Added JSON-RPC over WebSocket.

Wslay library must be placed under deps/wslay.

1 files changed, 251 insertions, 0 deletions

diff --git a/src/WebSocketSession.cc b/src/WebSocketSession.cc
new file mode 100644
index 00000000..5fa416e0
--- /dev/null
+++ b/src/WebSocketSession.cc
@@ -0,0 +1,251 @@
+/* <!-- copyright */
+/*
+ * aria2 - The high speed download utility
+ *
+ * Copyright (C) 2012 Tatsuhiro Tsujikawa
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * In addition, as a special exception, the copyright holders give
+ * permission to link the code of portions of this program with the
+ * OpenSSL library under certain conditions as described in each
+ * individual source file, and distribute linked combinations
+ * including the two.
+ * You must obey the GNU General Public License in all respects
+ * for all of the code used other than OpenSSL.  If you modify
+ * file(s) with this exception, you may extend this exception to your
+ * version of the file(s), but you are not obligated to do so.  If you
+ * do not wish to do so, delete this exception statement from your
+ * version.  If you delete this exception statement from all source
+ * files in the program, then also delete it here.
+ */
+/* copyright --> */
+#include "WebSocketSession.h"
+
+#include <cerrno>
+#include <cstring>
+
+#include "SocketCore.h"
+#include "LogFactory.h"
+#include "RecoverableException.h"
+#include "message.h"
+#include "DownloadEngine.h"
+#include "rpc_helper.h"
+#include "RpcResponse.h"
+#include "json.h"
+
+namespace aria2 {
+
+namespace rpc {
+
+namespace {
+ssize_t sendCallback(wslay_event_context_ptr wsctx,
+                      const uint8_t* data, size_t len, int flags,
+                      void* userData)
+{
+  WebSocketSession* session = reinterpret_cast<WebSocketSession*>(userData);
+  const SharedHandle<SocketCore>& socket = session->getSocket();
+  try {
+    ssize_t r = socket->writeData(data, len);
+    if(r == 0) {
+      if(socket->wantRead() || socket->wantWrite()) {
+        wslay_event_set_error(wsctx, WSLAY_ERR_WOULDBLOCK);
+      } else {
+        wslay_event_set_error(wsctx, WSLAY_ERR_CALLBACK_FAILURE);
+      }
+      r = -1;
+    }
+    return r;
+  } catch(RecoverableException& e) {
+    A2_LOG_DEBUG_EX(EX_EXCEPTION_CAUGHT, e);
+    wslay_event_set_error(wsctx, WSLAY_ERR_CALLBACK_FAILURE);
+    return -1;
+  }
+}
+} // namespace
+
+namespace {
+ssize_t recvCallback(wslay_event_context_ptr wsctx,
+                     uint8_t* buf, size_t len, int flags,
+                     void* userData)
+{
+  WebSocketSession* session = reinterpret_cast<WebSocketSession*>(userData);
+  const SharedHandle<SocketCore>& socket = session->getSocket();
+  try {
+    ssize_t r;
+    socket->readData(buf, len);
+    if(len == 0) {
+      if(socket->wantRead() || socket->wantWrite()) {
+        wslay_event_set_error(wsctx, WSLAY_ERR_WOULDBLOCK);
+      } else {
+        wslay_event_set_error(wsctx, WSLAY_ERR_CALLBACK_FAILURE);
+      }
+      r = -1;
+    } else {
+      r = len;
+    }
+    return r;
+  } catch(RecoverableException& e) {
+    A2_LOG_DEBUG_EX(EX_EXCEPTION_CAUGHT, e);
+    wslay_event_set_error(wsctx, WSLAY_ERR_CALLBACK_FAILURE);
+    return -1;
+  }
+}
+} // namespace
+
+namespace {
+void addResponse(WebSocketSession* wsSession, const RpcResponse& res)
+{
+  std::string response = toJson(res, "", false);
+  wsSession->addTextMessage(response);
+}
+} // namespace
+
+namespace {
+void addResponse(WebSocketSession* wsSession,
+                 const std::vector<RpcResponse>& results)
+{
+  std::string response = toJsonBatch(results, "", false);
