internal static string ComputeHash(string value)
{
if (s_useEncryption)
{
EnsureConfig();
HashAlgorithm algorithm = (HashAlgorithm)s_oHashAlgoStack.Pop();
if (null == algorithm)
{
algorithm = NewHashAlgorithm();
}
byte[] encrypted;
byte[] bytes = new byte[ADP.CharSize * value.Length];
GCHandle handle = GCHandle.Alloc(bytes, GCHandleType.Pinned);
try {
System.Text.Encoding.Unicode.GetBytes(value, 0, value.Length, bytes, 0);
encrypted = algorithm.ComputeHash(bytes);
}
finally {
Array.Clear(bytes, 0, bytes.Length);
if (handle.IsAllocated)
{
handle.Free();
}
}
s_oHashAlgoStack.Push(algorithm);
return(System.Text.Encoding.Unicode.GetString(encrypted, 0, encrypted.Length));
}
return(value);
}
private static ICryptoTransform GetCryptoTransform(bool fEncrypt)
{
InterlockedStack st = (fEncrypt ? s_oEncryptorStack : s_oDecryptorStack);
ICryptoTransform ct = (st.Pop() as ICryptoTransform);
if (null == ct)
{
ct = NewCryptTransform(fEncrypt);
}
return(ct);
}
private void CleanupCallback(Object state)
{
// Called when the cleanup-timer ticks over.
//
// This is the automatic prunning method. Every period, we will perform a two-step
// process. First, for the objects above MinPool, we will obtain the semaphore for
// the object and then destroy it if it was on the old stack. We will continue this
// until we either reach MinPool size, or we are unable to obtain a free object, or
// until we have exhausted all the objects on the old stack. After that, push all
// objects on the new stack to the old stack. So, every period the objects on the
// old stack are destroyed and the objects on the new stack are pushed to the old
// stack. All objects that are currently out and in use are not on either stack.
// With this logic, a object is prunned if unused for at least one period but not
// more than two periods.
// Destroy free objects above MinPool size from old stack.
#if USECOUNTEROBJECT
while (_poolCounter.TotalCount > _ctrl.MinPool)
#else //!USECOUNTEROBJECT
while (Count > _ctrl.MinPool)
#endif //!USECOUNTEROBJECT
{
// While above MinPoolSize...
if (_waitHandles[SEMAPHORE_HANDLE].WaitOne(0, false) /* != WAIT_TIMEOUT */)
{
// We obtained a objects from the semaphore.
DBPooledObject obj = (DBPooledObject)_stackOld.Pop();
if (null != obj)
{
// If we obtained one from the old stack, destroy it.
#if USECOUNTEROBJECT
_poolCounter.Modify(-cAddFree);
#endif //USECOUNTEROBJECT
DestroyObject(obj);
}
else
{
// Else we exhausted the old stack, so break.
SafeNativeMethods.ReleaseSemaphore(_waitHandles[SEMAPHORE_HANDLE].Handle, 1, IntPtr.Zero);
break;
}
}
else
{
break;
}
}
// Push to the old-stack. For each free object, move object from new stack
// to old stack.
if (_waitHandles[SEMAPHORE_HANDLE].WaitOne(0, false) /* != WAIT_TIMEOUT */)
{
for (;;)
{
DBPooledObject obj = (DBPooledObject)_stackNew.Pop();
if (null == obj)
{
break;
}
_stackOld.Push(obj);
}
SafeNativeMethods.ReleaseSemaphore(_waitHandles[SEMAPHORE_HANDLE].Handle, 1, IntPtr.Zero);
}
// Make sure we're at quota by posting a callback to the threadpool.
ThreadPool.QueueUserWorkItem(new WaitCallback(PoolCreateRequest));
}
