3 * Copyright (C) 2017 Amazon.com, Inc. or its affiliates. All Rights Reserved.
5 * Permission is hereby granted, free of charge, to any person obtaining a copy of
6 * this software and associated documentation files (the "Software"), to deal in
7 * the Software without restriction, including without limitation the rights to
8 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
9 * the Software, and to permit persons to whom the Software is furnished to do so,
10 * subject to the following conditions:
12 * The above copyright notice and this permission notice shall be included in all
13 * copies or substantial portions of the Software.
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
17 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
18 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
19 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
20 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22 * http://aws.amazon.com/freertos
23 * http://www.FreeRTOS.org
26 /* Standard includes. */
29 /* FreeRTOS includes. */
34 /* FreeRTOS+TCP includes. */
35 #include "FreeRTOS_UDP_IP.h"
36 #include "FreeRTOS_IP.h"
37 #include "FreeRTOS_Sockets.h"
38 #include "FreeRTOS_IP_Private.h"
41 * uxStreamBufferAdd( )
42 * Adds data to a stream buffer. If uxOffset > 0, data will be written at
43 * an offset from uxHead while uxHead will not be moved yet. This possibility
44 * will be used when TCP data is received while earlier data is still missing.
45 * If 'pucData' equals NULL, the function is called to advance 'uxHead' only.
47 size_t uxStreamBufferAdd( StreamBuffer_t *pxBuffer, size_t uxOffset, const uint8_t *pucData, size_t uxCount )
49 size_t uxSpace, uxNextHead, uxFirst;
51 uxSpace = uxStreamBufferGetSpace( pxBuffer );
53 /* If uxOffset > 0, items can be placed in front of uxHead */
54 if( uxSpace > uxOffset )
63 /* The number of bytes that can be written is the minimum of the number of
64 bytes requested and the number available. */
65 uxCount = FreeRTOS_min_uint32( uxSpace, uxCount );
69 uxNextHead = pxBuffer->uxHead;
73 /* ( uxOffset > 0 ) means: write in front if the uxHead marker */
74 uxNextHead += uxOffset;
75 if( uxNextHead >= pxBuffer->LENGTH )
77 uxNextHead -= pxBuffer->LENGTH;
83 /* Calculate the number of bytes that can be added in the first
84 write - which may be less than the total number of bytes that need
85 to be added if the buffer will wrap back to the beginning. */
86 uxFirst = FreeRTOS_min_uint32( pxBuffer->LENGTH - uxNextHead, uxCount );
88 /* Write as many bytes as can be written in the first write. */
89 memcpy( ( void* ) ( pxBuffer->ucArray + uxNextHead ), pucData, uxFirst );
91 /* If the number of bytes written was less than the number that
92 could be written in the first write... */
93 if( uxCount > uxFirst )
95 /* ...then write the remaining bytes to the start of the
97 memcpy( ( void * )pxBuffer->ucArray, pucData + uxFirst, uxCount - uxFirst );
103 /* ( uxOffset == 0 ) means: write at uxHead position */
104 uxNextHead += uxCount;
105 if( uxNextHead >= pxBuffer->LENGTH )
107 uxNextHead -= pxBuffer->LENGTH;
109 pxBuffer->uxHead = uxNextHead;
112 if( xStreamBufferLessThenEqual( pxBuffer, pxBuffer->uxFront, uxNextHead ) != pdFALSE )
114 /* Advance the front pointer */
115 pxBuffer->uxFront = uxNextHead;
121 /*-----------------------------------------------------------*/
124 * uxStreamBufferGet( )
125 * 'uxOffset' can be used to read data located at a certain offset from 'lTail'.
126 * If 'pucData' equals NULL, the function is called to advance 'lTail' only.
127 * if 'xPeek' is pdTRUE, or if 'uxOffset' is non-zero, the 'lTail' pointer will
130 size_t uxStreamBufferGet( StreamBuffer_t *pxBuffer, size_t uxOffset, uint8_t *pucData, size_t uxMaxCount, BaseType_t xPeek )
132 size_t uxSize, uxCount, uxFirst, uxNextTail;
134 /* How much data is available? */
135 uxSize = uxStreamBufferGetSize( pxBuffer );
137 if( uxSize > uxOffset )
146 /* Use the minimum of the wanted bytes and the available bytes. */
147 uxCount = FreeRTOS_min_uint32( uxSize, uxMaxCount );
151 uxNextTail = pxBuffer->uxTail;
155 uxNextTail += uxOffset;
156 if( uxNextTail >= pxBuffer->LENGTH )
158 uxNextTail -= pxBuffer->LENGTH;
162 if( pucData != NULL )
164 /* Calculate the number of bytes that can be read - which may be
165 less than the number wanted if the data wraps around to the start of
167 uxFirst = FreeRTOS_min_uint32( pxBuffer->LENGTH - uxNextTail, uxCount );
169 /* Obtain the number of bytes it is possible to obtain in the first
171 memcpy( pucData, pxBuffer->ucArray + uxNextTail, uxFirst );
173 /* If the total number of wanted bytes is greater than the number
174 that could be read in the first read... */
175 if( uxCount > uxFirst )
177 /*...then read the remaining bytes from the start of the buffer. */
178 memcpy( pucData + uxFirst, pxBuffer->ucArray, uxCount - uxFirst );
182 if( ( xPeek == pdFALSE ) && ( uxOffset == 0UL ) )
184 /* Move the tail pointer to effecively remove the data read from
186 uxNextTail += uxCount;
188 if( uxNextTail >= pxBuffer->LENGTH )
190 uxNextTail -= pxBuffer->LENGTH;
193 pxBuffer->uxTail = uxNextTail;