rework client using async api

autotest/CMakeLists.txt

@@ -1,24 +1,2 @@
-# Automation test
+add_subdirectory(client_autotest)
-
+add_subdirectory(client_timeout_autotest)
-set(AT_SRCS
-    client_autotest.cc
-    client_timeout_autotest.cc
-    main.cc
-    )
-
-# Common libraries to link.
-set(AT_LIBS
-    webcc
-    jsoncpp
-    GTest::GTest)
-
-if(UNIX)
-    # Add `-ldl` for Linux to avoid "undefined reference to `dlopen'".
-    set(AT_LIBS ${AT_LIBS} ${CMAKE_DL_LIBS})
-endif()
-
-set(AT_TARGET_NAME autotest)
-
-add_executable(${AT_TARGET_NAME} ${AT_SRCS})
-target_link_libraries(${AT_TARGET_NAME} ${AT_LIBS})
-set_target_properties(${AT_TARGET_NAME} PROPERTIES FOLDER "Tests")

autotest/client_autotest/CMakeLists.txt

@@ -0,0 +1,24 @@
+set(SRCS
+    client_autotest.cc
+    main.cc
+    )
+
+# Common libraries to link.
+set(LIBS
+    webcc
+    jsoncpp
+    GTest::GTest
+    )
+
+if(UNIX)
+    # Add `-ldl` for Linux to avoid "undefined reference to `dlopen'".
+    set(LIBS ${LIBS} ${CMAKE_DL_LIBS})
+endif()
+
+set(TARGET_NAME client_autotest)
+
+add_executable(${TARGET_NAME} ${SRCS})
+
+target_link_libraries(${TARGET_NAME} ${LIBS})
+
+set_target_properties(${TARGET_NAME} PROPERTIES FOLDER "Tests")

autotest/client_timeout_autotest/CMakeLists.txt

@@ -0,0 +1,22 @@
+set(SRCS
+    client_timeout_autotest.cc
+    main.cc
+    )
+
+# Common libraries to link.
+set(LIBS
+    webcc
+    jsoncpp
+    GTest::GTest
+    )
+
+if(UNIX)
+    # Add `-ldl` for Linux to avoid "undefined reference to `dlopen'".
+    set(LIBS ${LIBS} ${CMAKE_DL_LIBS})
+endif()
+
+set(TARGET_NAME client_timeout_autotest)
+
+add_executable(${TARGET_NAME} ${SRCS})
+target_link_libraries(${TARGET_NAME} ${LIBS})
+set_target_properties(${TARGET_NAME} PROPERTIES FOLDER "Tests")

autotest/client_timeout_autotest/client_timeout_autotest.cc

@@ -9,7 +9,7 @@
 
 namespace {
 
-const char* kData = "Hello, World!";
+const char* const kData = "Hello, World!";
 
 const std::uint16_t kPort = 8080;
 
@@ -83,8 +83,8 @@ TEST_F(ClientTimeoutTest, NoTimeout) {
 TEST_F(ClientTimeoutTest, Timeout) {
   webcc::ClientSession session;
 
-  // Change timeout to 1s.
+  // Change read timeout to 1s.
-  session.set_timeout(1);
+  session.set_read_timeout(1);
 
   webcc::ResponsePtr r;
   bool timeout = false;

autotest/client_timeout_autotest/main.cc

@@ -0,0 +1,11 @@
+#include "gtest/gtest.h"
+
+#include "webcc/logger.h"
+
+int main(int argc, char* argv[]) {
+  // Set webcc::LOG_CONSOLE to enable logging.
+  WEBCC_LOG_INIT("", 0);
+
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}

examples/client_basics.cc

@@ -8,7 +8,8 @@ int main() {
   WEBCC_LOG_INIT("", webcc::LOG_CONSOLE);
 
   webcc::ClientSession session;
-
+  session.set_connect_timeout(5);
+  session.set_read_timeout(5);
   session.Accept("application/json");
 
   webcc::ResponsePtr r;

examples/concurrency_test.cc

@@ -30,7 +30,7 @@ int main(int argc, const char* argv[]) {
     threads.emplace_back([&url]() {
       // NOTE: Each thread has its own client session.
       webcc::ClientSession session;
-      session.set_timeout(180);
+      session.set_read_timeout(180);
 
       try {
         LOG_USER("Start");

examples/file_downloader.cc

@@ -27,7 +27,10 @@ int main(int argc, char* argv[]) {
   webcc::ClientSession session;
 
   try {
-    auto r = session.Send(webcc::RequestBuilder{}.Get(url)(), true);
+    auto r = session.Send(webcc::RequestBuilder{}.Get(url)(), true,
+                          [](std::size_t length, std::size_t total_length) {
+      std::cout << "Progress " << length << " / " << total_length << std::endl;
+    });
 
     if (auto file_body = r->file_body()) {
       file_body->Move(path);

webcc/client.cc

@@ -3,23 +3,40 @@
 #include "webcc/logger.h"
 
 using boost::asio::ip::tcp;
+using namespace std::placeholders;
 
 namespace webcc {
 
-Client::Client()
+#if WEBCC_ENABLE_SSL
-    : timer_(io_context_),
+
-      ssl_verify_(true),
+Client::Client(boost::asio::io_context& io_context,
-      buffer_size_(kBufferSize),
+               boost::asio::ssl::context& ssl_context)
-      timeout_(kMaxReadSeconds),
+    : io_context_(io_context),
-      closed_(false),
+      ssl_context_(ssl_context),
-      timer_canceled_(false) {
+      resolver_(io_context),
+      deadline_timer_(io_context) {
+
 }
 
-Error Client::Request(RequestPtr request, bool connect, bool stream) {
+#else
-  closed_ = false;
+
-  timer_canceled_ = false;
+Client::Client(boost::asio::io_context& io_context)
+    : io_context_(io_context),
+      resolver_(io_context),
+      deadline_timer_(io_context) {
+}
+
+#endif  // WEBCC_ENABLE_SSL
+
+Error Client::Request(RequestPtr request, bool stream) {
+  LOG_VERB("Request begin");
+
+  request_finished_ = false;
   error_ = Error{};
 
+  request_ = request;
+
+  length_read_ = 0;
   response_.reset(new Response{});
   response_parser_.Init(response_.get(), stream);
 
@@ -35,246 +52,312 @@ Error Client::Request(RequestPtr request, bool connect, bool stream) {
   //     have Content-Length;
   //   - If request.Accept-Encoding is "identity", the response will have
   //     Content-Length.
-  if (request->method() == methods::kHead) {
+  if (request_->method() == methods::kHead) {
     response_parser_.set_ignore_body(true);
   } else {
     // Reset in case the connection is persistent.
     response_parser_.set_ignore_body(false);
   }
 
-  io_context_.restart();
+  if (!connected_) {
-
+    AsyncConnect();
-  if (connect) {
+  } else {
-    // No existing socket connection was specified, create a new one.
+    AsyncWrite();
-    Connect(request);
-
-    if (error_) {
-      return error_;
-    }
   }
 
-  WriteRequest(request);
+  // Wait for the request to be finished.
+  std::unique_lock<std::mutex> response_lock{ request_mutex_ };
+  request_cv_.wait(response_lock, [=] { return request_finished_; });
 
-  if (error_) {
+  LOG_VERB("Request end");
-    return error_;
-  }
-
-  ReadResponse();
 
   return error_;
 }
 
 void Client::Close() {
-  if (closed_) {
+  if (!connected_) {
+    //resolver_.cancel();  // TODO
+    if (socket_) {
+      // Cancel any async operations on the socket.
+      LOG_VERB("Close socket");
+      socket_->Close();
+      // Make sure the current request, if any, could be finished.
+      FinishRequest();
+    }
     return;
   }
 
-  closed_ = true;
+  connected_ = false;
-
-  LOG_INFO("Close socket...");
 
+  if (socket_) {
+    LOG_INFO("Shutdown & close socket");
+    socket_->Shutdown();
     socket_->Close();
+    // Make sure the current request, if any, could be finished.
+    FinishRequest();
   }
 
-void Client::Connect(RequestPtr request) {
+  LOG_INFO("Socket closed");
-  if (request->url().scheme() == "https") {
+}
+
+void Client::AsyncConnect() {
+  if (request_->url().scheme() == "https") {
 #if WEBCC_ENABLE_SSL
-    socket_.reset(new SslSocket{ io_context_, ssl_verify_ });
+    socket_.reset(new SslSocket{ io_context_, ssl_context_, ssl_verify_ });
-    DoConnect(request, "443");
+    AsyncResolve("443");
 #else
     LOG_ERRO("SSL/HTTPS support is not enabled.");
     error_.Set(Error::kSyntaxError, "SSL/HTTPS is not supported");
+    FinishRequest();
 #endif  // WEBCC_ENABLE_SSL
   } else {
     socket_.reset(new Socket{ io_context_ });
-    DoConnect(request, "80");
+    AsyncResolve("80");
   }
 }
 
-void Client::DoConnect(RequestPtr request, const std::string& default_port) {
+void Client::AsyncResolve(const std::string& default_port) {
-  tcp::resolver resolver(io_context_);
+  std::string port = request_->port();
-
-  std::string port = request->port();
   if (port.empty()) {
     port = default_port;
   }
 
-  LOG_VERB("Resolve host (%s)...", request->host().c_str());
+  LOG_VERB("Resolve host (%s)", request_->host().c_str());
-
-  boost::system::error_code ec;
 
