Pepper UDP socket: buffer received packets in the plugin process to improve performance.

ppapi/proxy/udp_socket_resource_base.h

 // Copyright 2013 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 PPAPI_PROXY_UDP_SOCKET_RESOURCE_BASE_H_
 #define PPAPI_PROXY_UDP_SOCKET_RESOURCE_BASE_H_
 
+#include <queue>
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "ppapi/c/ppb_udp_socket.h"
 #include "ppapi/c/private/ppb_net_address_private.h"
 #include "ppapi/proxy/plugin_resource.h"
 #include "ppapi/proxy/ppapi_proxy_export.h"
 #include "ppapi/shared_impl/tracked_callback.h"
 
 namespace ppapi {
 namespace proxy {
 
 class ResourceMessageReplyParams;
 
 class PPAPI_PROXY_EXPORT UDPSocketResourceBase: public PluginResource {
  public:
-  // The maximum number of bytes that each PpapiHostMsg_PPBUDPSocket_RecvFrom
-  // message is allowed to request.
+  // The maximum number of bytes that each
+  // PpapiPluginMsg_PPBUDPSocket_PushRecvResult message is allowed to carry.
   static const int32_t kMaxReadSize;
   // The maximum number of bytes that each PpapiHostMsg_PPBUDPSocket_SendTo
   // message is allowed to carry.
   static const int32_t kMaxWriteSize;
 
   // The maximum number that we allow for setting
   // PP_UDPSOCKET_OPTION_SEND_BUFFER_SIZE. This number is only for input
   // argument sanity check, it doesn't mean the browser guarantees to support
   // such a buffer size.
   static const int32_t kMaxSendBufferSize;
   // The maximum number that we allow for setting
   // PP_UDPSOCKET_OPTION_RECV_BUFFER_SIZE. This number is only for input
   // argument sanity check, it doesn't mean the browser guarantees to support
   // such a buffer size.
   static const int32_t kMaxReceiveBufferSize;
 
+  // The maximum number of received packets that we allow instances of this
+  // class to buffer.
+  static const size_t kPluginReceiveBufferSlots;
+
  protected:
   UDPSocketResourceBase(Connection connection,
                         PP_Instance instance,
                         bool private_api);
   virtual ~UDPSocketResourceBase();
 
   int32_t SetOptionImpl(PP_UDPSocket_Option name,
                         const PP_Var& value,
                         scoped_refptr<TrackedCallback> callback);
   int32_t BindImpl(const PP_NetAddress_Private* addr,
                    scoped_refptr<TrackedCallback> callback);
   PP_Bool GetBoundAddressImpl(PP_NetAddress_Private* addr);
   // |addr| could be NULL to indicate that an output value is not needed.
   int32_t RecvFromImpl(char* buffer,
                        int32_t num_bytes,
                        PP_Resource* addr,
                        scoped_refptr<TrackedCallback> callback);
   PP_Bool GetRecvFromAddressImpl(PP_NetAddress_Private* addr);
   int32_t SendToImpl(const char* buffer,
                      int32_t num_bytes,
                      const PP_NetAddress_Private* addr,
                      scoped_refptr<TrackedCallback> callback);
   void CloseImpl();
 
  private:
+  struct RecvBuffer {
+    int32_t result;
+    std::string data;
+    PP_NetAddress_Private addr;
+  };
+
+  // Resource overrides.
+  virtual void OnReplyReceived(const ResourceMessageReplyParams& params,
+                               const IPC::Message& msg) OVERRIDE;
+
   void PostAbortIfNecessary(scoped_refptr<TrackedCallback>* callback);
 
   // IPC message handlers.
   void OnPluginMsgSetOptionReply(scoped_refptr<TrackedCallback> callback,
                                  const ResourceMessageReplyParams& params);
   void OnPluginMsgBindReply(const ResourceMessageReplyParams& params,
                             const PP_NetAddress_Private& bound_addr);
-  void OnPluginMsgRecvFromReply(PP_Resource* output_addr,
-                                const ResourceMessageReplyParams& params,
-                                const std::string& data,
-                                const PP_NetAddress_Private& addr);
+  void OnPluginMsgPushRecvResult(const ResourceMessageReplyParams& params,
+                                 int32_t result,
+                                 const std::string& data,
+                                 const PP_NetAddress_Private& addr);
   void OnPluginMsgSendToReply(const ResourceMessageReplyParams& params,
                               int32_t bytes_written);
 
   void RunCallback(scoped_refptr<TrackedCallback> callback, int32_t pp_result);
 
+  // Callers must ensure that |output_buffer| is big enough to store |data|.
+  int32_t SetRecvFromOutput(int32_t browser_result,
+                            const std::string& data,
+                            const PP_NetAddress_Private& addr,
+                            char* output_buffer,
+                            int32_t num_bytes,
+                            PP_Resource* output_addr);
+
   bool private_api_;
   bool bound_;
   bool closed_;
 
   scoped_refptr<TrackedCallback> bind_callback_;
   scoped_refptr<TrackedCallback> recvfrom_callback_;
   scoped_refptr<TrackedCallback> sendto_callback_;
 
   char* read_buffer_;
   int32_t bytes_to_read_;
+  PP_Resource* recvfrom_addr_resource_;
 
   PP_NetAddress_Private recvfrom_addr_;
   PP_NetAddress_Private bound_addr_;
 
+  std::queue<RecvBuffer> recv_buffers_;
+
   DISALLOW_COPY_AND_ASSIGN(UDPSocketResourceBase);
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PROXY_UDP_SOCKET_RESOURCE_BASE_H_