Merge HttpClient and HttpSslClient; draft of client connection pool.

example/http_client/main.cc

@@ -3,23 +3,37 @@
 #include "webcc/http_client_session.h"
 #include "webcc/logger.h"
 
-void GetBoostOrgLicense(webcc::HttpClientSession& session) {
-  auto r = session.Get("https://www.boost.org/LICENSE_1_0.txt");
+using namespace webcc;
+
+// -----------------------------------------------------------------------------
+
+#if (defined(WIN32) || defined(_WIN64))
+// You need to set environment variable SSL_CERT_FILE properly to enable
+// SSL verification.
+bool kSslVerify = false;
+#else
+bool kSslVerify = true;
+#endif
+
+// -----------------------------------------------------------------------------
+
+void GetBoostOrgLicense(HttpClientSession& session) {
+  try {
+    auto r = session.Request(HttpRequestArgs{ "GET" }.
+                             url("https://www.boost.org/LICENSE_1_0.txt").
+                             ssl_verify(kSslVerify));
 
-  if (r) {
     std::cout << r->content() << std::endl;
+
+  } catch (const webcc::Exception& e) {
+    std::cout << "Exception: " << e.what() << std::endl;
   }
 }
 
-int main() {
-  WEBCC_LOG_INIT("", webcc::LOG_CONSOLE);
-
-  using namespace webcc;
-
+// TODO
+void Test(HttpClientSession& session) {
   HttpResponsePtr r;
 
-  HttpClientSession session;
-
   // ---------------------------------------------------------------------------
 
   r = session.Request(HttpRequestArgs{ "GET" }.
@@ -66,6 +80,73 @@ int main() {
   } catch (const webcc::Exception& e) {
     std::cout << "Exception: " << e.what() << std::endl;
   }
+}
+
+void TestKeepAlive1(HttpClientSession& session) {
+  try {
+    auto r = session.Request(HttpRequestArgs{ "GET" }.
+                             url("http://httpbin.org/get").
+                             parameters({ "key1", "value1", "key2", "value2" }).
+                             headers({ "Accept", "application/json" }).
+                             buffer_size(1000));
+
+    std::cout << r->content() << std::endl;
+
+  } catch (const Exception& e) {
+    std::cout << "Exception: " << e.what() << std::endl;
+  }
+}
+
+void TestKeepAlive2(HttpClientSession& session) {
+  try {
+    auto r = session.Request(webcc::HttpRequestArgs("GET").
+                             url("https://api.github.com/events").
+                             ssl_verify(false).buffer_size(1500));
+
+    //std::cout << r->content() << std::endl;
+
+  } catch (const Exception& e) {
+    std::cout << "Exception: " << e.what() << std::endl;
+  }
+}
+
+void TestKeepAlive3(HttpClientSession& session) {
+  try {
+    auto r = session.Request(webcc::HttpRequestArgs("GET").
+                             url("https://www.boost.org/LICENSE_1_0.txt").
+                             ssl_verify(false));
+
+    //std::cout << r->content() << std::endl;
+
+  } catch (const Exception& e) {
+    std::cout << "Exception: " << e.what() << std::endl;
+  }
+}
+
+void TestKeepAlive4(HttpClientSession& session) {
+  try {
+    auto r = session.Request(webcc::HttpRequestArgs("GET").
+                             url("https://www.google.com").
+                             ssl_verify(false));
+
+    //std::cout << r->content() << std::endl;
+
+  } catch (const Exception& e) {
+    std::cout << "Exception: " << e.what() << std::endl;
+  }
+}
+
+// -----------------------------------------------------------------------------
+
+int main() {
+  WEBCC_LOG_INIT("", LOG_CONSOLE);
+
+  HttpClientSession session;
+
+  GetBoostOrgLicense(session);
+
+  //TestKeepAlive1(session);
+  //TestKeepAlive1(session);
 
   return 0;
 }

webcc/CMakeLists.txt

@@ -15,8 +15,8 @@ include(GNUInstallDirs)
 
 set(HEADERS
     globals.h
-    http_client_base.h
     http_client.h
+    http_client_pool.h
     http_client_session.h
     http_connection.h
     http_message.h
@@ -28,7 +28,7 @@ set(HEADERS
     http_response.h
     http_response_parser.h
     http_server.h
-    http_ssl_client.h
+    http_socket.h
     queue.h
     url.h
     utility.h
@@ -37,8 +37,8 @@ set(HEADERS
 
 set(SOURCES
     globals.cc
-    http_client_base.cc
     http_client.cc
+    http_client_pool.cc
     http_client_session.cc
     http_connection.cc
     http_message.cc
@@ -49,7 +49,7 @@ set(SOURCES
     http_response.cc
     http_response_parser.cc
     http_server.cc
-    http_ssl_client.cc
+    http_socket.cc
     logger.cc
     url.cc
     utility.cc

webcc/http_client.cc

@@ -1,31 +1,243 @@
 #include "webcc/http_client.h"
 