   // The protocol depends on the `host`, both V4 and V6 are supported.
-  auto endpoints = resolver.resolve(request->host(), port, ec);
+  resolver_.async_resolve(request_->host(), port,
+                          std::bind(&Client::OnResolve, this, _1, _2));
+}
 
+void Client::OnResolve(boost::system::error_code ec,
+                       tcp::resolver::results_type endpoints) {
   if (ec) {
-    LOG_ERRO("Host resolve error (%s): %s, %s.", ec.message().c_str(),
+    LOG_ERRO("Host resolve error (%s)", ec.message().c_str());
-             request->host().c_str(), port.c_str());
     error_.Set(Error::kResolveError, "Host resolve error");
+    FinishRequest();
     return;
   }
 
-  LOG_VERB("Connect to server...");
+  LOG_VERB("Connect socket");
 
-  // Use sync API directly since we don't need timeout control.
+  AsyncWaitDeadlineTimer(connect_timeout_);
 
-  if (!socket_->Connect(request->host(), endpoints)) {
+  socket_->AsyncConnect(request_->host(), endpoints,
-    error_.Set(Error::kConnectError, "Endpoint connect error");
+                        std::bind(&Client::OnConnect, this, _1, _2));
-    Close();
-    return;
 }
 
-  LOG_VERB("Socket connected.");
+void Client::OnConnect(boost::system::error_code ec, tcp::endpoint) {
-}
+  LOG_VERB("On connect");
 
-void Client::WriteRequest(RequestPtr request) {
+  StopDeadlineTimer();
-  LOG_VERB("HTTP request:\n%s", request->Dump().c_str());
-
-  // NOTE:
-  // It doesn't make much sense to set a timeout for socket write.
-  // I find that it's almost impossible to simulate a situation in the server
-  // side to test this timeout.
-
-  // Use sync API directly since we don't need timeout control.
-
-  boost::system::error_code ec;
-
-  if (socket_->Write(request->GetPayload(), &ec)) {
-    // Write request body.
-    auto body = request->body();
-    body->InitPayload();
-    for (auto p = body->NextPayload(true); !p.empty();
-         p = body->NextPayload(true)) {
-      if (!socket_->Write(p, &ec)) {
-        break;
-      }
-    }
-  }
 
   if (ec) {
-    LOG_ERRO("Socket write error (%s).", ec.message().c_str());
+    if (ec == boost::asio::error::operation_aborted) {
+      // Socket has been closed by OnDeadlineTimer() or Close().
+      LOG_WARN("Connect operation aborted");
+    } else {
+      LOG_INFO("Connect error");
+      // No need to close socket since no async operation is on it.
+      //   socket_->Close();
+    }
+
+    error_.Set(Error::kConnectError, "Socket connect error");
+    FinishRequest();
+    return;
+  }
+
+  LOG_INFO("Socket connected");
+
+  connected_ = true;
+
+  AsyncWrite();
+}
+
+void Client::AsyncWrite() {
+  LOG_VERB("Request:\n%s", request_->Dump().c_str());
+
+  socket_->AsyncWrite(request_->GetPayload(),
+                      std::bind(&Client::OnWrite, this, _1, _2));
+}
+
+void Client::OnWrite(boost::system::error_code ec, std::size_t length) {
+  if (ec) {
+    HandleWriteError(ec);
+    return;
+  }
+
+  request_->body()->InitPayload();
+
+  AsyncWriteBody();
+}
+
+void Client::AsyncWriteBody() {
+  auto p = request_->body()->NextPayload(true);
+
+  if (!p.empty()) {
+    socket_->AsyncWrite(p, std::bind(&Client::OnWriteBody, this, _1, _2));
+  } else {
+    LOG_INFO("Request send");
+
+    // Start the read deadline timer.
+    AsyncWaitDeadlineTimer(read_timeout_);
+
+    // Start to read response.
+    AsyncRead();
+  }
+}
+
+void Client::OnWriteBody(boost::system::error_code ec, std::size_t legnth) {
+  if (ec) {
+    HandleWriteError(ec);
+    return;
+  }
+
+  // Continue to write the next payload of body.
+  AsyncWriteBody();
+}
+
+void Client::HandleWriteError(boost::system::error_code ec) {
+  if (ec == boost::asio::error::operation_aborted) {
+    // Socket has been closed by OnDeadlineTimer() or Close().
+    LOG_WARN("Write operation aborted");
+  } else {
+    LOG_ERRO("Socket write error (%s)", ec.message().c_str());
     Close();
+  }
+
   error_.Set(Error::kSocketWriteError, "Socket write error");
+  FinishRequest();
 }
 
-  LOG_INFO("Request sent.");
+void Client::AsyncRead() {
+  socket_->AsyncReadSome(std::bind(&Client::OnRead, this, _1, _2), &buffer_);
 }
 
-void Client::ReadResponse() {
+void Client::OnRead(boost::system::error_code ec, std::size_t length) {
-  LOG_VERB("Read response (timeout: %ds)...", timeout_);
+  StopDeadlineTimer();
 
-  DoReadResponse();
+  if (ec) {
-
+    if (ec == boost::asio::error::operation_aborted) {
-  if (!error_) {
+      // Socket has been closed by OnDeadlineTimer() or Close().
-    LOG_VERB("HTTP response:\n%s", response_->Dump().c_str());
+      LOG_WARN("Read operation aborted");
-  }
+    } else {
-}
+      LOG_ERRO("Socket read error (%s)", ec.message().c_str());
-
-void Client::DoReadResponse() {
-  boost::system::error_code ec = boost::asio::error::would_block;
-  std::size_t length = 0;
-
-  // The read handler.
-  auto handler = [&ec, &length](boost::system::error_code inner_ec,
-                                std::size_t inner_length) {
-    ec = inner_ec;
-    length = inner_length;
-  };
-
-  while (true) {
-    ec = boost::asio::error::would_block;
-    length = 0;
-
-    socket_->AsyncReadSome(std::move(handler), &buffer_);
-
-    // Start the timer.
-    DoWaitTimer();
-
-    // Block until the asynchronous operation has completed.
-    do {
-      io_context_.run_one();
-    } while (ec == boost::asio::error::would_block);
-
-    // Stop the timer.
-    CancelTimer();
-
-    // The error normally is caused by timeout. See OnTimer().
-    if (ec || length == 0) {
       Close();
-      error_.Set(Error::kSocketReadError, "Socket read error");
-      LOG_ERRO("Socket read error (%s).", ec.message().c_str());
-      break;
     }
 
-    LOG_INFO("Read data, length: %u.", length);
+    error_.Set(Error::kSocketReadError, "Socket read error");
+    FinishRequest();
+    return;
+  }
+
+  length_read_ += length;
+
+  LOG_INFO("Read length: %u", length);
 
   // Parse the piece of data just read.
   if (!response_parser_.Parse(buffer_.data(), length)) {
+    LOG_ERRO("Failed to parse the response");
     Close();
-      error_.Set(Error::kParseError, "HTTP parse error");
+    error_.Set(Error::kParseError, "Response parse error");
-      LOG_ERRO("Failed to parse the HTTP response.");
+    FinishRequest();
-      break;
+    return;
+  }
+
+  // Inform progress callback if it's specified.
+  if (progress_callback_) {
+    if (response_parser_.header_ended()) {
+      // NOTE: Need to get rid of the header length.
+      progress_callback_(length_read_ - response_parser_.header_length(),
+                         response_parser_.content_length());
+    }
   }
 
   if (response_parser_.finished()) {
-      // Stop trying to read once all content has been received, because
+    LOG_VERB("Response:\n%s", response_->Dump().c_str());
-      // some servers will block extra call to read_some().
 
     if (response_->IsConnectionKeepAlive()) {
-        // Close the timer but keep the socket connection.
+      LOG_INFO("Keep the socket connection alive");
-        LOG_INFO("Keep the socket connection alive.");
     } else {
       Close();
     }
 
-      // Stop reading.
+    // Stop trying to read once all content has been received, because some
-      LOG_INFO("Finished to read the HTTP response.");
+    // servers will block extra call to read_some().
-      break;
+
-    }
+    LOG_INFO("Finished to read the response");
-  }
+    FinishRequest();
+    return;
   }
 
-void Client::DoWaitTimer() {
+  // Continue to read the response.
-  LOG_VERB("Wait timer asynchronously.");
+  AsyncRead();
-  timer_.expires_after(std::chrono::seconds(timeout_));
-  timer_.async_wait(std::bind(&Client::OnTimer, this, std::placeholders::_1));
 }
 
-void Client::OnTimer(boost::system::error_code ec) {
+void Client::AsyncWaitDeadlineTimer(int seconds) {
-  LOG_VERB("On timer.");
+  if (seconds <= 0) {
+    deadline_timer_stopped_ = true;
+    return;
+  }
 
-  // timer_.cancel() was called.
+  LOG_VERB("Async wait deadline timer");
+
+  deadline_timer_stopped_ = false;
+
+  deadline_timer_.expires_after(std::chrono::seconds(seconds));
+  deadline_timer_.async_wait(std::bind(&Client::OnDeadlineTimer, this, _1));
+}
+
+void Client::OnDeadlineTimer(boost::system::error_code ec) {
+  LOG_VERB("On deadline timer");
+
+  deadline_timer_stopped_ = true;
+
+  // deadline_timer_.cancel() was called.
   if (ec == boost::asio::error::operation_aborted) {
-    LOG_VERB("Timer canceled.");
+    LOG_VERB("Deadline timer canceled");
     return;
   }
 
