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Diffstat (limited to 'StdLib/Include/Containers/Fifo.h')
| -rw-r--r-- | StdLib/Include/Containers/Fifo.h | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/StdLib/Include/Containers/Fifo.h b/StdLib/Include/Containers/Fifo.h new file mode 100644 index 0000000000..3b232fec23 --- /dev/null +++ b/StdLib/Include/Containers/Fifo.h @@ -0,0 +1,206 @@ +/** @file
+ Class for arbitrary sized FIFO queues.
+
+ Copyright (c) 2012, Intel Corporation. All rights reserved.<BR>
+ This program and the accompanying materials are licensed and made available
+ under the terms and conditions of the BSD License which accompanies this
+ distribution. The full text of the license may be found at
+ http://opensource.org/licenses/bsd-license.php.
+
+ THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+**/
+#ifndef _FIFO_CLASS_H
+#define _FIFO_CLASS_H
+#include <Uefi.h>
+#include <wchar.h>
+#include <Containers/ModuloUtil.h>
+#include <sys/types.h>
+
+__BEGIN_DECLS
+
+typedef struct _FIFO_CLASS cFIFO;
+
+/// Constants to select what is counted by the FIFO_NumInQueue function.
+typedef enum {
+ AsElements, ///< Count the number of readable elements in the queue.
+ AsBytes ///< Count the number of readable bytes in the queue.
+} FIFO_ElemBytes;
+
+/** Construct a new instance of a FIFO Queue.
+
+ @param[in] NumElements Number of elements to be contained in the new FIFO.
+ @param[in] ElementSize Size, in bytes, of an element
+
+ @retval NULL Unable to create the instance.
+ @retval NonNULL Pointer to the new FIFO instance.
+**/
+cFIFO * EFIAPI New_cFIFO(UINT32 NumElements, size_t ElementSize);
+
+/** Add one or more elements to the FIFO.
+
+ This function allows one to add one or more elements, as specified by Count,
+ to the FIFO. Each element is of the size specified when the FIFO object
+ was instantiated (FIFO.ElementSize).
+
+ pElement points to the first byte of the first element to be added.
+ If multiple elements are to be added, the elements are expected to be
+ organized as a packed array.
+
+ @param[in] Self Pointer to the FIFO instance.
+ @param[in] pElement Pointer to the element(s) to enqueue (add).
+ @param[in] Count Number of elements to add.
+
+ @retval 0 The FIFO is full.
+ @retval >=0 The number of elements added to the FIFO.
+**/
+typedef size_t (EFIAPI *cFIFO_Enqueue) (cFIFO *Self, const void *ElementPointer, size_t Count);
+
+/** Read or copy elements from the FIFO.
+
+ This function allows one to read one or more elements, as specified by Count,
+ from the FIFO. Each element is of the size specified when the FIFO object
+ was instantiated (FIFO.ElementSize).
+
+ pElement points to the destination of the first byte of the first element
+ to be read. If multiple elements are to be read, the elements are expected
+ to be organized as a packed array.
+
+ @param[in] Self Pointer to the FIFO instance.
+ @param[out] pElement Pointer to where to store the element(s) read from the FIFO.
+ @param[in] Count Number of elements to dequeue.
+ @param[in] Consume If TRUE, consume read elements. Otherwise, preserve.
+
+ @retval 0 The FIFO is empty.
+ @retval >=0 The number of elements read from the FIFO.
+**/
+typedef size_t (EFIAPI *cFIFO_Dequeue) (cFIFO *Self, void *ElementPointer, size_t Count);
+
+/** Make a copy of the FIFO's data.
+ The contents of the FIFO is copied out and linearized without affecting the
+ FIFO contents.
+
+ @param[in] Self Pointer to the FIFO instance.
+ @param[out] ElementPointer Pointer to where to store the elements copied from the FIFO.
+ @param[in] Count Number of elements to copy.
+
+ @retval 0 The FIFO is empty.
+ @retval >=0 The number of elements copied from the FIFO.
+**/
+typedef size_t (EFIAPI *cFIFO_Copy) (cFIFO *Self, void *ElementPointer, size_t Count);
+
+/** Test whether the FIFO is empty.
+
+ @param[in] Self Pointer to the FIFO instance.
+
+ @retval TRUE The FIFO is empty.
+ @retval FALSE The FIFO is NOT empty.
+**/
+typedef BOOLEAN (EFIAPI *cFIFO_IsEmpty) (cFIFO *Self);
+
+/** Test whether the FIFO is full.
+
+ @param[in] Self Pointer to the FIFO instance.
+
+ @retval TRUE The FIFO is full.
