add websocket lib

speechx/speechx/websocket/CMakeLists.txt

+project(websocket)
+
+add_library(websocket STATIC
+  websocket_server.cc
+  websocket_client.cc
+)
+target_link_libraries(websocket PUBLIC frontend decoder nnet)

speechx/speechx/websocket/websocket_client.cc

+// Copyright (c) 2022 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "websocket/websocket_client.h"
+
+#include "boost/json/src.hpp"
+
+namespace json = boost::json;
+
+namespace ppspeech {
+
+WebSocketClient::WebSocketClient(const std::string& host, int port)
+    : host_(host), port_(port) {
+    Connect();
+    t_.reset(new std::thread(&WebSocketClient::ReadLoopFunc, this));
+}
+
+void WebSocketClient::Connect() {
+    tcp::resolver resolver{ioc_};
+    // Look up the domain name
+    auto const results = resolver.resolve(host_, std::to_string(port_));
+    // Make the connection on the IP address we get from a lookup
+    auto ep = asio::connect(ws_.next_layer(), results);
+    // Update the host_ string. This will provide the value of the
+    // Host HTTP header during the WebSocket handshake.
+    // See https://tools.ietf.org/html/rfc7230#section-5.4
+    std::string host = host_ + ":" + std::to_string(ep.port());
+    // Perform the websocket handshake
+    ws_.handshake(host, "/");
+}
+
+void WebSocketClient::SendTextData(const std::string& data) {
+    ws_.text(true);
+    ws_.write(asio::buffer(data));
+}
+
+void WebSocketClient::SendBinaryData(const void* data, size_t size) {
+    ws_.binary(true);
+    ws_.write(asio::buffer(data, size));
+}
+
+void WebSocketClient::Close() { ws_.close(websocket::close_code::normal); }
+
+void WebSocketClient::ReadLoopFunc() {
+    try {
+        while (true) {
+            beast::flat_buffer buffer;
+            ws_.read(buffer);
+            std::string message = beast::buffers_to_string(buffer.data());
+            LOG(INFO) << message;
+            CHECK(ws_.got_text());
+            json::object obj = json::parse(message).as_object();
+            if (obj["status"] != "ok") {
+                break;
+            }
+            if (obj["type"] == "final_result") {
+                result_ = obj["result"].as_string().c_str();
+            }
+            if (obj["type"] == "speech_end") {
+                done_ = true;
+                break;
+            }
+        }
+    } catch (beast::system_error const& se) {
+        // This indicates that the session was closed
+        if (se.code() != websocket::error::closed) {
+            LOG(ERROR) << se.code().message();
+        }
+    } catch (std::exception const& e) {
+        LOG(ERROR) << e.what();
+    }
+}
+
+void WebSocketClient::Join() { t_->join(); }
+
+void WebSocketClient::SendStartSignal() {
+    json::value start_tag = {{"signal", "start"}};
+    std::string start_message = json::serialize(start_tag);
+    this->SendTextData(start_message);
+}
+
+void WebSocketClient::SendDataEnd() {
+    json::value end_tag = {{"data", "end"}};
+    std::string end_message = json::serialize(end_tag);
+    this->SendTextData(end_message);
+}
+
+void WebSocketClient::SendEndSignal() {
+    json::value end_tag = {{"signal", "end"}};
+    std::string end_message = json::serialize(end_tag);
+    this->SendTextData(end_message);
+}
+
+}  // namespace ppspeech

speechx/speechx/websocket/websocket_client.h

+// Copyright (c) 2022 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "base/common.h"
+
+#include "boost/asio/connect.hpp"
+#include "boost/asio/ip/tcp.hpp"
+#include "boost/beast/core.hpp"
+#include "boost/beast/websocket.hpp"
+
+namespace beast = boost::beast;          // from <boost/beast.hpp>
+namespace http = beast::http;            // from <boost/beast/http.hpp>
+namespace websocket = beast::websocket;  // from <boost/beast/websocket.hpp>
+namespace asio = boost::asio;            // from <boost/asio.hpp>
+using tcp = boost::asio::ip::tcp;        // from <boost/asio/ip/tcp.hpp>
+
+namespace ppspeech {
+
+class WebSocketClient {
+  public:
+    WebSocketClient(const std::string& host, int port);
+
+    void SendTextData(const std::string& data);
+    void SendBinaryData(const void* data, size_t size);
+    void ReadLoopFunc();
+    void Close();
+    void Join();
+    void SendStartSignal();
+    void SendEndSignal();
+    void SendDataEnd();
+    bool Done() const { return done_; }
+    std::string GetResult() { return result_; }
+
+  private:
+    void Connect();
+    std::string host_;
+    std::string result_;
+    int port_;
+    bool done_ = false;
+    asio::io_context ioc_;
+    websocket::stream<tcp::socket> ws_{ioc_};
+    std::unique_ptr<std::thread> t_{nullptr};
+};
+}
\ No newline at end of file

