logger.h

// Copyright 2012-2021:
//   GobySoft, LLC (2013-)
//   Massachusetts Institute of Technology (2007-2014)
//   Community contributors (see AUTHORS file)
// File authors:
//   Toby Schneider <toby@gobysoft.org>
//   Chris Murphy <cmurphy@aphysci.com>
//
//
// This file is part of the Dynamic Compact Control Language Library
// ("DCCL").
//
// DCCL is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 2.1 of the License, or
// (at your option) any later version.
//
// DCCL is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with DCCL.  If not, see <http://www.gnu.org/licenses/>.
#ifndef DCCLLOGGER20121009H
#define DCCLLOGGER20121009H
 
#include <cstdio>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
 
#include "thread_safety.h"
 
namespace dccl
{
namespace logger
{
enum Verbosity
{
    WARN = 1 << 1,
    INFO = 1 << 2,
    DEBUG1 = 1 << 3,
    DEBUG2 = 1 << 4,
    DEBUG3 = 1 << 5,
    ALL = DEBUG3 | (DEBUG3 - 1),
    WARN_PLUS = WARN | (WARN - 1),
    INFO_PLUS = INFO | (INFO - 1),
    DEBUG1_PLUS = DEBUG1 | (DEBUG1 - 1),
    DEBUG2_PLUS = DEBUG2 | (DEBUG2 - 1),
    DEBUG3_PLUS = DEBUG3 | (DEBUG3 - 1),
    UNKNOWN = 0
};
enum Group
{
    GENERAL,
    ENCODE,
    DECODE,
    SIZE
};
 
} // namespace logger
 
void to_ostream(const std::string& msg, dccl::logger::Verbosity vrb, dccl::logger::Group grp,
                std::ostream* os, bool add_timestamp);
 
class Logger;
 
namespace internal
{
class LogBuffer : public std::streambuf
{
  public:
    LogBuffer() : buffer_(1) {}
    ~LogBuffer() override = default;
 
    template <typename Slot> void connect(int verbosity_mask, Slot slot)
    {
        enabled_verbosities_ |= verbosity_mask;
        if (verbosity_mask & logger::WARN)
            warn_signal.emplace_back(slot);
        if (verbosity_mask & logger::INFO)
            info_signal.emplace_back(slot);
        if (verbosity_mask & logger::DEBUG1)
            debug1_signal.emplace_back(slot);
        if (verbosity_mask & logger::DEBUG2)
            debug2_signal.emplace_back(slot);
        if (verbosity_mask & logger::DEBUG3)
            debug3_signal.emplace_back(slot);
    }
 
    void disconnect(int verbosity_mask)
    {
        enabled_verbosities_ &= ~verbosity_mask;
        if (verbosity_mask & logger::WARN)
            warn_signal.clear();
        if (verbosity_mask & logger::INFO)
            info_signal.clear();
        if (verbosity_mask & logger::DEBUG1)
            debug1_signal.clear();
        if (verbosity_mask & logger::DEBUG2)
            debug2_signal.clear();
        if (verbosity_mask & logger::DEBUG3)
            debug3_signal.clear();
    }
 
    void set_verbosity(logger::Verbosity verbosity) { verbosity_.push(verbosity); }
 
    void set_group(logger::Group group) { group_.push(group); }
 
    bool contains(logger::Verbosity verbosity) const { return verbosity & enabled_verbosities_; }
 
  private:
    int sync() override;
 
    int overflow(int c = EOF) override;
 
    void display(const std::string& s)
    {
        if (verbosity() & logger::WARN)
        {
            for (auto& slot : warn_signal) slot(s, logger::WARN, group());
        }
        if (verbosity() & logger::INFO)
        {
            for (auto& slot : info_signal) slot(s, logger::INFO, group());
        }
        if (verbosity() & logger::DEBUG1)
        {
            for (auto& slot : debug1_signal) slot(s, logger::DEBUG1, group());
        }
        if (verbosity() & logger::DEBUG2)
        {
            for (auto& slot : debug2_signal) slot(s, logger::DEBUG2, group());
        }
        if (verbosity() & logger::DEBUG3)
        {
            for (auto& slot : debug3_signal) slot(s, logger::DEBUG3, group());
        }
    }
 
    logger::Verbosity verbosity()
    {
        return verbosity_.empty() ? logger::UNKNOWN : verbosity_.top();
    }
    logger::Group group() { return group_.empty() ? logger::GENERAL : group_.top(); }
 
  private:
    std::stack<logger::Verbosity> verbosity_;
    std::stack<logger::Group> group_;
    std::deque<std::string> buffer_;
    int enabled_verbosities_; // mask of verbosity settings enabled
 
    using LogSignal = std::vector<
        std::function<void(const std::string& msg, logger::Verbosity vrb, logger::Group grp)>>;
 
    LogSignal warn_signal, info_signal, debug1_signal, debug2_signal, debug3_signal;
};
} // namespace internal
 
class Logger : public std::ostream
{
  public:
    Logger() : std::ostream(&buf_) {}
    ~Logger() override = default;
 
    bool check(logger::Verbosity verbosity) { return buf_.contains(verbosity); }
 
    bool is(logger::Verbosity verbosity, logger::Group group = logger::GENERAL)
    {
        if (!buf_.contains(verbosity))
        {
            return false;
        }
        else
        {
#if DCCL_THREAD_SUPPORT
            g_dlog_mutex.lock();
#endif
            buf_.set_verbosity(verbosity);
            buf_.set_group(group);
            return true;
        }
    }
 
    template <typename Slot> void connect(int verbosity_mask, Slot slot)
    {
        DCCL_LOCK_DLOG_MUTEX
        buf_.connect(verbosity_mask, slot);
    }
 
    template <typename Obj>
    void connect(int verbosity_mask, Obj* obj,
                 void (Obj::*mem_func)(const std::string& msg, logger::Verbosity vrb,
                                       logger::Group grp))
    {
        DCCL_LOCK_DLOG_MUTEX
        connect(verbosity_mask, std::bind(mem_func, obj, std::placeholders::_1,
                                          std::placeholders::_2, std::placeholders::_3));
    }
 
    void connect(int verbosity_mask, std::ostream* os, bool add_timestamp = true)
    {
        DCCL_LOCK_DLOG_MUTEX
        buf_.connect(verbosity_mask,
                     std::bind(to_ostream, std::placeholders::_1, std::placeholders::_2,
                               std::placeholders::_3, os, add_timestamp));
    }
 
    void disconnect(int verbosity_mask)
    {
        DCCL_LOCK_DLOG_MUTEX
        buf_.disconnect(verbosity_mask);
    }
 
  private:
    internal::LogBuffer buf_;
};
 
extern Logger dlog;
 
inline std::string hash_as_string(std::size_t hash)
{
    std::stringstream hash_stream;
    hash_stream << "0x" << std::setfill('0') << std::setw(sizeof(std::size_t) * 2) << std::hex
                << hash;
    return hash_stream.str();
}
 
} // namespace dccl
 
#endif // DCCLLOGGER20121009H