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使用ofstream出错，谁能帮帮我~

时间：2010-08-31

来源：互联网

本帖最后由 smallest10 于 2010-08-31 19:37 编辑

很简单的一段代码

std::ofstream outp;
outp.open("omg.txt");
outp<<"oh my god,what's the hell";
outp.flush();
outp.close();

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情况是这样的，我们之前做了一个软件，用VC 6 开发的，现在要加一个日志模块，我打算借用std标准库中的ofstream来实现软件中的日志模块。但是上边一段代码始终不能成功。

是个MFC 程序，我把这段代码放在 MFCTestApp::InitInstance()中。新建一个空的MFC程序，加上这段代码，一点问题没有。可是在我们目前已经开发好的代码中加上上边那段代码就出问题了，文件能正常创建，但是写入失败！程序执行完关闭后，omg.txt中内容为空（0字节）。在代码中间加了 outp.tellp()，返回值为-1。 outp.is_open() 返回为true. outp.good()为true,

这个该怎么整啊？
哪位大侠知道怎么查outp.tellp()返回-1是什么问题吗？试过 outp.seekp(0) , outp.seekp(10) ，再调用 outp.tellp() ，返回值仍是 -1 ，谁能指点一二？

谢啦~~
++++++++++++++++++++++++++++++++++++++
另外，我脸皮厚，不怕丢人，无敌了~~~~~顺便贴上我自己赶时间速写的一个日志类，抄的 log4cplus，log4cplus里边那个Appender和Logger分开我很喜欢，很灵活，所以抄它的。抄的不好，见笑，大家指点一下。是时间该转向linux了，希望这个项目尽快完结。

