ipc/ipc_test_sink.h

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef IPC_IPC_TEST_SINK_H_
   6 #define IPC_IPC_TEST_SINK_H_
   7
   8 #include <stdint.h>
   9
  10 #include <utility>
  11 #include <vector>
  12
  13 #include "base/basictypes.h"
  14 #include "base/observer_list.h"
  15 #include "ipc/ipc_channel.h"
  16
  17 namespace IPC {
  18
  19 class Message;
  20
  21 // This test sink provides a "sink" for IPC messages that are sent. It allows
  22 // the caller to query messages received in various different ways.  It is
  23 // designed for tests for objects that use the IPC system.
  24 //
  25 // Typical usage:
  26 //
  27 //   test_sink.ClearMessages();
  28 //   do_something();
  29 //
  30 //   // We should have gotten exactly one update state message.
  31 //   EXPECT_TRUE(test_sink.GetUniqeMessageMatching(ViewHostMsg_Update::ID));
  32 //   // ...and no start load messages.
  33 //   EXPECT_FALSE(test_sink.GetFirstMessageMatching(ViewHostMsg_Start::ID));
  34 //
  35 //   // Now inspect a message. This assumes a message that was declared like
  36 //   // this: IPC_MESSAGE_ROUTED2(ViewMsg_Foo, bool, int)
  37 //   IPC::Message* msg = test_sink.GetFirstMessageMatching(ViewMsg_Foo::ID));
  38 //   ASSERT_TRUE(msg);
  39 //   bool first_param;
  40 //   int second_param;
  41 //   ViewMsg_Foo::Read(msg, &first_param, &second_param);
  42 //
  43 //   // Go on to the next phase of the test.
  44 //   test_sink.ClearMessages();
  45 //
  46 // To read a sync reply, do this:
  47 //
  48 //   IPC::Message* msg = test_sink.GetUniqueMessageMatching(IPC_REPLY_ID);
  49 //   ASSERT_TRUE(msg);
  50 //   base::TupleTypes<ViewHostMsg_Foo::ReplyParam>::ValueTuple reply_data;
  51 //   EXPECT_TRUE(ViewHostMsg_Foo::ReadReplyParam(msg, &reply_data));
  52 //
  53 // You can also register to be notified when messages are posted to the sink.
  54 // This can be useful if you need to wait for a particular message that will
  55 // be posted asynchronously.  Example usage:
  56 //
  57 //   class MyListener : public IPC::Listener {
  58 //    public:
  59 //     virtual bool OnMessageReceived(const IPC::Message& msg) {
  60 //       <do something with the message>
  61 //       MessageLoop::current()->Quit();
  62 //       return false;  // to store the message in the sink, or true to drop it
  63 //     }
  64 //   };
  65 //
  66 //   MyListener listener;
  67 //   test_sink.AddFilter(&listener);
  68 //   StartSomeAsynchronousProcess(&test_sink);
  69 //   MessageLoop::current()->Run();
  70 //   <inspect the results>
  71 //   ...
  72 //
  73 // To hook up the sink, all you need to do is call OnMessageReceived when a
  74 // message is received.
  75 class TestSink : public Channel {
  76  public:
  77   TestSink();
  78   ~TestSink() override;
  79
  80   // Interface in IPC::Channel. This copies the message to the sink and then
  81   // deletes it.
  82   bool Send(IPC::Message* message) override;
  83   bool Connect() override WARN_UNUSED_RESULT;
  84   void Close() override;
  85   base::ProcessId GetPeerPID() const override;
  86   base::ProcessId GetSelfPID() const override;
  87
  88 #if defined(OS_POSIX) && !defined(OS_NACL)
  89   int GetClientFileDescriptor() const override;
  90   base::ScopedFD TakeClientFileDescriptor() override;
  91 #endif  // defined(OS_POSIX) && !defined(OS_NACL)
  92
  93   // Used by the source of the messages to send the message to the sink. This
  94   // will make a copy of the message and store it in the list.
  95   bool OnMessageReceived(const Message& msg);
  96
  97   // Returns the number of messages in the queue.
  98   size_t message_count() const { return messages_.size(); }
  99
 100   // Clears the message queue of saved messages.
 101   void ClearMessages();
 102
 103   // Returns the message at the given index in the queue. The index may be out
 104   // of range, in which case the return value is NULL. The returned pointer will
 105   // only be valid until another message is received or the list is cleared.
 106   const Message* GetMessageAt(size_t index) const;
 107
 108   // Returns the first message with the given ID in the queue. If there is no
 109   // message with the given ID, returns NULL. The returned pointer will only be
 110   // valid until another message is received or the list is cleared.
 111   const Message* GetFirstMessageMatching(uint32_t id) const;
 112
 113   // Returns the message with the given ID in the queue. If there is no such
 114   // message or there is more than one of that message, this will return NULL
 115   // (with the expectation that you'll do an ASSERT_TRUE() on the result).
 116   // The returned pointer will only be valid until another message is received
 117   // or the list is cleared.
 118   const Message* GetUniqueMessageMatching(uint32_t id) const;
 119
 120   // Adds the given listener as a filter to the TestSink.
 121   // When a message is received by the TestSink, it will be dispatched to
 122   // the filters, in the order they were added.  If a filter returns true
 123   // from OnMessageReceived, subsequent filters will not receive the message
 124   // and the TestSink will not store it.
 125   void AddFilter(Listener* filter);
 126
 127   // Removes the given filter from the TestSink.
 128   void RemoveFilter(Listener* filter);
 129
 130  private:
 131   // The actual list of received messages.
 132   std::vector<Message> messages_;
 133   base::ObserverList<Listener> filter_list_;
 134
 135   DISALLOW_COPY_AND_ASSIGN(TestSink);
 136 };
 137
 138 }  // namespace IPC
 139
 140 #endif  // IPC_IPC_TEST_SINK_H_