cpl_error.cpp

用于读取TAB、MIF、SHP文件的类

    {
        CPLMutexHolderD( &hErrorMutex );
        if( pfnErrorHandler != NULL )
            pfnErrorHandler( CE_Debug, CPLE_None, pszMessage );
    }

    VSIFree( pszMessage );
}

/**********************************************************************
 *                          CPLErrorReset()
 **********************************************************************/

/**
 * Erase any traces of previous errors.
 *
 * This is normally used to ensure that an error which has been recovered
 * from does not appear to be still in play with high level functions.
 */

void CPL_STDCALL CPLErrorReset()
{
    CPLErrorContext *psCtx = CPLGetErrorContext();

    psCtx->nLastErrNo = CPLE_None;
    psCtx->szLastErrMsg[0] = '\0';
    psCtx->eLastErrType = CE_None;
}


/**********************************************************************
 *                          CPLGetLastErrorNo()
 **********************************************************************/

/**
 * Fetch the last error number.
 *
 * This is the error number, not the error class.
 *
 * @return the error number of the last error to occur, or CPLE_None (0)
 * if there are no posted errors.
 */

int CPL_STDCALL CPLGetLastErrorNo()
{
    CPLErrorContext *psCtx = CPLGetErrorContext();

    return psCtx->nLastErrNo;
}

/**********************************************************************
 *                          CPLGetLastErrorType()
 **********************************************************************/

/**
 * Fetch the last error type.
 *
 * This is the error class, not the error number.
 *
 * @return the error number of the last error to occur, or CE_None (0)
 * if there are no posted errors.
 */

CPLErr CPL_STDCALL CPLGetLastErrorType()
{
    CPLErrorContext *psCtx = CPLGetErrorContext();

    return psCtx->eLastErrType;
}

/**********************************************************************
 *                          CPLGetLastErrorMsg()
 **********************************************************************/

/**
 * Get the last error message.
 *
 * Fetches the last error message posted with CPLError(), that hasn't
 * been cleared by CPLErrorReset().  The returned pointer is to an internal
 * string that should not be altered or freed.
 *
 * @return the last error message, or NULL if there is no posted error
 * message.
 */

const char* CPL_STDCALL CPLGetLastErrorMsg()
{
    CPLErrorContext *psCtx = CPLGetErrorContext();

    return psCtx->szLastErrMsg;
}

/************************************************************************/
/*                       CPLDefaultErrorHandler()                       */
/************************************************************************/

void CPL_STDCALL CPLDefaultErrorHandler( CPLErr eErrClass, int nError, 
                             const char * pszErrorMsg )

{
    static int       bLogInit = FALSE;
    static FILE *    fpLog = stderr;

    if( !bLogInit )
    {
        bLogInit = TRUE;

        fpLog = stderr;
        if( CPLGetConfigOption( "CPL_LOG", NULL ) != NULL )
        {
            fpLog = fopen( CPLGetConfigOption("CPL_LOG",""), "wt" );
            if( fpLog == NULL )
                fpLog = stderr;
        }
    }

    if( eErrClass == CE_Debug )
        fprintf( fpLog, "%s\n", pszErrorMsg );
    else if( eErrClass == CE_Warning )
        fprintf( fpLog, "Warning %d: %s\n", nError, pszErrorMsg );
    else
        fprintf( fpLog, "ERROR %d: %s\n", nError, pszErrorMsg );

    fflush( fpLog );
}

/************************************************************************/
/*                        CPLQuietErrorHandler()                        */
/************************************************************************/

void CPL_STDCALL CPLQuietErrorHandler( CPLErr eErrClass , int nError, 
                           const char * pszErrorMsg )

{
    if( eErrClass == CE_Debug )
        CPLDefaultErrorHandler( eErrClass, nError, pszErrorMsg );
}

/************************************************************************/
/*                       CPLLoggingErrorHandler()                       */
/************************************************************************/

void CPL_STDCALL CPLLoggingErrorHandler( CPLErr eErrClass, int nError, 
                             const char * pszErrorMsg )

{
    static int       bLogInit = FALSE;
    static FILE *    fpLog = stderr;

    if( !bLogInit )
    {
        const char *cpl_log = NULL;

        CPLSetConfigOption( "CPL_TIMESTAMP", "ON" );

        bLogInit = TRUE;

        cpl_log = CPLGetConfigOption("CPL_LOG", NULL );

        fpLog = stderr;
        if( cpl_log != NULL && EQUAL(cpl_log,"OFF") )
        {
            fpLog = NULL;
        }
        else if( cpl_log != NULL )
        {
            char      path[5000];
            int       i = 0;

            strcpy( path, cpl_log );

            while( (fpLog = fopen( path, "rt" )) != NULL ) 
            {
                fclose( fpLog );

                /* generate sequenced log file names, inserting # before ext.*/
                if (strrchr(cpl_log, '.') == NULL)
                {
                    sprintf( path, "%s_%d%s", cpl_log, i++,
                             ".log" );
                }
                else
                {
                    size_t pos = 0;
                    char *cpl_log_base = strdup(cpl_log);
                    pos = strcspn(cpl_log_base, ".");
                    if (pos > 0)
                    {
                        cpl_log_base[pos] = '\0';
                    }
                    sprintf( path, "%s_%d%s", cpl_log_base,
                             i++, ".log" );
                }
            }

            fpLog = fopen( path, "wt" );
        }
    }

    if( fpLog == NULL )
        return;

    if( eErrClass == CE_Debug )
        fprintf( fpLog, "%s\n", pszErrorMsg );
    else if( eErrClass == CE_Warning )
        fprintf( fpLog, "Warning %d: %s\n", nError, pszErrorMsg );
    else
        fprintf( fpLog, "ERROR %d: %s\n", nError, pszErrorMsg );

    fflush( fpLog );
}

/**********************************************************************
 *                          CPLSetErrorHandler()
 **********************************************************************/

