HUGE.C

/******************************************************************************\ 
*       This is a part of the Microsoft Source Code Samples. 
*       Copyright 1993 - 1998 Microsoft Corporation. 
*       All rights reserved. 
*       This source code is only intended as a supplement to 
*       Microsoft Development Tools and/or WinHelp documentation. 
*       See these sources for detailed information regarding the 
*       Microsoft samples programs. 
\******************************************************************************/ 
 
/*************************************************************************** 
 *                                                                         * 
 *  MODULE      : huge.c                                                   * 
 *                                                                         * 
 *  PURPOSE     : This contains functions useful for generating and        * 
 *                verifying huge text data blocks.                         * 
 *                                                                         * 
 ***************************************************************************/ 
 
#include <string.h> 
#include <tchar.h> 
#include <stdio.h> 
#include <windows.h> 
#include <ddeml.h> 
#include "huge.h" 
 
extern DWORD idInst; 
#define BUFSZ   435 
 
LONG lseed, lmult, ladd; 
TCHAR szT[BUFSZ]; 
 
VOID SetMyRand(LONG seed, LONG mult, LONG add); 
TCHAR MyRand(VOID); 
BOOL RandTest(LONG length, LONG seed, LONG mult, LONG add); 
 
/**************************************************************************** 
 *                                                                          * 
 *  FUNCTION   : SetMyRand()                                                * 
 *                                                                          * 
 *  PURPOSE    : Transfers random sequence generation variables to globals. * 
 *                                                                          * 
 ****************************************************************************/ 
VOID SetMyRand( 
LONG seed, 
LONG mult, 
LONG add) 
{ 
    lseed = seed; 
    lmult = mult; 
    ladd = add; 
} 
 
 
/**************************************************************************** 
 *                                                                          * 
 *  FUNCTION   : MyRand()                                                   * 
 *                                                                          * 
 *  PURPOSE    : Generates the next random character in a sequence.         * 
 *                                                                          * 
 *  RETURNS    : the character generated                                    * 
 *                                                                          * 
 ****************************************************************************/ 
TCHAR MyRand() 
{ 
    TCHAR c; 
 
    lseed = lseed * lmult + ladd; 
    c = (TCHAR)(LOWORD(lseed) ^ HIWORD(lseed)); 
    return((TCHAR)((c & (TCHAR)0x4f) + TEXT(' ')));   // 0x20 - 0x6f - all printable 
} 
 
 
/* 
 * This function allocates and fills a HUGE data handle with a verifiable 
 * text string. 
 * 
 * The format of the text string is: 
 * "<length>=<seed>*<mult>+<add>;---data of length <length>---\0" 
 * all values are stored in base 16 numbers. 
 */ 
/**************************************************************************** 
 *                                                                          * 
 *  FUNCTION   : CreateHugeDataHandle()                                     * 
 *                                                                          * 
 *  PURPOSE    : Generates a huge pseudo-random sequence of printable       * 
 *               characters of the length given and places then into        * 
 *               a DDEML data handle.                                       * 
 *                                                                          * 
 *  RETURNS    : The data handle created or 0 on failure.                   * 
 *                                                                          * 
 ****************************************************************************/ 
HDDEDATA CreateHugeDataHandle( 
LONG length, 
LONG seed, 
LONG mult, 
LONG add, 
HSZ hszItem, 
UINT wFmt, 
WORD afCmd) 
{ 
    register WORD cb; 
    HDDEDATA hData; 
    DWORD cbData; 
    TCHAR *psz; 
 
    wsprintf(szT, TEXT("%ld=%ld*%ld+%ld;"), length, seed, mult, add); 
    cb = (_tcslen(szT) + 1) * sizeof(TCHAR); 
    hData = DdeCreateDataHandle(idInst, (PBYTE)szT, cb, 0, 
            hszItem, wFmt, afCmd); 
    if (hData) 
        hData = DdeAddData(hData, NULL, 0, cb + length); 
    cbData = cb; 
    SetMyRand(seed, mult, add); 
    while (hData && (length > 0)) { 
        psz = szT; 
        cb = BUFSZ; 
        while (cb--) 
            *psz++ = MyRand(); 
        hData = DdeAddData(hData, (PBYTE)szT, min(length, BUFSZ), cbData); 
        cbData += BUFSZ; 
        length -= BUFSZ; 
    } 
    return(hData); 
} 
 
/**************************************************************************** 
 *                                                                          * 
 *  FUNCTION   : CheckHugeData()                                            * 
 *                                                                          * 
 *  PURPOSE    : Verifies the correctness of a pseudo-random character      * 
 *               sequence generated by CreateHugeData.                      * 
 *                                                                          * 
 *  RETURNS    : TRUE if verified ok, FALSE otherwise.                      * 
 *                                                                          * 
 ****************************************************************************/ 
BOOL CheckHugeData( 
HDDEDATA hData) 
{ 
    LONG length; 
    LONG seed; 
    LONG mult; 
    LONG add; 
    TCHAR *psz; 
    DWORD cbOff; 
    WORD cb; 
 
    if (!DdeGetData(hData, (PBYTE)szT, BUFSZ, 0)) 
        return(FALSE); 
    szT[BUFSZ - 1] = TEXT('\0'); 
    psz = _tcschr(szT, TEXT(';')); 
    if (psz == NULL) 
        return(FALSE); 
    *psz = TEXT('\0'); 
 
    if (_stscanf(szT, TEXT("%ld=%ld*%ld+%ld"), &length, &seed, &mult, &add) != 4) 
        return(FALSE); 
 
    if (length < 0) 
        return(FALSE); 
    SetMyRand(seed, mult, add); 
    cbOff = (_tcslen(szT) + 1) * sizeof(TCHAR); 
    while (length > 0) { 
        DdeGetData(hData, (PBYTE)szT, BUFSZ, cbOff); 
        psz = szT; 
        cb = BUFSZ; 
        while (length-- && cb--) 
            if (*psz++ != MyRand()) 
                return(FALSE); 
        cbOff += BUFSZ; 
        length -= BUFSZ; 
    } 
    return(TRUE); 
} 
 
#if 0 
/**************************************************************************** 
 *                                                                          * 
 *  FUNCTION   : RandTest()                                                 * 
 *                                                                          * 
 *  PURPOSE    : Verifies the correctness of CreateHugeDataHandle() and     * 
 *               CheckHugeData().                                           * 
 *                                                                          * 
 *  RETURNS    :                                                            * 
 *                                                                          * 
 ****************************************************************************/ 
BOOL RandTest( 
LONG length, 
LONG seed, 
LONG mult, 
LONG add) 
{ 
    HDDEDATA hData; 
    BOOL fSuccess; 
 
    hData = CreateHugeDataHandle(length, seed, mult, add, 0, 1, 0); 
    if (!hData) 
        return(FALSE); 
    fSuccess = CheckHugeData(hData); 
    DdeFreeDataHandle(hData); 
    return(fSuccess); 
} 
#endif