Merge branch 'release/v1.4.0'

Author: i-vovk

CHANGELOG.md

@@ -1,3 +1,10 @@
+## 1.4.0 (2022-02-18)
+
+### Features
+
+* Implement logger facility and support user-defined overriding - (#19)
+
+
 ## 1.3.0 (2022-02-16)
 
 ### Features

CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.0 FATAL_ERROR)
 
 set(STREAMCLIENT_VERSION_MAJOR "1")
-set(STREAMCLIENT_VERSION_MINOR "3")
+set(STREAMCLIENT_VERSION_MINOR "4")
 set(STREAMCLIENT_VERSION_RELEASE "0")
 set(STREAMCLIENT_SUMMARY "C++ library")
 set(STREAMCLIENT_REPOSITORY_URL "https://github.com/TinkoffCreditSystems/stream-client")

README.md

@@ -120,8 +120,9 @@ client->receive(boost::asio::buffer(&recv_data[0], send_data.size()));
 Represents container occupied with opened sockets. Uses [connector](#connector) to open new sockets in the background thread which is triggered once there are vacant places in the pool. User can call *get_session()* to obtain a socket from the pool and *return_session()* to give it back.
 
 There are two strategies to refill the pool:
-- greedy (`stream_client::connector::greedy_strategy`). If there are vacant places it will try to fill them with new sessions simultaneously.
-- conservative (`stream_client::connector::conservative_strategy`). Will try to fill up to 2/3 of vacant places in the poll. If failed will back of for some time and retry later. Also, after failures it will create only one new session.
+- **greedy** (`stream_client::connector::greedy_strategy`). If there are vacant places it will try to fill them with new sessions simultaneously. This is the default one.
+- **conservative** (`stream_client::connector::conservative_strategy`). Will try to fill up to 2/3 of vacant places in the poll. If failed will back of for some time and retry later. Also, after failures it will create only one new session.
+
 Both of them are defined in terms of `stream_client::connector::pool_strategy` interface, so you are free to implement new one.
 
 Limitations:
@@ -143,7 +144,12 @@ Connection pools:
 * `stream_client::connector::http_pool` - pool of `stream_client::http::http_client` sockets.
 * `stream_client::connector::https_pool` - pool of `stream_client::http::https_client` sockets.
 
-*All these pools are using `stream_client::connector::greedy_strategy`.*
+There are also aliases for the same pools but using conservative reconnection strategy:
+* `stream_client::connector::tcp_conservative_pool`
+* `stream_client::connector::udp_conservative_pool`
+* `stream_client::connector::ssl_conservative_pool`
+* `stream_client::connector::http_conservative_pool`
+* `stream_client::connector::https_conservative_pool`
 
 #### Example
 ```c++
@@ -181,6 +187,44 @@ for (auto& t : threads) {
 }
 ```
 
+### Logging
+
+The library uses basic logger interface implemented internally. You can modify logger level using `stream_client::set_log_level()` or `stream_client::get_log_level()` functions.
+
+These levels are supported:
+```cpp
+enum class log_level : int
+{
+    trace = 0,
+    debug,
+    info,
+    warning,
+    error,
+};
+```
+
+By default library prints messages to stdout with decent formatting. If you want to overwrite this behavior you can set you own logger via:
+```cpp
+void stream_client::set_logger(std::shared_ptr<stream_client::log_interface> logger);
+
+void stream_client::set_logger(stream_client::log_level level, stream_client::log_func_type log_func);
+```
+
+Which allows to either overwrite logger instance of use a callback of with proper signature. These types are defines as:
+```cpp
+class log_interface
+{
+public:
+    virtual void set_level(log_level level) noexcept = 0;
+    virtual log_level get_level() const noexcept = 0;
+    virtual void message(log_level level, const std::string& location, const std::string& message) const = 0;
+};
+
+using log_func_type = std::function<void(log_level level, const std::string& location, const std::string& message)>;
+```
+
+For more information please look inside [logger.hpp](./include/stream-client/logger.hpp).
+
 ## How to build
 
 This library supposed to be somewhat multi-platform, however, it was tested and mainly used on ubuntu and macOS. </br>

include/stream-client/connector/connection_pool.hpp

@@ -314,7 +314,8 @@ class base_connection_pool
     /// Background routine used to maintain the pool.
     void watch_pool_routine();
 
-    Strategy reconnection_;
+    std::string name_; ///< Name pf the pool.
+    Strategy reconnection_; ///< Instance of reconnection strategy used to fill the pool.
     connector_type connector_; ///< Underlying connector used to establish sockets.
 
     std::size_t pool_max_size_; ///< Number of stream to keep in the @p sesson_pool_.
@@ -330,16 +331,21 @@ class base_connection_pool
 
 //! Connections pool with sockets over plain TCP protocol.
 using tcp_pool = base_connection_pool<tcp_connector>;
+using tcp_conservative_pool = base_connection_pool<tcp_connector, conservative_strategy<tcp_connector>>;
 //! Connections pool with sockets over plain UDP protocol.
 using udp_pool = base_connection_pool<udp_connector>;
+using udp_conservative_pool = base_connection_pool<udp_connector, conservative_strategy<udp_connector>>;
 
 //! Connections pool with sockets over encrypted TCP protocol.
 using ssl_pool = base_connection_pool<ssl_connector>;
+using ssl_conservative_pool = base_connection_pool<ssl_connector, conservative_strategy<ssl_connector>>;
 