-#include "boost/asio/connect.hpp"
-#include "boost/asio/read.hpp"
-#include "boost/asio/write.hpp"
+#include "boost/date_time/posix_time/posix_time.hpp"
+
+#include "webcc/logger.h"
+#include "webcc/utility.h"
+
+using boost::asio::ip::tcp;
 
 namespace webcc {
 
-HttpClient::HttpClient(std::size_t buffer_size)
-    : HttpClientBase(buffer_size), socket_(io_context_) {
+HttpClient::HttpClient(std::size_t buffer_size, bool ssl_verify)
+    : buffer_(buffer_size == 0 ? kBufferSize : buffer_size),
+      deadline_(io_context_),
+      ssl_verify_(ssl_verify),
+      timeout_seconds_(kMaxReadSeconds),
+      stopped_(false),
+      timed_out_(false),
+      error_(kNoError) {
 }
 
-void HttpClient::SocketConnect(const Endpoints& endpoints,
-                               boost::system::error_code* ec) {
-  boost::asio::connect(socket_, endpoints, *ec);
+void HttpClient::SetTimeout(int seconds) {
+  if (seconds > 0) {
+    timeout_seconds_ = seconds;
+  }
 }
 
-void HttpClient::SocketWrite(const HttpRequest& request,
-                             boost::system::error_code* ec) {
-  boost::asio::write(socket_, request.ToBuffers(), *ec);
+bool HttpClient::Request(const HttpRequest& request,
+                         std::size_t buffer_size,
+                         bool connect) {
+  io_context_.restart();
+
+  response_.reset(new HttpResponse());
+  response_parser_.reset(new HttpResponseParser(response_.get()));
+
+  stopped_ = false;
+  timed_out_ = false;
+  error_ = kNoError;
+
+  BufferResizer buffer_resizer(&buffer_, buffer_size);
+
+  if (connect) {
+    if ((error_ = Connect(request)) != kNoError) {
+      return false;
+    }
+  }
+
+  if ((error_ = WriteReqeust(request)) != kNoError) {
+    return false;
+  }
+
+  if ((error_ = ReadResponse()) != kNoError) {
+    return false;
+  }
+
+  return true;
 }
 
-void HttpClient::SocketAsyncReadSome(ReadHandler&& handler) {
-  socket_.async_read_some(boost::asio::buffer(buffer_), std::move(handler));
+Error HttpClient::Connect(const HttpRequest& request) {
+  if (request.url().scheme() == "https") {
+    socket_.reset(new HttpSslSocket{ io_context_, ssl_verify_ });
+    return DoConnect(request, kPort443);
+  } else {
+    socket_.reset(new HttpSocket{ io_context_ });
+    return DoConnect(request, kPort80);
+  }
 }
 
-void HttpClient::SocketClose(boost::system::error_code* ec) {
-  socket_.close(*ec);
+Error HttpClient::DoConnect(const HttpRequest& request,
+                            const std::string& default_port) {
+  tcp::resolver resolver(io_context_);
+
+  std::string port = request.port(default_port);
+
+  boost::system::error_code ec;
+  auto endpoints = resolver.resolve(tcp::v4(), request.host(), port, ec);
+
+  if (ec) {
+    LOG_ERRO("Host resolve error (%s): %s, %s.", ec.message().c_str(),
+             request.host().c_str(), port.c_str());
+    return kHostResolveError;
+  }
+
+  LOG_VERB("Connect to server...");
+
+  // Use sync API directly since we don't need timeout control.
+  socket_->Connect(request.host(), endpoints, &ec);
+
+  // Determine whether a connection was successfully established.
+  if (ec) {
+    LOG_ERRO("Socket connect error (%s).", ec.message().c_str());
+    Stop();
+    return kEndpointConnectError;
+  }
+
+  LOG_VERB("Socket connected.");
+
+  return kNoError;
+}
+
+Error HttpClient::WriteReqeust(const HttpRequest& request) {
+  LOG_VERB("HTTP request:\n%s", request.Dump(4, "> ").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.
+
+  boost::system::error_code ec;
+
+  // Use sync API directly since we don't need timeout control.
+  socket_->Write(request, &ec);
+
+  if (ec) {
+    LOG_ERRO("Socket write error (%s).", ec.message().c_str());
+    Stop();
+    return kSocketWriteError;
+  }
+
+  LOG_INFO("Request sent.");
+
+  return kNoError;
+}
+
+Error HttpClient::ReadResponse() {
+  LOG_VERB("Read response (timeout: %ds)...", timeout_seconds_);
+
+  deadline_.expires_from_now(boost::posix_time::seconds(timeout_seconds_));
+  DoWaitDeadline();
+
+  Error error = kNoError;
+  DoReadResponse(&error);
+
+  if (error == kNoError) {
+    LOG_VERB("HTTP response:\n%s", response_->Dump(4, "> ").c_str());
+  }
+
+  return error;
+}
+
+void HttpClient::DoReadResponse(Error* error) {
+  boost::system::error_code ec = boost::asio::error::would_block;
+
+  auto handler = [this, &ec, error](boost::system::error_code inner_ec,
+                                    std::size_t length) {
+    ec = inner_ec;
+
+    LOG_VERB("Socket async read handler.");
+
+    if (ec || length == 0) {
+      Stop();
+      *error = kSocketReadError;
+      LOG_ERRO("Socket read error (%s).", ec.message().c_str());
+      return;
+    }
+
+    LOG_INFO("Read data, length: %u.", length);
+
+    // Parse the response piece just read.
+    if (!response_parser_->Parse(buffer_.data(), length)) {
+      Stop();
+      *error = kHttpError;
+      LOG_ERRO("Failed to parse HTTP response.");
+      return;
+    }
+
+    if (response_parser_->finished()) {
+      // Stop trying to read once all content has been received, because
+      // some servers will block extra call to read_some().
+      Stop();  // TODO: Keep-Alive
+
+      LOG_INFO("Finished to read and parse HTTP response.");
+
+      return;
+    }
+
+    if (!stopped_) {
+      DoReadResponse(error);
+    }
+  };
+
+  socket_->AsyncReadSome(std::move(handler), &buffer_);
+
+  // Block until the asynchronous operation has completed.
+  do {
+    io_context_.run_one();
+  } while (ec == boost::asio::error::would_block);
+}
+
+void HttpClient::DoWaitDeadline() {
+  deadline_.async_wait(
+      std::bind(&HttpClient::OnDeadline, this, std::placeholders::_1));
+}
+
+void HttpClient::OnDeadline(boost::system::error_code ec) {
+  if (stopped_) {
+    return;
+  }
+
+  LOG_VERB("OnDeadline.");
+
+  // NOTE: Can't check this:
+  //   if (ec == boost::asio::error::operation_aborted) {
+  //     LOG_VERB("Deadline timer canceled.");
+  //     return;
+  //   }
+
+  if (deadline_.expires_at() <=
+      boost::asio::deadline_timer::traits_type::now()) {
+    // The deadline has passed.
+    // The socket is closed so that any outstanding asynchronous operations
+    // are canceled.
+    LOG_WARN("HTTP client timed out.");
+    timed_out_ = true;
+    Stop();
+    return;
+  }
+
+  // Put the actor back to sleep.
+  DoWaitDeadline();
+}
+
+void HttpClient::Stop() {
+  if (stopped_) {
+    return;
+  }
+
+  stopped_ = true;
+
+  LOG_INFO("Close socket...");
+
+  boost::system::error_code ec;
+  socket_->Close(&ec);
+
+  if (ec) {
+    LOG_ERRO("Socket close error (%s).", ec.message().c_str());
+  }
+
+  LOG_INFO("Cancel deadline timer...");
+  deadline_.cancel();
 }
 