-  if (closed_) {
+  LOG_WARN("Timeout");
-    LOG_VERB("Socket has been closed.");
-    return;
-  }
 
-  if (timer_.expiry() <= boost::asio::steady_timer::clock_type::now()) {
+  // Cancel the async operations on the socket.
-    // The deadline has passed. The socket is closed so that any outstanding
+  // OnXxx() will be called with `error::operation_aborted`.
-    // asynchronous operations are canceled.
+  if (connected_) {
-    LOG_WARN("HTTP client timed out.");
-    error_.set_timeout(true);
     Close();
+  } else {
+    socket_->Close();
+  }
+
+  error_.set_timeout(true);
+}
+
+void Client::StopDeadlineTimer() {
+  if (deadline_timer_stopped_) {
     return;
   }
 
-  // Put the actor back to sleep.
+  LOG_INFO("Cancel deadline timer");
-  DoWaitTimer();
+
+  try {
+    // Cancel the async wait operation on this timer.
+    deadline_timer_.cancel();
+  } catch (const boost::system::system_error&) {
   }
 
-void Client::CancelTimer() {
+  deadline_timer_stopped_ = true;
-  if (timer_canceled_) {
+}
+
+void Client::FinishRequest() {
+  {
+    std::lock_guard<std::mutex> lock{ request_mutex_ };
+    if (!request_finished_) {
+      request_finished_ = true;
+    } else {
       return;
     }
-
+  }
-  LOG_INFO("Cancel timer...");
+  request_cv_.notify_one();
-  timer_.cancel();
-
-  timer_canceled_ = true;
 }
 
 }  // namespace webcc

webcc/client.h

@@ -1,8 +1,9 @@
 #ifndef WEBCC_CLIENT_H_
 #define WEBCC_CLIENT_H_
 
-#include <cassert>
+#include <condition_variable>
 #include <memory>
+#include <mutex>
 #include <string>
 #include <vector>
 
@@ -19,18 +20,22 @@
 namespace webcc {
 
 // Synchronous HTTP & HTTPS client.
-// In synchronous mode, a request won't return until the response is received
+// A request won't return until the response is received or timeout occurs.
-// or timeout occurs.
-// Please don't use the same client object in multiple threads.
 class Client {
 public:
-  Client();
+  // TODO
-
+#if WEBCC_ENABLE_SSL
-  ~Client() = default;
+  Client(boost::asio::io_context& io_context,
+         boost::asio::ssl::context& ssl_context);
+#else
+  explicit Client(boost::asio::io_context& io_context);
+#endif
 
   Client(const Client&) = delete;
   Client& operator=(const Client&) = delete;
 
+  ~Client() = default;
+
   void set_ssl_verify(bool ssl_verify) {
     ssl_verify_ = ssl_verify;
   }
@@ -41,19 +46,35 @@ public:
     }
   }
 
-  // Set the timeout (in seconds) for reading response.
+  void set_connect_timeout(int timeout) {
-  void set_timeout(int timeout)  {
     if (timeout > 0) {
-      timeout_ = timeout;
+      connect_timeout_ = timeout;
     }
   }
 
-  // Connect to server, send request, wait until response is received.
+  void set_read_timeout(int timeout)  {
-  Error Request(RequestPtr request, bool connect = true, bool stream = false);
+    if (timeout > 0) {
+      read_timeout_ = timeout;
+    }
+  }
+
+  // Set progress callback to be informed about the read progress.
+  // TODO: What about write?
+  // TODO: std::move?
+  void set_progress_callback(ProgressCallback callback) {
+    progress_callback_ = callback;
+  }
+
+  // Connect, send request, wait until response is received.
+  Error Request(RequestPtr request, bool stream = false);
 
   // Close the socket.
   void Close();
 
+  bool connected() const {
+    return connected_;
+  }
+
   ResponsePtr response() const {
     return response_;
   }
@@ -66,57 +87,82 @@ public:
     response_parser_.Init(nullptr, false);
   }
 
-  bool closed() const {
+private:
-    return closed_;
+  void AsyncConnect();
-  }
+
+  void AsyncResolve(const std::string& default_port);
+
+  void OnResolve(boost::system::error_code ec,
+                 boost::asio::ip::tcp::resolver::results_type endpoints);
+
+  void OnConnect(boost::system::error_code ec, boost::asio::ip::tcp::endpoint);
+
+  void AsyncWrite();
+  void OnWrite(boost::system::error_code ec, std::size_t length);
+
+  void AsyncWriteBody();
+  void OnWriteBody(boost::system::error_code ec, std::size_t length);
+
+  void HandleWriteError(boost::system::error_code ec);
+
+  void AsyncRead();
+  void OnRead(boost::system::error_code ec, std::size_t length);
+
+  void AsyncWaitDeadlineTimer(int seconds);
+  void OnDeadlineTimer(boost::system::error_code ec);
+  void StopDeadlineTimer();
+
+  void FinishRequest();
 
 private:
-  void Connect(RequestPtr request);
+  boost::asio::io_context& io_context_;
 
-  void DoConnect(RequestPtr request, const std::string& default_port);
+#if WEBCC_ENABLE_SSL
+  boost::asio::ssl::context& ssl_context_;
+#endif
 
-  void WriteRequest(RequestPtr request);
-
-  void ReadResponse();
-
-  void DoReadResponse();
-
-  void DoWaitTimer();
-  void OnTimer(boost::system::error_code ec);
-
-  // Cancel any async-operations waiting on the timer.
-  void CancelTimer();
-
-private:
-  boost::asio::io_context io_context_;
-
-  // Socket connection.
   std::unique_ptr<SocketBase> socket_;
 
+  boost::asio::ip::tcp::resolver resolver_;
+
+  bool request_finished_ = true;
+  std::condition_variable request_cv_;
+  std::mutex request_mutex_;
+
+  RequestPtr request_;
+
   ResponsePtr response_;
   ResponseParser response_parser_;
 
-  // Timer for the timeout control.
+  // The length already read.
-  boost::asio::steady_timer timer_;
+  std::size_t length_read_ = 0;
 
   // The buffer for reading response.
   std::vector<char> buffer_;
 
   // Verify the certificate of the peer or not (for HTTPS).
-  bool ssl_verify_;
+  bool ssl_verify_ = true;
 
   // The size of the buffer for reading response.
   // 0 means default value will be used.
-  std::size_t buffer_size_;
+  std::size_t buffer_size_ = kBufferSize;
 
-  // Timeout (seconds) for receiving response.
+  // Timeout (seconds) for connecting to server.
-  int timeout_;
+  // Default as 0 to disable our own control (i.e., deadline_timer_).
+  int connect_timeout_ = 0;
 
-  // Connection closed.
+  // Timeout (seconds) for reading response.
-  bool closed_;
+  int read_timeout_ = kMaxReadSeconds;
 
-  // Deadline timer canceled.
+  // Deadline timer for connecting to server.
-  bool timer_canceled_;
+  boost::asio::steady_timer deadline_timer_;
+  bool deadline_timer_stopped_ = true;
+
+  // Socket connected or not.
+  bool connected_ = false;
+
+  // Progress callback (optional).
+  ProgressCallback progress_callback_;
 
   Error error_;
 };

webcc/client_pool.cc

@@ -6,7 +6,7 @@ namespace webcc {
 
 ClientPool::~ClientPool() {
   if (!clients_.empty()) {
-    LOG_INFO("Close socket for all (%u) connections in the pool.",
+    LOG_INFO("Close socket for all (%u) connections in the pool",
              clients_.size());
 
     for (auto& pair : clients_) {
@@ -21,21 +21,21 @@ ClientPtr ClientPool::Get(const Key& key) const {
   if (it != clients_.end()) {
     return it->second;
   } else {
-    return ClientPtr{};
+    return {};
   }
 }
 
 void ClientPool::Add(const Key& key, ClientPtr client) {
   clients_[key] = client;
 
-  LOG_INFO("Added connection to pool (%s, %s, %s).",
+  LOG_INFO("Connection added to pool (%s, %s, %s)",
            key.scheme.c_str(), key.host.c_str(), key.port.c_str());
 }
 
 void ClientPool::Remove(const Key& key) {
   clients_.erase(key);
 
-  LOG_INFO("Removed connection from pool (%s, %s, %s).",
+  LOG_INFO("Connection removed from pool (%s, %s, %s)",
            key.scheme.c_str(), key.host.c_str(), key.port.c_str());
 }
 

webcc/client_session.cc

@@ -1,16 +1,123 @@
 #include "webcc/client_session.h"
 
+#include <cassert>
+
 #include "webcc/base64.h"
 #include "webcc/logger.h"
 #include "webcc/url.h"
 #include "webcc/utility.h"
  
