WebSocket Pepper API: SRPC proxy implementation

ppapi/native_client/src/shared/ppapi_proxy/plugin_ppb_websocket.cc

+// Copyright (c) 2012 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.
+
+#include "native_client/src/shared/ppapi_proxy/plugin_ppb_websocket.h"
+
+#include "native_client/src/include/nacl_scoped_ptr.h"
+#include "native_client/src/shared/ppapi_proxy/object_serialize.h"
+#include "native_client/src/shared/ppapi_proxy/plugin_callback.h"
+#include "native_client/src/shared/ppapi_proxy/plugin_globals.h"
+#include "native_client/src/shared/ppapi_proxy/utility.h"
+#include "native_client/src/shared/srpc/nacl_srpc.h"
+#include "ppapi/c/pp_completion_callback.h"
+#include "ppapi/c/pp_errors.h"
+#include "ppapi/c/pp_var.h"
+#include "ppapi/c/dev/ppb_websocket_dev.h"
+#include "srpcgen/ppb_rpc.h"
+
+namespace ppapi_proxy {
+
+namespace {
+
+PP_Resource Create(PP_Instance instance) {
+  DebugPrintf("PPB_WebSocket::Create: instance=%"NACL_PRIu32"\n", instance);
+
+  PP_Resource resource;
+  NaClSrpcError srpc_result =
+      PpbWebSocketRpcClient::PPB_WebSocket_Create(
+          GetMainSrpcChannel(), instance, &resource);
+  DebugPrintf("PPB_WebSocket::Create: %s\n", NaClSrpcErrorString(srpc_result));
+
+  if (srpc_result == NACL_SRPC_RESULT_OK)
+    return resource;
+  return kInvalidResourceId;
+}
+
+PP_Bool IsWebSocket(PP_Resource resource) {
+  DebugPrintf(
+      "PPB_WebSocket::IsWebSocket: resource=%"NACL_PRIu32"\n", resource);
+
+  int32_t is_websocket;
+  NaClSrpcError srpc_result =
+      PpbWebSocketRpcClient::PPB_WebSocket_IsWebSocket(
+          GetMainSrpcChannel(), resource, &is_websocket);
+  DebugPrintf("PPB_WebSocket::IsWebSocket: %s\n",
+      NaClSrpcErrorString(srpc_result));
+
+  if (srpc_result == NACL_SRPC_RESULT_OK && is_websocket)
+    return PP_TRUE;
+  return PP_FALSE;
+}
+
+int32_t Connect(PP_Resource ws,
+                PP_Var url,
+                const PP_Var protocols[],
+                uint32_t protocol_count,
+                PP_CompletionCallback callback) {
+  DebugPrintf("PPB_WebSocket::Connect: ws=%"NACL_PRIu32"\n", ws);
+
+  nacl_abi_size_t url_size = kMaxReturnVarSize;

[dmichael (off chromium), 2012/01/17 23:32:45]

nit: kMaxReturnVarSize is meant for out-params; url_size is ignored when passed
to Serialize. I'd rather you initialize it to 0 for clarity. (same elsewhere)

[Takashi Toyoshima, 2012/01/18 11:07:16]

Done.

+  nacl::scoped_array<char> url_bytes(Serialize(&url, 1, &url_size));
+
+  nacl_abi_size_t protocols_size = kMaxReturnVarSize;
+  nacl::scoped_array<char> protocols_bytes(
+      Serialize(protocols, protocol_count, &protocols_size));
+
+  int32_t callback_id = CompletionCallbackTable::Get()->AddCallback(callback);
+  if (callback_id == 0)
+    return PP_ERROR_BLOCKS_MAIN_THREAD;
+
+  int32_t pp_error;
+  NaClSrpcError srpc_result =
+      PpbWebSocketRpcClient::PPB_WebSocket_Connect(
+          GetMainSrpcChannel(),
+          ws,
+          url_size, url_bytes.get(),
+          protocols_size, protocols_bytes.get(),
+          static_cast<int32_t>(protocol_count),
+          callback_id,
+          &pp_error);
+  DebugPrintf("PPB_WebSocket::Connect: %s\n",
+      NaClSrpcErrorString(srpc_result));
+
+  if (srpc_result != NACL_SRPC_RESULT_OK)
+    pp_error = PP_ERROR_FAILED;
+  return MayForceCallback(callback, pp_error);
+}
+
+int32_t Close(PP_Resource ws,
+              uint16_t code,
+              PP_Var reason,
+              PP_CompletionCallback callback) {
+  DebugPrintf("PPB_WebSocket::Close: ws=%"NACL_PRIu32"\n", ws);
+
+  nacl_abi_size_t reason_size = kMaxReturnVarSize;
+  nacl::scoped_array<char> reason_bytes(Serialize(&reason, 1, &reason_size));
+
+  int32_t callback_id = CompletionCallbackTable::Get()->AddCallback(callback);
+  if (callback_id == 0)
+    return PP_ERROR_BLOCKS_MAIN_THREAD;
+
+  int32_t pp_error;
+  NaClSrpcError srpc_result =
+      PpbWebSocketRpcClient::PPB_WebSocket_Close(
+          GetMainSrpcChannel(),
+          ws,
+          code,
+          reason_size, reason_bytes.get(),
+          callback_id,
+          &pp_error);
+  DebugPrintf("PPB_WebSocket::Close: %s\n", NaClSrpcErrorString(srpc_result));
+
+  if (srpc_result != NACL_SRPC_RESULT_OK)
+    pp_error = PP_ERROR_FAILED;
+  return MayForceCallback(callback, pp_error);
+}
+
+int32_t ReceiveMessage(PP_Resource ws,
+                       PP_Var* message,
+                       PP_CompletionCallback callback) {
+  DebugPrintf("PPB_WebSocket::ReceiveMessage: ws=%"NACL_PRIu32"\n", ws);
+
+  int32_t callback_id =
+      CompletionCallbackTable::Get()->AddCallback(callback, message);
+  if (callback_id == 0)
+    return PP_ERROR_BLOCKS_MAIN_THREAD;
+
+  int32_t pp_error;
+  NaClSrpcError srpc_result =
+      PpbWebSocketRpcClient::PPB_WebSocket_ReceiveMessage(
+          GetMainSrpcChannel(),
+          ws,
+          callback_id,
+          &pp_error);