 }  // namespace webcc

webcc/http_client.h

@@ -1,33 +1,110 @@
 #ifndef WEBCC_HTTP_CLIENT_H_
 #define WEBCC_HTTP_CLIENT_H_
 
-#include "webcc/http_client_base.h"
+#include <cassert>
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "boost/asio/deadline_timer.hpp"
+#include "boost/asio/io_context.hpp"
+#include "boost/asio/ip/tcp.hpp"
+
+#include "webcc/globals.h"
+#include "webcc/http_request.h"
+#include "webcc/http_response.h"
+#include "webcc/http_response_parser.h"
+#include "webcc/http_socket.h"
 
 namespace webcc {
 
-// HTTP synchronous client.
-class HttpClient : public HttpClientBase {
+class HttpSocketBase;
+
+// The base class of synchronous HTTP clients.
+// In synchronous mode, a request won't return until the response is received
+// or timeout occurs.
+// Please don't use the same client object in multiple threads.
+class HttpClient {
 public:
-  explicit HttpClient(std::size_t buffer_size = 0);
+  // The |buffer_size| is the bytes of the buffer for reading response.
+  // 0 means default value (e.g., 1024) will be used.
+  explicit HttpClient(std::size_t buffer_size = 0, bool ssl_verify = true);
 
-  ~HttpClient() = default;
+  virtual ~HttpClient() = default;
 
-private:
-  Error Connect(const HttpRequest& request) final {
-    return DoConnect(request, kPort80);
+  HttpClient(const HttpClient&) = delete;
+  HttpClient& operator=(const HttpClient&) = delete;
+
+  // Set the timeout seconds for reading response.
+  // The |seconds| is only effective when greater than 0.
+  void SetTimeout(int seconds);
+
+  // Connect to server, send request, wait until response is received.
+  // Set |buffer_size| to non-zero to use a different buffer size for this
+  // specific request.
+  bool Request(const HttpRequest& request,
+               std::size_t buffer_size = 0,
+               bool connect = true);
+
+  HttpResponsePtr response() const { return response_; }
+
+  int response_status() const {
+    assert(response_);
+    return response_->status();
   }
 
-  void SocketConnect(const Endpoints& endpoints,
-                     boost::system::error_code* ec) final;
+  const std::string& response_content() const {
+    assert(response_);
+    return response_->content();
+  }
 
-  void SocketWrite(const HttpRequest& request,
-                   boost::system::error_code* ec) final;
+  bool timed_out() const { return timed_out_; }
 
-  void SocketAsyncReadSome(ReadHandler&& handler) final;
+  Error error() const { return error_; }
 
-  void SocketClose(boost::system::error_code* ec) final;
+public:
+  Error Connect(const HttpRequest& request);
 