+namespace ssl = boost::asio::ssl;
+
 namespace webcc {
 
-ClientSession::ClientSession(int timeout, bool ssl_verify,
+#if WEBCC_ENABLE_SSL
-                             std::size_t buffer_size)
+#if (defined(_WIN32) || defined(_WIN64))
-    : timeout_(timeout), ssl_verify_(ssl_verify), buffer_size_(buffer_size) {
+
+// Let OpenSSL on Windows use the system certificate store
+//   1. Load your certificate (in PCCERT_CONTEXT structure) from Windows Cert
+//      store using Crypto APIs.
+//   2. Get encrypted content of it in binary format as it is.
+//      [PCCERT_CONTEXT->pbCertEncoded].
+//   3. Parse this binary buffer into X509 certificate Object using OpenSSL's
+//      d2i_X509() method.
+//   4. Get handle to OpenSSL's trust store using SSL_CTX_get_cert_store()
+//      method.
+//   5. Load above parsed X509 certificate into this trust store using
+//      X509_STORE_add_cert() method.
+//   6. You are done!
+// NOTES: Enum Windows store with "ROOT" (not "CA").
+// See: https://stackoverflow.com/a/11763389/6825348
+
+static bool UseSystemCertificateStore(SSL_CTX* ssl_ctx) {
+  // NOTE: Cannot use nullptr to replace NULL.
+  HCERTSTORE cert_store = ::CertOpenSystemStoreW(NULL, L"ROOT");
+  if (cert_store == nullptr) {
+    LOG_ERRO("Cannot open Windows system certificate store.");
+    return false;
+  }
+
+  X509_STORE* x509_store = SSL_CTX_get_cert_store(ssl_ctx);
+  PCCERT_CONTEXT cert_context = nullptr;
+
+  while (cert_context = CertEnumCertificatesInStore(cert_store, cert_context)) {
+    auto in = (const unsigned char**)&cert_context->pbCertEncoded;
+    X509* x509 = d2i_X509(nullptr, in, cert_context->cbCertEncoded);
+
+    if (x509 != nullptr) {
+      if (X509_STORE_add_cert(x509_store, x509) == 0) {
+        LOG_ERRO("Cannot add Windows root certificate.");
+      }
+
+      X509_free(x509);
+    }
+  }
+
+  CertFreeCertificateContext(cert_context);
+  CertCloseStore(cert_store, 0);
+  return true;
+}
+
+#endif  // defined(_WIN32) || defined(_WIN64)
+#endif  // WEBCC_ENABLE_SSL
+
+ClientSession::ClientSession(bool ssl_verify, std::size_t buffer_size)
+    : work_guard_(boost::asio::make_work_guard(io_context_)),
+#if WEBCC_ENABLE_SSL
+      ssl_context_(ssl::context::sslv23),
+#endif
+      ssl_verify_(ssl_verify), buffer_size_(buffer_size) {
+#if WEBCC_ENABLE_SSL
+#if (defined(_WIN32) || defined(_WIN64))
+  // if (ssl_verify_) {
+    UseSystemCertificateStore(ssl_context_.native_handle());
+  // }
+#else
+  // Use the default paths for finding CA certificates.
+  ssl_context_.set_default_verify_paths();
+#endif  // defined(_WIN32) || defined(_WIN64)
+#endif  // WEBCC_ENABLE_SSL
+
   InitHeaders();
+
+  Start();
+}
+
+ClientSession::~ClientSession() {
+  Stop();
+}
+
+void ClientSession::Start() {
+  if (started_) {
+    return;
+  }
+
+  started_ = true;
+
+  io_context_.restart();
+
+  // Run the io context off in its own thread so that it operates completely
+  // asynchronously with respect to the rest of the program.
+
+  io_thread_.reset(new std::thread{ [this]() { io_context_.run(); }});
+
+  LOG_INFO("Loop is now running");
+}
+
+void ClientSession::Stop() {
+  if (!started_) {
+    return;
+  }
+
+  Cancel();
+
+  io_context_.stop();
+
+  io_thread_->join();
+
+  LOG_INFO("Loop stopped");
+
+  started_ = false;
 }
 
 void ClientSession::Accept(const std::string& content_types) {
@@ -68,9 +175,16 @@ void ClientSession::AuthToken(const std::string& token) {
   return Auth("Token", token);
 }
 
-ResponsePtr ClientSession::Send(RequestPtr request, bool stream) {
+ResponsePtr ClientSession::Send(RequestPtr request, bool stream,
+                                ProgressCallback callback) {
   assert(request);
 
+  std::lock_guard<std::mutex> lock{ mutex_ };
+
+  if (!started_) {
+    throw Error{ Error::kStateError, "Loop is not running" };
+  }
+
   for (auto& h : headers_.data()) {
     if (!request->HasHeader(h.first)) {
       request->SetHeader(h.first, h.second);
@@ -84,7 +198,13 @@ ResponsePtr ClientSession::Send(RequestPtr request, bool stream) {
 
   request->Prepare();
 
-  return DoSend(request, stream);
+  return DoSend(request, stream, callback);
+}
+
+void ClientSession::Cancel() {
+  if (client_) {
+    client_->Close();
+  }
 }
 
 void ClientSession::InitHeaders() {
@@ -99,34 +219,40 @@ void ClientSession::InitHeaders() {
   headers_.Set(headers::kConnection, "Keep-Alive");
 }
 
-ResponsePtr ClientSession::DoSend(RequestPtr request, bool stream) {
+ResponsePtr ClientSession::DoSend(RequestPtr request, bool stream,
+                                  ProgressCallback callback) {
   const ClientPool::Key key{ request->url() };
 
   // Reuse a pooled connection.
   bool reuse = false;
 
   ClientPtr client = pool_.Get(key);
+  
   if (!client) {
-    client.reset(new Client{});
+#if WEBCC_ENABLE_SSL
+    client.reset(new Client{ io_context_, ssl_context_ });
+#else
+    client.reset(new Client{ io_context_ });
+#endif  // WEBCC_ENABLE_SSL
     reuse = false;
   } else {
-    LOG_VERB("Reuse an existing connection.");
+    LOG_VERB("Reuse an existing connection");
     reuse = true;
   }
 
   client->set_ssl_verify(ssl_verify_);
   client->set_buffer_size(buffer_size_);
-  client->set_timeout(timeout_);
+  client->set_connect_timeout(connect_timeout_);
+  client->set_read_timeout(read_timeout_);
 
-  Error error = client->Request(request, !reuse, stream);
+  client->set_progress_callback(callback);
 
-  if (error) {
+  // Save current client for cancel.
-    if (reuse && error.code() == Error::kSocketWriteError) {
+  client_ = client;
-      LOG_WARN("Cannot send request with the reused connection. "
+
-               "The server must have closed it, reconnect and try again.");
+  Error error = client->Request(request, stream);
-      error = client->Request(request, true, stream);
+
-    }
+  client_.reset();
-  }
 
   if (error) {
     // Remove the failed connection from pool.
@@ -139,11 +265,11 @@ ResponsePtr ClientSession::DoSend(RequestPtr request, bool stream) {
   // Update connection pool.
 
   if (reuse) {
-    if (client->closed()) {
+    if (!client->connected()) {
       pool_.Remove(key);
     }
   } else {
-    if (!client->closed()) {
+    if (client->connected()) {
       pool_.Add(key, client);
     }
   }

webcc/client_session.h

@@ -1,9 +1,14 @@
 #ifndef WEBCC_CLIENT_SESSION_H_
 #define WEBCC_CLIENT_SESSION_H_
 
+#include <memory>
+#include <mutex>
 #include <string>
+#include <thread>
 #include <vector>
 
+#include "boost/asio/io_context.hpp"
+
 #include "webcc/client_pool.h"
 #include "webcc/request_builder.h"
 #include "webcc/response.h"
@@ -11,18 +16,32 @@
 namespace webcc {
 
 // HTTP requests session providing connection-pooling, configuration and more.
-// A session shouldn't be shared by multiple threads. Please create a new
+// NOTE: If a session is shared by multiple threads, the requests sent through
-// session for each thread instead.
+//       it will be serialized by using a mutex.
 class ClientSession {
 public:
-  explicit ClientSession(int timeout = 0, bool ssl_verify = true,
+  explicit ClientSession(bool ssl_verify = true, std::size_t buffer_size = 0);
-                         std::size_t buffer_size = 0);
 
-  ~ClientSession() = default;
+  ~ClientSession();
 
-  void set_timeout(int timeout) {
+  // Start Asio loop in a thread.
+  // You don't have to call Start() manually because it's called by the
+  // constructor.
+  void Start();
+
+  // Stop Asio loop.
+  // You can call Start() to resume the loop.
+  void Stop();
+
+  void set_connect_timeout(int timeout) {
     if (timeout > 0) {
-      timeout_ = timeout;
+      connect_timeout_ = timeout;
+    }
+  }
+
+  void set_read_timeout(int timeout) {
+    if (timeout > 0) {
+      read_timeout_ = timeout;
     }
   }
 
@@ -73,14 +92,35 @@ public:
   // the response body will be FileBody, and you can easily move the temp file
   // to another path with FileBody::Move(). So, |stream| is really useful for
   // downloading files (JPEG, etc.) or saving memory for huge data responses.
-  ResponsePtr Send(RequestPtr request, bool stream = false);
+  ResponsePtr Send(RequestPtr request, bool stream = false,
+                   ProgressCallback callback = {});
+
+  // Cancel any in-progress connecting, writing or reading.
+  void Cancel();
 
 private:
   void InitHeaders();
 
-  ResponsePtr DoSend(RequestPtr request, bool stream);
+  ResponsePtr DoSend(RequestPtr request, bool stream,
+                     ProgressCallback callback);
 
 private:
+  boost::asio::io_context io_context_;
+
+  // The thread to run Asio loop.
+  std::unique_ptr<std::thread> io_thread_;
+
+  using ExecutorType = boost::asio::io_context::executor_type;
+  boost::asio::executor_work_guard<ExecutorType> work_guard_;
+
+  // TODO
+#if WEBCC_ENABLE_SSL
+  boost::asio::ssl::context ssl_context_;
+#endif
+
+  // Is Asio loop running?
+  bool started_ = false;
+
   // The media (or MIME) type of `Content-Type` header.
   // E.g., "application/json".
   std::string media_type_;
@@ -92,18 +132,27 @@ private:
   // Additional headers for each request.
   Headers headers_;
 
