mirror of https://github.com/acidanthera/audk.git
207 lines
8.5 KiB
C
207 lines
8.5 KiB
C
/** @file
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Class for arbitrary sized FIFO queues.
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Copyright (c) 2012, Intel Corporation. All rights reserved.<BR>
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This program and the accompanying materials are licensed and made available
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under the terms and conditions of the BSD License which accompanies this
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distribution. The full text of the license may be found at
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http://opensource.org/licenses/bsd-license.php.
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THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
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WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
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**/
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#ifndef _FIFO_CLASS_H
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#define _FIFO_CLASS_H
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#include <Uefi.h>
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#include <wchar.h>
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#include <Containers/ModuloUtil.h>
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#include <sys/types.h>
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__BEGIN_DECLS
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typedef struct _FIFO_CLASS cFIFO;
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/// Constants to select what is counted by the FIFO_NumInQueue function.
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typedef enum {
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AsElements, ///< Count the number of readable elements in the queue.
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AsBytes ///< Count the number of readable bytes in the queue.
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} FIFO_ElemBytes;
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/** Construct a new instance of a FIFO Queue.
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@param[in] NumElements Number of elements to be contained in the new FIFO.
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@param[in] ElementSize Size, in bytes, of an element
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@retval NULL Unable to create the instance.
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@retval NonNULL Pointer to the new FIFO instance.
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**/
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cFIFO * EFIAPI New_cFIFO(UINT32 NumElements, size_t ElementSize);
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/** Add one or more elements to the FIFO.
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This function allows one to add one or more elements, as specified by Count,
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to the FIFO. Each element is of the size specified when the FIFO object
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was instantiated (FIFO.ElementSize).
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pElement points to the first byte of the first element to be added.
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If multiple elements are to be added, the elements are expected to be
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organized as a packed array.
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@param[in] Self Pointer to the FIFO instance.
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@param[in] pElement Pointer to the element(s) to enqueue (add).
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@param[in] Count Number of elements to add.
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@retval 0 The FIFO is full.
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@retval >=0 The number of elements added to the FIFO.
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**/
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typedef size_t (EFIAPI *cFIFO_Enqueue) (cFIFO *Self, const void *ElementPointer, size_t Count);
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/** Read or copy elements from the FIFO.
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This function allows one to read one or more elements, as specified by Count,
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from the FIFO. Each element is of the size specified when the FIFO object
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was instantiated (FIFO.ElementSize).
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pElement points to the destination of the first byte of the first element
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to be read. If multiple elements are to be read, the elements are expected
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to be organized as a packed array.
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@param[in] Self Pointer to the FIFO instance.
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@param[out] pElement Pointer to where to store the element(s) read from the FIFO.
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@param[in] Count Number of elements to dequeue.
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@param[in] Consume If TRUE, consume read elements. Otherwise, preserve.
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@retval 0 The FIFO is empty.
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@retval >=0 The number of elements read from the FIFO.
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**/
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typedef size_t (EFIAPI *cFIFO_Dequeue) (cFIFO *Self, void *ElementPointer, size_t Count);
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/** Make a copy of the FIFO's data.
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The contents of the FIFO is copied out and linearized without affecting the
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FIFO contents.
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@param[in] Self Pointer to the FIFO instance.
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@param[out] ElementPointer Pointer to where to store the elements copied from the FIFO.
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@param[in] Count Number of elements to copy.
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@retval 0 The FIFO is empty.
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@retval >=0 The number of elements copied from the FIFO.
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**/
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typedef size_t (EFIAPI *cFIFO_Copy) (cFIFO *Self, void *ElementPointer, size_t Count);
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/** Test whether the FIFO is empty.
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@param[in] Self Pointer to the FIFO instance.
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@retval TRUE The FIFO is empty.
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@retval FALSE The FIFO is NOT empty.
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**/
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typedef BOOLEAN (EFIAPI *cFIFO_IsEmpty) (cFIFO *Self);
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/** Test whether the FIFO is full.
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@param[in] Self Pointer to the FIFO instance.
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@retval TRUE The FIFO is full.
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@retval FALSE The FIFO is NOT full.
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**/
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typedef BOOLEAN (EFIAPI *cFIFO_IsFull) (cFIFO *Self);
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/** Determine number of items available to read from the FIFO.
