C++ 设置文件最近修改时间

利用VS开发C++项目,经常发现修改系统时间后,每次编译过程会变得很慢,其原因就是当你把系统时间调到未来的一个时间点,然后有意或者无意编辑过一些代码文件,那么这些文件的时间戳就停留在未来.

当你把系统时间调到现在后,编译器每次编译的时候,总会判定这些文件是最新的(因为它的时间戳总是大于目标文件的时间戳),所以总是会把这些文件编译一遍,如果这些文件中有某些被其他文件引用,那么会有更多的文件被重新编译,而且这种过程每次编译都会执行一遍,导致编译速度降低.为了解决这个问题,我特意写了一个小工具.

这个工具的原理跟简单,找出指定目录下时间戳大于当前时间的文件,并把它们的时间戳设置为现在时间.

调用的时候,配合一个bat脚本,把需要检查的代码目录传进去就好了,例如

echo off
ResetFileTime MsgDefine Server
pause

#include <io.h>
#include <windows.h>
#include <stdint.h>
#include <vector>
#include <string>
#include <set>
#include <stdio.h>
#include <iostream>

bool IsCompileFile(const std::string & extension)
{
    static std::set<std::string> setComplieFileExtension = {".cpp", ".c", ".cc", ".h", ".hpp"};
    return setComplieFileExtension.find(extension) != setComplieFileExtension.end();
}

std::string GetFileNameExtension(const std::string & fileName)
{
    /*
    DWORD dwAttrib = GetFileAttributes(fileName.c_str());
    if (dwAttrib == INVALID_FILE_ATTRIBUTES)
    {
        return "";
    }
    if (dwAttrib & FILE_ATTRIBUTE_DIRECTORY)
    {
        return "";
    }*/
    size_t dotpos = fileName.find_last_of(".");
    if(dotpos == std::string::npos)
    {
        return fileName;
    }
    return fileName.substr(dotpos, fileName.length() - dotpos);
}

bool CompareSystemTime(const SYSTEMTIME & lhs, const SYSTEMTIME & rhs)
{
    if(lhs.wYear > rhs.wYear)
    {
        return true;
    }
    else if(lhs.wYear == rhs.wYear && lhs.wMonth > rhs.wMonth)
    {
        return true;
    }
    else if(lhs.wYear == rhs.wYear && lhs.wMonth == rhs.wMonth && lhs.wDay > rhs.wDay)
    {
        return true;
    }
    else if(lhs.wYear == rhs.wYear && lhs.wMonth == rhs.wMonth && lhs.wDay == rhs.wDay
            && lhs.wHour > rhs.wHour)
    {
        return true;
    }
    else if(lhs.wYear == rhs.wYear && lhs.wMonth == rhs.wMonth && lhs.wDay == rhs.wDay
            && lhs.wHour == rhs.wHour && lhs.wMinute > rhs.wMinute)
    {
        return true;
    }
    else if(lhs.wYear == rhs.wYear && lhs.wMonth == rhs.wMonth && lhs.wDay == rhs.wDay
            && lhs.wHour == rhs.wHour && lhs.wMinute == rhs.wMinute && lhs.wSecond > rhs.wSecond)
    {
        return true;
    }
    else if(lhs.wYear == rhs.wYear && lhs.wMonth == rhs.wMonth && lhs.wDay == rhs.wDay
            && lhs.wHour == rhs.wHour && lhs.wMinute == rhs.wMinute && lhs.wSecond == rhs.wSecond && lhs.wMilliseconds > rhs.wMilliseconds)
    {
        return true;
    }
    return false;
}

void DumpSystemTime(const std::string & prefix, const SYSTEMTIME & t)
{
    printf("%s %04d-%02d-%02d %02d:%02d:%02d
", prefix.c_str(), t.wYear, t.wMonth, t.wDay, t.wHour, t.wMinute, t.wSecond);
}

void ResetFileTime(const std::string & dir)
{
    WIN32_FIND_DATA fileInfo;
    HANDLE hFile = nullptr;
    char tmpPath[MAX_PATH] = { 0 };
    sprintf_s(tmpPath, "%s\*.*", dir.c_str());
    if((hFile = FindFirstFile(tmpPath, &fileInfo)) == HANDLE(-1))
    {
        return;
    }
    do
    {
        if(fileInfo.dwFileAttributes & _A_SUBDIR)
        {
            if(strcmp(fileInfo.cFileName, ".") == 0 || strcmp(fileInfo.cFileName, "..") == 0)
            {
                continue;
            }
            sprintf_s(tmpPath, "%s\%s", dir.c_str(), fileInfo.cFileName);
            ResetFileTime(tmpPath);
        }
        else
        {
            sprintf_s(tmpPath, "%s\%s", dir.c_str(), fileInfo.cFileName);
            std::string extension = GetFileNameExtension(fileInfo.cFileName);
            if(IsCompileFile(extension))
            {
                FILETIME lastWriteLocalFileTime;
                FileTimeToLocalFileTime(&fileInfo.ftLastWriteTime, &lastWriteLocalFileTime);
                SYSTEMTIME lastWriteLocalSysTime, nowTime;
                FileTimeToSystemTime(&lastWriteLocalFileTime, &lastWriteLocalSysTime);
                GetLocalTime(&nowTime);
                if(CompareSystemTime(lastWriteLocalSysTime, nowTime))
                {
                    HANDLE file =  ::CreateFile(tmpPath, GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, NULL, NULL);

                    DumpSystemTime(fileInfo.cFileName, lastWriteLocalSysTime);
                    FILETIME nowWriteLocalFileTime;
                    SystemTimeToFileTime(&nowTime, &nowWriteLocalFileTime);
                    FILETIME nowWriteSysFileTime;
                    LocalFileTimeToFileTime(&nowWriteLocalFileTime, &nowWriteSysFileTime);
                    BOOL ret = SetFileTime(file, &nowWriteSysFileTime, &nowWriteSysFileTime, &nowWriteSysFileTime);
                    if(ret == TRUE)
                    {
                        printf("reset time succ.
");
                    }
                    else
                    {
                        printf("reset time fail.error=%d
", GetLastError());
                    }
                }
            }
        }
    }
    while(FindNextFile(hFile, &fileInfo) == TRUE);
    FindClose(hFile);
}

int32_t main(int32_t argc, char *argv[])
{
    for(int32_t i = 1; i < argc; ++i)
    {
        std::string dir = argv[i];
        ResetFileTime(dir);
    }
    return 0;
}