-  boost::asio::ip::tcp::socket socket_;
+  Error DoConnect(const HttpRequest& request, const std::string& default_port);
+
+  Error WriteReqeust(const HttpRequest& request);
+
+  Error ReadResponse();
+
+  void DoReadResponse(Error* error);
+
+  void DoWaitDeadline();
+  void OnDeadline(boost::system::error_code ec);
+
+  void Stop();
+
+  boost::asio::io_context io_context_;
+
+  std::unique_ptr<HttpSocketBase> socket_;
+
+  std::vector<char> buffer_;
+
+  HttpResponsePtr response_;
+  std::unique_ptr<HttpResponseParser> response_parser_;
+
+  // Timer for the timeout control.
+  boost::asio::deadline_timer deadline_;
+
+  // Verify the certificate of the peer (remote server) or not.
+  // HTTPS only.
+  bool ssl_verify_;
+
+  // Maximum seconds to wait before the client cancels the operation.
+  // Only for reading response from server.
+  int timeout_seconds_;
+
+  // Request stopped due to timeout or socket error.
+  bool stopped_;
+
+  // If the error was caused by timeout or not.
+  bool timed_out_;
+
+  Error error_;
 };
 
 }  // namespace webcc

webcc/http_client_base.cc

@@ -1,229 +0,0 @@
-#include "webcc/http_client_base.h"
-
-#include "boost/date_time/posix_time/posix_time.hpp"
-
-#include "webcc/logger.h"
-#include "webcc/utility.h"
-
-using boost::asio::ip::tcp;
-
-namespace webcc {
-
-HttpClientBase::HttpClientBase(std::size_t buffer_size)
-    : buffer_(buffer_size == 0 ? kBufferSize : buffer_size),
-      deadline_(io_context_),
-      timeout_seconds_(kMaxReadSeconds),
-      stopped_(false),
-      timed_out_(false),
-      error_(kNoError) {
-}
-
-void HttpClientBase::SetTimeout(int seconds) {
-  if (seconds > 0) {
-    timeout_seconds_ = seconds;
-  }
-}
-
-bool HttpClientBase::Request(const HttpRequest& request,
-                             std::size_t buffer_size) {
-  io_context_.restart();
-
-  response_.reset(new HttpResponse());
-  response_parser_.reset(new HttpResponseParser(response_.get()));
-
-  stopped_ = false;
-  timed_out_ = false;
-  error_ = kNoError;
-
-  BufferResizer buffer_resizer(&buffer_, buffer_size);
-
-  if ((error_ = Connect(request)) != kNoError) {
-    return false;
-  }
-
-  if ((error_ = WriteReqeust(request)) != kNoError) {
-    return false;
-  }
-
-  if ((error_ = ReadResponse()) != kNoError) {
-    return false;
-  }
-
-  return true;
-}
-
-Error HttpClientBase::DoConnect(const HttpRequest& request,
-                                const std::string& default_port) {
-  tcp::resolver resolver(io_context_);
-
-  std::string port = request.port(default_port);
-
-  boost::system::error_code ec;
-  auto endpoints = resolver.resolve(tcp::v4(), request.host(), port, ec);
-
-  if (ec) {
-    LOG_ERRO("Host resolve error (%s): %s, %s.", ec.message().c_str(),
-             request.host().c_str(), port.c_str());
-    return kHostResolveError;
-  }
-
-  LOG_VERB("Connect to server...");
-
-  // Use sync API directly since we don't need timeout control.
-  SocketConnect(endpoints, &ec);
-
-  // Determine whether a connection was successfully established.
-  if (ec) {
-    LOG_ERRO("Socket connect error (%s).", ec.message().c_str());
-    Stop();
-    return kEndpointConnectError;
-  }
-
-  LOG_VERB("Socket connected.");
-
-  return kNoError;
-}
-
-Error HttpClientBase::WriteReqeust(const HttpRequest& request) {
-  LOG_VERB("HTTP request:\n%s", request.Dump(4, "> ").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.
-
-  boost::system::error_code ec;
-
-  // Use sync API directly since we don't need timeout control.
-  SocketWrite(request, &ec);
-
-  if (ec) {
-    LOG_ERRO("Socket write error (%s).", ec.message().c_str());
-    Stop();
-    return kSocketWriteError;
-  }
-
-  LOG_INFO("Request sent.");
-
-  return kNoError;
-}
-
-Error HttpClientBase::ReadResponse() {
-  LOG_VERB("Read response (timeout: %ds)...", timeout_seconds_);
-
-  deadline_.expires_from_now(boost::posix_time::seconds(timeout_seconds_));
-  DoWaitDeadline();
-
-  Error error = kNoError;
-  DoReadResponse(&error);
-
-  if (error == kNoError) {
-    LOG_VERB("HTTP response:\n%s", response_->Dump(4, "> ").c_str());
-  }
-
-  return error;
-}
-
-void HttpClientBase::DoReadResponse(Error* error) {
-  boost::system::error_code ec = boost::asio::error::would_block;
-
-  auto handler = [this, &ec, error](boost::system::error_code inner_ec,
-                                    std::size_t length) {
-    ec = inner_ec;
-
-    LOG_VERB("Socket async read handler.");
-
-    if (ec || length == 0) {
-      Stop();
-      *error = kSocketReadError;
-      LOG_ERRO("Socket read error (%s).", ec.message().c_str());
-      return;
-    }
-
-    LOG_INFO("Read data, length: %u.", length);
-
-    // Parse the response piece just read.
-    if (!response_parser_->Parse(buffer_.data(), length)) {
-      Stop();
-      *error = kHttpError;
-      LOG_ERRO("Failed to parse HTTP response.");
-      return;
-    }
-
-    if (response_parser_->finished()) {
-      // Stop trying to read once all content has been received, because
-      // some servers will block extra call to read_some().
-      Stop();
-
-      LOG_INFO("Finished to read and parse HTTP response.");
-
-      return;
-    }
-
-    if (!stopped_) {
-      DoReadResponse(error);
-    }
-  };
-
-  SocketAsyncReadSome(std::move(handler));
-
-  // Block until the asynchronous operation has completed.
-  do {
-    io_context_.run_one();
-  } while (ec == boost::asio::error::would_block);
-}
-
-void HttpClientBase::DoWaitDeadline() {
-  deadline_.async_wait(
-      std::bind(&HttpClientBase::OnDeadline, this, std::placeholders::_1));
-}
-
-void HttpClientBase::OnDeadline(boost::system::error_code ec) {
-  if (stopped_) {
-    return;
-  }
-
-  LOG_VERB("OnDeadline.");
-
-  // NOTE: Can't check this:
-  //   if (ec == boost::asio::error::operation_aborted) {
-  //     LOG_VERB("Deadline timer canceled.");
-  //     return;
-  //   }
-
-  if (deadline_.expires_at() <=
-      boost::asio::deadline_timer::traits_type::now()) {
-    // The deadline has passed.
-    // The socket is closed so that any outstanding asynchronous operations
-    // are canceled.
-    LOG_WARN("HTTP client timed out.");
-    timed_out_ = true;
-    Stop();
-    return;
-  }
-
-  // Put the actor back to sleep.
-  DoWaitDeadline();
-}
-
-void HttpClientBase::Stop() {
-  if (stopped_) {
-    return;
-  }
-
-  stopped_ = true;
-
-  LOG_INFO("Close socket...");
-
-  boost::system::error_code ec;
-  SocketClose(&ec);
-
-  if (ec) {
-    LOG_ERRO("Socket close error (%s).", ec.message().c_str());
-  }
-
-  LOG_INFO("Cancel deadline timer...");
-  deadline_.cancel();
-}
-
-}  // namespace webcc