+  wsSession->addTextMessage(response);
+}
+} // namespace
+
+namespace {
+void onMsgRecvCallback(wslay_event_context_ptr wsctx,
+                       const struct wslay_event_on_msg_recv_arg* arg,
+                       void* userData)
+{
+  WebSocketSession* wsSession = reinterpret_cast<WebSocketSession*>(userData);
+  if(!wslay_is_ctrl_frame(arg->opcode)) {
+    // TODO Only process text frame
+    SharedHandle<ValueBase> json;
+    try {
+      json = json::decode(arg->msg, arg->msg_length);
+    } catch(RecoverableException& e) {
+      A2_LOG_INFO_EX("Failed to parse JSON-RPC request", e);
+      RpcResponse res
+        (createJsonRpcErrorResponse(-32700, "Parse error.", Null::g()));
+      addResponse(wsSession, res);
+      return;
+    }
+    const Dict* jsondict = downcast<Dict>(json);
+    if(jsondict) {
+      RpcResponse res = processJsonRpcRequest(jsondict,
+                                              wsSession->getDownloadEngine());
+      addResponse(wsSession, res);
+    } else {
+      const List* jsonlist = downcast<List>(json);
+      if(jsonlist) {
+        // This is batch call
+        std::vector<RpcResponse> results;
+        for(List::ValueType::const_iterator i = jsonlist->begin(),
+              eoi = jsonlist->end(); i != eoi; ++i) {
+          const Dict* jsondict = downcast<Dict>(*i);
+          if(jsondict) {
+            RpcResponse r = processJsonRpcRequest
+              (jsondict, wsSession->getDownloadEngine());
+            results.push_back(r);
+          }
+        }
+        addResponse(wsSession, results);
+      } else {
+        RpcResponse res(createJsonRpcErrorResponse
+                        (-32600, "Invalid Request.", Null::g()));
+        addResponse(wsSession, res);
+      }
+    }
+  } else {
+    RpcResponse res(createJsonRpcErrorResponse
+                    (-32600, "Invalid Request.", Null::g()));
+    addResponse(wsSession, res);
+  }
+}
+} // namespace
+
+WebSocketSession::WebSocketSession(const SharedHandle<SocketCore>& socket,
+                                   DownloadEngine* e)
+  : socket_(socket),
+    e_(e)
+{
+  wslay_event_callbacks callbacks;
+  memset(&callbacks, 0, sizeof(wslay_event_callbacks));
+  callbacks.recv_callback = recvCallback;
+  callbacks.send_callback = sendCallback;
+  callbacks.on_msg_recv_callback = onMsgRecvCallback;
+  int r = wslay_event_context_server_init(&wsctx_, &callbacks, this);
+  assert(r == 0);
+}
+    
+WebSocketSession::~WebSocketSession()
+{
+  wslay_event_context_free(wsctx_);
+}
+
+bool WebSocketSession::wantRead()
+{
+  return wslay_event_want_read(wsctx_);
+}
+
+bool WebSocketSession::wantWrite()
+{
+  return wslay_event_want_write(wsctx_);
+}
+
+bool WebSocketSession::finish()
+{
+  return !wantRead() && !wantWrite();
+}
+
+int WebSocketSession::onReadEvent()
+{
+  if(wslay_event_recv(wsctx_) == 0) {
+    return 0;
+  } else {
+    return -1;
+  }
+}
+
+int WebSocketSession::onWriteEvent()
+{
+  if(wslay_event_send(wsctx_) == 0) {
+    return 0;
+  } else {
+    return -1;
+  }
+}
+
+void WebSocketSession::addTextMessage(const std::string& msg)
+{
+  // TODO Don't add text message if the size of outbound queue in
+  // wsctx_ exceeds certain limit.
+  wslay_event_msg arg = {
+    WSLAY_TEXT_FRAME, reinterpret_cast<const uint8_t*>(msg.c_str()), msg.size()
+  };
+  wslay_event_queue_msg(wsctx_, &arg);
+}
+
+bool WebSocketSession::closeReceived()
+{
+  return wslay_event_get_close_received(wsctx_);
+}
+
+bool WebSocketSession::closeSent()
+{
+  return wslay_event_get_close_sent(wsctx_);
+}
+
+} // namespace rpc
+
+} // namespace aria2