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The number of items are either the number of bytes, or the number of elements
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depending upon the value of the As enumerator.
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@param[in] Self Pointer to the FIFO instance.
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@param[in] As An enumeration variable whose value determines whether the
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returned value is the number of bytes or the number of elements
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currently contained by the FIFO.
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@retval 0 The FIFO is empty.
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@retval >=0 The number of items contained in the FIFO.
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**/
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typedef size_t (EFIAPI *cFIFO_NumInQueue) (cFIFO *Self, FIFO_ElemBytes As);
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/** Determine amount of free space in the FIFO that can be written into.
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The number of items are either the number of bytes, or the number of elements
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depending upon the value of the As enumerator.
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@param[in] Self Pointer to the FIFO instance.
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@param[in] As An enumeration variable whose value determines whether the
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returned value is the number of bytes or the number of elements
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currently available in the FIFO.
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@retval 0 The FIFO is full.
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@retval >=0 The number of items which can be accepted by the FIFO.
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**/
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typedef size_t (EFIAPI *cFIFO_FreeSpace) (cFIFO *Self, FIFO_ElemBytes As);
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/** Empty the FIFO, discarding up to NumToFlush elements.
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@param[in] Self Pointer to the FIFO instance.
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@param[in] NumToFlush Number of elements to flush from the FIFO.
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If larger than the number of elements in the
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FIFO, the FIFO is emptied.
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@return Returns the number of elements remaining in the FIFO after the flush.
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**/
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typedef size_t (EFIAPI *cFIFO_Flush) (cFIFO *Self, size_t NumToFlush);
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/** Remove the most recent element from the FIFO.
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@param[in] Self Pointer to the FIFO instance.
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**/
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typedef void (EFIAPI *cFIFO_Truncate) (cFIFO *Self);
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/** Cleanly delete a FIFO instance.
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@param[in] Self Pointer to the FIFO instance.
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**/
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typedef void (EFIAPI *cFIFO_Delete) (cFIFO *Self);
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/** Get the FIFO's current Read Index.
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@param[in] Self Pointer to the FIFO instance.
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@return The current value of the FIFO's ReadIndex member is returned.
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**/
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typedef UINT32 (EFIAPI *cFIFO_GetRDex) (cFIFO *Self);
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/** Get the FIFO's current Write Index.
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@param[in] Self Pointer to the FIFO instance.
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@return The current value of the FIFO's WriteIndex member is returned.
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**/
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typedef UINT32 (EFIAPI *cFIFO_GetWDex) (cFIFO *Self);
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/// Structure declaration for FIFO objects.
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struct _FIFO_CLASS {
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/* ######## Public Functions ######## */
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cFIFO_Enqueue Write; ///< Write an element into the FIFO.
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cFIFO_Dequeue Read; ///< Read an element from the FIFO.
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cFIFO_Copy Copy; ///< Non-destructive copy from FIFO.
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cFIFO_IsEmpty IsEmpty; ///< Test whether the FIFO is empty.
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cFIFO_IsFull IsFull; ///< Test whether the FIFO is full.
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cFIFO_NumInQueue Count; ///< Return the number of elements contained in the FIFO.
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cFIFO_FreeSpace FreeSpace; ///< Return the number of available elements in the FIFO.
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cFIFO_Flush Flush; ///< Remove the N earliest elements from the FIFO.
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cFIFO_Truncate Truncate; ///< Remove the most recent element from the FIFO.
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cFIFO_Delete Delete; ///< Delete the FIFO object.
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/* ######## Protected Functions ######## */
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cFIFO_GetRDex GetRDex; ///< Get a copy of the current Read Index.
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cFIFO_GetWDex GetWDex; ///< Get a copy of the current Write Index.
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/* ######## PRIVATE Data ######## */
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void *Queue; ///< The FIFO's data storage.
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UINT32 ElementSize; ///< Number of bytes in an element.
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UINT32 NumElements; ///< Number of elements the FIFO can store.
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UINT32 ReadIndex; ///< Index of next element to Read.
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UINT32 WriteIndex; ///< Index of where next element will be Written.
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};
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__END_DECLS
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#endif /* _FIFO_CLASS_H */
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