[dmichael (off chromium), 2012/01/17 23:32:45]

Should you have a faster path, as PPB_URLLoader does, for when there's data
immediately available? There's already overhead with the way the NaCl proxy
implements URLLoader :-(.

But written this way, it seems you're *always* sending an callback separately,
which will mean:
1) an extra RPC call, and
2) Re-entry in to the plugin code. That might work fine, but it's likely to
cause some hard-to-debug problems.

I'd rather you did it like PPB_URLLoader and pass back the var immediately as an
SRPC out-parameter if the browser returns it immediately. The downside is that
it will limit your frame size to just less than 64k. Is that okay?


[Not for this CL:  Also note that when you do the Chrome IPC proxy, it will be
significantly different. You'll want to model after the URLLoader proxy there,
and I think that one pushes data from the Browser to the Plugin.]

[Takashi Toyoshima, 2012/01/18 11:07:16]

This first implementation doesn't care about performance optimization, then
apply straightforward way.
How about making another CL to improve ReceiveMessage performance?

Actually, WebSocket frame size could be int64 max in the spec, so 64k is not
enough to handle it.
Simple hack is to adapt optimization for <64k frames as you mentioned.
And the best way is adding another path in order to handle receiving frames as
soon as possible.

To tell the truth, I couldn't perfectly understand the details of out of process
proxy mechanism yet.
I feel it's more difficult than SRPC and will require some structural change on
thunk API to support it.
That's why I apply the simplest way to SRPC for now.
I'd like to apply optimization after out of process proxy implementation because
it require perfect understanding over all proxy mechanisms.

[dmichael (off chromium), 2012/01/18 17:04:40]

For what it's worth, I'm not *only* concerned with performance here. I was
afraid you were doing a re-entrant SRPC call back from the browser to the
plugin, but I guess not. Since you are not making the callback "optional", I
think your response will fire asynchronously, so there's not a problem of
re-entrancy (though the overhead is fairly big; the response gets posted as a
task to run later, which then does the extra SRPC call back to the plugin).


As for the out-of-process proxy... it is a bit more complicated. But it's easier
to make that proxy more efficient, too. In any case, the SRPC proxy is
definitely the priority, since that's what will allow NaCl apps to use your
stuff.