-  // Timeout in seconds for receiving response.
+  // Timeout (seconds) for connecting to server.
-  int timeout_;
+  int connect_timeout_ = 0;
+
+  // Timeout (seconds) for reading response.
+  int read_timeout_ = 0;
 
   // Verify the certificate of the peer or not.
-  bool ssl_verify_;
+  bool ssl_verify_ = true;
 
   // The size of the buffer for reading response.
   // 0 means default value will be used.
   std::size_t buffer_size_;
 
-  // Pool for Keep-Alive client connections.
+  // Keep-Alive client connections.
   ClientPool pool_;
+
+  // Current requested client.
+  ClientPtr client_;
+
+  // The mutex to guard the request.
+  std::mutex mutex_;
 };
 
 }  // namespace webcc

webcc/connection.cc

@@ -32,7 +32,7 @@ void Connection::Start() {
 }
 
 void Connection::Close() {
-  LOG_INFO("Shutdown socket...");
+  LOG_INFO("Shutdown socket");
 
   // Initiate graceful connection closure.
   // Socket close VS. shutdown:
@@ -41,17 +41,17 @@ void Connection::Close() {
   socket_.shutdown(tcp::socket::shutdown_both, ec);
 
   if (ec) {
-    LOG_WARN("Socket shutdown error (%s).", ec.message().c_str());
+    LOG_WARN("Socket shutdown error (%s)", ec.message().c_str());
     ec.clear();
     // Don't return, try to close the socket anywhere.
   }
 
-  LOG_INFO("Close socket...");
+  LOG_INFO("Close socket");
 
   socket_.close(ec);
 
   if (ec) {
-    LOG_ERRO("Socket close error (%s).", ec.message().c_str());
+    LOG_ERRO("Socket close error (%s)", ec.message().c_str());
   }
 }
 
@@ -92,13 +92,13 @@ void Connection::DoRead() {
 void Connection::OnRead(boost::system::error_code ec, std::size_t length) {
   if (ec) {
     if (ec == boost::asio::error::eof) {
-      LOG_INFO("Socket read EOF (%s).", ec.message().c_str());
+      LOG_INFO("Socket read EOF (%s)", ec.message().c_str());
     } else if (ec == boost::asio::error::operation_aborted) {
       // The socket of this connection has been closed.
       // This happens, e.g., when the server was stopped by a signal (Ctrl-C).
-      LOG_WARN("Socket operation aborted (%s).", ec.message().c_str());
+      LOG_WARN("Socket operation aborted (%s)", ec.message().c_str());
     } else {
-      LOG_ERRO("Socket read error (%s).", ec.message().c_str());
+      LOG_ERRO("Socket read error (%s)", ec.message().c_str());
     }
 
     // Don't try to send any response back.
@@ -111,7 +111,7 @@ void Connection::OnRead(boost::system::error_code ec, std::size_t length) {
   }
 
   if (!request_parser_.Parse(buffer_.data(), length)) {
-    LOG_ERRO("Failed to parse HTTP request.");
+    LOG_ERRO("Failed to parse request");
     // Send Bad Request (400) to the client and no Keep-Alive.
     SendResponse(Status::kBadRequest, true);
     // Close the socket connection.
@@ -125,7 +125,7 @@ void Connection::OnRead(boost::system::error_code ec, std::size_t length) {
     return;
   }
 
-  LOG_VERB("HTTP request:\n%s", request_->Dump().c_str());
+  LOG_VERB("Request:\n%s", request_->Dump().c_str());
 
   // Enqueue this connection once the request has been read.
   // Some worker thread will handle the request later.
@@ -133,7 +133,7 @@ void Connection::OnRead(boost::system::error_code ec, std::size_t length) {
 }
 
 void Connection::DoWrite() {
-  LOG_VERB("HTTP response:\n%s", response_->Dump().c_str());
+  LOG_VERB("Response:\n%s", response_->Dump().c_str());
 
   // Firstly, write the headers.
   boost::asio::async_write(socket_, response_->GetPayload(),
@@ -177,11 +177,11 @@ void Connection::OnWriteBody(boost::system::error_code ec, std::size_t length) {
 }
 
 void Connection::OnWriteOK() {
-  LOG_INFO("Response has been sent back.");
+  LOG_INFO("Response has been sent back");
 
   if (request_->IsConnectionKeepAlive()) {
-    LOG_INFO("The client asked for a keep-alive connection.");
+    LOG_INFO("The client asked for a keep-alive connection");
-    LOG_INFO("Continue to read the next request...");
+    LOG_INFO("Continue to read the next request");
     Start();
   } else {
     pool_->Close(shared_from_this());
@@ -189,7 +189,7 @@ void Connection::OnWriteOK() {
 }
 
 void Connection::OnWriteError(boost::system::error_code ec) {
-  LOG_ERRO("Socket write error (%s).", ec.message().c_str());
+  LOG_ERRO("Socket write error (%s)", ec.message().c_str());
 
   if (ec != boost::asio::error::operation_aborted) {
     pool_->Close(shared_from_this());

webcc/connection_pool.cc

@@ -5,11 +5,11 @@
 namespace webcc {
 
 void ConnectionPool::Start(ConnectionPtr c) {
-  LOG_VERB("Starting connection...");
+  LOG_VERB("Start connection");
 
   {
     // Lock the container only.
-    std::lock_guard<std::mutex> lock(mutex_);
+    std::lock_guard<std::mutex> lock{ mutex_ };
     connections_.insert(c);
   }
 
@@ -17,11 +17,11 @@ void ConnectionPool::Start(ConnectionPtr c) {
 }
 
 void ConnectionPool::Close(ConnectionPtr c) {
-  LOG_VERB("Closing connection...");
+  LOG_VERB("Close connection");
 
   {
     // Lock the container only.
-    std::lock_guard<std::mutex> lock(mutex_);
+    std::lock_guard<std::mutex> lock{ mutex_ };
     connections_.erase(c);
   }
 
@@ -30,10 +30,10 @@ void ConnectionPool::Close(ConnectionPtr c) {
 
 void ConnectionPool::Clear() {
   // Lock all since we are going to stop anyway.
-  std::lock_guard<std::mutex> lock(mutex_);
+  std::lock_guard<std::mutex> lock{ mutex_ };
 
   if (!connections_.empty()) {
-    LOG_VERB("Closing all (%u) connections...", connections_.size());
+    LOG_VERB("Close all (%u) connections", connections_.size());
     for (auto& c : connections_) {
       c->Close();
     }

webcc/globals.h

@@ -3,6 +3,7 @@
 
 #include <cassert>
 #include <exception>
+#include <functional>
 #include <iosfwd>
 #include <string>
 #include <vector>
@@ -23,11 +24,14 @@ using UrlArgs = std::vector<std::string>;
 
 using Payload = std::vector<boost::asio::const_buffer>;
 
+using ProgressCallback =
+    std::function<void(std::size_t length, std::size_t total_length)>;
+
 // -----------------------------------------------------------------------------
 
 const char* const kCRLF = "\r\n";
 
-const std::size_t kInvalidLength = std::string::npos;
+const std::size_t kInvalidLength = -1;
 
 // Default timeout for reading response.
 const int kMaxReadSeconds = 30;
@@ -150,6 +154,7 @@ public:
   enum Code {
     kUnknownError = -1,
     kOK = 0,
+    kStateError,
     kSyntaxError,
     kResolveError,
     kConnectError,

webcc/logger.cc

@@ -45,7 +45,12 @@ static FILE* FOpen(const bfs::path& path, bool overwrite) {
 }
 
 struct Logger {
-  Logger() : file(nullptr), modes(0) {
+  Logger() = default;
+
+  ~Logger() {
+    if (file != nullptr) {
+      fclose(file);
+    }
   }
 
   void Init(const bfs::path& path, int _modes) {
@@ -57,14 +62,8 @@ struct Logger {
     }
   }
 
-  ~Logger() {
+  FILE* file = nullptr;
-    if (file != nullptr) {
+  int modes = 0;
-      fclose(file);
-    }
-  }
-
-  FILE* file;
-  int modes;
   std::mutex mutex;
 };
 
@@ -161,10 +160,10 @@ static bfs::path InitLogPath(const bfs::path& dir) {
     return bfs::current_path() / WEBCC_LOG_FILE_NAME;
   }
 
-  if (!bfs::exists(dir) || !bfs::is_directory(dir)) {
   boost::system::error_code ec;
+  if (!bfs::exists(dir, ec) || !bfs::is_directory(dir, ec)) {
     if (!bfs::create_directories(dir, ec) || ec) {
-      return bfs::path{};
+      return {};
     }
   }
 
@@ -216,7 +215,7 @@ void Log(int level, const char* file, int line, const char* format, ...) {
     va_list args;
     va_start(args, format);
 
-    fprintf(g_logger.file, "%s, %s, %7s, %20s, %4d, ",
+    fprintf(g_logger.file, "%s, %s, %7s, %25s, %4d, ",
             timestamp.c_str(), kLevelNames[level], thread_id.c_str(),
             file, line);
 