speechx/speechx/websocket/websocket_server.cc

+// Copyright (c) 2022 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+
+#include "websocket/websocket_server.h"
+
+#include "base/common.h"
+#include "boost/json/src.hpp"
+
+namespace json = boost::json;
+
+namespace ppspeech {
+
+ConnectionHandler::ConnectionHandler(
+    tcp::socket&& socket, const RecognizerResource& recognizer_resource)
+    : ws_(std::move(socket)), recognizer_resource_(recognizer_resource) {}
+
+void ConnectionHandler::OnSpeechStart() {
+    LOG(INFO) << "Recieved speech start signal, start reading speech";
+    got_start_tag_ = true;
+    json::value rv = {{"status", "ok"}, {"type", "server_ready"}};
+    ws_.text(true);
+    ws_.write(asio::buffer(json::serialize(rv)));
+    recognizer_ = std::make_shared<Recognizer>(recognizer_resource_);
+    // Start decoder thread
+    decode_thread_ = std::make_shared<std::thread>(
+        &ConnectionHandler::DecodeThreadFunc, this);
+}
+
+void ConnectionHandler::OnSpeechEnd() {
+    LOG(INFO) << "Recieved speech end signal";
+    CHECK(recognizer_ != nullptr);
+    recognizer_->SetFinished();
+    got_end_tag_ = true;
+}
+
+void ConnectionHandler::OnFinalResult(const std::string& result) {
+    LOG(INFO) << "Final result: " << result;
+    json::value rv = {
+        {"status", "ok"}, {"type", "final_result"}, {"result", result}};
+    ws_.text(true);
+    ws_.write(asio::buffer(json::serialize(rv)));
+}
+
+void ConnectionHandler::OnFinish() {
+    // Send finish tag
+    json::value rv = {{"status", "ok"}, {"type", "speech_end"}};
+    ws_.text(true);
+    ws_.write(asio::buffer(json::serialize(rv)));
+}
+
+void ConnectionHandler::OnSpeechData(const beast::flat_buffer& buffer) {
+    // Read binary PCM data
+    int num_samples = buffer.size() / sizeof(int16_t);
+    kaldi::Vector<kaldi::BaseFloat> pcm_data(num_samples);
+    const int16_t* pdata = static_cast<const int16_t*>(buffer.data().data());
+    for (int i = 0; i < num_samples; i++) {
+        pcm_data(i) = static_cast<float>(*pdata);
+        pdata++;
+    }
+    VLOG(2) << "Recieved " << num_samples << " samples";
+    LOG(INFO) << "Recieved " << num_samples << " samples";
+    CHECK(recognizer_ != nullptr);
+    recognizer_->Accept(pcm_data);
+}
+
+void ConnectionHandler::DecodeThreadFunc() {
+    try {
+        while (true) {
+            recognizer_->Decode();
+            if (recognizer_->IsFinished()) {
+                LOG(INFO) << "enter finish";
+                recognizer_->Decode();
+                LOG(INFO) << "finish";
+                std::string result = recognizer_->GetFinalResult();
+                OnFinalResult(result);
+                OnFinish();
+                stop_recognition_ = true;
+                break;
+            }
+        }
+    } catch (std::exception const& e) {
+        LOG(ERROR) << e.what();
+    }
+}
+
+void ConnectionHandler::OnError(const std::string& message) {
+    json::value rv = {{"status", "failed"}, {"message", message}};
+    ws_.text(true);
+    ws_.write(asio::buffer(json::serialize(rv)));
+    // Close websocket
+    ws_.close(websocket::close_code::normal);
+}
+
+void ConnectionHandler::OnText(const std::string& message) {
+    json::value v = json::parse(message);
+    if (v.is_object()) {
+        json::object obj = v.get_object();
+        if (obj.find("signal") != obj.end()) {
+            json::string signal = obj["signal"].as_string();
+            if (signal == "start") {
+                OnSpeechStart();
+            } else if (signal == "end") {
+                OnSpeechEnd();
+            } else {
+                OnError("Unexpected signal type");
+            }
+        } else {
+            OnError("Wrong message header");
+        }
+    } else {
+        OnError("Wrong protocol");
+    }
+}
+
+void ConnectionHandler::operator()() {
+    try {
+        // Accept the websocket handshake
+        ws_.accept();
+        for (;;) {
+            // This buffer will hold the incoming message
+            beast::flat_buffer buffer;
+            // Read a message
+            ws_.read(buffer);
+            if (ws_.got_text()) {
+                std::string message = beast::buffers_to_string(buffer.data());
+                LOG(INFO) << message;
+                OnText(message);
+                if (got_end_tag_) {
+                    break;
+                }
+            } else {
+                if (!got_start_tag_) {
+                    OnError("Start signal is expected before binary data");
+                } else {
+                    if (stop_recognition_) {
+                        break;
+                    }
+                    OnSpeechData(buffer);
+                }
+            }
+        }
+
+        LOG(INFO) << "Read all pcm data, wait for decoding thread";
+        if (decode_thread_ != nullptr) {
+            decode_thread_->join();
+        }
+    } catch (beast::system_error const& se) {
+        // This indicates that the session was closed
+        if (se.code() != websocket::error::closed) {
+            if (decode_thread_ != nullptr) {
+                decode_thread_->join();
+            }
+            OnSpeechEnd();
+            LOG(ERROR) << se.code().message();
+        }
+    } catch (std::exception const& e) {
+        LOG(ERROR) << e.what();
+    }
+}
+
+void WebSocketServer::Start() {
+    try {
+        auto const address = asio::ip::make_address("0.0.0.0");
+        tcp::acceptor acceptor{ioc_, {address, static_cast<uint16_t>(port_)}};
+        for (;;) {
+            // This will receive the new connection
+            tcp::socket socket{ioc_};
+            // Block until we get a connection
+            acceptor.accept(socket);
+            // Launch the session, transferring ownership of the socket
+            ConnectionHandler handler(std::move(socket), recognizer_resource_);
+            std::thread t(std::move(handler));
+            t.detach();
+        }
+    } catch (const std::exception& e) {
+        LOG(FATAL) << e.what();
+    }
+}
+
+}  // namespace ppspeech