+  DebugPrintf("PPB_WebSocket::ReceiveMessage: %s\n",
+      NaClSrpcErrorString(srpc_result));
+
+  if (srpc_result != NACL_SRPC_RESULT_OK)
+    pp_error = PP_ERROR_FAILED;
+  return MayForceCallback(callback, pp_error);
+}
+
+int32_t SendMessage(PP_Resource ws,
+                    PP_Var message) {
+  DebugPrintf("PPB_WebSocket::SendMessage: ws=%"NACL_PRIu32"\n", ws);
+
+  nacl_abi_size_t message_size = kMaxReturnVarSize;
+  nacl::scoped_array<char> message_bytes(
+      Serialize(&message, 1, &message_size));
+
+  int32_t pp_error;
+  NaClSrpcError srpc_result =
+      PpbWebSocketRpcClient::PPB_WebSocket_SendMessage(
+          GetMainSrpcChannel(),
+          ws,
+          message_size, message_bytes.get(),
+          &pp_error);
+  DebugPrintf("PPB_WebSocket::SendMessage: %s\n",
+      NaClSrpcErrorString(srpc_result));
+
+  if (srpc_result != NACL_SRPC_RESULT_OK)
+    return PP_ERROR_FAILED;
+  return pp_error;
+}
+
+uint64_t GetBufferedAmount(PP_Resource ws) {
+  DebugPrintf("PPB_WebSocket::GetBufferedAmount: ws=%"NACL_PRIu32"\n", ws);
+
+  int64_t buffered_amount = 0;
+  NaClSrpcError srpc_result =
+      PpbWebSocketRpcClient::PPB_WebSocket_GetBufferedAmount(
+          GetMainSrpcChannel(), ws, &buffered_amount);
+  DebugPrintf("PPB_WebSocket::GetBufferedAmount: %s\n",
+      NaClSrpcErrorString(srpc_result));
+
+  return static_cast<uint64_t>(buffered_amount);
+}
+
+uint16_t GetCloseCode(PP_Resource ws) {
+  DebugPrintf("PPB_WebSocket::GetCloseCode: ws=%"NACL_PRIu32"\n", ws);
+
+  int32_t close_code = 0;
+  NaClSrpcError srpc_result =
+      PpbWebSocketRpcClient::PPB_WebSocket_GetCloseCode(
+          GetMainSrpcChannel(), ws, &close_code);
+  DebugPrintf("PPB_WebSocket::GetCloseCode: %s\n",
+      NaClSrpcErrorString(srpc_result));
+
+  return static_cast<uint16_t>(close_code);
+}
+
+PP_Var GetCloseReason(PP_Resource ws) {
+  DebugPrintf("PPB_WebSocket::GetCloseReason: ws=%"NACL_PRIu32"\n", ws);
+
+  nacl_abi_size_t reason_size = kMaxReturnVarSize;
+  nacl::scoped_array<char> reason_bytes(new char[reason_size]);
+  NaClSrpcError srpc_result =
+      PpbWebSocketRpcClient::PPB_WebSocket_GetCloseReason(
+          GetMainSrpcChannel(), ws, &reason_size, reason_bytes.get());
+  DebugPrintf("PPB_WebSocket::GetCloseReason: %s\n",
+      NaClSrpcErrorString(srpc_result));
+
+  if (srpc_result == NACL_SRPC_RESULT_OK) {
+    PP_Var reason = PP_MakeUndefined();
+    if (DeserializeTo(reason_bytes.get(), reason_size, 1, &reason))
+      return reason;
+  }
+
+  return PP_MakeUndefined();
+}
+
+PP_Bool GetCloseWasClean(PP_Resource ws) {
+  DebugPrintf(
+      "PPB_WebSocket::GetCloseWasClean: ws=%"NACL_PRIu32"\n", ws);
+
+  int32_t was_clean;
+  NaClSrpcError srpc_result =
+      PpbWebSocketRpcClient::PPB_WebSocket_GetCloseWasClean(
+          GetMainSrpcChannel(), ws, &was_clean);
+  DebugPrintf("PPB_WebSocket::GetCloseWasClean: %s\n",
+      NaClSrpcErrorString(srpc_result));
+
+  if (srpc_result == NACL_SRPC_RESULT_OK && was_clean)
+    return PP_TRUE;
+  return PP_FALSE;
+}
+
+PP_Var GetExtensions(PP_Resource ws) {
+  DebugPrintf("PPB_WebSocket::GetExtensions: ws=%"NACL_PRIu32"\n", ws);
+
+  nacl_abi_size_t extensions_size = kMaxReturnVarSize;
+  nacl::scoped_array<char> extensions_bytes(new char[extensions_size]);
+  NaClSrpcError srpc_result =
+      PpbWebSocketRpcClient::PPB_WebSocket_GetExtensions(
+          GetMainSrpcChannel(), ws, &extensions_size, extensions_bytes.get());
+  DebugPrintf("PPB_WebSocket::GetExtensions: %s\n",
+      NaClSrpcErrorString(srpc_result));
+
+  if (srpc_result == NACL_SRPC_RESULT_OK) {
+    PP_Var extensions = PP_MakeUndefined();
+    if (DeserializeTo(extensions_bytes.get(), extensions_size, 1, &extensions))
