android_sink.h

Go to the documentation of this file.

// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
// Distributed under the MIT License (http://opensource.org/licenses/MIT)
 
#pragma once
 
#ifdef __ANDROID__
 
#include <spdlog/details/fmt_helper.h>
#include <spdlog/details/null_mutex.h>
#include <spdlog/details/os.h>
#include <spdlog/sinks/base_sink.h>
#include <spdlog/details/synchronous_factory.h>
 
#include <android/log.h>
#include <chrono>
#include <mutex>
#include <string>
#include <thread>
#include <type_traits>
 
#if !defined(SPDLOG_ANDROID_RETRIES)
#define SPDLOG_ANDROID_RETRIES 2
#endif
 
namespace spdlog
{
    namespace sinks
    {
 
        /*
         * Android sink
         * (logging using __android_log_write or __android_log_buf_write depending on the specified BufferID)
         */
        template <typename Mutex, int BufferID = log_id::LOG_ID_MAIN>
        class android_sink final : public base_sink<Mutex>
        {
        public:
            explicit android_sink(std::string tag = "spdlog", bool use_raw_msg = false)
                : tag_(std::move(tag)), use_raw_msg_(use_raw_msg)
            {
            }
 
        protected:
            void sink_it_(const details::log_msg& msg) override
            {
                const android_LogPriority priority = convert_to_android_(msg.level);
                memory_buf_t              formatted;
                if (use_raw_msg_)
                {
                    details::fmt_helper::append_string_view(msg.payload, formatted);
                }
                else
                {
                    base_sink<Mutex>::formatter_->format(msg, formatted);
                }
                formatted.push_back('\0');
                const char* msg_output = formatted.data();
 
                // See system/core/liblog/logger_write.c for explanation of return value
                int ret         = android_log(priority, tag_.c_str(), msg_output);
                int retry_count = 0;
                while ((ret == -11 /*EAGAIN*/) && (retry_count < SPDLOG_ANDROID_RETRIES))
                {
                    details::os::sleep_for_millis(5);
                    ret = android_log(priority, tag_.c_str(), msg_output);
                    retry_count++;
                }
 
                if (ret < 0)
                {
                    throw_spdlog_ex("logging to Android failed", ret);
                }
            }
 
            void flush_() override
            {
            }
 
        private:
            // There might be liblog versions used, that do not support __android_log_buf_write. So we only compile and link against
            // __android_log_buf_write, if user explicitly provides a non-default log buffer. Otherwise, when using the default log buffer, always
            // log via __android_log_write.
            template <int ID = BufferID>
            typename std::enable_if<ID == static_cast<int>(log_id::LOG_ID_MAIN), int>::type android_log(int prio, const char* tag, const char* text)
            {
                return __android_log_write(prio, tag, text);
            }
 
            template <int ID = BufferID>
            typename std::enable_if<ID != static_cast<int>(log_id::LOG_ID_MAIN), int>::type android_log(int prio, const char* tag, const char* text)
            {
                return __android_log_buf_write(ID, prio, tag, text);
            }
 
            static android_LogPriority convert_to_android_(spdlog::level::level_enum level)
            {
                switch (level)
                {
                case spdlog::level::trace:
                    return ANDROID_LOG_VERBOSE;
                case spdlog::level::debug:
                    return ANDROID_LOG_DEBUG;
                case spdlog::level::info:
                    return ANDROID_LOG_INFO;
                case spdlog::level::warn:
                    return ANDROID_LOG_WARN;
                case spdlog::level::err:
                    return ANDROID_LOG_ERROR;
                case spdlog::level::critical:
                    return ANDROID_LOG_FATAL;
                default:
                    return ANDROID_LOG_DEFAULT;
                }
            }
 
            std::string tag_;
            bool        use_raw_msg_;
        };
 
        using android_sink_mt = android_sink<std::mutex>;
        using android_sink_st = android_sink<details::null_mutex>;
 
        template <int BufferId = log_id::LOG_ID_MAIN>
        using android_sink_buf_mt = android_sink<std::mutex, BufferId>;
        template <int BufferId = log_id::LOG_ID_MAIN>
        using android_sink_buf_st = android_sink<details::null_mutex, BufferId>;
 
    } // namespace sinks
 
    // Create and register android syslog logger
 
    template <typename Factory = spdlog::synchronous_factory>
    inline std::shared_ptr<logger> android_logger_mt(const std::string& logger_name, const std::string& tag = "spdlog")
    {
        return Factory::template create<sinks::android_sink_mt>(logger_name, tag);
    }
 
    template <typename Factory = spdlog::synchronous_factory>
    inline std::shared_ptr<logger> android_logger_st(const std::string& logger_name, const std::string& tag = "spdlog")
    {
        return Factory::template create<sinks::android_sink_st>(logger_name, tag);
    }
 
} // namespace spdlog
 
#endif // __ANDROID__