/**
 * Install custom error handler.
 *
 * Allow the library's user to specify his own error handler function.
 * A valid error handler is a C function with the following prototype:
 *
 * <pre>
 *     void MyErrorHandler(CPLErr eErrClass, int err_no, const char *msg)
 * </pre>
 *
 * Pass NULL to come back to the default behavior.  The default behaviour
 * (CPLDefaultErrorHandler()) is to write the message to stderr. 
 *
 * The msg will be a partially formatted error message not containing the
 * "ERROR %d:" portion emitted by the default handler.  Message formatting
 * is handled by CPLError() before calling the handler.  If the error
 * handler function is passed a CE_Fatal class error and returns, then
 * CPLError() will call abort(). Applications wanting to interrupt this
 * fatal behaviour will have to use longjmp(), or a C++ exception to
 * indirectly exit the function.
 *
 * Another standard error handler is CPLQuietErrorHandler() which doesn't
 * make any attempt to report the passed error or warning messages but
 * will process debug messages via CPLDefaultErrorHandler.
 *
 * Note that error handlers set with CPLSetErrorHandler() apply to all
 * threads in an application, while error handlers set with CPLPushErrorHandler
 * are thread-local.  However, any error handlers pushed with 
 * CPLPushErrorHandler (and not removed with CPLPopErrorHandler) take 
 * precidence over the global error handlers set with CPLSetErrorHandler(). 
 * Generally speaking CPLSetErrorHandler() would be used to set a desired
 * global error handler, while CPLPushErrorHandler() would be used to install
 * a temporary local error handler, such as CPLQuietErrorHandler() to suppress
 * error reporting in a limited segment of code. 
 *
 * @param pfnErrorHandlerNew new error handler function.
 * @return returns the previously installed error handler.
 */ 

CPLErrorHandler CPL_STDCALL 
CPLSetErrorHandler( CPLErrorHandler pfnErrorHandlerNew )
{
    CPLErrorHandler     pfnOldHandler = pfnErrorHandler;
    CPLErrorContext *psCtx = CPLGetErrorContext();

    if( psCtx->psHandlerStack != NULL )
    {
        CPLDebug( "CPL", 
                  "CPLSetErrorHandler() called with an error handler on\n"
                  "the local stack.  New error handler will not be used immediately.\n" );
    }


    {
        CPLMutexHolderD( &hErrorMutex );

        pfnOldHandler = pfnErrorHandler;
        
        if( pfnErrorHandler == NULL )
            pfnErrorHandler = CPLDefaultErrorHandler;
        else
            pfnErrorHandler = pfnErrorHandlerNew;
    }

    return pfnOldHandler;
}

/************************************************************************/
/*                        CPLPushErrorHandler()                         */
/************************************************************************/

/**
 * Push a new CPLError handler.
 *
 * This pushes a new error handler on the thread-local error handler
 * stack.  This handler will be used untill removed with CPLPopErrorHandler().
 *
 * The CPLSetErrorHandler() docs have further information on how 
 * CPLError handlers work.
 *
 * @param pfnErrorHandlerNew new error handler function.
 */

void CPL_STDCALL CPLPushErrorHandler( CPLErrorHandler pfnErrorHandlerNew )

{
    CPLErrorContext *psCtx = CPLGetErrorContext();
    CPLErrorHandlerNode         *psNode;

    psNode = (CPLErrorHandlerNode *) VSIMalloc(sizeof(CPLErrorHandlerNode));
    psNode->psNext = psCtx->psHandlerStack;
    psNode->pfnHandler = pfnErrorHandlerNew;

    psCtx->psHandlerStack = psNode;
}

/************************************************************************/
/*                         CPLPopErrorHandler()                         */
/************************************************************************/

/**
 * Pop error handler off stack.
 *
 * Discards the current error handler on the error handler stack, and restores 
 * the one in use before the last CPLPushErrorHandler() call.  This method
 * has no effect if there are no error handlers on the current threads error
 * handler stack. 
 */ 

void CPL_STDCALL CPLPopErrorHandler()

{
    CPLErrorContext *psCtx = CPLGetErrorContext();

    if( psCtx->psHandlerStack != NULL )
    {
        CPLErrorHandlerNode     *psNode = psCtx->psHandlerStack;

        psCtx->psHandlerStack = psNode->psNext;
        VSIFree( psNode );
    }
}

/************************************************************************/
/*                             _CPLAssert()                             */
/*                                                                      */
/*      This function is called only when an assertion fails.           */
/************************************************************************/

/**
 * Report failure of a logical assertion.
 *
 * Applications would normally use the CPLAssert() macro which expands
 * into code calling _CPLAssert() only if the condition fails.  _CPLAssert()
 * will generate a CE_Fatal error call to CPLError(), indicating the file
 * name, and line number of the failed assertion, as well as containing
 * the assertion itself.
 *
 * There is no reason for application code to call _CPLAssert() directly.
 */

void CPL_STDCALL _CPLAssert( const char * pszExpression, const char * pszFile,
                 int iLine )

{
    CPLError( CE_Fatal, CPLE_AssertionFailed,
              "Assertion `%s' failed\n"
              "in file `%s', line %d\n",
              pszExpression, pszFile, iLine );
}