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/* Cairo - a vector graphics library with display and print output

 *

 * Copyright © 2009 Intel Corporation

 *

 * This library is free software; you can redistribute it and/or

 * modify it either under the terms of the GNU Lesser General Public

 * License version 2.1 as published by the Free Software Foundation

 * (the "LGPL") or, at your option, under the terms of the Mozilla

 * Public License Version 1.1 (the "MPL"). If you do not alter this

 * notice, a recipient may use your version of this file under either

 * the MPL or the LGPL.

 *

 * You should have received a copy of the LGPL along with this library

 * in the file COPYING-LGPL-2.1; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA

 * You should have received a copy of the MPL along with this library

 * in the file COPYING-MPL-1.1

 *

 * The contents of this file are subject to the Mozilla Public License

 * Version 1.1 (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.mozilla.org/MPL/

 *

 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY

 * OF ANY KIND, either express or implied. See the LGPL or the MPL for

 * the specific language governing rights and limitations.

 *

 * The Original Code is the cairo graphics library.

 *

 * The Initial Developer of the Original Code is Intel Corporation.

 *

 * Contributors(s):

 *	Chris Wilson 

 */

#include "cairoint.h"

#include "cairo-device-private.h"

#include "cairo-error-private.h"

/**

 * SECTION:cairo-device

 * @Title: cairo_device_t

 * @Short_Description: interface to underlying rendering system

 * @See_Also: #cairo_surface_t

 *

 * Devices are the abstraction Cairo employs for the rendering system

 * used by a #cairo_surface_t. You can get the device of a surface using

 * cairo_surface_get_device().

 *

 * Devices are created using custom functions specific to the rendering

 * system you want to use. See the documentation for the surface types

 * for those functions.

 *

 * An important function that devices fulfill is sharing access to the

 * rendering system between Cairo and your application. If you want to

 * access a device directly that you used to draw to with Cairo, you must

 * first call cairo_device_flush() to ensure that Cairo finishes all

 * operations on the device and resets it to a clean state.

 *

 * Cairo also provides the functions cairo_device_acquire() and

 * cairo_device_release() to synchronize access to the rendering system

 * in a multithreaded environment. This is done internally, but can also

 * be used by applications.

 *

 * Putting this all together, a function that works with devices should

 * look something like this:

 * 

 * void

 * my_device_modifying_function (cairo_device_t *device)

 * {

 *   cairo_status_t status;

 *

 *   // Ensure the device is properly reset

 *   cairo_device_flush (device);

 *   // Try to acquire the device

 *   status = cairo_device_acquire (device);

 *   if (status != CAIRO_STATUS_SUCCESS) {

 *     printf ("Failed to acquire the device: %s\n", cairo_status_to_string (status));

 *     return;

 *   }

 *

 *   // Do the custom operations on the device here.

 *   // But do not call any Cairo functions that might acquire devices.

 *

 *   // Release the device when done.

 *   cairo_device_release (device);

 * }

 * 

 *

 * Please refer to the documentation of each backend for

 * additional usage requirements, guarantees provided, and

 * interactions with existing surface API of the device functions for

 * surfaces of that type.

 * 

 **/

static const cairo_device_t _nil_device = {

    CAIRO_REFERENCE_COUNT_INVALID,

    CAIRO_STATUS_NO_MEMORY,

};

static const cairo_device_t _mismatch_device = {

    CAIRO_REFERENCE_COUNT_INVALID,

    CAIRO_STATUS_DEVICE_TYPE_MISMATCH,

};

static const cairo_device_t _invalid_device = {

    CAIRO_REFERENCE_COUNT_INVALID,

    CAIRO_STATUS_DEVICE_ERROR,

};

cairo_device_t *

_cairo_device_create_in_error (cairo_status_t status)

{

    switch (status) {

    case CAIRO_STATUS_NO_MEMORY:

	return (cairo_device_t *) &_nil_device;

    case CAIRO_STATUS_DEVICE_ERROR:

	return (cairo_device_t *) &_invalid_device;

    case CAIRO_STATUS_DEVICE_TYPE_MISMATCH:

	return (cairo_device_t *) &_mismatch_device;

    case CAIRO_STATUS_SUCCESS:

    case CAIRO_STATUS_LAST_STATUS:

	ASSERT_NOT_REACHED;

