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- //==========================================================================;
- //
- // THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY
- // KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
- // IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR
- // PURPOSE.
- //
- // Copyright (c) 1992 - 1996 Microsoft Corporation. All Rights Reserved.
- //
- //--------------------------------------------------------------------------;
-
- //
- // helper classes for building multimedia filters
- //
-
- #include <streams.h>
-
- //
- // Declare function from largeint.h we need so that PPC can build
- //
-
- //
- // Enlarged integer divide - 64-bits / 32-bits > 32-bits
- //
-
- #ifndef _X86_
-
- #define LLtoU64(x) (*(unsigned __int64*)(void*)(&(x)))
-
- __inline
- ULONG
- WINAPI
- EnlargedUnsignedDivide (
- IN ULARGE_INTEGER Dividend,
- IN ULONG Divisor,
- IN PULONG Remainder
- )
- {
- // return remainder if necessary
- if (Remainder != NULL)
- *Remainder = (ULONG)(LLtoU64(Dividend) % Divisor);
- return (ULONG)(LLtoU64(Dividend) / Divisor);
- }
-
- #else
- __inline
- ULONG
- WINAPI
- EnlargedUnsignedDivide (
- IN ULARGE_INTEGER Dividend,
- IN ULONG Divisor,
- IN PULONG Remainder
- )
- {
- ULONG ulResult;
- _asm {
- mov eax,Dividend.LowPart
- mov edx,Dividend.HighPart
- mov ecx,Remainder
- div Divisor
- or ecx,ecx
- jz short label
- mov [ecx],edx
- label:
- mov ulResult,eax
- }
- return ulResult;
- }
- #endif
-
- // --- CAMEvent -----------------------
- CAMEvent::CAMEvent(BOOL fManualReset)
- {
- m_hEvent = CreateEvent(NULL, fManualReset, FALSE, NULL);
- }
-
- CAMEvent::~CAMEvent()
- {
- if (m_hEvent) {
- EXECUTE_ASSERT(CloseHandle(m_hEvent));
- }
- }
-
- // --- CThread ----------------------
-
-
- CThread::CThread()
- : m_EventSend(TRUE) // must be manual-reset for CheckRequest()
- {
- m_hThread = NULL;
- }
-
- CThread::~CThread() {
-
- if (ThreadExists()) {
-
- // can't kill the thread, we just have to block until it exits.
-
- // wait for termination and close handle
- Close();
- }
- }
-
-
- // ThreadExists
- // Return TRUE if the thread exists. FALSE otherwise
- BOOL
- CThread::ThreadExists(void)
- {
-
- if (m_hThread == 0) {
- return FALSE;
- }
-
- DWORD dwExitCode;
-
- BOOL fErr = GetExitCodeThread(m_hThread, &dwExitCode);
- if (!fErr) {
- return FALSE; // Assuming the error was caused by a bad
- // handle or similar
- }
- if (dwExitCode == STILL_ACTIVE) {
- return TRUE;
- }
- else {
- return FALSE;
- }
- }
-
-
- // when the thread starts, it calls this function. We unwrap the 'this'
- //pointer and call ThreadProc.
- DWORD WINAPI
- CThread::InitialThreadProc(LPVOID pv)
- {
- CThread * pThread = (CThread *) pv;
-
- return pThread->ThreadProc();
- }
-
- BOOL
- CThread::Create()
- {
- DWORD threadid;
-
- CAutoLock lock(&m_AccessLock);
-
- if (ThreadExists()) {
- return FALSE;
- }
-
- m_hThread = CreateThread(
- NULL,
- 0,
- CThread::InitialThreadProc,
- this,
- 0,
- &threadid);
-
- if (!m_hThread) {
- return FALSE;
- }
-
- return TRUE;
- }
-
- DWORD
- CThread::CallWorker(DWORD dwParam)
- {
- // lock access to the worker thread for scope of this object
- CAutoLock lock(&m_AccessLock);
-
- if (!ThreadExists()) {
- return E_FAIL;
- }
-
- // set the parameter
- m_dwParam = dwParam;
-
- // signal the worker thread
- m_EventSend.Set();
-
- // wait for the completion to be signalled
- m_EventComplete.Wait();
-
- // done - this is the thread's return value
- return m_dwReturnVal;
- }
-
- // Wait for a request from the client
- DWORD
- CThread::GetRequest()
- {
- m_EventSend.Wait();
- return m_dwParam;
- }
-
- // is there a request?
