Separates ipc code from common (http://crbug.com/16829)

ipc/ipc_message.h

+// Copyright (c) 2006-2008 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 IPC_IPC_MESSAGE_H__
+#define IPC_IPC_MESSAGE_H__
+
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/pickle.h"
+
+#ifndef NDEBUG
+#define IPC_MESSAGE_LOG_ENABLED
+#endif
+
+#if defined(OS_POSIX)
+#include "base/ref_counted.h"
+#endif
+
+namespace base {
+class FileDescriptor;
+}
+
+class FileDescriptorSet;
+
+namespace IPC {
+
+//------------------------------------------------------------------------------
+
+class Channel;
+class Message;
+struct LogData;
+
+class Message : public Pickle {
+ public:
+  // Implemented by objects that can send IPC messages across a channel.
+  class Sender {
+   public:
+    virtual ~Sender() {}
+
+    // Sends the given IPC message.  The implementor takes ownership of the
+    // given Message regardless of whether or not this method succeeds.  This
+    // is done to make this method easier to use.  Returns true on success and
+    // false otherwise.
+    virtual bool Send(Message* msg) = 0;
+  };
+
+  enum PriorityValue {
+    PRIORITY_LOW = 1,
+    PRIORITY_NORMAL,
+    PRIORITY_HIGH
+  };
+
+  virtual ~Message();
+
+  Message();
+
+  // Initialize a message with a user-defined type, priority value, and
+  // destination WebView ID.
+  Message(int32 routing_id, uint16 type, PriorityValue priority);
+
+  // Initializes a message from a const block of data.  The data is not copied;
+  // instead the data is merely referenced by this message.  Only const methods
+  // should be used on the message when initialized this way.
+  Message(const char* data, int data_len);
+
+  Message(const Message& other);
+  Message& operator=(const Message& other);
+
+  PriorityValue priority() const {
+    return static_cast<PriorityValue>(header()->flags & PRIORITY_MASK);
+  }
+
+  // True if this is a synchronous message.
+  bool is_sync() const {
+    return (header()->flags & SYNC_BIT) != 0;
+  }
+
+  // Set this on a reply to a synchronous message.
+  void set_reply() {
+    header()->flags |= REPLY_BIT;
+  }
+
+  bool is_reply() const {
+    return (header()->flags & REPLY_BIT) != 0;
+  }
+
+  // Set this on a reply to a synchronous message to indicate that no receiver
+  // was found.
+  void set_reply_error() {
+    header()->flags |= REPLY_ERROR_BIT;
+  }
+
+  bool is_reply_error() const {
+    return (header()->flags & REPLY_ERROR_BIT) != 0;
+  }
+
+  // Normally when a receiver gets a message and they're blocked on a
+  // synchronous message Send, they buffer a message.  Setting this flag causes
+  // the receiver to be unblocked and the message to be dispatched immediately.
+  void set_unblock(bool unblock) {
+    if (unblock) {
+      header()->flags |= UNBLOCK_BIT;
+    } else {
+      header()->flags &= ~UNBLOCK_BIT;
+    }
+  }
+
+  bool should_unblock() const {
+    return (header()->flags & UNBLOCK_BIT) != 0;
+  }
+
+  // Tells the receiver that the caller is pumping messages while waiting
+  // for the result.
+  bool is_caller_pumping_messages() const {
+    return (header()->flags & PUMPING_MSGS_BIT) != 0;
+  }
+
+  uint16 type() const {
+    return header()->type;
+  }
+
+  int32 routing_id() const {
+    return header()->routing;
+  }
+
+  void set_routing_id(int32 new_id) {
+    header()->routing = new_id;
+  }
+
+  template<class T>
+  static bool Dispatch(const Message* msg, T* obj, void (T::*func)()) {
+    (obj->*func)();
+    return true;
+  }
+
+  template<class T>
+  static bool Dispatch(const Message* msg, T* obj, void (T::*func)() const) {
+    (obj->*func)();
+    return true;
+  }
+
+  template<class T>
+  static bool Dispatch(const Message* msg, T* obj,
+                       void (T::*func)(const Message&)) {
+    (obj->*func)(*msg);
+    return true;
+  }
+
+  template<class T>
+  static bool Dispatch(const Message* msg, T* obj,
+                       void (T::*func)(const Message&) const) {
+    (obj->*func)(*msg);
+    return true;
+  }
+
+  // Used for async messages with no parameters.
