Refine client session and its examples.

example/github_client/main.cc

@@ -1,5 +1,4 @@
 #include <iostream>
-#include <map>
 
 #include "json/json.h"
 
@@ -21,9 +20,13 @@ bool kSslVerify = true;
 
 const std::size_t kBufferSize = 1500;
 
+const std::string kUrlRoot = "https://api.github.com";
+
 // -----------------------------------------------------------------------------
+// JSON helper functions (based on cppjson).
 
-static Json::Value StringToJson(const std::string& str) {
+// Parse a string to JSON object.
+Json::Value StringToJson(const std::string& str) {
   Json::Value json;
 
   Json::CharReaderBuilder builder;
@@ -37,7 +40,7 @@ static Json::Value StringToJson(const std::string& str) {
 }
 
 // Print the JSON string in pretty format.
-static void PrettyPrintJsonString(const std::string& str) {
+void PrettyPrintJsonString(const std::string& str) {
   Json::Value json = StringToJson(str);
 
   Json::StreamWriterBuilder builder;
@@ -57,48 +60,48 @@ static void PrettyPrintJsonString(const std::string& str) {
 #define PRINT_JSON_STRING(str)
 #endif  // PRINT_RESPONSE
 
-//static void PrintError(const webcc::RestSslClient& client) {
-//  std::cout << webcc::DescribeError(client.error());
-//  if (client.timed_out()) {
-//    std::cout << " (timed out)";
-//  }
-//  std::cout << std::endl;
-//}
-//
-//// -----------------------------------------------------------------------------
-//
-//// List public events.
-//static void ListEvents(webcc::RestSslClient& client) {
-//  if (client.Get("/events")) {
-//    PRINT_JSON_STRING(client.response_content());
-//  } else {
-//    PrintError(client);
-//  }
-//}
-//
-//// List the followers of the given user.
-//static void ListUserFollowers(webcc::RestSslClient& client,
-//                              const std::string& user) {
-//  if (client.Get("/users/" + user + "/followers")) {
-//    PRINT_JSON_STRING(client.response_content());
-//  } else {
-//    PrintError(client);
-//  }
-//}
+// -----------------------------------------------------------------------------
+
+// List public events.
+void ListEvents() {
+  webcc::HttpClientSession session;
+  session.set_ssl_verify(kSslVerify);
+
+  try {
+    auto r = session.Get(kUrlRoot + "/events");
+    PRINT_JSON_STRING(r->content());
+  } catch (const webcc::Exception& e) {
+    std::cout << e.what() << std::endl;
+  }
+}
+
+// List the followers of the given user.
+void ListUserFollowers(const std::string& user) {
+  webcc::HttpClientSession session;
+  session.set_ssl_verify(kSslVerify);
+
+  try {
+    auto r = session.Get(kUrlRoot + "/users/" + user + "/followers");
+    PRINT_JSON_STRING(r->content());
+  } catch (const webcc::Exception& e) {
+    std::cout << e.what() << std::endl;
+  }
+}
 
 // List the followers of the current authorized user.
 // Header syntax: Authorization: <type> <credentials>
-static void ListAuthorizedUserFollowers(webcc::HttpClientSession& session,
-                                        const std::string& auth) {
-  auto r = session.Request(webcc::HttpRequestArgs("GET").
-                           url("https://api.github.com/user/followers").
-                           headers({ { "Authorization", auth } }).
-                           ssl_verify(kSslVerify).buffer_size(kBufferSize));
-
-  if (r) {
+void ListAuthUserFollowers(const std::string& auth) {
+  webcc::HttpClientSession session;
+  session.set_ssl_verify(kSslVerify);
+
+  try {
+    auto r = session.Get(kUrlRoot + "/user/followers", {},
+                        { "Authorization", auth });
+
     PRINT_JSON_STRING(r->content());
-  } else {
-    //PrintError(client);
+
+  } catch (const webcc::Exception& e) {
+    std::cout << e.what() << std::endl;
   }
 }
 
@@ -107,10 +110,11 @@ static void ListAuthorizedUserFollowers(webcc::HttpClientSession& session,
 int main() {
   WEBCC_LOG_INIT("", webcc::LOG_CONSOLE);
 
-  webcc::HttpClientSession session;
+  //ListEvents();
+
+  //ListUserFollowers("<login>");
 