作者: smallest10 发布时间: 2010-08-31

本帖最后由 smallest10 于 2010-08-31 19:37 编辑

// Logger.h: interface for the Logger class.
//
//////////////////////////////////////////////////////////////////////
#if !defined(AFX_LOGGER_H__5C97FAE9_F998_42F3_B797_ADC910889447__INCLUDED_)
#define AFX_LOGGER_H__5C97FAE9_F998_42F3_B797_ADC910889447__INCLUDED_
#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000
#include <string>
#include <fstream>
#include <vector>
#include <sstream>
using std::string;
namespace skgLogger{
typedef int LogLevelType;
const LogLevelType INFO_LOG_LEVEL = 0x03; // 0011
const LogLevelType ERROR_LOG_LEVEL = 0x02; // 0010
const LogLevelType WARN_LOG_LEVEL= 0x01; // 0001
const LogLevelType NONE_LOG_LEVEL = 0x00; // 0000
//const LogLevelType LEVEL_TRACE= 0x04 // 0100 ===== another output way
typedef std::ios::openmode LOG_OPEN_MODE_TYPE;
#define LOG_TRACE_MACRO_BODY(logEvent) \
do { \
if(Logger::isTraceable()) { \
std::ostringstream _out_buf; \
_out_buf << logEvent << "\n"; \
TRACE((_out_buf.str().append(__FILE__).append(__LINE__)).c_str()); \
} \
} while (0)
// note that the logEvent argument is string type
#define LOG_TRACE_MACRO_STR_BODY(logEvent) \
do { \
if(Logger::isTraceable()) { \
TRACE((logEvent.append(__FILE__).append(__LINE__).append("\n")).c_str()) \
} \
} while (0)
#define LOG_MACRO_BODY(logger, logEvent, logLevel) \
do { \
if((logger)->isEnabledFor(logLevel##_LOG_LEVEL)) { \
std::ostringstream _out_buf; \
_out_buf << logEvent; \
(logger)->WriteLog(logLevel##_LOG_LEVEL, \
_out_buf.str(), __FILE__, __LINE__); \
} \
} while (0)
// if logEvent is a string, then we could call this MACRO instead of LOG_MACRO_BODY()
// note that the logEvent argument is string type
#define LOG_MACRO_STR_BODY(logger, logEvent, logLevel) \
do { \
if((logger)->isEnabledFor(logLevel##_LOG_LEVEL)) { \
(logger)->WriteLog(logLevel##_LOG_LEVEL, \
logEvent, __FILE__, __LINE__); \
} \
} while (0)
// LOG_TRACE() 与 LOG_TRACE_STR() 有问题.未进行具体调试.
#if !defined(LOG_DISABLE_TRACE)
#define LOG_TRACE(logEvent) \
LOG_TRACE_MACRO_BODY (logEvent)
#define LOG_TRACE_STR(logEvent) \
LOG_TRACE_MACRO_STR_BODY (logEvent)
#else
#define LOG_TRACE(logEvent) do { } while (0)
#define LOG_TRACE_STR(logEvent) do { } while (0)
#endif
#if !defined(LOG_DISABLE_DEBUG)
#define LOG_DEBUG(logger, logEvent) \
LOG_MACRO_BODY (logger, logEvent, DEBUG)
#define LOG_DEBUG_STR(logger, logEvent) \
LOG_MACRO_STR_BODY (logger, logEvent, DEBUG)
#else
#define LOG_DEBUG(logger, logEvent) do { } while (0)
#define LOG_DEBUG_STR(logger, logEvent) do { } while (0)
#endif
#if !defined(LOG_DISABLE_INFO)
#define LOG_INFO(logger, logEvent) \
LOG_MACRO_BODY (logger, logEvent, INFO)
#define LOG_INFO_STR(logger, logEvent) \
LOG_MACRO_STR_BODY (logger, logEvent, INFO)
#else
#define LOG_INFO(logger, logEvent) do { } while (0)
#define LOG_INFO_STR(logger, logEvent) do { } while (0)
#endif
#if !defined(LOG_DISABLE_WARN)
#define LOG_WARN(logger, logEvent) \
LOG_MACRO_BODY (logger, logEvent, WARN)
#define LOG_WARN_STR(logger, logEvent) \
LOG_MACRO_STR_BODY (logger, logEvent, WARN)
#else
#define LOG_WARN(logger, logEvent) do { } while (0)
#define LOG_WARN_STR(logger, logEvent) do { } while (0)
#endif
#if !defined(LOG_DISABLE_ERROR)
#define LOG_ERROR(logger, logEvent) \
LOG_MACRO_BODY (logger, logEvent, ERROR)
#define LOG_ERROR_STR(logger, logEvent) \
LOG_MACRO_STR_BODY (logger, logEvent, ERROR)
#else
#define LOG_ERROR(logger, logEvent) do { } while (0)
#define LOG_ERROR_STR(logger, logEvent) do { } while (0)
#endif
#if !defined(LOG_DISABLE_FATAL)
#define LOG_FATAL(logger, logEvent) \
LOG_MACRO_BODY (logger, logEvent, FATAL)
#define LOG_FATAL_STR(logger, logEvent) \
LOG_MACRO_STR_BODY (logger, logEvent, FATAL)
#else
#define LOG_FATAL(logger, logEvent) do { } while (0)
#define LOG_FATAL_STR(logger, logEvent) do { } while (0)
#endif
/************************************************************************/
/* define class Logger */
/************************************************************************/
class Logger
{
public:
static BOOL InitLogger();
static Logger* GetInstance(const string& name); // 获得日志类的实例
static void RemoveInstance(const string& name);
static void RemoveInstance(const Logger* logger);
static BOOL isTraceable();
static void EnableTrace(BOOL traceable);
// LOG_WANR 等宏会调用此函数
void WriteLog(LogLevelType level, const string& message, const char* file="unkonw",int line=-1); // 日志打印接口
virtual void PrintLog(const string& message); // 打印输出信息 --- not implemented yet.
// LOG_WANR 等宏会调用此函数
BOOL isEnabledFor(LogLevelType logLevel);
inline string GetName() const;// the class member 'name' can only be assigned via GetInstance()
inline LogLevelType GetLogLevel() const;
inline void SetLogLevel(LogLevelType logLevel);
BOOL initLogFile(const string& basename,
long maxFileSize=10*1024*1024, // 10 MB
BOOL immediateFlush=TRUE,
LOG_OPEN_MODE_TYPE mode = std::ios::app);// call Open()
// Logger 级别成员
private:
BOOL b_inited;//记录是否已经调用过 initLogFile() 方法
string name;//name of this logger. 若想控制每个文件只对应一个Logger对象,将此变量的值改为basename的值即可.
LogLevelType m_LogLevel; //日志输出等级, 默认为 LEVEL_INFO
CRITICAL_SECTION cs_file; // 对象级别的临界区变量
static CRITICAL_SECTION cs_loggerClassLevel;// 类级别的临界区变量
static std::vector<Logger*> loggerList;
static BOOL b_traceable;
// 默认按 %y-%m-%d %H:%M:%S 格式来取得时间
string GetTimeString(const char* timeFormat="%Y-%m-%d %H:%M:%S"); // 按格式获得日期
// 文件级别成员
private:
string openedFilename;// 输出日志文件名 , 文件名格式如 basename_date_seq.log
string basename;// 用于日志文件更换时,作为基文件名存在. 文件名格式如 basename_date_seq.log .如 srbw_20100901_1.log
BOOL immediateFlush;
std::ofstream stream_out;
char* buffer;
unsigned long bufferSize;
long currentFileSize;
long maxFileSize;
int currentFileSeq;
void Open(LOG_OPEN_MODE_TYPE mode);
BOOL ReOpen();
BOOL Rollover();// 当前日志文件已记录满,更换日志文件进行存储.
private:
// Disallow copying of instances of this class
Logger(const string& name);
Logger(const Logger&){} ////////////// need code, to prevent someone call this func in this class
Logger(Logger*){} ////////////// need code, to prevent someone call this func in this class
Logger& operator=(const Logger&){}////////////// need code, to prevent someone call this func in this class
// Disallow deleting of instances of this class
virtual ~Logger();
};// end class Logger
} // end namespace skgLogger
#endif // !defined(AFX_LOGGER_H__5C97FAE9_F998_42F3_B797_ADC910889447__INCLUDED_)