+  static void Log(const Message* msg, std::wstring* l) {
+  }
+
+  // Find the end of the message data that starts at range_start.  Returns NULL
+  // if the entire message is not found in the given data range.
+  static const char* FindNext(const char* range_start, const char* range_end) {
+    return Pickle::FindNext(sizeof(Header), range_start, range_end);
+  }
+
+#if defined(OS_POSIX)
+  // On POSIX, a message supports reading / writing FileDescriptor objects.
+  // This is used to pass a file descriptor to the peer of an IPC channel.
+
+  // Add a descriptor to the end of the set. Returns false iff the set is full.
+  bool WriteFileDescriptor(const base::FileDescriptor& descriptor);
+  // Get a file descriptor from the message. Returns false on error.
+  //   iter: a Pickle iterator to the current location in the message.
+  bool ReadFileDescriptor(void** iter, base::FileDescriptor* descriptor) const;
+#endif
+
+#ifdef IPC_MESSAGE_LOG_ENABLED
+  // Adds the outgoing time from Time::Now() at the end of the message and sets
+  // a bit to indicate that it's been added.
+  void set_sent_time(int64 time);
+  int64 sent_time() const;
+
+  void set_received_time(int64 time) const;
+  int64 received_time() const { return received_time_; }
+  void set_output_params(const std::wstring& op) const { output_params_ = op; }
+  const std::wstring& output_params() const { return output_params_; }
+  // The following four functions are needed so we can log sync messages with
+  // delayed replies.  We stick the log data from the sent message into the
+  // reply message, so that when it's sent and we have the output parameters
+  // we can log it.  As such, we set a flag on the sent message to not log it.
+  void set_sync_log_data(LogData* data) const { log_data_ = data; }
+  LogData* sync_log_data() const { return log_data_; }
+  void set_dont_log() const { dont_log_ = true; }
+  bool dont_log() const { return dont_log_; }
+#endif
+
+ protected:
+  friend class Channel;
+  friend class MessageReplyDeserializer;
+  friend class SyncMessage;
+
+  void set_sync() {
+    header()->flags |= SYNC_BIT;
+  }
+
+  // flags
+  enum {
+    PRIORITY_MASK   = 0x0003,
+    SYNC_BIT        = 0x0004,
+    REPLY_BIT       = 0x0008,
+    REPLY_ERROR_BIT = 0x0010,
+    UNBLOCK_BIT     = 0x0020,
+    PUMPING_MSGS_BIT= 0x0040,
+    HAS_SENT_TIME_BIT = 0x0080,
+  };
+
+#pragma pack(push, 2)
+  struct Header : Pickle::Header {
+    int32 routing;  // ID of the view that this message is destined for
+    uint16 type;    // specifies the user-defined message type
+    uint16 flags;   // specifies control flags for the message
+#if defined(OS_POSIX)
+    uint32 num_fds; // the number of descriptors included with this message
+#endif
+  };
+#pragma pack(pop)
+
+  Header* header() {
+    return headerT<Header>();
+  }
+  const Header* header() const {
+    return headerT<Header>();
+  }
+
+  void InitLoggingVariables();
+
+#if defined(OS_POSIX)
+  // The set of file descriptors associated with this message.
+  scoped_refptr<FileDescriptorSet> file_descriptor_set_;
+
+  // Ensure that a FileDescriptorSet is allocated
+  void EnsureFileDescriptorSet();
+
+  FileDescriptorSet* file_descriptor_set() {
+    EnsureFileDescriptorSet();
+    return file_descriptor_set_.get();
+  }
+  const FileDescriptorSet* file_descriptor_set() const {
+    return file_descriptor_set_.get();
+  }
+#endif
+
+#ifdef IPC_MESSAGE_LOG_ENABLED
+  // Used for logging.
+  mutable int64 received_time_;
+  mutable std::wstring output_params_;
+  mutable LogData* log_data_;
+  mutable bool dont_log_;
+#endif
+};
+
+//------------------------------------------------------------------------------
+
+}  // namespace IPC
+
+enum SpecialRoutingIDs {
+  // indicates that we don't have a routing ID yet.
+  MSG_ROUTING_NONE = -2,
+
+  // indicates a general message not sent to a particular tab.
+  MSG_ROUTING_CONTROL = kint32max,
+};
+
+#define IPC_REPLY_ID 0xFFF0  // Special message id for replies
+#define IPC_LOGGING_ID 0xFFF1  // Special message id for logging
+
+#endif  // IPC_IPC_MESSAGE_H__