STRMHELP.CXX

//+--------------------------------------------------------------------------- 
// 
//  Microsoft Windows 
//  Copyright 1992 - 1998 Microsoft Corporation. 
// 
//  File:       strmhelp.cxx 
// 
//  Contents:   Routines for writting variables to a stream in an 
//              architecture independent manner. 
// 
//  Classes: 
// 
//  Functions:  WriteDouble 
//              ReadDouble 
//              SizeDouble 
// 
//  History:    4-26-94   stevebl   Created 
// 
//---------------------------------------------------------------------------- 
 
#include <windows.h> 
#include <ole2.h> 
#include "strmhelp.h" 
#include <stdio.h> 
 
#define MAX_SIZE 128 
 
//+--------------------------------------------------------------------------- 
// 
//  Function:   SizeDouble 
// 
//  Synopsis:   returns the maximum number of bytes that WriteDouble will 
//              take to write a double to an IStream 
// 
//  Arguments:  none 
// 
//  Returns:    maximum number of bytes needed to write a double to an IStream 
// 
//  History:    4-26-94   stevebl   Created 
// 
//---------------------------------------------------------------------------- 
 
DWORD SizeDouble(void) 
{ 
    return(MAX_SIZE); 
} 
 
//+--------------------------------------------------------------------------- 
// 
//  Function:   WriteDouble 
// 
//  Synopsis:   rrites a double to an OLE stream in a machine independent manner 
// 
//  Arguments:  [pstm]       - pointer to an IStream 
//              [d]          - the double to be written 
//              [pcbWritten] - pointer to the number of bytes actually written 
//                             (may be NULL) 
// 
//  Returns:    same return values as IStream::Write 
// 
//  History:    4-26-94   stevebl   Created 
// 
//---------------------------------------------------------------------------- 
 
HRESULT WriteDouble(IStream * pstm, double d, ULONG FAR * pcbWritten) 
{ 
    char szTemp[MAX_SIZE]; 
    sprintf(szTemp,"%.100lg", d); 
    WORD cch = strlen(szTemp); 
    return(pstm->Write(szTemp, cch + 1, pcbWritten)); 
} 
 
//+--------------------------------------------------------------------------- 
// 
//  Function:   ReadDouble 
// 
//  Synopsis:   reads a double from an OLE stream in a machine independent 
//              manner 
// 
//  Arguments:  [pstm]    - pointer to an IStream 
//              [pd]      - pointer to the double to be read 
//              [pcbRead] - pointer to the number of bytes actually read 
//                          (may be NULL) 
// 
//  Returns:    same return values as IStream::Read 
// 
//  History:    4-26-94   stevebl   Created 
// 
//---------------------------------------------------------------------------- 
 
HRESULT ReadDouble(IStream * pstm, double * pd, ULONG FAR * pcbRead) 
{ 
    HRESULT hr; 
    char szTemp[MAX_SIZE]; 
    ULONG cbRead; 
    DWORD cch = 0; 
    do 
    { 
        hr = pstm->Read(&szTemp[cch], sizeof(char), &cbRead); 
        if (pcbRead && SUCCEEDED(hr)) 
        { 
            pcbRead += cbRead; 
        } 
 
    } while (SUCCEEDED(hr) && szTemp[cch++]); 
    if (SUCCEEDED(hr)) 
    { 
        sscanf(szTemp, "%lf",pd); 
    } 
    return(hr); 
}