speechx/speechx/websocket/websocket_server.h

+// Copyright (c) 2022 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+
+#pragma once
+
+#include "base/common.h"
+
+#include "boost/asio/connect.hpp"
+#include "boost/asio/ip/tcp.hpp"
+#include "boost/beast/core.hpp"
+#include "boost/beast/websocket.hpp"
+
+#include "decoder/recognizer.h"
+#include "frontend/audio/feature_pipeline.h"
+
+namespace beast = boost::beast;          // from <boost/beast.hpp>
+namespace http = beast::http;            // from <boost/beast/http.hpp>
+namespace websocket = beast::websocket;  // from <boost/beast/websocket.hpp>
+namespace asio = boost::asio;            // from <boost/asio.hpp>
+using tcp = boost::asio::ip::tcp;        // from <boost/asio/ip/tcp.hpp>
+
+namespace ppspeech {
+class ConnectionHandler {
+  public:
+    ConnectionHandler(tcp::socket&& socket,
+                      const RecognizerResource& recognizer_resource_);
+    void operator()();
+
+  private:
+    void OnSpeechStart();
+    void OnSpeechEnd();
+    void OnText(const std::string& message);
+    void OnFinish();
+    void OnSpeechData(const beast::flat_buffer& buffer);
+    void OnError(const std::string& message);
+    void OnPartialResult(const std::string& result);
+    void OnFinalResult(const std::string& result);
+    void DecodeThreadFunc();
+    std::string SerializeResult(bool finish);
+
+    bool continuous_decoding_ = false;
+    int nbest_ = 1;
+    websocket::stream<tcp::socket> ws_;
+    RecognizerResource recognizer_resource_;
+
+    bool got_start_tag_ = false;
+    bool got_end_tag_ = false;
+    // When endpoint is detected, stop recognition, and stop receiving data.
+    bool stop_recognition_ = false;
+    std::shared_ptr<ppspeech::Recognizer> recognizer_ = nullptr;
+    std::shared_ptr<std::thread> decode_thread_ = nullptr;
+};
+
+class WebSocketServer {
+  public:
+    WebSocketServer(int port, const RecognizerResource& recognizer_resource)
+        : port_(port), recognizer_resource_(recognizer_resource) {}
+
+    void Start();
+
+  private:
+    int port_;
+    RecognizerResource recognizer_resource_;
+    // The io_context is required for all I/O
+    asio::io_context ioc_{1};
+};
+
+}  // namespace ppspeech