/* * FreeRTOS+TCP V2.3.2 * Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a copy of * this software and associated documentation files (the "Software"), to deal in * the Software without restriction, including without limitation the rights to * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of * the Software, and to permit persons to whom the Software is furnished to do so, * subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all * copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. * * http://aws.amazon.com/freertos * http://www.FreeRTOS.org */ /* * FreeRTOS_Stream_Buffer.h * * A circular character buffer * An implementation of a circular buffer without a length field * If LENGTH defines the size of the buffer, a maximum of (LENGTH-1) bytes can be stored * In order to add or read data from the buffer, memcpy() will be called at most 2 times */ #ifndef FREERTOS_STREAM_BUFFER_H #define FREERTOS_STREAM_BUFFER_H #ifdef __cplusplus extern "C" { #endif /** * structure to store all the details of a stream buffer. */ typedef struct xSTREAM_BUFFER { volatile size_t uxTail; /**< next item to read */ volatile size_t uxMid; /**< iterator within the valid items */ volatile size_t uxHead; /**< next position store a new item */ volatile size_t uxFront; /**< iterator within the free space */ size_t LENGTH; /**< const value: number of reserved elements */ uint8_t ucArray[ sizeof( size_t ) ]; /**< array big enough to store any pointer address */ } StreamBuffer_t; static portINLINE void vStreamBufferClear( StreamBuffer_t * pxBuffer ); static portINLINE void vStreamBufferClear( StreamBuffer_t * pxBuffer ) { /* Make the circular buffer empty */ pxBuffer->uxHead = 0U; pxBuffer->uxTail = 0U; pxBuffer->uxFront = 0U; pxBuffer->uxMid = 0U; } /*-----------------------------------------------------------*/ static portINLINE size_t uxStreamBufferSpace( const StreamBuffer_t * pxBuffer, const size_t uxLower, const size_t uxUpper ); static portINLINE size_t uxStreamBufferSpace( const StreamBuffer_t * pxBuffer, const size_t uxLower, const size_t uxUpper ) { /* Returns the space between uxLower and uxUpper, which equals to the distance minus 1 */ size_t uxCount; uxCount = pxBuffer->LENGTH + uxUpper - uxLower - 1U; if( uxCount >= pxBuffer->LENGTH ) { uxCount -= pxBuffer->LENGTH; } return uxCount; } /*-----------------------------------------------------------*/ static portINLINE size_t uxStreamBufferDistance( const StreamBuffer_t * pxBuffer, const size_t uxLower, const size_t uxUpper ); static portINLINE size_t uxStreamBufferDistance( const StreamBuffer_t * pxBuffer, const size_t uxLower, const size_t uxUpper ) { /* Returns the distance between uxLower and uxUpper */ size_t uxCount; uxCount = pxBuffer->LENGTH + uxUpper - uxLower; if( uxCount >= pxBuffer->LENGTH ) { uxCount -= pxBuffer->LENGTH; } return uxCount; } /*-----------------------------------------------------------*/ static portINLINE size_t uxStreamBufferGetSpace( const StreamBuffer_t * pxBuffer ); static portINLINE size_t uxStreamBufferGetSpace( const StreamBuffer_t * pxBuffer ) { /* Returns the number of items which can still be added to uxHead * before hitting on uxTail */ size_t uxHead = pxBuffer->uxHead; size_t uxTail = pxBuffer->uxTail; return uxStreamBufferSpace( pxBuffer, uxHead, uxTail ); } /*-----------------------------------------------------------*/ static portINLINE size_t uxStreamBufferFrontSpace( const StreamBuffer_t * pxBuffer ); static portINLINE size_t uxStreamBufferFrontSpace( const StreamBuffer_t * pxBuffer ) { /* Distance between uxFront and uxTail * or the number of items which can still be added to uxFront, * before hitting on uxTail */ size_t