- BOOL
- CThread::CheckRequest(DWORD * pParam)
- {
- if (!m_EventSend.Check()) {
- return FALSE;
- } else {
- if (pParam) {
- *pParam = m_dwParam;
- }
- return TRUE;
- }
- }
-
- // reply to the request
- void
- CThread::Reply(DWORD dw)
- {
- m_dwReturnVal = dw;
-
- // The request is now complete so CheckRequest should fail from
- // now on
- //
- // This event should be reset BEFORE we signal the client or
- // the client may Set it before we reset it and we'll then
- // reset it (!)
-
- m_EventSend.Reset();
-
- // Tell the client we're finished
-
- m_EventComplete.Set();
- }
-
-
- // destructor for CMsgThread - cleans up any messages left in the
- // queue when the thread exited
- CMsgThread::~CMsgThread()
- {
- if (m_hThread != NULL) {
- WaitForSingleObject(m_hThread, INFINITE);
- EXECUTE_ASSERT(CloseHandle(m_hThread));
- }
-
- POSITION pos = m_ThreadQueue.GetHeadPosition();
- while (pos) {
- CMsg * pMsg = m_ThreadQueue.GetNext(pos);
- delete pMsg;
- }
- m_ThreadQueue.RemoveAll();
-
- if (m_hSem != NULL) {
- EXECUTE_ASSERT(CloseHandle(m_hSem));
- }
- }
-
- BOOL
- CMsgThread::CreateThread(
- )
- {
- m_hSem = CreateSemaphore(NULL, 0, 0x7FFFFFFF, NULL);
- if (m_hSem == NULL) {
- return FALSE;
- }
-
- m_hThread = ::CreateThread(NULL, 0, DefaultThreadProc,
- (LPVOID)this, 0, &m_ThreadId);
- return m_hThread != NULL;
- }
-
-
- // This is the threads message pump. Here we get and dispatch messages to
- // clients thread proc until the client refuses to process a message.
- // The client returns a non-zero value to stop the message pump, this
- // value becomes the threads exit code.
-
- DWORD WINAPI
- CMsgThread::DefaultThreadProc(
- LPVOID lpParam
- )
- {
- CMsgThread *lpThis = (CMsgThread *)lpParam;
- CMsg msg;
- LRESULT lResult;
-
- // !!!
- CoInitialize(NULL);
-
- // allow a derived class to handle thread startup
- lpThis->OnThreadInit();
-
- do {
- lpThis->GetThreadMsg(&msg);
- lResult = lpThis->ThreadMessageProc(msg.uMsg,msg.dwFlags,
- msg.lpParam, msg.pEvent);
- } while (lResult == 0L);
-
- // !!!
- CoUninitialize();
-
- return (DWORD)lResult;
- }
-
-
- // Block until the next message is placed on the list m_ThreadQueue.
- // copies the message to the message pointed to by *pmsg
- void
- CMsgThread::GetThreadMsg(CMsg *msg)
- {
- CMsg * pmsg = NULL;
-
- // keep trying until a message appears
- while (TRUE) {
- {
- CAutoLock lck(&m_Lock);
- pmsg = m_ThreadQueue.RemoveHead();
- if (pmsg == NULL) {
- m_lWaiting++;
- } else {
- break;
- }
- }
- // the semaphore will be signalled when it is non-empty
- WaitForSingleObject(m_hSem, INFINITE);
- }
- // copy fields to caller's CMsg
- *msg = *pmsg;
-
- // this CMsg was allocated by the 'new' in PutThreadMsg
- delete pmsg;
-
- }
-
-
- #ifndef UNICODE
- // NOTE: as we need to use the same binaries on Win95 as on NT this code should
- // be compiled WITHOUT unicode being defined. Otherwise we will not pick up
- // these internal routines and the binary will not run on Win95.
-
- // Windows 95 doesn't implement this, so we provide an implementation.
- LPWSTR
- WINAPI
- lstrcpyWInternal(
- LPWSTR lpString1,
- LPCWSTR lpString2
- )
- {
- LPWSTR lpReturn = lpString1;
- while (*lpString1++ = *lpString2++);
-
- return lpReturn;
- }
-
- // Windows 95 doesn't implement this, so we provide an implementation.
- LPWSTR
- WINAPI
- lstrcpynWInternal(
- LPWSTR lpString1,
- LPCWSTR lpString2,
- int iMaxLength
- )
- {
- ASSERT(iMaxLength);
- LPWSTR lpReturn = lpString1;
- if (iMaxLength) {
- while (--iMaxLength && (*lpString1++ = *lpString2++));
-
- // If we ran out of room (which will be the case if
- // iMaxLength is now 0) we still need to terminate the
- // string.