@@ -239,12 +238,12 @@ void Log(int level, const char* file, int line, const char* format, ...) {
 
     if (g_terminal_has_color) {
       if (level < WEBCC_WARN) {
-        fprintf(stderr, "%s%s, %s, %7s, %20s, %4d, ",
+        fprintf(stderr, "%s%s, %s, %7s, %25s, %4d, ",
                 TERM_RESET,
                 timestamp.c_str(), kLevelNames[level], thread_id.c_str(),
                 file, line);
       } else {
-        fprintf(stderr, "%s%s%s, %s, %7s, %20s, %4d, ",
+        fprintf(stderr, "%s%s%s, %s, %7s, %25s, %4d, ",
                 TERM_RESET,
                 level == WEBCC_WARN ? TERM_YELLOW : TERM_RED,
                 timestamp.c_str(), kLevelNames[level], thread_id.c_str(),
@@ -255,7 +254,7 @@ void Log(int level, const char* file, int line, const char* format, ...) {
 
       fprintf(stderr, "%s\n", TERM_RESET);
     } else {
-      fprintf(stderr, "%s, %s, %7s, %20s, %4d, ",
+      fprintf(stderr, "%s, %s, %7s, %25s, %4d, ",
               timestamp.c_str(), kLevelNames[level], thread_id.c_str(),
               file, line);
 

webcc/message.cc

@@ -8,7 +8,7 @@
 
 namespace webcc {
 
-Message::Message() : body_(new Body{}), content_length_(kInvalidLength) {
+Message::Message() : body_(new Body{}) {
 }
 
 void Message::SetBody(BodyPtr body, bool set_length) {

webcc/message.h

@@ -118,7 +118,7 @@ protected:
 
   std::string start_line_;
 
-  std::size_t content_length_;
+  std::size_t content_length_ = kInvalidLength;
 };
 
 }  // namespace webcc

webcc/parser.cc

@@ -49,14 +49,14 @@ bool StringBodyHandler::Finish() {
   auto body = std::make_shared<StringBody>(std::move(content_), IsCompressed());
 
 #if WEBCC_ENABLE_GZIP
-  LOG_INFO("Decompress the HTTP content...");
+  LOG_INFO("Decompress the HTTP content");
   if (!body->Decompress()) {
-    LOG_ERRO("Cannot decompress the HTTP content!");
+    LOG_ERRO("Cannot decompress the HTTP content");
     return false;
   }
 #else
   if (body->compressed()) {
-    LOG_WARN("Compressed HTTP content remains untouched.");
+    LOG_WARN("Compressed HTTP content remains untouched");
   }
 #endif  // WEBCC_ENABLE_GZIP
 
@@ -79,7 +79,7 @@ bool FileBodyHandler::OpenFile() {
              temp_path_.string().c_str());
 
   } catch (const bfs::filesystem_error&) {
-    LOG_ERRO("Failed to generate temp path for streaming.");
+    LOG_ERRO("Failed to generate temp path for streaming");
     return false;
   }
 
@@ -132,6 +132,8 @@ bool Parser::Parse(const char* data, std::size_t length) {
     return ParseContent(data, length);
   }
 
+  header_length_ += length;
+
   // Append the new data to the pending data.
   pending_data_.append(data, length);
 
@@ -140,11 +142,13 @@ bool Parser::Parse(const char* data, std::size_t length) {
   }
 
   if (!header_ended_) {
-    LOG_INFO("HTTP headers will continue in next read.");
+    LOG_INFO("HTTP headers will continue in next read");
     return true;
   }
 
-  LOG_INFO("HTTP headers just ended.");
+  LOG_INFO("HTTP headers just ended");
+
+  header_length_ -= pending_data_.size();
 
   if (!OnHeadersEnd()) {
     // Only request parser can reach here when no view matches the request.
@@ -170,6 +174,7 @@ void Parser::Reset() {
   stream_ = false;
 
   pending_data_.clear();
+  header_length_ = 0;
 
   content_length_ = kInvalidLength;
   content_type_.Reset();
@@ -336,7 +341,7 @@ bool Parser::ParseChunkedContent(const char* data, std::size_t length) {
         return false;
       }
 
-      LOG_VERB("Chunk size: %u.", chunk_size_);
+      LOG_VERB("Chunk size: %u", chunk_size_);
     }
 
     if (chunk_size_ == 0) {
@@ -378,14 +383,14 @@ bool Parser::ParseChunkedContent(const char* data, std::size_t length) {
 }
 
 bool Parser::ParseChunkSize() {
-  LOG_VERB("Parse chunk size.");
+  LOG_VERB("Parse chunk size");
 
   std::string line;
   if (!GetNextLine(0, &line, true)) {
     return true;
   }
 
-  LOG_VERB("Chunk size line: [%s].", line.c_str());
+  LOG_VERB("Chunk size line: [%s]", line.c_str());
 
   std::string hex_str;  // e.g., "cf0" (3312)
 
@@ -397,7 +402,7 @@ bool Parser::ParseChunkSize() {
   }
 
   if (!to_size_t(hex_str, 16, &chunk_size_)) {
-    LOG_ERRO("Invalid chunk-size: %s.", hex_str.c_str());
+    LOG_ERRO("Invalid chunk-size: %s", hex_str.c_str());
     return false;
   }
 

webcc/parser.h

@@ -94,17 +94,35 @@ private:
 class Parser {
 public:
   Parser();
-  virtual ~Parser() = default;
 
   Parser(const Parser&) = delete;
   Parser& operator=(const Parser&) = delete;
 
+  virtual ~Parser() = default;
+
   void Init(Message* message);
 
   bool finished() const {
     return finished_;
   }
 
+  // If the headers part has been parsed or not.
+  bool header_ended() const {
+  return header_ended_;
+  }
+
+  // Get the length of the headers part.
+  // Available after the headers have been parsed (see header_ended()).
+  std::size_t header_length() const {
+    return header_length_;
+  }
+
+  // The content length parsed from `Content-Length` header.
+  // kInvalidLength if the content is chunked.
+  std::size_t content_length() const {
+    return content_length_;
+  }
+
   bool Parse(const char* data, std::size_t length);
 
 protected:
@@ -144,25 +162,28 @@ protected:
   bool Finish();
 
 protected:
-  Message* message_;
+  Message* message_ = nullptr;
 
   std::unique_ptr<BodyHandler> body_handler_;
 
   // Data streaming or not.
-  bool stream_;
+  bool stream_ = false;
 
   // Data waiting to be parsed.
   std::string pending_data_;
 
+  // The length of the headers part.
+  std::size_t header_length_ = 0;
+
   // Temporary data and helper flags for parsing.
-  std::size_t content_length_;
+  std::size_t content_length_ = kInvalidLength;
   ContentType content_type_;
-  bool start_line_parsed_;
+  bool start_line_parsed_ = false;
-  bool content_length_parsed_;
+  bool content_length_parsed_ = false;
-  bool header_ended_;
+  bool header_ended_ = false;
-  bool chunked_;
+  bool chunked_ = false;
-  std::size_t chunk_size_;
+  std::size_t chunk_size_ = kInvalidLength;
-  bool finished_;
+  bool finished_ = false;
 };
 
 }  // namespace webcc

webcc/server.cc

@@ -23,9 +23,6 @@ Server::Server(boost::asio::ip::tcp protocol, std::uint16_t port,
     : protocol_(protocol),
       port_(port),
       doc_root_(doc_root),
-      buffer_size_(kBufferSize),
-      file_chunk_size_(1024),
-      running_(false),
       acceptor_(io_context_),
       signals_(io_context_) {
   AddSignals();
@@ -35,12 +32,12 @@ void Server::Run(std::size_t workers, std::size_t loops) {
   assert(workers > 0);
 
   {
-    std::lock_guard<std::mutex> lock(state_mutex_);
+    std::lock_guard<std::mutex> lock{ state_mutex_ };
 
     assert(worker_threads_.empty());
 
     if (IsRunning()) {
-      LOG_WARN("Server is already running.");
+      LOG_WARN("Server is already running");
       return;
     }
 
@@ -48,11 +45,11 @@ void Server::Run(std::size_t workers, std::size_t loops) {
     io_context_.restart();
 
     if (!Listen(port_)) {
-      LOG_ERRO("Server is NOT going to run.");
+      LOG_ERRO("Server is NOT going to run");
       return;
     }
 
-    LOG_INFO("Server is going to run...");
+    LOG_INFO("Server is going to run");
 
     AsyncWaitSignals();
 
@@ -70,7 +67,7 @@ void Server::Run(std::size_t workers, std::size_t loops) {
   // asynchronous operation outstanding: the asynchronous accept call waiting
   // for new incoming connections.
 
