Split the IPC code into ipc/

This splits the ipc code from the common project.  The 'common' project pulls in
all of webkit, the v8 bindings, skia, googleurl, and a number of other projects
which makes it very difficult to deal with especially for external projects
wanting just to use some of Chromium's infrastructure.  This puts the ipc code
into its top-level ipc/ directory with a dependency only on base.  The common
project depends on the new ipc/ipc.gyp:ipc target so that all projects currently
pulling common in to get the IPC code still have it available.  This mostly
follows agl's pre-gyp attempt to do this which was r13062.

Known issues:
- Currently a number of projects depend on chrome/chrome.gyp:common in order to
use the IPC infrastructure.  Rather than fixing all of these dependencies I have
made common depend on ipc/ipc.gyp:ipc and added "ipc" to the include_rules
section of DEPS so that checkdeps.py doesn't complain.  Over time projects that
need IPC should depend on the IPC project themselves and dependencies on common
removed, although I don't think many projects that need IPC will be able to get
away without common currently.
- ipc/ipc_message_macros.h still has #include "chrome/common/..." inside of a
ipc/ should not refer to files in chrome/... now.  I'm not sure how to resolve
this since it's really an IDE bug
- the named pipe name (windows+linux) and the logging event name (all) + env
variable (posix) refer explicitly to 'Chrome' which somewhat hurts the illusion
of ipc/ being an independent library.  I think this should be examined in a
subsequent, much smaller patch.
- I've eliminated the IPC.SendMsgCount counter since it was implemented in a way
to create a dependency from ipc/ to chrome/common/chrome_counters. This is the
same approach that r13062 took.

http://codereview.chromium.org/155905

(Patch from James Robinson)


git-svn-id: svn://svn.chromium.org/chrome/trunk/src@21342 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 279 insertions, 0 deletions

diff --git a/ipc/ipc_message.h b/ipc/ipc_message.h
new file mode 100644
index 0000000..6357c0b
--- /dev/null
+++ b/ipc/ipc_message.h
@@ -0,0 +1,279 @@
+// 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__