- if (!iMaxLength) *lpString1 = L'\0';
- }
- return lpReturn;
- }
-
- int
- WINAPI
- lstrcmpWInternal(
- LPCWSTR lpString1,
- LPCWSTR lpString2
- )
- {
- do {
- WCHAR c1 = *lpString1;
- WCHAR c2 = *lpString2;
- if (c1 != c2)
- return (int) c1 - (int) c2;
- } while (*lpString1++ && *lpString2++);
- return 0;
- }
-
-
- int
- WINAPI
- lstrcmpiWInternal(
- LPCWSTR lpString1,
- LPCWSTR lpString2
- )
- {
- do {
- WCHAR c1 = *lpString1;
- WCHAR c2 = *lpString2;
- if (c1 >= L'A' && c1 <= L'Z')
- c1 -= (WCHAR) (L'A' - L'a');
- if (c2 >= L'A' && c2 <= L'Z')
- c2 -= (WCHAR) (L'A' - L'a');
-
- if (c1 != c2)
- return (int) c1 - (int) c2;
- } while (*lpString1++ && *lpString2++);
-
- return 0;
- }
-
-
- int
- WINAPI
- lstrlenWInternal(
- LPCWSTR lpString
- )
- {
- int i = -1;
- while (*(lpString+(++i)))
- ;
- return i;
- }
-
- #endif // NOT UNICODE
-
-
- #ifndef UNICODE
- int WINAPIV wsprintfWInternal(LPWSTR wszOut, LPCWSTR pszFmt, ...)
- {
- char fmt[256]; // !!!
- char ach[256]; // !!!
- int i;
-
- va_list va;
- va_start(va, pszFmt);
- WideCharToMultiByte(GetACP(), 0, pszFmt, -1, fmt, 256, NULL, NULL);
- i = wvsprintf(ach, fmt, va);
- va_end(va);
-
- MultiByteToWideChar(CP_ACP, 0, ach, -1, wszOut, i+1);
-
- return i;
- }
- #endif
-
- // Helper function - convert int to WSTR
- void WINAPI IntToWstr(int i, LPWSTR wstr)
- {
- #ifdef UNICODE
- wsprintf(wstr, L"%d", i);
- #else
- TCHAR temp[32];
- wsprintf(temp, "%d", i);
- MultiByteToWideChar(CP_ACP, 0, temp, -1, wstr, 32);
- #endif
- } // IntToWstr
-
-
-
- void * __cdecl memchrInternal(const void *pv, int c, size_t sz)
- {
- BYTE *pb = (BYTE *) pv;
- while (sz--) {
- if (*pb == c)
- return (void *) pb;
- pb++;
- }
- return NULL;
- }
-
- /* Arithmetic functions to help with time format conversions
- */
-
- /* Compute (a * b + d) / c */
- LONGLONG llMulDiv(LONGLONG a, LONGLONG b, LONGLONG c, LONGLONG d)
- {
- /* Compute the absolute values to avoid signed arithmetic problems */
- ULARGE_INTEGER ua, ub;
- DWORDLONG uc;
-
- ua.QuadPart = (DWORDLONG)(a >= 0 ? a : -a);
- ub.QuadPart = (DWORDLONG)(b >= 0 ? b : -b);
- uc = (DWORDLONG)(c >= 0 ? c : -c);
- BOOL bSign = (a < 0) ^ (b < 0);
-
- /* Do long multiplication */
- ULARGE_INTEGER p[2];
- p[0].QuadPart = UInt32x32To64(ua.LowPart, ub.LowPart);
-
- /* This next computation cannot overflow into p[1].HighPart because
- the max number we can compute here is:
-
- (2 ** 32 - 1) * (2 ** 32 - 1) + // ua.LowPart * ub.LowPart
- (2 ** 32) * (2 ** 31) * (2 ** 32 - 1) * 2 // x.LowPart * y.HighPart * 2
-
- == 2 ** 96 - 2 ** 64 + (2 ** 64 - 2 ** 33 + 1)
- == 2 ** 96 - 2 ** 33 + 1
- < 2 ** 96
- */
-
- ULARGE_INTEGER x;
- x.QuadPart = UInt32x32To64(ua.LowPart, ub.HighPart) +
- UInt32x32To64(ua.HighPart, ub.LowPart) +
- p[0].HighPart;
- p[0].HighPart = x.LowPart;
- p[1].QuadPart = UInt32x32To64(ua.HighPart, ub.HighPart) + x.HighPart;
-
- if (d != 0) {
- ULARGE_INTEGER ud[2];
- if (bSign) {
- ud[0].QuadPart = (DWORDLONG)(-d);
- if (d > 0) {
- /* -d < 0 */
- ud[1].QuadPart = (DWORDLONG)(LONGLONG)-1;