	/* fall-through */

    case CAIRO_STATUS_SURFACE_TYPE_MISMATCH:

    case CAIRO_STATUS_INVALID_STATUS:

    case CAIRO_STATUS_INVALID_FORMAT:

    case CAIRO_STATUS_INVALID_VISUAL:

    case CAIRO_STATUS_READ_ERROR:

    case CAIRO_STATUS_WRITE_ERROR:

    case CAIRO_STATUS_FILE_NOT_FOUND:

    case CAIRO_STATUS_TEMP_FILE_ERROR:

    case CAIRO_STATUS_INVALID_STRIDE:

    case CAIRO_STATUS_INVALID_SIZE:

    case CAIRO_STATUS_INVALID_RESTORE:

    case CAIRO_STATUS_INVALID_POP_GROUP:

    case CAIRO_STATUS_NO_CURRENT_POINT:

    case CAIRO_STATUS_INVALID_MATRIX:

    case CAIRO_STATUS_NULL_POINTER:

    case CAIRO_STATUS_INVALID_STRING:

    case CAIRO_STATUS_INVALID_PATH_DATA:

    case CAIRO_STATUS_SURFACE_FINISHED:

    case CAIRO_STATUS_PATTERN_TYPE_MISMATCH:

    case CAIRO_STATUS_INVALID_DASH:

    case CAIRO_STATUS_INVALID_DSC_COMMENT:

    case CAIRO_STATUS_INVALID_INDEX:

    case CAIRO_STATUS_CLIP_NOT_REPRESENTABLE:

    case CAIRO_STATUS_FONT_TYPE_MISMATCH:

    case CAIRO_STATUS_USER_FONT_IMMUTABLE:

    case CAIRO_STATUS_USER_FONT_ERROR:

    case CAIRO_STATUS_NEGATIVE_COUNT:

    case CAIRO_STATUS_INVALID_CLUSTERS:

    case CAIRO_STATUS_INVALID_SLANT:

    case CAIRO_STATUS_INVALID_WEIGHT:

    case CAIRO_STATUS_USER_FONT_NOT_IMPLEMENTED:

    case CAIRO_STATUS_INVALID_CONTENT:

    case CAIRO_STATUS_INVALID_MESH_CONSTRUCTION:

    case CAIRO_STATUS_DEVICE_FINISHED:

    default:

	_cairo_error_throw (CAIRO_STATUS_NO_MEMORY);

	return (cairo_device_t *) &_nil_device;

    }

}

void

_cairo_device_init (cairo_device_t *device,

		    const cairo_device_backend_t *backend)

{

    CAIRO_REFERENCE_COUNT_INIT (&device->ref_count, 1);

    device->status = CAIRO_STATUS_SUCCESS;

    device->backend = backend;

    CAIRO_RECURSIVE_MUTEX_INIT (device->mutex);

    device->mutex_depth = 0;

    device->finished = FALSE;

    _cairo_user_data_array_init (&device->user_data);

}

/**

 * cairo_device_reference:

 * @device: a #cairo_device_t

 *

 * Increases the reference count on @device by one. This prevents

 * @device from being destroyed until a matching call to

 * cairo_device_destroy() is made.

 *

 * The number of references to a #cairo_device_t can be get using

 * cairo_device_get_reference_count().

 *

 * Return value: the referenced #cairo_device_t.

 *

 * Since: 1.10

 **/

cairo_device_t *

cairo_device_reference (cairo_device_t *device)

{

    if (device == NULL ||

	CAIRO_REFERENCE_COUNT_IS_INVALID (&device->ref_count))

    {

	return device;

    }

    assert (CAIRO_REFERENCE_COUNT_HAS_REFERENCE (&device->ref_count));

    _cairo_reference_count_inc (&device->ref_count);

    return device;

}

slim_hidden_def (cairo_device_reference);

/**

 * cairo_device_status:

 * @device: a #cairo_device_t

 *

 * Checks whether an error has previously occurred for this

 * device.

 *

 * Return value: %CAIRO_STATUS_SUCCESS on success or an error code if

 *               the device is in an error state.

 *

 * Since: 1.10

 **/

cairo_status_t

cairo_device_status (cairo_device_t *device)

{

    if (device == NULL)

	return CAIRO_STATUS_NULL_POINTER;

    return device->status;

}

/**

 * cairo_device_flush:

 * @device: a #cairo_device_t

 *

 * Finish any pending operations for the device and also restore any

 * temporary modifications cairo has made to the device's state.