 //! Connections pool with sockets over HTTP protocol.
 using http_pool = base_connection_pool<http_connector>;
+using http_conservative_pool = base_connection_pool<http_connector, conservative_strategy<http_connector>>;
 //! Connections pool with sockets over HTTPS protocol.
 using https_pool = base_connection_pool<https_connector>;
+using https_conservative_pool = base_connection_pool<https_connector, conservative_strategy<https_connector>>;
 
 } // namespace connector
 } // namespace stream_client

include/stream-client/connector/impl/connection_pool.ipp

@@ -1,5 +1,7 @@
 #pragma once
 
+#include "stream-client/logger.hpp"
+
 namespace stream_client {
 namespace connector {
 
@@ -12,7 +14,9 @@ base_connection_pool<Connector, Strategy>::base_connection_pool(std::size_t size
     , idle_timeout_(idle_timeout)
     , watch_pool_(true)
 {
+    name_ = "connection_pool[" + connector_.get_target() + "](" + std::to_string(pool_max_size_) + ")";
     pool_watcher_ = std::thread([this]() { this->watch_pool_routine(); });
+    STREAM_LOG_TRACE(name_ + " has been created");
 }
 
 template <typename Connector, typename Strategy>

include/stream-client/connector/impl/pool_strategy.ipp

@@ -1,5 +1,7 @@
 #pragma once
 
+#include "stream-client/logger.hpp"
+
 #include <boost/system/system_error.hpp>
 
 #include <atomic>
@@ -31,7 +33,7 @@ bool greedy_strategy<Connector>::refill(connector_type& connector, std::size_t v
             auto new_session = connector.new_session();
             append_func(std::move(new_session));
         } catch (const boost::system::system_error& e) {
-            // TODO: log errors ?
+            STREAM_LOG_ERROR("failed to establish new session to " + connector.get_target() + ": " + e.what());
         }
     };
 
@@ -75,7 +77,7 @@ bool conservative_strategy<Connector>::refill(connector_type& connector, std::si
             append_func(std::move(new_session));
             is_added = true;
         } catch (const boost::system::system_error& e) {
-            // TODO: log errors ?
+            STREAM_LOG_ERROR("failed to establish new session to " + connector.get_target() + ": " + e.what());
         }
     };
 

include/stream-client/impl/logger.ipp

@@ -0,0 +1,108 @@
+#pragma once
+
+#include <iomanip>
+#include <iostream>
+#include <mutex>
+#include <sstream>
+
+namespace stream_client {
+namespace detail {
+
+/// Get/set global logger instance.
+inline std::shared_ptr<log_interface> logger_instance(std::shared_ptr<log_interface> new_logger)
+{
+    // By default use cout logger with trace level
+    static std::shared_ptr<log_interface> glob_instance = std::make_shared<cout_logger>();
+
+    if (new_logger) {
+        glob_instance = new_logger;
+    }
+    return glob_instance;
+}
+
+} // namespace detail
+
+base_logger::base_logger(log_level level)
+    : level_(level)
+{
+}
+
+void base_logger::set_level(log_level level) noexcept
+{
+    level_ = level;
+}
+
+log_level base_logger::get_level() const noexcept
+{
+    return level_;
+}
+
+func_logger::func_logger(log_level level, stream_client::log_func_type log_func)
+    : base_logger(level)
+    , log_func_(log_func)
+{
+}
+
+void func_logger::message(log_level level, const std::string& location, const std::string& message) const
+{
+    if (log_func_) {
+        log_func_(level, location, message);
+    }
+}
+
+cout_logger::cout_logger(log_level level)
+    : base_logger(level)
+{
+}
+
+void cout_logger::message(log_level level, const std::string& location, const std::string& message) const
+{
+    static constexpr const char* kLevelPrefixes[] = {
+        "TRACE", "DEBUG", "INFO", "WARNING", "ERROR",
+    };
+
+    std::stringstream ss;
+    const auto now = std::chrono::system_clock::now();
+    const std::time_t t_c = std::chrono::system_clock::to_time_t(now);
+    std::lock_guard<std::mutex> lock(mutex_);
+    ss << std::put_time(std::localtime(&t_c), "%Y-%m-%dT%H:%M:%SZ") << ": " << kLevelPrefixes[static_cast<int>(level)]
+       << ": " << location << ": " << message << std::endl;
+    std::cout << ss.str();
+}
+
+inline void set_logger(std::shared_ptr<log_interface> logger)
+{
+    detail::logger_instance(std::move(logger));
+}
+
+inline void set_logger(log_level level, stream_client::log_func_type log_func)
+{
+    detail::logger_instance(std::make_shared<func_logger>(level, std::move(log_func)));
+}
+
+inline void set_log_level(log_level level)
+{
+    const auto logger = detail::logger_instance();
+    if (logger) {
+        logger->set_level(level);
+    }
+}
+
+inline log_level get_log_level()
+{
+    const auto logger = detail::logger_instance();
+    if (logger) {
+        return logger->get_level();
+    }
+    return log_level::mute;
+}
+
+inline void log_message(log_level level, const std::string& location, const std::string& message)
+{
+    const auto logger = detail::logger_instance();
+    if (logger) {
+        logger->message(level, location, message);
+    }
+}
+
+} // namespace stream_client