- } else {
- ud[1].QuadPart = (DWORDLONG)0;
- }
- } else {
- ud[0].QuadPart = (DWORDLONG)d;
- if (d < 0) {
- ud[1].QuadPart = (DWORDLONG)(LONGLONG)-1;
- } else {
- ud[1].QuadPart = (DWORDLONG)0;
- }
- }
- /* Now do extended addition */
- ULARGE_INTEGER uliTotal;
-
- /* Add ls DWORDs */
- uliTotal.QuadPart = (DWORDLONG)ud[0].LowPart + p[0].LowPart;
- p[0].LowPart = uliTotal.LowPart;
-
- /* Propagate carry */
- uliTotal.LowPart = uliTotal.HighPart;
- uliTotal.HighPart = 0;
-
- /* Add 2nd most ls DWORDs */
- uliTotal.QuadPart += (DWORDLONG)ud[0].HighPart + p[0].HighPart;
- p[0].HighPart = uliTotal.LowPart;
-
- /* Propagate carry */
- uliTotal.LowPart = uliTotal.HighPart;
- uliTotal.HighPart = 0;
-
- /* Add MS DWORDLONGs - no carry expected */
- p[1].QuadPart += ud[1].QuadPart + uliTotal.QuadPart;
-
- /* Now see if we got a sign change from the addition */
- if ((LONG)p[1].HighPart < 0) {
- bSign = !bSign;
-
- /* Negate the current value (ugh!) */
- p[0].QuadPart = ~p[0].QuadPart;
- p[1].QuadPart = ~p[1].QuadPart;
- p[0].QuadPart += 1;
- p[1].QuadPart += (p[0].QuadPart == 0);
- }
- }
-
- /* Now for the division */
- if (c < 0) {
- bSign = !bSign;
- }
-
-
- /* This will catch c == 0 and overflow */
- if (uc <= p[1].QuadPart) {
- return bSign ? (LONGLONG)0x8000000000000000 :
- (LONGLONG)0x7FFFFFFFFFFFFFFF;
- }
-
- DWORDLONG ullResult;
-
- /* Do the division */
- /* If the dividend is a DWORD_LONG use the compiler */
- if (p[1].QuadPart == 0) {
- ullResult = p[0].QuadPart / uc;
- return bSign ? -(LONGLONG)ullResult : (LONGLONG)ullResult;
- }
-
- /* If the divisor is a DWORD then its simpler */
- ULARGE_INTEGER ulic;
- ulic.QuadPart = uc;
- if (ulic.HighPart == 0) {
- ULARGE_INTEGER uliDividend;
- ULARGE_INTEGER uliResult;
- DWORD dwDivisor = (DWORD)uc;
- // ASSERT(p[1].HighPart == 0 && p[1].LowPart < dwDivisor);
- uliDividend.HighPart = p[1].LowPart;
- uliDividend.LowPart = p[0].HighPart;
- #ifndef USE_LARGEINT
- uliResult.HighPart = (DWORD)(uliDividend.QuadPart / dwDivisor);
- p[0].HighPart = (DWORD)(uliDividend.QuadPart % dwDivisor);
- uliResult.LowPart = 0;
- uliResult.QuadPart = p[0].QuadPart / dwDivisor + uliResult.QuadPart;
- #else
- /* NOTE - this routine will take exceptions if
- the result does not fit in a DWORD
- */
- if (uliDividend.QuadPart >= (DWORDLONG)dwDivisor) {
- uliResult.HighPart = EnlargedUnsignedDivide(
- uliDividend,
- dwDivisor,
- &p[0].HighPart);
- } else {
- uliResult.HighPart = 0;
- }
- uliResult.LowPart = EnlargedUnsignedDivide(
- p[0],
- dwDivisor,
- NULL);
- #endif
- return bSign ? -(LONGLONG)uliResult.QuadPart :
- (LONGLONG)uliResult.QuadPart;
- }
-
-
- ullResult = 0;
-
- /* OK - do long division */
- for (int i = 0; i < 64; i++) {
- ullResult <<= 1;
-
- /* Shift 128 bit p left 1 */
- p[1].QuadPart <<= 1;
- if ((p[0].HighPart & 0x80000000) != 0) {
- p[1].LowPart++;
- }
- p[0].QuadPart <<= 1;
-
- /* Compare */
- if (uc <= p[1].QuadPart) {
- p[1].QuadPart -= uc;
- ullResult += 1;
- }
- }
-
