2 * FreeRTOS+TCP V2.0.0
\r
3 * Copyright (C) 2017 Amazon.com, Inc. or its affiliates. All Rights Reserved.
\r
5 * Permission is hereby granted, free of charge, to any person obtaining a copy of
\r
6 * this software and associated documentation files (the "Software"), to deal in
\r
7 * the Software without restriction, including without limitation the rights to
\r
8 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
\r
9 * the Software, and to permit persons to whom the Software is furnished to do so,
\r
10 * subject to the following conditions:
\r
12 * The above copyright notice and this permission notice shall be included in all
\r
13 * copies or substantial portions of the Software. If you wish to use our Amazon
\r
14 * FreeRTOS name, please do so in a fair use way that does not cause confusion.
\r
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
\r
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
\r
18 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
\r
19 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
\r
20 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
\r
21 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
\r
23 * http://www.FreeRTOS.org
\r
24 * http://aws.amazon.com/freertos
\r
26 * 1 tab == 4 spaces!
\r
30 * FreeRTOS_Stream_Buffer.h
\r
32 * A cicular character buffer
\r
33 * An implementation of a circular buffer without a length field
\r
34 * If LENGTH defines the size of the buffer, a maximum of (LENGT-1) bytes can be stored
\r
35 * In order to add or read data from the buffer, memcpy() will be called at most 2 times
\r
38 #ifndef FREERTOS_STREAM_BUFFER_H
\r
39 #define FREERTOS_STREAM_BUFFER_H
\r
45 typedef struct xSTREAM_BUFFER {
\r
46 volatile size_t uxTail; /* next item to read */
\r
47 volatile size_t uxMid; /* iterator within the valid items */
\r
48 volatile size_t uxHead; /* next position store a new item */
\r
49 volatile size_t uxFront; /* iterator within the free space */
\r
50 size_t LENGTH; /* const value: number of reserved elements */
\r
51 uint8_t ucArray[ sizeof( size_t ) ];
\r
54 static portINLINE void vStreamBufferClear( StreamBuffer_t *pxBuffer );
\r
55 static portINLINE void vStreamBufferClear( StreamBuffer_t *pxBuffer )
\r
57 /* Make the circular buffer empty */
\r
58 pxBuffer->uxHead = 0u;
\r
59 pxBuffer->uxTail = 0u;
\r
60 pxBuffer->uxFront = 0u;
\r
61 pxBuffer->uxMid = 0u;
\r
63 /*-----------------------------------------------------------*/
\r
65 static portINLINE size_t uxStreamBufferSpace( const StreamBuffer_t *pxBuffer, const size_t uxLower, const size_t uxUpper );
\r
66 static portINLINE size_t uxStreamBufferSpace( const StreamBuffer_t *pxBuffer, const size_t uxLower, const size_t uxUpper )
\r
68 /* Returns the space between uxLower and uxUpper, which equals to the distance minus 1 */
\r
71 uxCount = pxBuffer->LENGTH + uxUpper - uxLower - 1u;
\r
72 if( uxCount >= pxBuffer->LENGTH )
\r
74 uxCount -= pxBuffer->LENGTH;
\r
79 /*-----------------------------------------------------------*/
\r
81 static portINLINE size_t uxStreamBufferDistance( const StreamBuffer_t *pxBuffer, const size_t uxLower, const size_t uxUpper );
\r
82 static portINLINE size_t uxStreamBufferDistance( const StreamBuffer_t *pxBuffer, const size_t uxLower, const size_t uxUpper )
\r
84 /* Returns the distance between uxLower and uxUpper */
\r
87 uxCount = pxBuffer->LENGTH + uxUpper - uxLower;
\r
88 if ( uxCount >= pxBuffer->LENGTH )
\r
90 uxCount -= pxBuffer->LENGTH;
\r
95 /*-----------------------------------------------------------*/
\r
97 static portINLINE size_t uxStreamBufferGetSpace( const StreamBuffer_t *pxBuffer );
\r
98 static portINLINE size_t uxStreamBufferGetSpace( const StreamBuffer_t *pxBuffer )
\r
100 /* Returns the number of items which can still be added to uxHead
\r
101 before hitting on uxTail */
\r
102 size_t uxHead = pxBuffer->uxHead;
\r
103 size_t uxTail = pxBuffer->uxTail;
\r
105 return uxStreamBufferSpace( pxBuffer, uxHead, uxTail );
\r
107 /*-----------------------------------------------------------*/
\r
109 static portINLINE size_t uxStreamBufferFrontSpace( const StreamBuffer_t *pxBuffer );
\r
110 static portINLINE size_t uxStreamBufferFrontSpace( const StreamBuffer_t *pxBuffer )
\r
112 /* Distance between uxFront and uxTail
\r
113 or the number of items which can still be added to uxFront,
\r
114 before hitting on uxTail */
\r
116 size_t uxFront = pxBuffer->uxFront;
\r
117 size_t uxTail = pxBuffer->uxTail;