-  LOG_INFO("Loop is running in %u thread(s).", loops);
+  LOG_INFO("Loop is running in %u thread(s)", loops);
 
   if (loops == 1) {
     // Run the loop in current thread.
@@ -88,7 +85,7 @@ void Server::Run(std::size_t workers, std::size_t loops) {
 }
 
 void Server::Stop() {
-  std::lock_guard<std::mutex> lock(state_mutex_);
+  std::lock_guard<std::mutex> lock{ state_mutex_ };
 
   DoStop();
 }
@@ -112,7 +109,7 @@ void Server::AsyncWaitSignals() {
         // The server is stopped by canceling all outstanding asynchronous
         // operations. Once all operations have finished the io_context::run()
         // call will exit.
-        LOG_INFO("On signal %d, stopping the server...", signo);
+        LOG_INFO("On signal %d, stop the server", signo);
 
         DoStop();
       });
@@ -121,12 +118,12 @@ void Server::AsyncWaitSignals() {
 bool Server::Listen(std::uint16_t port) {
   boost::system::error_code ec;
 
-  tcp::endpoint endpoint(protocol_, port);
+  tcp::endpoint endpoint{ protocol_, port };
 
   // Open the acceptor.
   acceptor_.open(endpoint.protocol(), ec);
   if (ec) {
-    LOG_ERRO("Acceptor open error (%s).", ec.message().c_str());
+    LOG_ERRO("Acceptor open error (%s)", ec.message().c_str());
     return false;
   }
 
@@ -141,7 +138,7 @@ bool Server::Listen(std::uint16_t port) {
   // Bind to the server address.
   acceptor_.bind(endpoint, ec);
   if (ec) {
-    LOG_ERRO("Acceptor bind error (%s).", ec.message().c_str());
+    LOG_ERRO("Acceptor bind error (%s)", ec.message().c_str());
     return false;
   }
 
@@ -150,7 +147,7 @@ bool Server::Listen(std::uint16_t port) {
   // has not started to accept the connection yet.
   acceptor_.listen(boost::asio::socket_base::max_listen_connections, ec);
   if (ec) {
-    LOG_ERRO("Acceptor listen error (%s).", ec.message().c_str());
+    LOG_ERRO("Acceptor listen error (%s)", ec.message().c_str());
     return false;
   }
 
@@ -167,9 +164,10 @@ void Server::AsyncAccept() {
         }
 
         if (!ec) {
-          LOG_INFO("Accepted a connection.");
+          LOG_INFO("Accepted a connection");
 
           using namespace std::placeholders;
+
           auto view_matcher = std::bind(&Server::MatchViewOrStatic, this, _1,
                                         _2, _3);
 
@@ -205,16 +203,16 @@ void Server::DoStop() {
 }
 
 void Server::WorkerRoutine() {
-  LOG_INFO("Worker is running.");
+  LOG_INFO("Worker is running");
 
   for (;;) {
     auto connection = queue_.PopOrWait();
 
     if (!connection) {
-      LOG_INFO("Worker is going to stop.");
+      LOG_INFO("Worker is going to stop");
 
       // For stopping next worker.
-      queue_.Push(ConnectionPtr());
+      queue_.Push({});
 
       // Stop this worker.
       break;
@@ -225,13 +223,13 @@ void Server::WorkerRoutine() {
 }
 
 void Server::StopWorkers() {
-  LOG_INFO("Stopping workers...");
+  LOG_INFO("Stop workers");
 
   // Clear/drop pending connections.
   // The connections will be closed later (see DoStop).
   // Alternatively, we can wait for the pending connections to be handled.
   if (queue_.Size() != 0) {
-    LOG_INFO("Clear pending connections...");
+    LOG_INFO("Clear pending connections");
     queue_.Clear();
   }
 
@@ -252,7 +250,7 @@ void Server::StopWorkers() {
   // last worker thread.
   queue_.Clear();
 
-  LOG_INFO("All workers have been stopped.");
+  LOG_INFO("Workers stopped");
 }
 
 void Server::Handle(ConnectionPtr connection) {
@@ -307,7 +305,9 @@ bool Server::MatchViewOrStatic(const std::string& method,
   // Try to match a static file.
   if (method == methods::kGet && !doc_root_.empty()) {
     bfs::path path = doc_root_ / url;
-    if (!bfs::is_directory(path) && bfs::exists(path)) {
+
+    boost::system::error_code ec;
+    if (!bfs::is_directory(path, ec) && bfs::exists(path, ec)) {
       return true;
     }
   }
@@ -319,7 +319,7 @@ ResponsePtr Server::ServeStatic(RequestPtr request) {
   assert(request->method() == methods::kGet);
 
   if (doc_root_.empty()) {
-    LOG_INFO("The doc root was not specified.");
+    LOG_INFO("The doc root was not specified");
     return {};
   }
 
@@ -340,7 +340,7 @@ ResponsePtr Server::ServeStatic(RequestPtr request) {
     return response;
 
   } catch (const Error& error) {
-    LOG_ERRO("File error: %s.", error.message().c_str());
+    LOG_ERRO("File error: %s", error.message().c_str());
     return {};
   }
 }

webcc/server.h

@@ -24,11 +24,11 @@ public:
   Server(boost::asio::ip::tcp protocol, std::uint16_t port,
          const boost::filesystem::path& doc_root = {});
 
-  ~Server() = default;
-
   Server(const Server&) = delete;
   Server& operator=(const Server&) = delete;
 
+  ~Server() = default;
+
   void set_buffer_size(std::size_t buffer_size) {
     if (buffer_size > 0) {
       buffer_size_ = buffer_size;
@@ -105,20 +105,20 @@ private:
   boost::asio::ip::tcp protocol_;
 
   // Port number.
-  std::uint16_t port_;
+  std::uint16_t port_ = 0;
 
   // The directory with the static files to be served.
   boost::filesystem::path doc_root_;
 
   // The size of the buffer for reading request.
-  std::size_t buffer_size_;
+  std::size_t buffer_size_ = kBufferSize;
 
   // The size of the chunk loaded into memory each time when serving a
   // static file.
-  std::size_t file_chunk_size_;
+  std::size_t file_chunk_size_ = 1024;
 
   // Is the server running?
-  bool running_;
+  bool running_ = false;
 
   // The mutex for guarding the state of the server.
   std::mutex state_mutex_;

webcc/socket.cc

@@ -3,9 +3,9 @@
 #if WEBCC_ENABLE_SSL
 #if (defined(_WIN32) || defined(_WIN64))
 
-#include <windows.h>
-#include <wincrypt.h>
 #include <cryptuiapi.h>
+#include <wincrypt.h>
+#include <windows.h>
 
 #include "openssl/x509.h"
 
@@ -18,6 +18,9 @@
 
 #include "webcc/logger.h"
 
+using boost::asio::ip::tcp;
+using namespace std::placeholders;
+
 namespace webcc {
 
 // -----------------------------------------------------------------------------
@@ -25,48 +28,37 @@ namespace webcc {
 Socket::Socket(boost::asio::io_context& io_context) : socket_(io_context) {
 }
 
-bool Socket::Connect(const std::string& /*host*/, const Endpoints& endpoints) {
+void Socket::AsyncConnect(const std::string& host, const Endpoints& endpoints,
-  boost::system::error_code ec;
+                          ConnectHandler&& handler) {
-  boost::asio::connect(socket_, endpoints, ec);
+  boost::asio::async_connect(socket_, endpoints, std::move(handler));
-
-  if (ec) {
-    LOG_ERRO("Socket connect error (%s).", ec.message().c_str());
-    return false;
 }
 
-  return true;
+void Socket::AsyncWrite(const Payload& payload, WriteHandler&& handler) {
-}
+  boost::asio::async_write(socket_, payload, std::move(handler));
-
-bool Socket::Write(const Payload& payload, boost::system::error_code* ec) {
-  boost::asio::write(socket_, payload, *ec);
-  return !(*ec);
-}
-
-bool Socket::ReadSome(std::vector<char>* buffer, std::size_t* size,
-                      boost::system::error_code* ec) {
-  *size = socket_.read_some(boost::asio::buffer(*buffer), *ec);
-  return (*size != 0 && !(*ec));
 }
 
 void Socket::AsyncReadSome(ReadHandler&& handler, std::vector<char>* buffer) {
   socket_.async_read_some(boost::asio::buffer(*buffer), std::move(handler));
 }
 
-bool Socket::Close() {
+bool Socket::Shutdown() {
   boost::system::error_code ec;
-
+  socket_.shutdown(tcp::socket::shutdown_both, ec);
-  socket_.shutdown(boost::asio::ip::tcp::socket::shutdown_both, ec);
 
   if (ec) {
-    LOG_WARN("Socket shutdown error (%s).", ec.message().c_str());
+    LOG_WARN("Socket shutdown error (%s)", ec.message().c_str());
-    ec.clear();
+    return false;
-    // Don't return, try to close the socket anywhere.
   }
 
+  return true;
+}
+
+bool Socket::Close() {
+  boost::system::error_code ec;
   socket_.close(ec);
 
   if (ec) {
-    LOG_WARN("Socket close error (%s).", ec.message().c_str());
+    LOG_WARN("Socket close error (%s)", ec.message().c_str());
     return false;
   }
 
@@ -77,105 +69,20 @@ bool Socket::Close() {
 
 #if WEBCC_ENABLE_SSL
 
-#if (defined(_WIN32) || defined(_WIN64))
-
-// Let OpenSSL on Windows use the system certificate store
-//   1. Load your certificate (in PCCERT_CONTEXT structure) from Windows Cert
-//      store using Crypto APIs.
-//   2. Get encrypted content of it in binary format as it is.
-//      [PCCERT_CONTEXT->pbCertEncoded].
-//   3. Parse this binary buffer into X509 certificate Object using OpenSSL's
-//      d2i_X509() method.
-//   4. Get handle to OpenSSL's trust store using SSL_CTX_get_cert_store()
-//      method.
-//   5. Load above parsed X509 certificate into this trust store using
-//      X509_STORE_add_cert() method.
-//   6. You are done!
-// NOTES: Enum Windows store with "ROOT" (not "CA").
-// See: https://stackoverflow.com/a/11763389/6825348
-
-static bool UseSystemCertificateStore(SSL_CTX* ssl_ctx) {
-  // NOTE: Cannot use nullptr to replace NULL.
-  HCERTSTORE cert_store = ::CertOpenSystemStoreW(NULL, L"ROOT");
-  if (cert_store == nullptr) {
-    LOG_ERRO("Cannot open Windows system certificate store.");
-    return false;
-  }
-
-  X509_STORE* x509_store = SSL_CTX_get_cert_store(ssl_ctx);
-  PCCERT_CONTEXT cert_context = nullptr;
-
-  while (cert_context = CertEnumCertificatesInStore(cert_store, cert_context)) {
-    auto in = (const unsigned char**)&cert_context->pbCertEncoded;
-    X509* x509 = d2i_X509(nullptr, in, cert_context->cbCertEncoded);
-
-    if (x509 != nullptr) {
-      if (X509_STORE_add_cert(x509_store, x509) == 0) {
-        LOG_ERRO("Cannot add Windows root certificate.");
-      }
-
-      X509_free(x509);
-    }
-  }
-
-  CertFreeCertificateContext(cert_context);
-  CertCloseStore(cert_store, 0);
-  return true;
-}
-
-#endif  // defined(_WIN32) || defined(_WIN64)
-
 namespace ssl = boost::asio::ssl;
 