-  //ListAuthorizedUserFollowers(client, "Basic c3ByaW5mYWxsQGdtYWlsLmNvbTpYaWFvTHVhbjFA");
-  ListAuthorizedUserFollowers(session, "Token 1d42e2cce49929f2d24b1b6e96260003e5b3e1b0");
+  //ListAuthUserFollowers("Basic <base64 encoded login:password>");
 
   return 0;
 }

example/http_client/main.cc

@@ -1,5 +1,4 @@
 #include <iostream>
-#include <thread>
 
 #include "webcc/http_client_session.h"
 #include "webcc/logger.h"
@@ -18,130 +17,99 @@ bool kSslVerify = true;
 
 // -----------------------------------------------------------------------------
 
-void GetBoostOrgLicense(HttpClientSession& session) {
-  try {
-    auto r = session.Request(HttpRequestArgs{ "GET" }.
-                             url("https://www.boost.org/LICENSE_1_0.txt").
-                             ssl_verify(kSslVerify));
-
-    std::cout << r->content() << std::endl;
-
-  } catch (const webcc::Exception& e) {
-    std::cout << "Exception: " << e.what() << std::endl;
-  }
-}
-
-// TODO
-void Test(HttpClientSession& session) {
-  HttpResponsePtr r;
-
-  // ---------------------------------------------------------------------------
+void ExampleBasic() {
+  HttpClientSession session;
 
-  r = session.Request(HttpRequestArgs{ "GET" }.
-                      url("http://httpbin.org/get").  // moved
-                      parameters({ "key1", "value1", "key2", "value2" }).  // moved
-                      headers({ "Accept", "application/json" }).  // moved
-                      buffer_size(1000));
+  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;
+}
 
-  // ---------------------------------------------------------------------------
-
-  // If you want to create the args object firstly, there'll be an extra call
-  // to its move constructor.
-  //   - constructor: HttpRequestArgs{ "GET" }
-  //   - move constructor: auto args = ...
-
-  auto args = HttpRequestArgs{"GET"}.
-      url("http://httpbin.org/get").
-      parameters({ "key1", "value1", "key2", "value2" }).
-      headers({ "Accept", "application/json" }).
-      buffer_size(1000);
-
-  r = session.Request(std::move(args));
+// If you want to create the args object firstly, there might be an extra
+// call to its move constructor (maybe only for MSVC).
+//   - constructor: HttpRequestArgs{ "GET" }
+//   - move constructor: auto args = ...
+void ExampleArgs() {
+  HttpClientSession session;
 
-  // ---------------------------------------------------------------------------
-  // Use pre-defined wrappers.
+  auto args = HttpRequestArgs{"GET"}
+                  .url("http://httpbin.org/get")
+                  .parameters({"key1", "value1", "key2", "value2"})
+                  .headers({"Accept", "application/json"})
+                  .buffer_size(1000);
 
-  r = session.Get("http://httpbin.org/get",
-                  { "key1", "value1", "key2", "value2" },
-                  { "Accept", "application/json" },
-                  HttpRequestArgs{}.buffer_size(1000));
+  // Note the std::move().
+  session.Request(std::move(args));
+}
 
-  // ---------------------------------------------------------------------------
-  // HTTPS is auto-detected from the URL schema.
+// Use pre-defined wrappers.
+void ExampleWrappers() {
+  HttpClientSession session;
 
-  try {
-    r = session.Post("httpt://httpbin.org/post", "{ 'key': 'value' }", true,
+  session.Get("http://httpbin.org/get", {"key1", "value1", "key2", "value2"},
               {"Accept", "application/json"},
-                     HttpRequestArgs{}.ssl_verify(false).buffer_size(1000));
-
-    std::cout << r->status() << std::endl << r->content() << std::endl;
+              HttpRequestArgs{}.buffer_size(1000));
 
-  } catch (const webcc::Exception& e) {
-    std::cout << "Exception: " << e.what() << std::endl;
-  }
+  session.Post("http://httpbin.org/post", "{ 'key': 'value' }", true,
+               {"Accept", "application/json"});
 }
 
-void TestKeepAlive2(HttpClientSession& session) {
-  try {
-    auto r = session.Request(webcc::HttpRequestArgs("GET").
-                             url("https://api.github.com/events").
-                             ssl_verify(false).buffer_size(1500));
-  } 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));
+// HTTPS is auto-detected from the URL scheme.
+void ExampleHttps() {
+  HttpClientSession session;
 