\r
119 return uxStreamBufferSpace( pxBuffer, uxFront, uxTail );
\r
121 /*-----------------------------------------------------------*/
\r
123 static portINLINE size_t uxStreamBufferGetSize( const StreamBuffer_t *pxBuffer );
\r
124 static portINLINE size_t uxStreamBufferGetSize( const StreamBuffer_t *pxBuffer )
\r
126 /* Returns the number of items which can be read from uxTail
\r
127 before reaching uxHead */
\r
128 size_t uxHead = pxBuffer->uxHead;
\r
129 size_t uxTail = pxBuffer->uxTail;
\r
131 return uxStreamBufferDistance( pxBuffer, uxTail, uxHead );
\r
133 /*-----------------------------------------------------------*/
\r
135 static portINLINE size_t uxStreamBufferMidSpace( const StreamBuffer_t *pxBuffer );
\r
136 static portINLINE size_t uxStreamBufferMidSpace( const StreamBuffer_t *pxBuffer )
\r
138 /* Returns the distance between uxHead and uxMid */
\r
139 size_t uxHead = pxBuffer->uxHead;
\r
140 size_t uxMid = pxBuffer->uxMid;
\r
142 return uxStreamBufferDistance( pxBuffer, uxMid, uxHead );
\r
144 /*-----------------------------------------------------------*/
\r
146 static portINLINE void vStreamBufferMoveMid( StreamBuffer_t *pxBuffer, size_t uxCount );
\r
147 static portINLINE void vStreamBufferMoveMid( StreamBuffer_t *pxBuffer, size_t uxCount )
\r
149 /* Increment uxMid, but no further than uxHead */
\r
150 size_t uxSize = uxStreamBufferMidSpace( pxBuffer );
\r
152 if( uxCount > uxSize )
\r
156 pxBuffer->uxMid += uxCount;
\r
157 if( pxBuffer->uxMid >= pxBuffer->LENGTH )
\r
159 pxBuffer->uxMid -= pxBuffer->LENGTH;
\r
162 /*-----------------------------------------------------------*/
\r
163 static portINLINE BaseType_t xStreamBufferIsEmpty( const StreamBuffer_t *pxBuffer );
\r
164 static portINLINE BaseType_t xStreamBufferIsEmpty( const StreamBuffer_t *pxBuffer )
\r
166 BaseType_t xReturn;
\r
168 /* True if no item is available */
\r
169 if( pxBuffer->uxHead == pxBuffer->uxTail )
\r
179 /*-----------------------------------------------------------*/
\r
181 static portINLINE BaseType_t xStreamBufferIsFull( const StreamBuffer_t *pxBuffer );
\r
182 static portINLINE BaseType_t xStreamBufferIsFull( const StreamBuffer_t *pxBuffer )
\r
184 /* True if the available space equals zero. */
\r
185 return ( BaseType_t ) ( uxStreamBufferGetSpace( pxBuffer ) == 0u );
\r
187 /*-----------------------------------------------------------*/
\r
189 static portINLINE BaseType_t xStreamBufferLessThenEqual( const StreamBuffer_t *pxBuffer, const size_t uxLeft, const size_t uxRight );
\r
190 static portINLINE BaseType_t xStreamBufferLessThenEqual( const StreamBuffer_t *pxBuffer, const size_t uxLeft, const size_t uxRight )
\r
192 BaseType_t xReturn;
\r
193 size_t uxTail = pxBuffer->uxTail;
\r
195 /* Returns true if ( uxLeft < uxRight ) */
\r
196 if( ( uxLeft < uxTail ) ^ ( uxRight < uxTail ) )
\r
198 if( uxRight < uxTail )
\r
209 if( uxLeft <= uxRight )
\r
220 /*-----------------------------------------------------------*/
\r
222 static portINLINE size_t uxStreamBufferGetPtr( StreamBuffer_t *pxBuffer, uint8_t **ppucData );
\r
223 static portINLINE size_t uxStreamBufferGetPtr( StreamBuffer_t *pxBuffer, uint8_t **ppucData )
\r
225 size_t uxNextTail = pxBuffer->uxTail;
\r
226 size_t uxSize = uxStreamBufferGetSize( pxBuffer );
\r
228 *ppucData = pxBuffer->ucArray + uxNextTail;
\r
230 return FreeRTOS_min_uint32( uxSize, pxBuffer->LENGTH - uxNextTail );
\r
234 * Add bytes to a stream buffer.
\r
236 * pxBuffer - The buffer to which the bytes will be added.
\r
237 * uxOffset - If uxOffset > 0, data will be written at an offset from uxHead
\r
238 * while uxHead will not be moved yet.
\r
239 * pucData - A pointer to the data to be added.
\r
240 * uxCount - The number of bytes to add.
\r
242 size_t uxStreamBufferAdd( StreamBuffer_t *pxBuffer, size_t uxOffset, const uint8_t *pucData, size_t uxCount );
\r
245 * Read bytes from a stream buffer.
\r
247 * pxBuffer - The buffer from which the bytes will be read.
\r
248 * uxOffset - Can be used to read data located at a certain offset from 'uxTail'.
\r
249 * pucData - A pointer to the buffer into which data will be read.
\r
250 * uxMaxCount - The number of bytes to read.
\r
251 * xPeek - If set to pdTRUE the data will remain in the buffer.
\r
253 size_t uxStreamBufferGet( StreamBuffer_t *pxBuffer, size_t uxOffset, uint8_t *pucData, size_t uxMaxCount, BaseType_t xPeek );
\r
259 #endif /* !defined( FREERTOS_STREAM_BUFFER_H ) */
\r