webcc/http_client_base.h

@@ -1,116 +0,0 @@
-#ifndef WEBCC_HTTP_CLIENT_BASE_H_
-#define WEBCC_HTTP_CLIENT_BASE_H_
-
-#include <cassert>
-#include <memory>
-#include <string>
-#include <vector>
-
-#include "boost/asio/deadline_timer.hpp"
-#include "boost/asio/io_context.hpp"
-#include "boost/asio/ip/tcp.hpp"
-
-#include "webcc/globals.h"
-#include "webcc/http_request.h"
-#include "webcc/http_response.h"
-#include "webcc/http_response_parser.h"
-
-namespace webcc {
-
-// The base class of synchronous HTTP clients.
-// In synchronous mode, a request won't return until the response is received
-// or timeout occurs.
-// Please don't use the same client object in multiple threads.
-class HttpClientBase {
-public:
-  // The |buffer_size| is the bytes of the buffer for reading response.
-  // 0 means default value (e.g., 1024) will be used.
-  explicit HttpClientBase(std::size_t buffer_size = 0);
-
-  virtual ~HttpClientBase() = default;
-
-  HttpClientBase(const HttpClientBase&) = delete;
-  HttpClientBase& operator=(const HttpClientBase&) = delete;
-
-  // Set the timeout seconds for reading response.
-  // The |seconds| is only effective when greater than 0.
-  void SetTimeout(int seconds);
-
-  // Connect to server, send request, wait until response is received.
-  // Set |buffer_size| to non-zero to use a different buffer size for this
-  // specific request.
-  bool Request(const HttpRequest& request, std::size_t buffer_size = 0);
-
-  HttpResponsePtr response() const { return response_; }
-
-  int response_status() const {
-    assert(response_);
-    return response_->status();
-  }
-
-  const std::string& response_content() const {
-    assert(response_);
-    return response_->content();
-  }
-
-  bool timed_out() const { return timed_out_; }
-
-  Error error() const { return error_; }
-
-public:
-  typedef boost::asio::ip::tcp::resolver::results_type Endpoints;
-
-  typedef std::function<void(boost::system::error_code, std::size_t)>
-      ReadHandler;
-
-  virtual Error Connect(const HttpRequest& request) = 0;
-
-  Error DoConnect(const HttpRequest& request, const std::string& default_port);
-
-  Error WriteReqeust(const HttpRequest& request);
-
-  Error ReadResponse();
-
-  void DoReadResponse(Error* error);
-
-  void DoWaitDeadline();
-  void OnDeadline(boost::system::error_code ec);
-
-  void Stop();
-
-  virtual void SocketConnect(const Endpoints& endpoints,
-                             boost::system::error_code* ec) = 0;
-
-  virtual void SocketWrite(const HttpRequest& request,
-                           boost::system::error_code* ec) = 0;
-
-  virtual void SocketAsyncReadSome(ReadHandler&& handler) = 0;
-
-  virtual void SocketClose(boost::system::error_code* ec) = 0;
-
-  boost::asio::io_context io_context_;
-
-  std::vector<char> buffer_;
-
-  HttpResponsePtr response_;
-  std::unique_ptr<HttpResponseParser> response_parser_;
-
-  // Timer for the timeout control.
-  boost::asio::deadline_timer deadline_;
-
-  // Maximum seconds to wait before the client cancels the operation.
-  // Only for reading response from server.
-  int timeout_seconds_;
-
-  // Request stopped due to timeout or socket error.
-  bool stopped_;
-
-  // If the error was caused by timeout or not.
-  bool timed_out_;
-
-  Error error_;
-};
-
-}  // namespace webcc
-
-#endif  // WEBCC_HTTP_CLIENT_BASE_H_