- return bSign ? - (LONGLONG)ullResult : (LONGLONG)ullResult;
- }
-
-
- LONGLONG Int64x32Div32(LONGLONG a, LONG b, LONG c, LONG d)
- {
- ULARGE_INTEGER ua;
- DWORD ub;
- DWORD uc;
-
- /* Compute the absolute values to avoid signed arithmetic problems */
- ua.QuadPart = (DWORDLONG)(a >= 0 ? a : -a);
- ub = (DWORD)(b >= 0 ? b : -b);
- uc = (DWORD)(c >= 0 ? c : -c);
- BOOL bSign = (a < 0) ^ (b < 0);
-
- /* Do long multiplication */
- ULARGE_INTEGER p0;
- DWORD p1;
- p0.QuadPart = UInt32x32To64(ua.LowPart, ub);
-
- if (ua.HighPart != 0) {
- ULARGE_INTEGER x;
- x.QuadPart = UInt32x32To64(ua.HighPart, ub) + p0.HighPart;
- p0.HighPart = x.LowPart;
- p1 = x.HighPart;
- } else {
- p1 = 0;
- }
-
- if (d != 0) {
- ULARGE_INTEGER ud0;
- DWORD ud1;
-
- if (bSign) {
- //
- // Cast d to LONGLONG first otherwise -0x80000000 sign extends
- // incorrectly
- //
- ud0.QuadPart = (DWORDLONG)(-(LONGLONG)d);
- if (d > 0) {
- /* -d < 0 */
- ud1 = (DWORD)-1;
- } else {
- ud1 = (DWORD)0;
- }
- } else {
- ud0.QuadPart = (DWORDLONG)d;
- if (d < 0) {
- ud1 = (DWORD)-1;
- } else {
- ud1 = (DWORD)0;
- }
- }
- /* Now do extended addition */
- ULARGE_INTEGER uliTotal;
-
- /* Add ls DWORDs */
- uliTotal.QuadPart = (DWORDLONG)ud0.LowPart + p0.LowPart;
- p0.LowPart = uliTotal.LowPart;
-
- /* Propagate carry */
- uliTotal.LowPart = uliTotal.HighPart;
- uliTotal.HighPart = 0;
-
- /* Add 2nd most ls DWORDs */
- uliTotal.QuadPart += (DWORDLONG)ud0.HighPart + p0.HighPart;
- p0.HighPart = uliTotal.LowPart;
-
- /* Add MS DWORDLONGs - no carry expected */
- p1 += ud1 + uliTotal.HighPart;
-
- /* Now see if we got a sign change from the addition */
- if ((LONG)p1 < 0) {
- bSign = !bSign;
-
- /* Negate the current value (ugh!) */
- p0.QuadPart = ~p0.QuadPart;
- p1 = ~p1;
- p0.QuadPart += 1;
- p1 += (p0.QuadPart == 0);
- }
- }
-
- /* Now for the division */
- if (c < 0) {
- bSign = !bSign;
- }
-
-
- /* This will catch c == 0 and overflow */
- if (uc <= p1) {
- return bSign ? (LONGLONG)0x8000000000000000 :
- (LONGLONG)0x7FFFFFFFFFFFFFFF;
- }
-
- /* Do the division */
-
- /* If the divisor is a DWORD then its simpler */
- ULARGE_INTEGER uliDividend;
- ULARGE_INTEGER uliResult;
- DWORD dwDivisor = uc;
- uliDividend.HighPart = p1;
- uliDividend.LowPart = p0.HighPart;
- /* NOTE - this routine will take exceptions if
- the result does not fit in a DWORD
- */
- if (uliDividend.QuadPart >= (DWORDLONG)dwDivisor) {
- uliResult.HighPart = EnlargedUnsignedDivide(
- uliDividend,
- dwDivisor,
- &p0.HighPart);
- } else {
- uliResult.HighPart = 0;
- }
- uliResult.LowPart = EnlargedUnsignedDivide(
- p0,
- dwDivisor,
- NULL);
- return bSign ? -(LONGLONG)uliResult.QuadPart :
- (LONGLONG)uliResult.QuadPart;
- }
-
- #ifdef DEBUG
- /******************************Public*Routine******************************\
- * Debug CCritSec helpers
- *
- * We provide debug versions of the Constructor, destructor, Lock and Unlock
- * routines. The debug code tracks who owns each critical section by
- * maintaining a depth count.