-    //std::cout << r->content() << std::endl;
+  auto r = session.Request(HttpRequestArgs{"GET"}
+                               .url("https://httpbin.org/get")
+                               .parameters({"key1", "value1", "key2", "value2"})
+                               .headers({"Accept", "application/json"})
+                               .ssl_verify(kSslVerify));
 
-  } catch (const Exception& e) {
-    std::cout << "Exception: " << e.what() << std::endl;
-  }
+  std::cout << r->content() << std::endl;
 }
 
-void TestKeepAlive4(HttpClientSession& session) {
-  try {
-    auto r = session.Request(webcc::HttpRequestArgs("GET").
-                             url("https://www.google.com").
-                             ssl_verify(false));
+void ExampleKeepAlive(const std::string& url) {
+  HttpClientSession session;
 
-    //std::cout << r->content() << std::endl;
+  // Keep-Alive
+  session.Request(webcc::HttpRequestArgs("GET").url(url).
+                  ssl_verify(kSslVerify));
 
-  } catch (const Exception& e) {
-    std::cout << "Exception: " << e.what() << std::endl;
-  }
+  // Close
+  session.Request(webcc::HttpRequestArgs("GET").url(url).
+                  ssl_verify(kSslVerify).
+                  headers({ "Connection", "Close" }));
+
+  // Keep-Alive
+  session.Request(webcc::HttpRequestArgs("GET").url(url).
+                  ssl_verify(kSslVerify));
 }
 
 // -----------------------------------------------------------------------------
 
-void Sleep(int seconds) {
-  if (seconds > 0) {
-    LOG_INFO("Sleep %d seconds...", seconds);
-    std::this_thread::sleep_for(std::chrono::seconds(seconds));
-  }
-}
-
 int main() {
   WEBCC_LOG_INIT("", LOG_CONSOLE);
 
-  HttpClientSession session;
-
-  // TEST keep-alive.
-
+  // Note that the exception handling is mandatory.
   try {
-    // Keep-Alive by default
-    session.Get("http://httpbin.org/get");
+    //ExampleBasic();
+    //ExampleArgs();
+    //ExampleWrappers();
+    //ExampleHttps();
+
+    // Boost.org doesn't support persistent connection so always includes
+    // "Connection: Close" header in the response.
 
-    session.Get("http://httpbin.org/get", {}, { "Connection", "Close" });
+    // Both Google and GitHub support persistent connection but they don't like
+    // to include "Connection: Keep-Alive" header in the responses.
 
-    session.Get("http://httpbin.org/get");
+    //ExampleKeepAlive("http://httpbin.org/get");
+    //ExampleKeepAlive("https://www.boost.org/LICENSE_1_0.txt");
+    //ExampleKeepAlive("https://www.google.com");
+    //ExampleKeepAlive("https://api.github.com/events");
 
   } catch (const Exception& e) {
     std::cout << "Exception: " << e.what() << std::endl;

webcc/globals.h

@@ -139,6 +139,10 @@ public:
     return msg_.c_str();
   }
 
+  Error error() const { return error_; }
+
+  bool timeout() const { return timeout_; }
+
 private:
   Error error_;
 

webcc/http_client_pool.cc

@@ -25,10 +25,16 @@ HttpClientPtr HttpClientPool::Get(const Key& key) const {
 
 void HttpClientPool::Add(const Key& key, HttpClientPtr client) {
   clients_[key] = client;
+
+  LOG_INFO("Added connection to pool (%s, %s, %s).",
+           key.scheme.c_str(), key.host.c_str(), key.port.c_str());
 }
 
 void HttpClientPool::Remove(const Key& key) {
   clients_.erase(key);
+
+  LOG_INFO("Removed connection from pool (%s, %s, %s).",
+           key.scheme.c_str(), key.host.c_str(), key.port.c_str());
 }
 
 }  // namespace webcc

webcc/http_client_session.cc

@@ -43,35 +43,39 @@ HttpResponsePtr HttpClientSession::Request(HttpRequestArgs&& args) {
 
   request.Prepare();
 