webcc/http_client_pool.cc

@@ -0,0 +1,16 @@
+#include "webcc/http_client_pool.h"
+
+namespace webcc {
+
+HttpClientPtr HttpClientPool::Get(const Url& url) const {
+  for (const auto& client : clients_) {
+    return client;
+  }
+  return HttpClientPtr{};
+}
+
+void HttpClientPool::Add(HttpClientPtr client) {
+  clients_.push_back(client);
+}
+
+}  // namespace webcc

webcc/http_client_pool.h

@@ -0,0 +1,31 @@
+#ifndef WEBCC_HTTP_CLIENT_POOL_H_
+#define WEBCC_HTTP_CLIENT_POOL_H_
+
+// HTTP client connection pool for keep-alive connections.
+
+#include <list>
+#include <memory>
+#include <string>
+
+#include "webcc/http_client.h"
+#include "webcc/url.h"
+
+namespace webcc {
+
+typedef std::shared_ptr<HttpClient> HttpClientPtr;
+
+class HttpClientPool {
+public:
+  HttpClientPool() = default;
+
+  HttpClientPtr Get(const Url& url) const;
+
+  void Add(HttpClientPtr client);
+
+private:
+  std::list<HttpClientPtr> clients_;
+};
+
+}  // namespace webcc
+
+#endif  // WEBCC_HTTP_CLIENT_POOL_H_

webcc/http_client_session.cc

@@ -1,12 +1,12 @@
 #include "webcc/http_client_session.h"
 
 #include "webcc/http_client.h"
-#include "webcc/http_ssl_client.h"
 #include "webcc/url.h"
 
 namespace webcc {
 
-HttpClientSession::HttpClientSession() {
+HttpClientSession::HttpClientSession()
+    : pool_(new HttpClientPool{}) {
   InitHeaders();
 }
 
@@ -45,18 +45,18 @@ HttpResponsePtr HttpClientSession::Request(HttpRequestArgs&& args) {
 
   request.Prepare();
 
-  std::shared_ptr<HttpClientBase> impl;
+  bool connect = false;
+  HttpClientPtr impl = pool_->Get(request.url());
 
-  if (request.url().scheme() == "http") {
-    impl.reset(new HttpClient);
-  } else if (request.url().scheme() == "https") {
-    impl.reset(new HttpSslClient{args.ssl_verify_});
-  } else {
-    throw Exception(kSchemaError, false,
-                    "unknown schema: " + request.url().scheme());
+  if (!impl) {
+    impl.reset(new HttpClient{ 0, args.ssl_verify_ });
+
+    connect = true;
+
+    pool_->Add(impl);
   }
 
-  if (!impl->Request(request, args.buffer_size_)) {
+  if (!impl->Request(request, args.buffer_size_, connect)) {
     throw Exception(impl->error(), impl->timed_out());
   }
 
@@ -67,17 +67,21 @@ HttpResponsePtr HttpClientSession::Get(const std::string& url,
                                        std::vector<std::string>&& parameters,
                                        std::vector<std::string>&& headers,
                                        HttpRequestArgs&& args) {
-  return Request(args.method(http::kGet).url(url)
-                 .parameters(std::move(parameters))
-                 .headers(std::move(headers)));
+  return Request(args.method(http::kGet)
+                     .url(url)
+                     .parameters(std::move(parameters))
+                     .headers(std::move(headers)));
 }
 
 HttpResponsePtr HttpClientSession::Post(const std::string& url,
                                         std::string&& data, bool json,
                                         std::vector<std::string>&& headers,
                                         HttpRequestArgs&& args) {
-  return Request(args.method(http::kPost).url(url).data(std::move(data))
-                 .json(json).headers(std::move(headers)));
+  return Request(args.method(http::kPost)
+                     .url(url)
+                     .data(std::move(data))
+                     .json(json)
+                     .headers(std::move(headers)));
 }
 
 void HttpClientSession::InitHeaders() {
@@ -89,8 +93,8 @@ void HttpClientSession::InitHeaders() {
 
   headers_.Add(http::headers::kAccept, "*/*");
 
-  // TODO: Support Keep-Alive connection.
-  //headers_.Add(http::headers::kConnection, "close");
+  // TODO
+  headers_.Add(http::headers::kConnection, "Keep-Alive");
 }
 
 }  // namespace webcc

webcc/http_client_session.h

@@ -1,9 +1,11 @@
 #ifndef WEBCC_HTTP_CLIENT_SESSION_H_
 #define WEBCC_HTTP_CLIENT_SESSION_H_
 
+#include <memory>
 #include <string>
 #include <vector>
 
+#include "webcc/http_client_pool.h"
 #include "webcc/http_request_args.h"
 #include "webcc/http_response.h"
 
@@ -49,6 +51,8 @@ private:
 
   // Headers for each request sent from this session.
   HttpHeaderDict headers_;
+
+  std::unique_ptr<HttpClientPool> pool_;
 };
 