+      return extensions;
+  }
+
+  return PP_MakeUndefined();
+}
+
+PP_Var GetProtocol(PP_Resource ws) {
+  DebugPrintf("PPB_WebSocket::GetProtocol: ws=%"NACL_PRIu32"\n", ws);
+
+  nacl_abi_size_t protocol_size = kMaxReturnVarSize;
+  nacl::scoped_array<char> protocol_bytes(new char[protocol_size]);
+  NaClSrpcError srpc_result =
+      PpbWebSocketRpcClient::PPB_WebSocket_GetProtocol(
+          GetMainSrpcChannel(), ws, &protocol_size, protocol_bytes.get());
+  DebugPrintf("PPB_WebSocket::GetProtocol: %s\n",
+      NaClSrpcErrorString(srpc_result));
+
+  if (srpc_result == NACL_SRPC_RESULT_OK) {
+    PP_Var protocol = PP_MakeUndefined();
+    if (DeserializeTo(protocol_bytes.get(), protocol_size, 1, &protocol))
+      return protocol;
+  }
+
+  return PP_MakeUndefined();
+}
+
+PP_WebSocketReadyState_Dev GetReadyState(PP_Resource ws) {
+  DebugPrintf(
+      "PPB_WebSocket::GetReadyState: ws=%"NACL_PRIu32"\n", ws);
+
+  int32_t ready_state;
+  NaClSrpcError srpc_result =
+      PpbWebSocketRpcClient::PPB_WebSocket_GetReadyState(
+          GetMainSrpcChannel(), ws, &ready_state);
+  DebugPrintf("PPB_WebSocket::GetReadyState: %s\n",
+      NaClSrpcErrorString(srpc_result));
+
+  if (srpc_result != NACL_SRPC_RESULT_OK)
+    return PP_WEBSOCKETREADYSTATE_INVALID_DEV;
+  return static_cast<PP_WebSocketReadyState_Dev>(ready_state);
+}
+
+PP_Var GetURL(PP_Resource ws) {
+  DebugPrintf("PPB_WebSocket::GetURL: ws=%"NACL_PRIu32"\n", ws);
+
+  nacl_abi_size_t url_size = kMaxReturnVarSize;
+  nacl::scoped_array<char> url_bytes(new char[url_size]);
+  NaClSrpcError srpc_result =
+      PpbWebSocketRpcClient::PPB_WebSocket_GetURL(
+          GetMainSrpcChannel(), ws, &url_size, url_bytes.get());
+  DebugPrintf("PPB_WebSocket::GetURL: %s\n",
+      NaClSrpcErrorString(srpc_result));
+
+  if (srpc_result == NACL_SRPC_RESULT_OK) {
+    PP_Var url = PP_MakeUndefined();
+    if (DeserializeTo(url_bytes.get(), url_size, 1, &url))
+      return url;
+  }
+
+  return PP_MakeUndefined();
+}
+
+PP_Bool SetBinaryType(PP_Resource ws,
+                      PP_WebSocketBinaryType_Dev binary_type) {
+  DebugPrintf("PPB_WebSocket::SetBinaryType: ws=%"NACL_PRIu32"\n", ws);
+
+  int32_t success;
+  NaClSrpcError srpc_result =
+      PpbWebSocketRpcClient::PPB_WebSocket_SetBinaryType(
+          GetMainSrpcChannel(),
+          ws,
+          static_cast<int32_t>(binary_type),
+          &success);
+  DebugPrintf("PPB_WebSocket::SetBinaryType: %s\n",
+      NaClSrpcErrorString(srpc_result));
+
+  if (srpc_result == NACL_SRPC_RESULT_OK && success)
+    return PP_TRUE;
+  return PP_FALSE;
+}
+
+PP_WebSocketBinaryType_Dev GetBinaryType(PP_Resource ws) {
+  DebugPrintf("PPB_WebSocket::GetBinaryType: ws=%"NACL_PRIu32"\n", ws);
+
+  int32_t binary_type;
+  NaClSrpcError srpc_result =
+      PpbWebSocketRpcClient::PPB_WebSocket_GetBinaryType(
+          GetMainSrpcChannel(),
+          ws,
+          &binary_type);
+  DebugPrintf("PPB_WebSocket::GetBinaryType: %s\n",
+      NaClSrpcErrorString(srpc_result));
+
+  if (srpc_result != NACL_SRPC_RESULT_OK)
+    return PP_WEBSOCKETBINARYTYPE_INVALID;
+  return static_cast<PP_WebSocketBinaryType_Dev>(binary_type);
+}
+
+}  // namespace
+
+const PPB_WebSocket_Dev* PluginWebSocket::GetInterface() {
+  static const PPB_WebSocket_Dev websocket_interface = {
+    &Create,
+    &IsWebSocket,
+    &Connect,
+    &Close,
+    &ReceiveMessage,
+    &SendMessage,
+    &GetBufferedAmount,
+    &GetCloseCode,
+    &GetCloseReason,
+    &GetCloseWasClean,
+    &GetExtensions,
+    &GetProtocol,
+    &GetReadyState,
+    &GetURL,
+    &SetBinaryType,
+    &GetBinaryType
+  };
+  return &websocket_interface;
+}
+
+}  // namespace ppapi_proxy