uxFront = pxBuffer->uxFront; size_t uxTail = pxBuffer->uxTail; return uxStreamBufferSpace( pxBuffer, uxFront, uxTail ); } /*-----------------------------------------------------------*/ static portINLINE size_t uxStreamBufferGetSize( const StreamBuffer_t * pxBuffer ); static portINLINE size_t uxStreamBufferGetSize( const StreamBuffer_t * pxBuffer ) { /* Returns the number of items which can be read from uxTail * before reaching uxHead */ size_t uxHead = pxBuffer->uxHead; size_t uxTail = pxBuffer->uxTail; return uxStreamBufferDistance( pxBuffer, uxTail, uxHead ); } /*-----------------------------------------------------------*/ static portINLINE size_t uxStreamBufferMidSpace( const StreamBuffer_t * pxBuffer ); static portINLINE size_t uxStreamBufferMidSpace( const StreamBuffer_t * pxBuffer ) { /* Returns the distance between uxHead and uxMid */ size_t uxHead = pxBuffer->uxHead; size_t uxMid = pxBuffer->uxMid; return uxStreamBufferDistance( pxBuffer, uxMid, uxHead ); } /*-----------------------------------------------------------*/ static portINLINE void vStreamBufferMoveMid( StreamBuffer_t * pxBuffer, size_t uxCount ); static portINLINE void vStreamBufferMoveMid( StreamBuffer_t * pxBuffer, size_t uxCount ) { /* Increment uxMid, but no further than uxHead */ size_t uxSize = uxStreamBufferMidSpace( pxBuffer ); size_t uxMoveCount = uxCount; if( uxMoveCount > uxSize ) { uxMoveCount = uxSize; } pxBuffer->uxMid += uxMoveCount; if( pxBuffer->uxMid >= pxBuffer->LENGTH ) { pxBuffer->uxMid -= pxBuffer->LENGTH; } } /*-----------------------------------------------------------*/ static portINLINE BaseType_t xStreamBufferLessThenEqual( const StreamBuffer_t * pxBuffer, const size_t uxLeft, const size_t uxRight ); static portINLINE BaseType_t xStreamBufferLessThenEqual( const StreamBuffer_t * pxBuffer, const size_t uxLeft, const size_t uxRight ) { BaseType_t xReturn; size_t uxTail = pxBuffer->uxTail; /* Returns true if ( uxLeft < uxRight ) */ if( ( ( ( uxLeft < uxTail ) ? 1U : 0U ) ^ ( ( uxRight < uxTail ) ? 1U : 0U ) ) != 0U ) { if( uxRight < uxTail ) { xReturn = pdTRUE; } else { xReturn = pdFALSE; } } else { if( uxLeft <= uxRight ) { xReturn = pdTRUE; } else { xReturn = pdFALSE; } } return xReturn; } /*-----------------------------------------------------------*/ static portINLINE size_t uxStreamBufferGetPtr( StreamBuffer_t * pxBuffer, uint8_t ** ppucData ); static portINLINE size_t uxStreamBufferGetPtr( StreamBuffer_t * pxBuffer, uint8_t ** ppucData ) { size_t uxNextTail = pxBuffer->uxTail; size_t uxSize = uxStreamBufferGetSize( pxBuffer ); *ppucData = pxBuffer->ucArray + uxNextTail; return FreeRTOS_min_uint32( uxSize, pxBuffer->LENGTH - uxNextTail ); } /* * Add bytes to a stream buffer. * * pxBuffer - The buffer to which the bytes will be added. * uxOffset - If uxOffset > 0, data will be written at an offset from uxHead * while uxHead will not be moved yet. * pucData - A pointer to the data to be added. * uxCount - The number of bytes to add. */ size_t uxStreamBufferAdd( StreamBuffer_t * pxBuffer, size_t uxOffset, const uint8_t * pucData, size_t uxByteCount ); /* * Read bytes from a stream buffer. * * pxBuffer - The buffer from which the bytes will be read. * uxOffset - Can be used to read data located at a certain offset from 'uxTail'. * pucData - A pointer to the buffer into which data will be read. * uxMaxCount - The number of bytes to read. * xPeek - If set to pdTRUE the data will remain in the buffer. */ size_t uxStreamBufferGet( StreamBuffer_t * pxBuffer, size_t uxOffset, uint8_t * pucData, size_t uxMaxCount, BaseType_t xPeek ); #ifdef __cplusplus } /* extern "C" */ #endif #endif /* !defined( FREERTOS_STREAM_BUFFER_H ) */