 }  // namespace webcc

webcc/http_socket.cc

@@ -0,0 +1,92 @@
+#include "webcc/http_socket.h"
+
+#include "boost/asio/connect.hpp"
+#include "boost/asio/read.hpp"
+#include "boost/asio/write.hpp"
+
+#include "webcc/logger.h"
+
+namespace ssl = boost::asio::ssl;
+
+namespace webcc {
+
+// -----------------------------------------------------------------------------
+
+HttpSocket::HttpSocket(boost::asio::io_context& io_context)
+    : socket_(io_context) {
+}
+
+void HttpSocket::Connect(const std::string& /*host*/,
+                         const Endpoints& endpoints,
+                         boost::system::error_code* ec) {
+  boost::asio::connect(socket_, endpoints, *ec);
+}
+
+void HttpSocket::Write(const HttpRequest& request,
+                       boost::system::error_code* ec) {
+  boost::asio::write(socket_, request.ToBuffers(), *ec);
+}
+
+void HttpSocket::AsyncReadSome(ReadHandler&& handler, std::vector<char>* buffer) {
+  socket_.async_read_some(boost::asio::buffer(*buffer), std::move(handler));
+}
+
+void HttpSocket::Close(boost::system::error_code* ec) {
+  socket_.close(*ec);
+}
+
+// -----------------------------------------------------------------------------
+
+HttpSslSocket::HttpSslSocket(boost::asio::io_context& io_context,
+                             bool ssl_verify)
+    : ssl_context_(ssl::context::sslv23),
+      ssl_socket_(io_context, ssl_context_),
+      ssl_verify_(ssl_verify) {
+  // Use the default paths for finding CA certificates.
+  ssl_context_.set_default_verify_paths();
+}
+
+void HttpSslSocket::Connect(const std::string& host,
+                            const Endpoints& endpoints,
+                            boost::system::error_code* ec) {
+  boost::asio::connect(ssl_socket_.lowest_layer(), endpoints, *ec);
+
+  if (*ec) {
+    return;
+  }
+
+  Handshake(host, ec);
+}
+
+void HttpSslSocket::Write(const HttpRequest& request,
+                          boost::system::error_code* ec) {
+  boost::asio::write(ssl_socket_, request.ToBuffers(), *ec);
+}
+
+void HttpSslSocket::AsyncReadSome(ReadHandler&& handler, std::vector<char>* buffer) {
+  ssl_socket_.async_read_some(boost::asio::buffer(*buffer), std::move(handler));
+}
+
+void HttpSslSocket::Close(boost::system::error_code* ec) {
+  ssl_socket_.lowest_layer().close(*ec);
+}
+
+void HttpSslSocket::Handshake(const std::string& host,
+                              boost::system::error_code* ec) {
+  if (ssl_verify_) {
+    ssl_socket_.set_verify_mode(ssl::verify_peer);
+  } else {
+    ssl_socket_.set_verify_mode(ssl::verify_none);
+  }
+
+  ssl_socket_.set_verify_callback(ssl::rfc2818_verification(host));
+
+  // Use sync API directly since we don't need timeout control.
+  ssl_socket_.handshake(ssl::stream_base::client, *ec);
+
+  if (*ec) {
+    LOG_ERRO("Handshake error (%s).", ec->message().c_str());
+  }
+}
+
+}  // namespace webcc

webcc/http_socket.h

@@ -0,0 +1,90 @@
+#ifndef WEBCC_HTTP_SOCKET_H_
+#define WEBCC_HTTP_SOCKET_H_
+
+#include <vector>
+
+#include "boost/asio/ip/tcp.hpp"
+#include "boost/asio/ssl.hpp"
+
+#include "webcc/http_request.h"
+
+namespace webcc {
+
+// -----------------------------------------------------------------------------
+
+class HttpSocketBase {
+public:
+  virtual ~HttpSocketBase() = default;
+
+  typedef boost::asio::ip::tcp::resolver::results_type Endpoints;
+
+  typedef std::function<void(boost::system::error_code, std::size_t)>
+      ReadHandler;
+
+  // TODO: Remove |host|
+  virtual void Connect(const std::string& host,
+                       const Endpoints& endpoints,
+                       boost::system::error_code* ec) = 0;
+
+  virtual void Write(const HttpRequest& request,
+                     boost::system::error_code* ec) = 0;
+
+  virtual void AsyncReadSome(ReadHandler&& handler,
+                             std::vector<char>* buffer) = 0;
+
+  virtual void Close(boost::system::error_code* ec) = 0;
+};
+
+// -----------------------------------------------------------------------------
+
+class HttpSocket : public HttpSocketBase {
+public:
+  explicit HttpSocket(boost::asio::io_context& io_context);
+
+  void Connect(const std::string& host,
+               const Endpoints& endpoints,
+               boost::system::error_code* ec) final;
+
+  void Write(const HttpRequest& request,
+             boost::system::error_code* ec) final;
+
+  void AsyncReadSome(ReadHandler&& handler, std::vector<char>* buffer) final;
+
+  void Close(boost::system::error_code* ec) final;
+
+private:
+  boost::asio::ip::tcp::socket socket_;
+};
+
+// -----------------------------------------------------------------------------
+
+class HttpSslSocket : public HttpSocketBase {
+public:
+  explicit HttpSslSocket(boost::asio::io_context& io_context,
+                         bool ssl_verify = true);
+
+  void Connect(const std::string& host,
+               const Endpoints& endpoints,
+               boost::system::error_code* ec) final;
+
+  void Write(const HttpRequest& request,
+             boost::system::error_code* ec) final;
+
+  void AsyncReadSome(ReadHandler&& handler, std::vector<char>* buffer) final;
+
+  void Close(boost::system::error_code* ec) final;
+
+private:
+  void Handshake(const std::string& host, boost::system::error_code* ec);
+
+  boost::asio::ssl::context ssl_context_;
+
+  boost::asio::ssl::stream<boost::asio::ip::tcp::socket> ssl_socket_;
+
+  // Verify the certificate of the peer (remote server) or not.
+  bool ssl_verify_;
+};
+
+}  // namespace webcc
+
+#endif  // WEBCC_HTTP_SOCKET_H_