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作者: smallest10 发布时间: 2010-08-31

/************************************************************************
*
* Logger.cpp / Logger.h 定义了日志类与其他一些辅助函数. 用于日志记录.
*
* how to use this class:
* 1. init Logger class
* Logger::InitLogger();
* 2. get an instance of Logger class
* Logger* testLog=Logger::GetInstance("testLogName");
* 3. init the instance ( here we determine the log filename, max file size,
* flush mode { immediate flush or not },
* file open mode { append, trunc, etc. } )
* testLog->initLogFile("testLogFile",10*1024*1024,TRUE,std::ios::app);
* 4. set log level
* testLog->SetLogLevel(skgLogger::LogLevelType::LEVEL_ERROR);
* 5. now we can log events. do it! ( use LOG_INFO(), LOG_WARN() or LOG_ERROR() )
* LOG_WARN(testLog,"this is a new log record.")
* 6. after all thing done,you should delete this instance. use RemoveInstance().
* RemoveInstance(testLog);
*
* Here, everything seems fine. You need test this Logger stuff,.
*
*
*
*
*
*
*
*
*
************************************************************************/
// Logger.cpp: implementation of the Logger class.
//
//////////////////////////////////////////////////////////////////////
#include "stdafx.h"
#include "phone.h"
#include "Logger.h"
#include <afx.h>
#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif
namespace skgLogger{
// 在此处对两个 static 成员进行定义
CRITICAL_SECTION Logger::cs_loggerClassLevel;
std::vector<Logger*> Logger::loggerList;
BOOL Logger::b_traceable;
BOOL Logger::InitLogger()
{
InitializeCriticalSection(&Logger::cs_loggerClassLevel);
Logger::b_traceable=FALSE;
return TRUE;
}
void Logger::EnableTrace(BOOL traceable)
{
EnterCriticalSection(&cs_loggerClassLevel);
b_traceable=traceable;
LeaveCriticalSection(&cs_loggerClassLevel);
}
BOOL Logger::isTraceable()
{
return b_traceable;
}
Logger* Logger::GetInstance(const string& name)
{
EnterCriticalSection(&cs_loggerClassLevel);
// if we find that we have created one instance named '&name' already. just return it.
for (std::vector<Logger*>::iterator iter=loggerList.begin();iter!=loggerList.end();iter++)
{
if (!(*iter)->GetName().compare(name))
{
LeaveCriticalSection(&cs_loggerClassLevel);
return (*iter);
}
}
// else we will simply create a new instance and return it.
Logger* instance=new Logger(name);
loggerList.push_back(instance);
LeaveCriticalSection(&cs_loggerClassLevel);
return instance;
}
void Logger::RemoveInstance(const Logger* logger)
{
EnterCriticalSection(&cs_loggerClassLevel);
for (std::vector<Logger*>::iterator iter=loggerList.begin();iter!=loggerList.end();iter++)
{
if ((*iter)==logger)
{
delete logger;
loggerList.erase(iter);
break;
}
}
LeaveCriticalSection(&cs_loggerClassLevel);
}
void Logger::RemoveInstance(const string& name)
{
EnterCriticalSection(&cs_loggerClassLevel);
for (std::vector<Logger*>::iterator iter=loggerList.begin();iter!=loggerList.end();iter++)
{
if (!(*iter)->GetName().compare(name))
{
delete iter;
loggerList.erase(iter);
break;
}
}
LeaveCriticalSection(&cs_loggerClassLevel);
}
//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////
Logger::Logger( const string& name )
{
this->name=name;
InitializeCriticalSection(&cs_file);
buffer=NULL;
bufferSize=1024;// for test
b_inited=FALSE;
m_LogLevel=skgLogger::INFO_LOG_LEVEL;
}
Logger::~Logger()
{
EnterCriticalSection(&cs_file);
stream_out.close();
delete[] buffer;
buffer=NULL;
bufferSize=0;
LeaveCriticalSection(&cs_file);
TRACE("loger deleted!\n");
}