 * This function must be called before switching from using the

 * device with Cairo to operating on it directly with native APIs.

 * If the device doesn't support direct access, then this function

 * does nothing.

 *

 * This function may acquire devices.

 *

 * Since: 1.10

 **/

void

cairo_device_flush (cairo_device_t *device)

{

    cairo_status_t status;

    if (device == NULL || device->status)

	return;

    if (device->finished)

	return;

    if (device->backend->flush != NULL) {

	status = device->backend->flush (device);

	if (unlikely (status))

	    status = _cairo_device_set_error (device, status);

    }

}

slim_hidden_def (cairo_device_flush);

/**

 * cairo_device_finish:

 * @device: the #cairo_device_t to finish

 *

 * This function finishes the device and drops all references to

 * external resources. All surfaces, fonts and other objects created

 * for this @device will be finished, too.

 * Further operations on the @device will not affect the @device but

 * will instead trigger a %CAIRO_STATUS_DEVICE_FINISHED error.

 *

 * When the last call to cairo_device_destroy() decreases the

 * reference count to zero, cairo will call cairo_device_finish() if

 * it hasn't been called already, before freeing the resources

 * associated with the device.

 *

 * This function may acquire devices.

 *

 * Since: 1.10

 **/

void

cairo_device_finish (cairo_device_t *device)

{

    if (device == NULL ||

	CAIRO_REFERENCE_COUNT_IS_INVALID (&device->ref_count))

    {

	return;

    }

    if (device->finished)

	return;

    cairo_device_flush (device);

    if (device->backend->finish != NULL)

	device->backend->finish (device);

    /* We only finish the device after the backend's callback returns because

     * the device might still be needed during the callback

     * (e.g. for cairo_device_acquire ()).

     */

    device->finished = TRUE;

}

slim_hidden_def (cairo_device_finish);

/**

 * cairo_device_destroy:

 * @device: a #cairo_device_t

 *

 * Decreases the reference count on @device by one. If the result is

 * zero, then @device and all associated resources are freed.  See

 * cairo_device_reference().

 *

 * This function may acquire devices if the last reference was dropped.

 *

 * Since: 1.10

 **/

void

cairo_device_destroy (cairo_device_t *device)

{

    cairo_user_data_array_t user_data;

    if (device == NULL ||

	CAIRO_REFERENCE_COUNT_IS_INVALID (&device->ref_count))

    {

	return;

    }

    assert (CAIRO_REFERENCE_COUNT_HAS_REFERENCE (&device->ref_count));

    if (! _cairo_reference_count_dec_and_test (&device->ref_count))

	return;

    cairo_device_finish (device);

    assert (device->mutex_depth == 0);

    CAIRO_MUTEX_FINI (device->mutex);

    user_data = device->user_data;

    device->backend->destroy (device);

    _cairo_user_data_array_fini (&user_data);

}

slim_hidden_def (cairo_device_destroy);

/**

 * cairo_device_get_type:

 * @device: a #cairo_device_t

 *

 * This function returns the type of the device. See #cairo_device_type_t

 * for available types.

 *

 * Return value: The type of @device.

 *

 * Since: 1.10

 **/

cairo_device_type_t

cairo_device_get_type (cairo_device_t *device)

{

    if (device == NULL ||

	CAIRO_REFERENCE_COUNT_IS_INVALID (&device->ref_count))

    {

	return CAIRO_DEVICE_TYPE_INVALID;

    }

    return device->backend->type;

}

/**

 * cairo_device_acquire:

 * @device: a #cairo_device_t

 *

 * Acquires the @device for the current thread. This function will block

 * until no other thread has acquired the device.

 *

 * If the return value is %CAIRO_STATUS_SUCCESS, you successfully acquired the

 * device. From now on your thread owns the device and no other thread will be

 * able to acquire it until a matching call to cairo_device_release(). It is

 * allowed to recursively acquire the device multiple times from the same

 * thread.

 *

 * You must never acquire two different devices at the same time

 * unless this is explicitly allowed. Otherwise the possibility of deadlocks

 * exist.

