tec_trace.hpp

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// Time-stamp: <Last changed 2026-02-25 16:20:43 by magnolia>
/*----------------------------------------------------------------------
------------------------------------------------------------------------
Copyright (c) 2020-2026 The Emacs Cat (https://github.com/olddeuteronomy/tec).
 
   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at
 
     http://www.apache.org/licenses/LICENSE-2.0
 
   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
------------------------------------------------------------------------
----------------------------------------------------------------------*/
 
#pragma once
 
#include <ostream>
#include <string>
#include <mutex>
 
#include "tec/tec_def.hpp" // IWYU pragma: keep
#include "tec/tec_print.hpp"
#include "tec/tec_utils.hpp"
 
 
// Default time resolution for tracing.
#if !defined(_TEC_TRACE_RES)
#define _TEC_TRACE_RES MilliSec
#endif
 
 
namespace tec {
 
namespace details {
 
struct trace_mutex {
    static std::mutex& mtx() {
        static std::mutex __mtx_trace;
        return __mtx_trace;
    }
};
 
} // namespace details
 
template <typename Duration = _TEC_TRACE_RES>
class Tracer {
private:
    std::string name_; 
    std::ostream* out_; 
 
public:
    using Lock = std::lock_guard<std::mutex>; 
 
    Tracer(const char* name, std::ostream* out)
        : name_{name}
        , out_{out}
    {}
 
    ~Tracer() {
        Lock lk(details::trace_mutex::mtx());
        auto tp = now<Duration>();
        *out_ << "[" << tp.count() << "] - " << name_ << " exited.\n";
    }
 
    void enter() {
        Lock lk(details::trace_mutex::mtx());
        auto tp = now<Duration>();
        *out_ << "[" << tp.count() << "] + " << name_ << " entered.\n";
    }
 
    template <typename T>
    void trace(const T& arg) {
        Lock lk(details::trace_mutex::mtx());
        auto tp = now<Duration>().count();
        *out_ << "[" << tp << "]     " << name_ << ": ";
        println<>(out_, arg);
    }
 
    template <typename T, typename... Targs>
    void trace(const char* fmt, const T& value, Targs&&... Args) {
        Lock lk(details::trace_mutex::mtx());
        auto tp = now<Duration>().count();
        *out_ << "[" << tp << "]     " << name_ << ": ";
        println<>(out_, fmt, value, Args...);
    }
}; // class Tracer
 
} // namespace tec
 
#if defined(_DEBUG) || defined(DEBUG)
  #define _TEC_DEBUG 1
#endif
 
#if defined(_TEC_TRACE_ON)
 
#if defined(__TEC_WINDOWS__)
  #define TEC_ENTER(name) Tracer<> tracer__(name, &std::cout); tracer__.enter()
#else
  #define TEC_ENTER(name) tec::Tracer<> tracer__(name, &std::cout); tracer__.enter()
#endif
 
#define TEC_TRACE(...) tracer__.trace(__VA_ARGS__)
 
#else
// _TEC_TRACE_ON undefined.
 
#define TEC_ENTER(name)
 
#define TEC_TRACE(...)
 
#endif