/* | |
* FreeRTOS+TCP Labs Build 160919 (C) 2016 Real Time Engineers ltd. | |
* Authors include Hein Tibosch and Richard Barry | |
* | |
******************************************************************************* | |
***** NOTE ******* NOTE ******* NOTE ******* NOTE ******* NOTE ******* NOTE *** | |
*** *** | |
*** *** | |
*** FREERTOS+TCP IS STILL IN THE LAB (mainly because the FTP and HTTP *** | |
*** demos have a dependency on FreeRTOS+FAT, which is only in the Labs *** | |
*** download): *** | |
*** *** | |
*** FreeRTOS+TCP is functional and has been used in commercial products *** | |
*** for some time. Be aware however that we are still refining its *** | |
*** design, the source code does not yet quite conform to the strict *** | |
*** coding and style standards mandated by Real Time Engineers ltd., and *** | |
*** the documentation and testing is not necessarily complete. *** | |
*** *** | |
*** PLEASE REPORT EXPERIENCES USING THE SUPPORT RESOURCES FOUND ON THE *** | |
*** URL: http://www.FreeRTOS.org/contact Active early adopters may, at *** | |
*** the sole discretion of Real Time Engineers Ltd., be offered versions *** | |
*** under a license other than that described below. *** | |
*** *** | |
*** *** | |
***** NOTE ******* NOTE ******* NOTE ******* NOTE ******* NOTE ******* NOTE *** | |
******************************************************************************* | |
* | |
* FreeRTOS+TCP can be used under two different free open source licenses. The | |
* license that applies is dependent on the processor on which FreeRTOS+TCP is | |
* executed, as follows: | |
* | |
* If FreeRTOS+TCP is executed on one of the processors listed under the Special | |
* License Arrangements heading of the FreeRTOS+TCP license information web | |
* page, then it can be used under the terms of the FreeRTOS Open Source | |
* License. If FreeRTOS+TCP is used on any other processor, then it can be used | |
* under the terms of the GNU General Public License V2. Links to the relevant | |
* licenses follow: | |
* | |
* The FreeRTOS+TCP License Information Page: http://www.FreeRTOS.org/tcp_license | |
* The FreeRTOS Open Source License: http://www.FreeRTOS.org/license | |
* The GNU General Public License Version 2: http://www.FreeRTOS.org/gpl-2.0.txt | |
* | |
* FreeRTOS+TCP is distributed in the hope that it will be useful. You cannot | |
* use FreeRTOS+TCP unless you agree that you use the software 'as is'. | |
* FreeRTOS+TCP is provided WITHOUT ANY WARRANTY; without even the implied | |
* warranties of NON-INFRINGEMENT, MERCHANTABILITY or FITNESS FOR A PARTICULAR | |
* PURPOSE. Real Time Engineers Ltd. disclaims all conditions and terms, be they | |
* implied, expressed, or statutory. | |
* | |
* 1 tab == 4 spaces! | |
* | |
* http://www.FreeRTOS.org | |
* http://www.FreeRTOS.org/plus | |
* http://www.FreeRTOS.org/labs | |
* | |
*/ | |
/* | |
* FreeRTOS_Stream_Buffer.h | |
* | |
* A cicular character buffer | |
* An implementation of a circular buffer without a length field | |
* If LENGTH defines the size of the buffer, a maximum of (LENGT-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 | |
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 ) ]; | |
} 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 ); | |
if( uxCount > uxSize ) | |
{ | |
uxCount = uxSize; | |
} | |
pxBuffer->uxMid += uxCount; | |
if( pxBuffer->uxMid >= pxBuffer->LENGTH ) | |
{ | |
pxBuffer->uxMid -= pxBuffer->LENGTH; | |
} | |
} | |
/*-----------------------------------------------------------*/ | |
static portINLINE BaseType_t xStreamBufferIsEmpty( const StreamBuffer_t *pxBuffer ); | |
static portINLINE BaseType_t xStreamBufferIsEmpty( const StreamBuffer_t *pxBuffer ) | |
{ | |
BaseType_t xReturn; | |
/* True if no item is available */ | |
if( pxBuffer->uxHead == pxBuffer->uxTail ) | |
{ | |
xReturn = pdTRUE; | |
} | |
else | |
{ | |
xReturn = pdFALSE; | |
} | |
return xReturn; | |
} | |
/*-----------------------------------------------------------*/ | |
static portINLINE BaseType_t xStreamBufferIsFull( const StreamBuffer_t *pxBuffer ); | |
static portINLINE BaseType_t xStreamBufferIsFull( const StreamBuffer_t *pxBuffer ) | |
{ | |
/* True if the available space equals zero. */ | |
return ( BaseType_t ) ( uxStreamBufferGetSpace( pxBuffer ) == 0u ); | |
} | |
/*-----------------------------------------------------------*/ | |
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 ) ^ ( uxRight < uxTail ) ) | |
{ | |
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 uxCount ); | |
/* | |
* 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 ) */ |