ciderpress/util/MyDebug.cpp

/*
 * CiderPress
 * Copyright (C) 2014 by CiderPress authors.  All Rights Reserved.
 * See the file LICENSE for distribution terms.
 */
/*
 * Debug log support.
 */
#include "stdafx.h"

DebugLog::DebugLog(const WCHAR* logFile)
    : fLogFp(NULL)
{
    fPid = getpid();

    if (logFile == NULL) {
        return;
    }

    PathName debugPath(logFile);
    time_t now = time(NULL);
    time_t when = debugPath.GetModWhen();
    if (when > 0 && now - when > kStaleLog) {
        /* log file is more than 8 hours old, remove it */
        /* [consider opening it and truncating with chsize() instead, so we
        don't hose somebody's custom access permissions. ++ATM 20041015] */
        _wunlink(logFile);
    }
    fLogFp = _wfopen(logFile, L"a");
    if (fLogFp == NULL) {
#ifdef _DEBUG
        _CrtDbgReport(_CRT_WARN, __FILE__, __LINE__, NULL,
            "Unable to open %ls: %d\n", logFile, errno);
#endif
    } else {
        // disable buffering so we don't lose anything if app crashes
        setvbuf(fLogFp, NULL, _IONBF, 0);

        fprintf(fLogFp, "\n");
        if (when > 0) {
            fprintf(fLogFp,
                "(Log file was %.3f hours old; logs are reset after %.3f)\n",
                (now - when) / 3600.0, kStaleLog / 3600.0);
        }
    }
}

DebugLog::~DebugLog() {
    if (fLogFp != NULL) {
        fclose(fLogFp);
    }
}

void DebugLog::Log(LogSeverity severity, const char* file, int line,
    _Printf_format_string_ const char* format, ...)
{
#ifndef _DEBUG
    if (fLogFp == NULL) {
        // nothing to do, don't waste time formatting the string
        return;
    }
#endif

    static const char kSeverityChars[] = "?VDIWE";
    if (severity < 0 || severity > sizeof(kSeverityChars) - 1) {
        severity = LOG_UNKNOWN;
    }
    if (severity == LOG_VERBOSE) {
        // Globally disable.  They still get compiled, which helps to
        // prevent bit-rot.  TODO: be fancier and have LOGV map to
        // a do-nothing inline function that the compiler will effectively
        // eliminate.
        return;
    }

    va_list argptr;
    char textBuf[4096];

    // TODO: _vsnprintf() doesn't deal with "%ls" well.  If it encounters a
    // character it can't translate, it stops and returns -1.  This is
    // very annoying if you're trying to print a wide-char filename that
    // includes characters that aren't in CP-1252.
    //
    // We can probably fix this by converting "format" to a wide string,
    // printing with _vsnwprintf(), and then converting the output back
    // to narrow manually (selecting options that prevent it from stopping
    // mid-string on failure).  As an optimization, we only need to do this
    // if the format string includes a "%ls" specifier.
    //
    // The interpretation of plain "%s" will change if we use a wide printf
    // function (it's a Microsoft extension, not ANSI behavior), so we'd also
    // want to check for "%s" and complain if we see it.  All callers must
    // use explicit "%hs" or "%ls".

    va_start(argptr, format);
    (void) _vsnprintf(textBuf, NELEM(textBuf) - 1, format, argptr);
    va_end(argptr);
    textBuf[NELEM(textBuf) - 1] = '\0';

    if (fLogFp) {
        struct tm tmbuf;
        time_t now = time(NULL);
        localtime_s(&tmbuf, &now);

        // The pid is useful when we spawn a new instance of CiderPress
        // to handle a disk image or NuFX archive inside an archive.  The
        // file is opened in "append" mode, so we shouldn't collide.
        fprintf(fLogFp, "%02d:%02d:%02d %05u %c %s\n", tmbuf.tm_hour,
            tmbuf.tm_min, tmbuf.tm_sec, fPid, kSeverityChars[severity],
            textBuf);
    }
#ifdef _DEBUG
     if (_CrtDbgReport(_CRT_WARN, file, line, NULL, "%s\n", textBuf) == 1) {
        // "retry" button causes a debugger break
         _CrtDbgBreak();
    }
#endif
}