 *

 * As various Cairo functions can acquire devices when called, these functions

 * may also cause deadlocks when you call them with an acquired device. So you

 * must not have a device acquired when calling them. These functions are

 * marked in the documentation.

 * 

 *

 * Return value: %CAIRO_STATUS_SUCCESS on success or an error code if

 *               the device is in an error state and could not be

 *               acquired. After a successful call to cairo_device_acquire(),

 *               a matching call to cairo_device_release() is required.

 *

 * Since: 1.10

 **/

cairo_status_t

cairo_device_acquire (cairo_device_t *device)

{

    if (device == NULL)

	return CAIRO_STATUS_SUCCESS;

    if (unlikely (device->status))

	return device->status;

    if (unlikely (device->finished))

	return _cairo_device_set_error (device, CAIRO_STATUS_DEVICE_FINISHED);

    CAIRO_MUTEX_LOCK (device->mutex);

    if (device->mutex_depth++ == 0) {

	if (device->backend->lock != NULL)

	    device->backend->lock (device);

    }

    return CAIRO_STATUS_SUCCESS;

}

slim_hidden_def (cairo_device_acquire);

/**

 * cairo_device_release:

 * @device: a #cairo_device_t

 *

 * Releases a @device previously acquired using cairo_device_acquire(). See

 * that function for details.

 *

 * Since: 1.10

 **/

void

cairo_device_release (cairo_device_t *device)

{

    if (device == NULL)

	return;

    assert (device->mutex_depth > 0);

    if (--device->mutex_depth == 0) {

	if (device->backend->unlock != NULL)

	    device->backend->unlock (device);

    }

    CAIRO_MUTEX_UNLOCK (device->mutex);

}

slim_hidden_def (cairo_device_release);

cairo_status_t

_cairo_device_set_error (cairo_device_t *device,

			 cairo_status_t  status)

{

    if (status == CAIRO_STATUS_SUCCESS)

        return CAIRO_STATUS_SUCCESS;

    _cairo_status_set_error (&device->status, status);

    return _cairo_error (status);

}

/**

 * cairo_device_get_reference_count:

 * @device: a #cairo_device_t

 *

 * Returns the current reference count of @device.

 *

 * Return value: the current reference count of @device.  If the

 * object is a nil object, 0 will be returned.

 *

 * Since: 1.10

 **/

unsigned int

cairo_device_get_reference_count (cairo_device_t *device)

{

    if (device == NULL ||

	CAIRO_REFERENCE_COUNT_IS_INVALID (&device->ref_count))

	return 0;

    return CAIRO_REFERENCE_COUNT_GET_VALUE (&device->ref_count);

}

/**

 * cairo_device_get_user_data:

 * @device: a #cairo_device_t

 * @key: the address of the #cairo_user_data_key_t the user data was

 * attached to

 *

 * Return user data previously attached to @device using the

 * specified key.  If no user data has been attached with the given

 * key this function returns %NULL.

 *

 * Return value: the user data previously attached or %NULL.

 *

 * Since: 1.10

 **/

void *

cairo_device_get_user_data (cairo_device_t		 *device,

			    const cairo_user_data_key_t *key)

{

    return _cairo_user_data_array_get_data (&device->user_data,

					    key);

}

/**

 * cairo_device_set_user_data:

 * @device: a #cairo_device_t

 * @key: the address of a #cairo_user_data_key_t to attach the user data to

 * @user_data: the user data to attach to the #cairo_device_t

 * @destroy: a #cairo_destroy_func_t which will be called when the

 * #cairo_t is destroyed or when new user data is attached using the

 * same key.

 *

 * Attach user data to @device.  To remove user data from a surface,

 * call this function with the key that was used to set it and %NULL

 * for @data.

 *

 * Return value: %CAIRO_STATUS_SUCCESS or %CAIRO_STATUS_NO_MEMORY if a

 * slot could not be allocated for the user data.

 *

 * Since: 1.10

 **/

cairo_status_t

cairo_device_set_user_data (cairo_device_t		 *device,

			    const cairo_user_data_key_t *key,

			    void			 *user_data,

			    cairo_destroy_func_t	  destroy)

{

    if (CAIRO_REFERENCE_COUNT_IS_INVALID (&device->ref_count))

	return device->status;

    return _cairo_user_data_array_set_data (&device->user_data,

					    key, user_data, destroy);

}