mojo/public/cpp/bindings/associated_interface_request.h"
#include "mojo/public/cpp/bindings/connection_error_callback.h"
#include "mojo/public/cpp/system/core.h"
namespace mojo {
template <typename Interface>
class StrongAssociatedBinding;
template <typename Interface>
using StrongAssociatedBindingPtr =
base::WeakPtr<StrongAssociatedBinding<Interface>>;
// This connects an interface implementation strongly to an associated pipe.
// When a connection error is detected the implementation is deleted. If the
// task runner that a StrongAssociatedBinding is bound on is stopped, the
// connection error handler will not be invoked and the implementation will not
// be deleted.
//
// To use, call StrongAssociatedBinding<T>::Create() (see below) or the helper
// MakeStrongAssociatedBinding function:
//
// mojo::MakeStrongAssociatedBinding(std::make_unique<FooImpl>(),
// std::move(foo_request));
//
template <typename Interface>
class StrongAssociatedBinding {
public:
// Create a new StrongAssociatedBinding instance. The instance owns itself,
// cleaning up only in the event of a pipe connection error. Returns a WeakPtr
// to the new StrongAssociatedBinding instance.
static StrongAssociatedBindingPtr<Interface> Create(
std::unique_ptr<Interface> impl,
AssociatedInterfaceRequest<Interface> request,
scoped_refptr<base::SequencedTaskRunner> task_runner = nullptr) {
StrongAssociatedBinding* binding = new StrongAssociatedBinding(
std::move(impl), std::move(request), std::move(task_runner));
return binding->weak_factory_.GetWeakPtr();
}
// Note: The error handler must not delete the interface implementation.
//
// This method may only be called after this StrongAssociatedBinding has been
// bound to a message pipe.
void set_connection_error_handler(base::OnceClosure error_handler) {
DCHECK(binding_.is_bound());
connection_error_handler_ = std::move(error_handler);
connection_error_with_reason_handler_.Reset();
}
void set_connection_error_with_reason_handler(
ConnectionErrorWithReasonCallback error_handler) {
DCHECK(binding_.is_bound());
connection_error_with_reason_handler_ = std::move(error_handler);
connection_error_handler_.Reset();
}
// Forces the binding to close. This destroys the StrongBinding instance.
void Close() { delete this; }
Interface* impl() { return impl_.get(); }
// Sends a message on the underlying message pipe and runs the current
// message loop until its response is received. This can be used in tests to
// verify that no message was sent on a message pipe in response to some
// stimulus.
void FlushForTesting() { binding_.FlushForTesting(); }
// Allows test code to swap the interface implementation.
std::unique_ptr<Interface> SwapImplForTesting(
std::unique_ptr<Interface> new_impl) {
binding_.SwapImplForTesting(new_impl.get());
impl_.swap(new_impl);
return new_impl;
}
private:
StrongAssociatedBinding(std::unique_ptr<Interface> impl,
AssociatedInterfaceRequest<Interface> request,
scoped_refptr<base::SequencedTaskRunner> task_runner)
: impl_(std::move(impl)),
binding_(impl_.get(), std::move(request), std::move(task_runner)) {
binding_.set_connection_error_with_reason_handler(base::Bind(
&StrongAssociatedBinding::OnConnectionError, base::Unretained(this)));
}
~StrongAssociatedBinding() {}
void OnConnectionError(uint32_t custom_reason,
const std::string& description) {
if (connection_error_handler_) {
std::move(connection_error_handler_).Run();
} else if (connection_error_with_reason_handler_) {
std::move(connection_error_with_reason_handler_)
.Run(custom_reason, description);
}
Close();
}
std::unique_ptr<Interface> impl_;
base::OnceClosure connection_error_handler_;
ConnectionErrorWithReasonCallback connection_error_with_reason_handler_;
AssociatedBinding<Interface> binding_;
base::WeakPtrFactory<StrongAssociatedBinding> weak_factory_{this};
DISALLOW_COPY_AND_ASSIGN(StrongAssociatedBinding);
};
template <typename Interface, typename Impl>
StrongAssociatedBindingPtr<Interface> MakeStrongAssociatedBinding(
std::unique_ptr<Impl> impl,
AssociatedInterfaceRequest<Interface> request,
scoped_refptr<base::SequencedTaskRunner> task_runner = nullptr) {
return StrongAssociatedBinding<Interface>::Create(
std::move(impl), std::move(request), std::move(task_runner));
}
} // namespace mojo
#endif // MOJO_PUBLIC_CPP_BINDINGS_STRONG_ASSOCIATED_BINDING_H_