- *
- * History:
- *
- \**************************************************************************/
-
- CCritSec::CCritSec()
- {
- InitializeCriticalSection(&m_CritSec);
- m_currentOwner = m_lockCount = 0;
- m_fTrace = FALSE;
- }
-
- CCritSec::~CCritSec()
- {
- DeleteCriticalSection(&m_CritSec);
- }
-
- void CCritSec::Lock()
- {
- UINT tracelevel=3;
- DWORD us = GetCurrentThreadId();
- DWORD currentOwner = m_currentOwner;
- if (currentOwner && (currentOwner != us)) {
- // already owned, but not by us
- if (m_fTrace) {
- DbgLog((LOG_LOCKING, 2, "Thread %d about to wait for lock %x owned by %d",
- GetCurrentThreadId(), &m_CritSec, currentOwner));
- tracelevel=2;
- // if we saw the message about waiting for the critical
- // section we ensure we see the message when we get the
- // critical section
- }
- }
- EnterCriticalSection(&m_CritSec);
- if (0 == m_lockCount++) {
- // we now own it for the first time. Set owner information
- m_currentOwner = us;
- //ASSERT(((PRTL_CRITICAL_SECTION)&m_CritSec)->OwningThread == (HANDLE)m_currentOwner);
- // only valid on NT
- if (m_fTrace) {
- DbgLog((LOG_LOCKING, tracelevel, "Thread %d now owns lock %x", m_currentOwner, &m_CritSec));
- }
- }
- }
-
- void CCritSec::Unlock() {
- if (0 == --m_lockCount) {
- // about to be unowned
- if (m_fTrace) {
- DbgLog((LOG_LOCKING, 3, "Thread %d releasing lock %x", m_currentOwner, &m_CritSec));
- //ASSERT(((PRTL_CRITICAL_SECTION)&m_CritSec)->OwningThread == (HANDLE)m_currentOwner);
- // only valid on NT
- }
- m_currentOwner = 0;
- }
- LeaveCriticalSection(&m_CritSec);
- }
-
- void DbgLockTrace(CCritSec * pcCrit, BOOL fTrace)
- {
- pcCrit->m_fTrace = fTrace;
- }
-
- BOOL CritCheckIn(CCritSec * pcCrit)
- {
- return (GetCurrentThreadId() == pcCrit->m_currentOwner);
- }
-
- BOOL CritCheckOut(CCritSec * pcCrit)
- {
- return (GetCurrentThreadId() != pcCrit->m_currentOwner);
- }
- #endif
-
-
- // Avoids us dyna-linking to SysAllocString to copy BSTR strings
-
- HRESULT WriteBSTR(BSTR *pstrDest, LPCWSTR szSrc)
- {
- // count length + terminating null
- int cch = lstrlenW(szSrc) + 1;
-
- // a BSTR is a DWORD length, then a null-terminated UNICODE string.
- // the pointer points *after* the length at the string
- // the length is in bytes, not including the null.
-
- DWORD* pLen = (DWORD*)CoTaskMemAlloc( sizeof(DWORD) + (cch * sizeof(OLECHAR)));
- if (pLen == NULL) {
- return E_OUTOFMEMORY;
- }
- // length (bytes, not chars) does not include terminating null.
- *pLen = (DWORD) (cch-1) * sizeof(OLECHAR);
-
- // BSTR pointer points after the initial DWORD length
- OLECHAR * str = (OLECHAR*) (pLen + 1);
-
- CopyMemory(str, szSrc, cch*sizeof(OLECHAR));
- *pstrDest = str;
-
- return S_OK;
- }
-
-
- // Free an OLE BSTR through the task allocator
-
- HRESULT FreeBSTR(BSTR* pstr)
- {
- if (*pstr != NULL) {
- // get pointer to string
- DWORD* p = (DWORD*) (*pstr);
-
- // back up to point at DWORD length
- p--;
-
- // set pointer to null
- *pstr = NULL;
-
- // and free this
- CoTaskMemFree(p);
-
- return S_OK;
- } else {
- return S_FALSE;
- }
- }
-
-
-
-
-