-SslSocket::SslSocket(boost::asio::io_context& io_context, bool ssl_verify)
+SslSocket::SslSocket(boost::asio::io_context& io_context,
-    : ssl_context_(ssl::context::sslv23),
+                     ssl::context& ssl_context, bool ssl_verify)
-      ssl_socket_(io_context, ssl_context_),
+    : ssl_socket_(io_context, ssl_context),
       ssl_verify_(ssl_verify) {
-#if (defined(_WIN32) || defined(_WIN64))
-  if (ssl_verify_) {
-    UseSystemCertificateStore(ssl_context_.native_handle());
-  }
-#else
-  // Use the default paths for finding CA certificates.
-  ssl_context_.set_default_verify_paths();
-#endif  // defined(_WIN32) || defined(_WIN64)
 }
 
-bool SslSocket::Connect(const std::string& host, const Endpoints& endpoints) {
+void SslSocket::AsyncConnect(const std::string& host,
-  boost::system::error_code ec;
+                             const Endpoints& endpoints,
-  boost::asio::connect(ssl_socket_.lowest_layer(), endpoints, ec);
+                             ConnectHandler&& handler) {
+  connect_handler_ = std::move(handler);
 
-  if (ec) {
-    LOG_ERRO("Socket connect error (%s).", ec.message().c_str());
-    return false;
-  }
 
-  return Handshake(host);
-}
-
-bool SslSocket::Write(const Payload& payload, boost::system::error_code* ec) {
-  boost::asio::write(ssl_socket_, payload, *ec);
-  return !(*ec);
-}
-
-bool SslSocket::ReadSome(std::vector<char>* buffer, std::size_t* size,
-                         boost::system::error_code* ec) {
-  *size = ssl_socket_.read_some(boost::asio::buffer(*buffer), *ec);
-  return (*size != 0 && !(*ec));
-}
-
-void SslSocket::AsyncReadSome(ReadHandler&& handler,
-                              std::vector<char>* buffer) {
-  ssl_socket_.async_read_some(boost::asio::buffer(*buffer), std::move(handler));
-}
-
-bool SslSocket::Close() {
-  boost::system::error_code ec;
-  ssl_socket_.lowest_layer().close(ec);
-  return !ec;
-}
-
-bool SslSocket::Handshake(const std::string& host) {
   if (ssl_verify_) {
     ssl_socket_.set_verify_mode(ssl::verify_peer);
   } else {
@@ -190,18 +97,63 @@ bool SslSocket::Handshake(const std::string& host) {
   ssl_socket_.set_verify_callback(ssl::host_name_verification(host));
 #endif  // BOOST_VERSION < 107300
 
-  // Use sync API directly since we don't need timeout control.
+  boost::asio::async_connect(ssl_socket_.lowest_layer(), endpoints,
+                             std::bind(&SslSocket::OnConnect, this, _1, _2));
+}
+
+void SslSocket::AsyncWrite(const Payload& payload, WriteHandler&& handler) {
+  boost::asio::async_write(ssl_socket_, payload, std::move(handler));
+}
+
+void SslSocket::AsyncReadSome(ReadHandler&& handler,
+                              std::vector<char>* buffer) {
+  ssl_socket_.async_read_some(boost::asio::buffer(*buffer), std::move(handler));
+}
+
+bool SslSocket::Shutdown() {
   boost::system::error_code ec;
-  ssl_socket_.handshake(ssl::stream_base::client, ec);
+  ssl_socket_.lowest_layer().shutdown(tcp::socket::shutdown_both, ec);
 
   if (ec) {
-    LOG_ERRO("Handshake error (%s).", ec.message().c_str());
+    LOG_WARN("Socket shutdown error (%s)", ec.message().c_str());
     return false;
   }
 
   return true;
 }
 
+bool SslSocket::Close() {
+  boost::system::error_code ec;
+  ssl_socket_.lowest_layer().close(ec);
+
+  if (ec) {
+    LOG_WARN("Socket close error (%s)", ec.message().c_str());
+    return false;
+  }
+
+  return true;
+}
+
+void SslSocket::OnConnect(boost::system::error_code ec,
+                          tcp::endpoint endpoint) {
+  if (ec) {
+    connect_handler_(ec, std::move(endpoint));
+    return;
+  }
+
+  // Backup endpoint
+  endpoint_ = std::move(endpoint);
+
+  ssl_socket_.async_handshake(ssl::stream_base::client,
+                              [this](boost::system::error_code ec) {
+    if (ec) {
+      LOG_ERRO("Handshake error (%s)", ec.message().c_str());
+    }
+
+    connect_handler_(ec, std::move(endpoint_));
+  });
+}
+
 #endif  // WEBCC_ENABLE_SSL
 
 }  // namespace webcc

webcc/socket.h

@@ -18,24 +18,29 @@ namespace webcc {
 
 class SocketBase {
 public:
-  virtual ~SocketBase() = default;
-
   using Endpoints = boost::asio::ip::tcp::resolver::results_type;
 
+  using ConnectHandler = std::function<void(boost::system::error_code,
+                                            boost::asio::ip::tcp::endpoint)>;
+
+  using WriteHandler =
+      std::function<void(boost::system::error_code, std::size_t)>;
+
   using ReadHandler =
       std::function<void(boost::system::error_code, std::size_t)>;
 
-  // TODO: Remove |host|
+  virtual ~SocketBase() = default;
-  virtual bool Connect(const std::string& host, const Endpoints& endpoints) = 0;
 
-  virtual bool Write(const Payload& payload, boost::system::error_code* ec) = 0;
+  virtual void AsyncConnect(const std::string& host, const Endpoints& endpoints,
+                            ConnectHandler&& handler) = 0;
 
-  virtual bool ReadSome(std::vector<char>* buffer, std::size_t* size,
+  virtual void AsyncWrite(const Payload& payload, WriteHandler&& handler) = 0;
-                        boost::system::error_code* ec) = 0;
 
   virtual void AsyncReadSome(ReadHandler&& handler,
                              std::vector<char>* buffer) = 0;
 
+  virtual bool Shutdown() = 0;
+
   virtual bool Close() = 0;
 };
 
@@ -45,15 +50,15 @@ class Socket : public SocketBase {
 public:
   explicit Socket(boost::asio::io_context& io_context);
 
-  bool Connect(const std::string& host, const Endpoints& endpoints) override;
+  void AsyncConnect(const std::string& host, const Endpoints& endpoints,
+                    ConnectHandler&& handler) override;
 
-  bool Write(const Payload& payload, boost::system::error_code* ec) override;
+  void AsyncWrite(const Payload& payload, WriteHandler&& handler) override;
-
-  bool ReadSome(std::vector<char>* buffer, std::size_t* size,
-                boost::system::error_code* ec) override;
 
   void AsyncReadSome(ReadHandler&& handler, std::vector<char>* buffer) override;
 
+  bool Shutdown() override;
+
   bool Close() override;
 
 private:
@@ -66,29 +71,32 @@ private:
 
 class SslSocket : public SocketBase {
 public:
-  explicit SslSocket(boost::asio::io_context& io_context,
+  SslSocket(boost::asio::io_context& io_context,
+            boost::asio::ssl::context& ssl_context,
             bool ssl_verify = true);
 
-  bool Connect(const std::string& host, const Endpoints& endpoints) override;
+  void AsyncConnect(const std::string& host, const Endpoints& endpoints,
+                    ConnectHandler&& handler) override;
 
-  bool Write(const Payload& payload, boost::system::error_code* ec) override;
+  void AsyncWrite(const Payload& payload, WriteHandler&& handler) override;
-
-  bool ReadSome(std::vector<char>* buffer, std::size_t* size,
-                boost::system::error_code* ec) override;
 
   void AsyncReadSome(ReadHandler&& handler, std::vector<char>* buffer) override;
 
+  bool Shutdown() override;
+
   bool Close() override;
 
 private:
-  bool Handshake(const std::string& host);
+  void OnConnect(boost::system::error_code ec,
+                 boost::asio::ip::tcp::endpoint endpoint);
 
-  boost::asio::ssl::context ssl_context_;
+  ConnectHandler connect_handler_;
+  boost::asio::ip::tcp::endpoint endpoint_;
 
   boost::asio::ssl::stream<boost::asio::ip::tcp::socket> ssl_socket_;
 
   // Verify the certificate of the peer (remote server) or not.
-  bool ssl_verify_;
+  bool ssl_verify_ = true;
 };
 
 #endif  // WEBCC_ENABLE_SSL