LoggerFile.cpp

/****************************************************************************
 * Platform Abstraction Layer
 * Daryl Borth 2026
 * LoggerFile.cpp
 ***************************************************************************/
#include "LoggerFile.h"
 
bool LoggerFile::init(const LogConfig & config)
{
    shutdown();
 
    // Append-only - never truncates a prior run's log
    file = fopen(config.filePath, "a");
    if (!file)
        return false;
 
    // Line-buffer rather than the default full-buffering libc picks for
    // a regular file - keeps a torn/half-written line out of the file if
    // a flush is skipped (see below) and the console loses power.
    setvbuf(file, nullptr, _IOLBF, 0);
 
    flushPolicy = config.flushPolicy;
    flushEveryNWrites = config.flushEveryNWrites > 0 ? config.flushEveryNWrites : 1;
    writesSinceFlush = 0;
    return true;
}
 
void LoggerFile::shutdown()
{
    if (file)
    {
        fflush(file);
        fclose(file);
        file = nullptr;
    }
    writesSinceFlush = 0;
}
 
void LoggerFile::write(LogLevel /*level*/, const char * line, size_t len)
{
    if (!file)
        return;
 
    fwrite(line, 1, len, file);
 
    switch (flushPolicy)
    {
        case LogFlushPolicy::Immediate:
            fflush(file);
            break;
 
        case LogFlushPolicy::EveryNWrites:
            if (++writesSinceFlush >= flushEveryNWrites)
            {
                fflush(file);
                writesSinceFlush = 0;
            }
            break;
 
        case LogFlushPolicy::Never:
        default:
            break;
    }
}