darling-libdispatch/dispatch/data.h
2020-06-04 11:50:31 -04:00

279 lines
11 KiB
C

/*
* Copyright (c) 2009-2013 Apple Inc. All rights reserved.
*
* @APPLE_APACHE_LICENSE_HEADER_START@
*
* 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.
*
* @APPLE_APACHE_LICENSE_HEADER_END@
*/
#ifndef __DISPATCH_DATA__
#define __DISPATCH_DATA__
#ifndef __DISPATCH_INDIRECT__
#error "Please #include <dispatch/dispatch.h> instead of this file directly."
#include <dispatch/base.h> // for HeaderDoc
#endif
DISPATCH_ASSUME_NONNULL_BEGIN
__BEGIN_DECLS
/*! @header
* Dispatch data objects describe contiguous or sparse regions of memory that
* may be managed by the system or by the application.
* Dispatch data objects are immutable, any direct access to memory regions
* represented by dispatch objects must not modify that memory.
*/
/*!
* @typedef dispatch_data_t
* A dispatch object representing memory regions.
*/
DISPATCH_DATA_DECL(dispatch_data);
/*!
* @var dispatch_data_empty
* @discussion The singleton dispatch data object representing a zero-length
* memory region.
*/
#define dispatch_data_empty \
DISPATCH_GLOBAL_OBJECT(dispatch_data_t, _dispatch_data_empty)
API_AVAILABLE(macos(10.7), ios(5.0))
DISPATCH_EXPORT struct dispatch_data_s _dispatch_data_empty;
/*!
* @const DISPATCH_DATA_DESTRUCTOR_DEFAULT
* @discussion The default destructor for dispatch data objects.
* Used at data object creation to indicate that the supplied buffer should
* be copied into internal storage managed by the system.
*/
#define DISPATCH_DATA_DESTRUCTOR_DEFAULT NULL
#ifdef __BLOCKS__
/*! @parseOnly */
#define DISPATCH_DATA_DESTRUCTOR_TYPE_DECL(name) \
DISPATCH_EXPORT const dispatch_block_t _dispatch_data_destructor_##name
#else
#define DISPATCH_DATA_DESTRUCTOR_TYPE_DECL(name) \
DISPATCH_EXPORT const dispatch_function_t \
_dispatch_data_destructor_##name
#endif /* __BLOCKS__ */
/*!
* @const DISPATCH_DATA_DESTRUCTOR_FREE
* @discussion The destructor for dispatch data objects created from a malloc'd
* buffer. Used at data object creation to indicate that the supplied buffer
* was allocated by the malloc() family and should be destroyed with free(3).
*/
#define DISPATCH_DATA_DESTRUCTOR_FREE (_dispatch_data_destructor_free)
API_AVAILABLE(macos(10.7), ios(5.0))
DISPATCH_DATA_DESTRUCTOR_TYPE_DECL(free);
/*!
* @const DISPATCH_DATA_DESTRUCTOR_MUNMAP
* @discussion The destructor for dispatch data objects that have been created
* from buffers that require deallocation with munmap(2).
*/
#define DISPATCH_DATA_DESTRUCTOR_MUNMAP (_dispatch_data_destructor_munmap)
API_AVAILABLE(macos(10.9), ios(7.0))
DISPATCH_DATA_DESTRUCTOR_TYPE_DECL(munmap);
#ifdef __BLOCKS__
/*!
* @function dispatch_data_create
* Creates a dispatch data object from the given contiguous buffer of memory. If
* a non-default destructor is provided, ownership of the buffer remains with
* the caller (i.e. the bytes will not be copied). The last release of the data
* object will result in the invocation of the specified destructor on the
* specified queue to free the buffer.
*
* If the DISPATCH_DATA_DESTRUCTOR_FREE destructor is provided the buffer will
* be freed via free(3) and the queue argument ignored.
*
* If the DISPATCH_DATA_DESTRUCTOR_DEFAULT destructor is provided, data object
* creation will copy the buffer into internal memory managed by the system.
*
* @param buffer A contiguous buffer of data.
* @param size The size of the contiguous buffer of data.
* @param queue The queue to which the destructor should be submitted.
* @param destructor The destructor responsible for freeing the data when it
* is no longer needed.
* @result A newly created dispatch data object.
*/
API_AVAILABLE(macos(10.7), ios(5.0))
DISPATCH_EXPORT DISPATCH_RETURNS_RETAINED DISPATCH_WARN_RESULT DISPATCH_NOTHROW
dispatch_data_t
dispatch_data_create(const void *buffer,
size_t size,
dispatch_queue_t _Nullable queue,
dispatch_block_t _Nullable destructor);
#endif /* __BLOCKS__ */
/*!
* @function dispatch_data_get_size
* Returns the logical size of the memory region(s) represented by the specified
* dispatch data object.
*
* @param data The dispatch data object to query.
* @result The number of bytes represented by the data object.
*/
API_AVAILABLE(macos(10.7), ios(5.0))
DISPATCH_EXPORT DISPATCH_PURE DISPATCH_NONNULL1 DISPATCH_NOTHROW
size_t
dispatch_data_get_size(dispatch_data_t data);
/*!
* @function dispatch_data_create_map
* Maps the memory represented by the specified dispatch data object as a single
* contiguous memory region and returns a new data object representing it.