webcc/http_ssl_client.cc

@@ -1,72 +0,0 @@
-#include "webcc/http_ssl_client.h"
-
-#include "boost/asio/connect.hpp"
-#include "boost/asio/read.hpp"
-#include "boost/asio/write.hpp"
-
-#include "webcc/logger.h"
-
-namespace ssl = boost::asio::ssl;
-
-namespace webcc {
-
-HttpSslClient::HttpSslClient(bool ssl_verify, std::size_t buffer_size)
-    : HttpClientBase(buffer_size),
-      ssl_context_(ssl::context::sslv23),
-      ssl_socket_(io_context_, ssl_context_),
-      ssl_verify_(ssl_verify) {
-  // Use the default paths for finding CA certificates.
-  ssl_context_.set_default_verify_paths();
-}
-
-Error HttpSslClient::Connect(const HttpRequest& request) {
-  Error error = DoConnect(request, kPort443);
-  
-  if (error != kNoError) {
-    return error;
-  }
-
-  return Handshake(request.host());
-}
-
-// NOTE: Don't check timeout. It doesn't make much sense.
-Error HttpSslClient::Handshake(const std::string& host) {
-  if (ssl_verify_) {
-    ssl_socket_.set_verify_mode(ssl::verify_peer);
-  } else {
-    ssl_socket_.set_verify_mode(ssl::verify_none);
-  }
-
-  ssl_socket_.set_verify_callback(ssl::rfc2818_verification(host));
-
-  // Use sync API directly since we don't need timeout control.
-  boost::system::error_code ec;
-  ssl_socket_.handshake(ssl::stream_base::client, ec);
-
-  if (ec) {
-    LOG_ERRO("Handshake error (%s).", ec.message().c_str());
-    return kHandshakeError;
-  }
-
-  return kNoError;
-}
-
-void HttpSslClient::SocketConnect(const Endpoints& endpoints,
-                                  boost::system::error_code* ec) {
-  boost::asio::connect(ssl_socket_.lowest_layer(), endpoints, *ec);
-}
-
-void HttpSslClient::SocketWrite(const HttpRequest& request,
-                                boost::system::error_code* ec) {
-  boost::asio::write(ssl_socket_, request.ToBuffers(), *ec);
-}
-
-void HttpSslClient::SocketAsyncReadSome(ReadHandler&& handler) {
-  ssl_socket_.async_read_some(boost::asio::buffer(buffer_), std::move(handler));
-}
-
-void HttpSslClient::SocketClose(boost::system::error_code* ec) {
-  ssl_socket_.lowest_layer().close(*ec);
-}
-
-}  // namespace webcc

webcc/http_ssl_client.h

@@ -1,45 +0,0 @@
-#ifndef WEBCC_HTTP_SSL_CLIENT_H_
-#define WEBCC_HTTP_SSL_CLIENT_H_
-
-#include "webcc/http_client_base.h"
-
-#include "boost/asio/ssl.hpp"
-
-namespace webcc {
-
-// HTTP SSL (a.k.a., HTTPS) synchronous client.
-class HttpSslClient : public HttpClientBase {
-public:
-  // SSL verification (|ssl_verify|) needs CA certificates to be found
-  // in the default verify paths of OpenSSL. On Windows, it means you need to
-  // set environment variable SSL_CERT_FILE properly.
-  explicit HttpSslClient(bool ssl_verify = true, std::size_t buffer_size = 0);
-
-  ~HttpSslClient() = default;
-
-private:
-  Error Handshake(const std::string& host);
-
-  // Override to do handshake after connected.
-  Error Connect(const HttpRequest& request) final;
-
-  void SocketConnect(const Endpoints& endpoints,
-                     boost::system::error_code* ec) final;
-
-  void SocketWrite(const HttpRequest& request,
-                   boost::system::error_code* ec) final;
-
-  void SocketAsyncReadSome(ReadHandler&& handler) final;
-
-  void SocketClose(boost::system::error_code* ec) final;
-
-  boost::asio::ssl::context ssl_context_;
-  boost::asio::ssl::stream<boost::asio::ip::tcp::socket> ssl_socket_;
-
-  // Verify the certificate of the peer (remote server) or not.
-  bool ssl_verify_;
-};
-
-}  // namespace webcc
-
-#endif  // WEBCC_HTTP_SSL_CLIENT_H_