/**

 * WinPR: Windows Portable Runtime

 * Message Queue

 *

 * Copyright 2012 Marc-Andre Moreau <marcandre.moreau@gmail.com>

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include <winpr/crt.h>

#include <winpr/sysinfo.h>

#include <winpr/collections.h>

/**

 * Message Queue inspired from Windows:

 * http://msdn.microsoft.com/en-us/library/ms632590/

 */

/**

 * Properties

 */

/**

 * Gets an event which is set when the queue is non-empty

 */

HANDLE MessageQueue_Event(wMessageQueue* queue)

{

	return queue->event;

}

/**

 * Gets the queue size

 */

int MessageQueue_Size(wMessageQueue* queue)

{

	return queue->size;

}

/**

 * Methods

 */

BOOL MessageQueue_Wait(wMessageQueue* queue)

{

	BOOL status = FALSE;

	if (WaitForSingleObject(queue->event, INFINITE) == WAIT_OBJECT_0)

		status = TRUE;

	return status;

}

BOOL MessageQueue_Dispatch(wMessageQueue* queue, wMessage* message)

{

	BOOL ret = FALSE;

	if (!queue || !message)

		return FALSE;

	EnterCriticalSection(&queue->lock);

	if (queue->size == queue->capacity)

	{

		int old_capacity;

		int new_capacity;

		wMessage* new_arr;

		old_capacity = queue->capacity;

		new_capacity = queue->capacity * 2;

		new_arr = (wMessage*)realloc(queue->array, sizeof(wMessage) * new_capacity);

		if (!new_arr)

			goto out;

		queue->array = new_arr;

		queue->capacity = new_capacity;

		ZeroMemory(&(queue->array[old_capacity]), (new_capacity - old_capacity) * sizeof(wMessage));

		/* rearrange wrapped entries */

		if (queue->tail <= queue->head)

		{

			CopyMemory(&(queue->array[old_capacity]), queue->array, queue->tail * sizeof(wMessage));

			queue->tail += old_capacity;

		}

	}

	CopyMemory(&(queue->array[queue->tail]), message, sizeof(wMessage));

	message = &(queue->array[queue->tail]);

	message->time = GetTickCount64();

	queue->tail = (queue->tail + 1) % queue->capacity;

	queue->size++;

	if (queue->size > 0)

		SetEvent(queue->event);

	ret = TRUE;

out:

	LeaveCriticalSection(&queue->lock);

	return ret;

}

BOOL MessageQueue_Post(wMessageQueue* queue, void* context, UINT32 type, void* wParam, void* lParam)

{

	wMessage message;

	message.context = context;

	message.id = type;

	message.wParam = wParam;

	message.lParam = lParam;

	message.Free = NULL;

	return MessageQueue_Dispatch(queue, &message);

}

BOOL MessageQueue_PostQuit(wMessageQueue* queue, int nExitCode)

{

	return MessageQueue_Post(queue, NULL, WMQ_QUIT, (void*)(size_t)nExitCode, NULL);

}

int MessageQueue_Get(wMessageQueue* queue, wMessage* message)

{

	int status = -1;

	if (!MessageQueue_Wait(queue))

		return status;

	EnterCriticalSection(&queue->lock);

	if (queue->size > 0)

	{

		CopyMemory(message, &(queue->array[queue->head]), sizeof(wMessage));

		ZeroMemory(&(queue->array[queue->head]), sizeof(wMessage));

		queue->head = (queue->head + 1) % queue->capacity;

		queue->size--;

		if (queue->size < 1)

			ResetEvent(queue->event);

		status = (message->id != WMQ_QUIT) ? 1 : 0;

	}

	LeaveCriticalSection(&queue->lock);

	return status;

}

int MessageQueue_Peek(wMessageQueue* queue, wMessage* message, BOOL remove)

{

	int status = 0;

	EnterCriticalSection(&queue->lock);

	if (queue->size > 0)

	{

		CopyMemory(message, &(queue->array[queue->head]), sizeof(wMessage));

		status = 1;

		if (remove)

		{

			ZeroMemory(&(queue->array[queue->head]), sizeof(wMessage));

			queue->head = (queue->head + 1) % queue->capacity;

			queue->size--;

			if (queue->size < 1)

				ResetEvent(queue->event);

		}

	}

	LeaveCriticalSection(&queue->lock);

	return status;

}

/**

 * Construction, Destruction

 */

wMessageQueue* MessageQueue_New(const wObject* callback)

{

	wMessageQueue* queue = NULL;

	queue = (wMessageQueue*)calloc(1, sizeof(wMessageQueue));

	if (!queue)

		return NULL;

	queue->capacity = 32;

	queue->array = (wMessage*)calloc(queue->capacity, sizeof(wMessage));

	if (!queue->array)

		goto error_array;

	if (!InitializeCriticalSectionAndSpinCount(&queue->lock, 4000))

		goto error_spinlock;

	queue->event = CreateEvent(NULL, TRUE, FALSE, NULL);

	if (!queue->event)

		goto error_event;

	if (callback)

		queue->object = *callback;

	return queue;

error_event:

	DeleteCriticalSection(&queue->lock);

error_spinlock:

	free(queue->array);

error_array:

	free(queue);

	return NULL;

}

void MessageQueue_Free(wMessageQueue* queue)

{

	if (!queue)

		return;

	MessageQueue_Clear(queue);

	CloseHandle(queue->event);

	DeleteCriticalSection(&queue->lock);

	free(queue->array);

	free(queue);

}

int MessageQueue_Clear(wMessageQueue* queue)

{

	int status = 0;

	EnterCriticalSection(&queue->lock);

	while (queue->size > 0)

	{

		wMessage* msg = &(queue->array[queue->head]);

		/* Free resources of message. */

		if (queue->object.fnObjectUninit)

			queue->object.fnObjectUninit(msg);

		if (queue->object.fnObjectFree)

			queue->object.fnObjectFree(msg);

		ZeroMemory(msg, sizeof(wMessage));

		queue->head = (queue->head + 1) % queue->capacity;

		queue->size--;

	}

	ResetEvent(queue->event);

	LeaveCriticalSection(&queue->lock);

	return status;

}