* If non-NULL references to a pointer and a size variable are provided, they
* are filled with the location and extent of that region. These allow direct
* read access to the represented memory, but are only valid until the returned
* object is released. Under ARC, if that object is held in a variable with
* automatic storage, care needs to be taken to ensure that it is not released
* by the compiler before memory access via the pointer has been completed.
*
* @param data The dispatch data object to map.
* @param buffer_ptr A pointer to a pointer variable to be filled with the
* location of the mapped contiguous memory region, or
* NULL.
* @param size_ptr A pointer to a size_t variable to be filled with the
* size of the mapped contiguous memory region, or NULL.
* @result A newly created dispatch data object.
*/
API_AVAILABLE(macos(10.7), ios(5.0))
DISPATCH_EXPORT DISPATCH_NONNULL1 DISPATCH_RETURNS_RETAINED
DISPATCH_WARN_RESULT DISPATCH_NOTHROW
dispatch_data_t
dispatch_data_create_map(dispatch_data_t data,
const void *_Nullable *_Nullable buffer_ptr,
size_t *_Nullable size_ptr);
/*!
* @function dispatch_data_create_concat
* Returns a new dispatch data object representing the concatenation of the
* specified data objects. Those objects may be released by the application
* after the call returns (however, the system might not deallocate the memory
* region(s) described by them until the newly created object has also been
* released).
*
* @param data1 The data object representing the region(s) of memory to place
* at the beginning of the newly created object.
* @param data2 The data object representing the region(s) of memory to place
* at the end of the newly created object.
* @result A newly created object representing the concatenation of the
* data1 and data2 objects.
*/
API_AVAILABLE(macos(10.7), ios(5.0))
DISPATCH_EXPORT DISPATCH_NONNULL_ALL DISPATCH_RETURNS_RETAINED
DISPATCH_WARN_RESULT DISPATCH_NOTHROW
dispatch_data_t
dispatch_data_create_concat(dispatch_data_t data1, dispatch_data_t data2);
/*!
* @function dispatch_data_create_subrange
* Returns a new dispatch data object representing a subrange of the specified
* data object, which may be released by the application after the call returns
* (however, the system might not deallocate the memory region(s) described by
* that object until the newly created object has also been released).
*
* @param data The data object representing the region(s) of memory to
* create a subrange of.
* @param offset The offset into the data object where the subrange
* starts.
* @param length The length of the range.
* @result A newly created object representing the specified
* subrange of the data object.
*/
API_AVAILABLE(macos(10.7), ios(5.0))
DISPATCH_EXPORT DISPATCH_NONNULL1 DISPATCH_RETURNS_RETAINED
DISPATCH_WARN_RESULT DISPATCH_NOTHROW
dispatch_data_t
dispatch_data_create_subrange(dispatch_data_t data,
size_t offset,
size_t length);
#ifdef __BLOCKS__
/*!
* @typedef dispatch_data_applier_t
* A block to be invoked for every contiguous memory region in a data object.
*
* @param region A data object representing the current region.
* @param offset The logical offset of the current region to the start
* of the data object.
* @param buffer The location of the memory for the current region.
* @param size The size of the memory for the current region.
* @result A Boolean indicating whether traversal should continue.
*/
typedef bool (^dispatch_data_applier_t)(dispatch_data_t region,
size_t offset,
const void *buffer,
size_t size);
/*!
* @function dispatch_data_apply
* Traverse the memory regions represented by the specified dispatch data object
* in logical order and invoke the specified block once for every contiguous
* memory region encountered.
*
* Each invocation of the block is passed a data object representing the current
* region and its logical offset, along with the memory location and extent of
* the region. These allow direct read access to the memory region, but are only
* valid until the passed-in region object is released. Note that the region
* object is released by the system when the block returns, it is the
* responsibility of the application to retain it if the region object or the
* associated memory location are needed after the block returns.
*
* @param data The data object to traverse.
* @param applier The block to be invoked for every contiguous memory
* region in the data object.
* @result A Boolean indicating whether traversal completed
* successfully.
*/
API_AVAILABLE(macos(10.7), ios(5.0))
DISPATCH_EXPORT DISPATCH_NONNULL_ALL DISPATCH_NOTHROW
bool
dispatch_data_apply(dispatch_data_t data,
DISPATCH_NOESCAPE dispatch_data_applier_t applier);
#endif /* __BLOCKS__ */
/*!
* @function dispatch_data_copy_region
* Finds the contiguous memory region containing the specified location among
* the regions represented by the specified object and returns a copy of the
* internal dispatch data object representing that region along with its logical
* offset in the specified object.
*
* @param data The dispatch data object to query.
* @param location The logical position in the data object to query.
* @param offset_ptr A pointer to a size_t variable to be filled with the
* logical offset of the returned region object to the
* start of the queried data object.
* @result A newly created dispatch data object.
*/
API_AVAILABLE(macos(10.7), ios(5.0))
DISPATCH_EXPORT DISPATCH_NONNULL1 DISPATCH_NONNULL3 DISPATCH_RETURNS_RETAINED
DISPATCH_WARN_RESULT DISPATCH_NOTHROW
dispatch_data_t
dispatch_data_copy_region(dispatch_data_t data,
size_t location,
size_t *offset_ptr);
__END_DECLS
DISPATCH_ASSUME_NONNULL_END
#endif /* __DISPATCH_DATA__ */