+ @retval FALSE The FIFO is NOT full.
+**/
+typedef BOOLEAN (EFIAPI *cFIFO_IsFull) (cFIFO *Self);
+
+/** Determine number of items available to read from the FIFO.
+
+ The number of items are either the number of bytes, or the number of elements
+ depending upon the value of the As enumerator.
+
+ @param[in] Self Pointer to the FIFO instance.
+ @param[in] As An enumeration variable whose value determines whether the
+ returned value is the number of bytes or the number of elements
+ currently contained by the FIFO.
+
+ @retval 0 The FIFO is empty.
+ @retval >=0 The number of items contained in the FIFO.
+**/
+typedef size_t (EFIAPI *cFIFO_NumInQueue) (cFIFO *Self, FIFO_ElemBytes As);
+
+/** Determine amount of free space in the FIFO that can be written into.
+
+ The number of items are either the number of bytes, or the number of elements
+ depending upon the value of the As enumerator.
+
+ @param[in] Self Pointer to the FIFO instance.
+ @param[in] As An enumeration variable whose value determines whether the
+ returned value is the number of bytes or the number of elements
+ currently available in the FIFO.
+
+ @retval 0 The FIFO is full.
+ @retval >=0 The number of items which can be accepted by the FIFO.
+**/
+typedef size_t (EFIAPI *cFIFO_FreeSpace) (cFIFO *Self, FIFO_ElemBytes As);
+
+/** Empty the FIFO, discarding up to NumToFlush elements.
+
+ @param[in] Self Pointer to the FIFO instance.
+ @param[in] NumToFlush Number of elements to flush from the FIFO.
+ If larger than the number of elements in the
+ FIFO, the FIFO is emptied.
+
+ @return Returns the number of elements remaining in the FIFO after the flush.
+**/
+typedef size_t (EFIAPI *cFIFO_Flush) (cFIFO *Self, size_t NumToFlush);
+
+/** Remove the most recent element from the FIFO.
+
+ @param[in] Self Pointer to the FIFO instance.
+**/
+typedef void (EFIAPI *cFIFO_Truncate) (cFIFO *Self);
+
+/** Cleanly delete a FIFO instance.
+
+ @param[in] Self Pointer to the FIFO instance.
+**/
+typedef void (EFIAPI *cFIFO_Delete) (cFIFO *Self);
+
+/** Get the FIFO's current Read Index.
+
+ @param[in] Self Pointer to the FIFO instance.
+
+ @return The current value of the FIFO's ReadIndex member is returned.
+**/
+typedef UINT32 (EFIAPI *cFIFO_GetRDex) (cFIFO *Self);
+
+/** Get the FIFO's current Write Index.
+
+ @param[in] Self Pointer to the FIFO instance.
+
+ @return The current value of the FIFO's WriteIndex member is returned.
+**/
+typedef UINT32 (EFIAPI *cFIFO_GetWDex) (cFIFO *Self);
+
+/// Structure declaration for FIFO objects.
+struct _FIFO_CLASS {
+ /* ######## Public Functions ######## */
+ cFIFO_Enqueue Write; ///< Write an element into the FIFO.
+ cFIFO_Dequeue Read; ///< Read an element from the FIFO.
+ cFIFO_Copy Copy; ///< Non-destructive copy from FIFO.
+ cFIFO_IsEmpty IsEmpty; ///< Test whether the FIFO is empty.
+ cFIFO_IsFull IsFull; ///< Test whether the FIFO is full.
+ cFIFO_NumInQueue Count; ///< Return the number of elements contained in the FIFO.
+ cFIFO_FreeSpace FreeSpace; ///< Return the number of available elements in the FIFO.
+ cFIFO_Flush Flush; ///< Remove the N earliest elements from the FIFO.
+ cFIFO_Truncate Truncate; ///< Remove the most recent element from the FIFO.
+ cFIFO_Delete Delete; ///< Delete the FIFO object.
+
+ /* ######## Protected Functions ######## */
+ cFIFO_GetRDex GetRDex; ///< Get a copy of the current Read Index.
+ cFIFO_GetWDex GetWDex; ///< Get a copy of the current Write Index.
+
+ /* ######## PRIVATE Data ######## */
+ void *Queue; ///< The FIFO's data storage.
+ UINT32 ElementSize; ///< Number of bytes in an element.
+ UINT32 NumElements; ///< Number of elements the FIFO can store.
+ UINT32 ReadIndex; ///< Index of next element to Read.
+ UINT32 WriteIndex; ///< Index of where next element will be Written.
+};
+
+__END_DECLS
+#endif /* _FIFO_CLASS_H */
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