string Logger::GetName() const
{
return name;
}
void Logger::SetLogLevel( LogLevelType logLevel )
{
EnterCriticalSection(&cs_file);
m_LogLevel=logLevel;
LeaveCriticalSection(&cs_file);
}
LogLevelType Logger::GetLogLevel() const
{
return m_LogLevel;
}
BOOL Logger::isEnabledFor(LogLevelType logLevel)
{
EnterCriticalSection(&cs_file);// must need ?
if ((m_LogLevel&logLevel)==logLevel)// m_LogLevel 包含 logLevel , 说明此级可用.
{
LeaveCriticalSection(&cs_file);
return TRUE;
}
LeaveCriticalSection(&cs_file);
return FALSE;
}
string Logger::GetTimeString( const char* timeFormat )
{
CString t=CTime::GetCurrentTime().Format(timeFormat);
string strNowTime=(LPTSTR)(LPCTSTR)t;
return strNowTime;
}
void Logger::PrintLog( const string& message )
{
// not implemented yet.
}
BOOL Logger::initLogFile( const string& basename, long maxFileSize/*=10*1024*1024*/, /* 10 MB */ BOOL immediateFlush/*=TRUE*/, LOG_OPEN_MODE_TYPE mode /*= ios::app*/ )
{
EnterCriticalSection(&cs_file);
if (b_inited)
{
delete[] buffer;
buffer=NULL;
b_inited=FALSE;
}
this->basename=basename;//再加上日期格式成为 (文件名+日期+序号).log
this->maxFileSize=maxFileSize;
this->immediateFlush=immediateFlush;
currentFileSeq=0;
Open(mode);
b_inited=TRUE;
LeaveCriticalSection(&cs_file);
return TRUE;
}
static BOOL FileExist(const char* strFileName)
{
CFileFind fFind;
return fFind.FindFile(strFileName);
}
// does not need to be locked since it is called by initLogFile() and ReOpen() which perform the locking
void Logger::Open(LOG_OPEN_MODE_TYPE mode)
{
char strSeq[10];
itoa(currentFileSeq,strSeq,10);
openedFilename=basename+"_"+strSeq+".txt";
while (FileExist(openedFilename.c_str()))
{
currentFileSeq++;
itoa(currentFileSeq,strSeq,10);
openedFilename=basename+"_"+strSeq+".txt";
}
stream_out.open(openedFilename.c_str(),mode);
if (bufferSize!=0)
{
TRACE("set buf\n");
this->buffer=new char[bufferSize];
stream_out.rdbuf()->pubsetbuf(buffer,bufferSize);
}
}
BOOL Logger::ReOpen()
{
stream_out.close();
stream_out.clear();
stream_out.open(openedFilename.c_str());
if (stream_out.tellp()>maxFileSize)
{
Open(std::ios::app);
}
if (stream_out.good())
{
return TRUE;
}
return FALSE;
}
BOOL Logger::Rollover()
{
EnterCriticalSection(&cs_file);
// just use another new file (filename).
stream_out.close();
stream_out.clear();
Open(std::ios::app);
LeaveCriticalSection(&cs_file);
return TRUE;
}
static string LL2String(LogLevelType level)
{
string str_logLevel;
switch(level)
{
case skgLogger::NONE_LOG_LEVEL:
str_logLevel="NONE";
break;
case skgLogger::WARN_LOG_LEVEL:
str_logLevel="WARNING";
break;
case skgLogger::ERROR_LOG_LEVEL:
str_logLevel="ERROR";
break;
case skgLogger::INFO_LOG_LEVEL:
str_logLevel="INFO/ALL";
break;
default:
str_logLevel="UNKNOWN";
}
return str_logLevel;
}
void Logger::WriteLog( LogLevelType level, const string& message, const char* file/*=NULL*/,int line/*=-1*/ )
{
EnterCriticalSection(&cs_file);
if (!stream_out.good())
{
TRACE("stream_out is not good()\n");
if (!ReOpen())
{
TRACE("file is not open--ReOpen():%s\n",openedFilename.c_str());
LeaveCriticalSection(&cs_file);
return;
}
}
// format the message, and then put it into the stream
stream_out << GetTimeString()
<< " | "
<< LL2String(level)
<< " | "
<< message
<< " || file: " << file
<< ", line: " << line << "\n";
if (immediateFlush)
{
TRACE("flush\n");
stream_out.flush();
}
if (stream_out.tellp()>maxFileSize)
{
this->Rollover();
}
LeaveCriticalSection(&cs_file);
}
} // end namespace skgLogger

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