+  // Determine SSL verify flag.
+  bool ssl_verify = true;
+  if (args.ssl_verify_) {
+    ssl_verify = args.ssl_verify_.value();
+  } else if (ssl_verify_) {
+    ssl_verify = ssl_verify_.value();
+  }
+
+  bool reuse = false;
   const HttpClientPool::Key key{ request.url() };
-  bool new_created = false;
 
   HttpClientPtr client = pool_.Get(key);
   if (!client) {
-    new_created = true;
-    client.reset(new HttpClient{ 0, args.ssl_verify_ });
+    client.reset(new HttpClient{ 0, ssl_verify });
+    reuse = false;
   } else {
-    new_created = false;
+    // TODO: Apply args.ssl_verify even if reuse a client.
+    reuse = false;
     LOG_VERB("Reuse an existing connection.");
   }
 
-  if (!client->Request(request, args.buffer_size_, new_created)) {
+  if (!client->Request(request, args.buffer_size_, !reuse)) {
     throw Exception(client->error(), client->timed_out());
   }
 
-  if (new_created) {
-    if (!client->closed()) {
-      pool_.Add(key, client);
-
-      LOG_VERB("Added connection to the pool (%s, %s, %s).",
-               key.scheme.c_str(), key.host.c_str(), key.port.c_str());
-    }
-  } else {
+  // Update pool.
+  if (reuse) {
     if (client->closed()) {
       pool_.Remove(key);
-
-      LOG_VERB("Removed connection from the pool (%s, %s, %s).",
-               key.scheme.c_str(), key.host.c_str(), key.port.c_str());
+    }
+  } else {
+    if (!client->closed()) {
+      pool_.Add(key, client);
     }
   }
 

webcc/http_client_session.h

@@ -5,6 +5,8 @@
 #include <string>
 #include <vector>
 
+#include "boost/optional.hpp"
+
 #include "webcc/http_client_pool.h"
 #include "webcc/http_request_args.h"
 #include "webcc/http_response.h"
@@ -29,6 +31,10 @@ public:
     headers_.Add(key, value);
   }
 
+  void set_ssl_verify(bool ssl_verify) {
+    ssl_verify_.emplace(ssl_verify);
+  }
+
   HttpResponsePtr Request(HttpRequestArgs&& args);
 
   HttpResponsePtr Get(const std::string& url,
@@ -43,6 +49,7 @@ public:
 private:
   void InitHeaders();
 
+private:
   // E.g., "application/json".
   std::string content_type_;
 
@@ -52,6 +59,9 @@ private:
   // Headers for each request sent from this session.
   HttpHeaderDict headers_;
 
+  // Verify the certificate of the peer or not.
+  boost::optional<bool> ssl_verify_;
+
   // Connection pool for keep-alive.
   HttpClientPool pool_;
 };

webcc/http_request_args.h

@@ -5,6 +5,8 @@
 #include <utility>
 #include <vector>
 
+#include "boost/optional.hpp"
+
 #include "webcc/globals.h"
 #include "webcc/logger.h"
 
@@ -17,7 +19,7 @@ class HttpClientSession;
 class HttpRequestArgs {
 public:
   explicit HttpRequestArgs(const std::string& method = "")
-      : method_(method), json_(false), ssl_verify_(true), buffer_size_(0) {
+      : method_(method), json_(false), buffer_size_(0) {
     LOG_VERB("HttpRequestArgs()");
   }
 
@@ -78,7 +80,7 @@ public:
   }
 
   HttpRequestArgs&& ssl_verify(bool ssl_verify = true) {
-    ssl_verify_ = ssl_verify;
+    ssl_verify_.emplace(ssl_verify);
     return std::move(*this);
   }
 
@@ -94,6 +96,7 @@ private:
 
   std::string url_;
 
+  // URL query parameters.
   std::vector<std::string> parameters_;
 
   // Data to send in the body of the request.
@@ -102,11 +105,11 @@ private:
   // Is the data to send a JSON string?
   bool json_;
 
+  // Additional request headers.
   std::vector<std::string> headers_;
 
-  // Verify the certificate of the peer (remote server) or not.
-  // HTTPS only.
-  bool ssl_verify_;
+  // Verify the certificate of the peer or not.
+  boost::optional<bool> ssl_verify_;
 
   // Size of the buffer to read response.
   // Leave it to 0 for using default value.