双文件日志记录

特点

1 采用双文件记录日志信息

2 当一个文件写满后,清空另外一个文件继续写入

3 可设置最大日志文件大小

4 文本文件使用unicode进行编码

 

 #define DEFAULT_STR_BUFF_LEN2048class DoubleLog{public:DoubleLog(void);~DoubleLog(void);bool Init(const string& logFileName);void SetMaxBytes(int nbyte);//void Close(void);bool WriteLog(LPCWSTR lpszFormat,...);private:static char lineEnd[4];static char newufile[2];static bool bclog;fstream fs;string filename1;string filename2;int maxLength;//bool isOpen;wchar_t szMsg[DEFAULT_STR_BUFF_LEN];//streampos curFilePos;bool bfile1;bool WriteFileHead();void ChangePoint();bool OpenFile();bool CheckFStream();bool OpenNewFile();};LPWSTR getNowTimeW(LPWSTR pbuff){SYSTEMTIME cSystime;GetLocalTime(&cSystime);//wchar_t pbuff[24] = {0};swprintf_s(pbuff, 20, L"%04d-%02d-%02d %02d:%02d:%02d", cSystime.wYear, cSystime.wMonth, cSystime.wDay, cSystime.wHour, cSystime.wMinute, cSystime.wSecond);//return wstring(pbuff);return pbuff;}#include <strsafe.h>#define DEFAULT_MAX_BUFF_LEN(1024*1024)char DoubleLog::lineEnd[4] = {0x0d,0x00,0x0a,0x00};char DoubleLog::newufile[2] = {0xff,0xfe};bool DoubleLog::bclog = false;DoubleLog::DoubleLog(void): maxLength(DEFAULT_MAX_BUFF_LEN){if (!bclog){CreateDirectory(L"log",NULL);bclog = true;}bfile1 = true;}DoubleLog::~DoubleLog(void){}int GetFstreamLen(fstream& infile){streampos cp = infile.tellg(); infile.seekg( 0, ios_base::end ); streampos len = infile.tellg(); infile.seekg( 0, cp );return len;}bool DoubleLog::WriteFileHead(){fs.write(newufile,2);return true;}void DoubleLog::ChangePoint(){bfile1 = !bfile1;}bool DoubleLog::OpenFile(){string fname;if (bfile1){fname = filename1;}else{fname = filename2;}if (fs.is_open()){fs.close();}fs.open(fname.c_str(),ios_base::app | ios_base::out | ios_base::binary);if (! fs.is_open()){return false;}return true;}bool DoubleLog::OpenNewFile(){string fname;if (bfile1){fname = filename1;}else{fname = filename2;}if (fs.is_open()){fs.close();}fs.open(fname.c_str(), ios::trunc | ios_base::out | ios_base::binary);if (! fs.is_open()){return false;}WriteFileHead();return true;}bool DoubleLog::CheckFStream(){if (!fs.is_open()){return false;}WriteFileHead();streampos curpos = fs.tellp();streampos zp = 2;if (curpos == zp){return true;}if (curpos >= maxLength){return false;}return true;}bool DoubleLog::Init(const string& logFileName){string curD("log/");filename1 = curD + logFileName + ".txt";filename2 = curD +logFileName + "_2.txt";OpenFile();if (!CheckFStream()){fs.close();ChangePoint();OpenFile();CheckFStream();}return true;}bool DoubleLog::WriteLog(LPCWSTR lpszFormat,...){va_list argList;va_start(argList, lpszFormat);HRESULT hr;hr = StringCchVPrintfW(szMsg,DEFAULT_STR_BUFF_LEN,lpszFormat,argList);if (hr == S_OK || hr == STRSAFE_E_INSUFFICIENT_BUFFER){szMsg[DEFAULT_STR_BUFF_LEN - 1]=0;}va_end(argList);wchar_t szfbuff[24] = {0};getNowTimeW(szfbuff);szfbuff[wcslen(szfbuff)] = L' ';szfbuff[wcslen(szfbuff)] = 0;fs.write((char*)szfbuff, wcslen(szfbuff) * 2);fs.write((char*)szMsg, wcslen(szMsg) * 2);fs.write(lineEnd,4);fs.flush();streampos curpos = fs.tellp();if (curpos >= maxLength || !(fs.good())){fs.close();ChangePoint();OpenNewFile();}return true;}void DoubleLog::SetMaxBytes(int nbyte){if (nbyte<512 || nbyte > 500*1024*1024){return;}maxLength = nbyte;}