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FreeRTOS-Plus-TCP/source/FreeRTOS_Stream_Buffer.c
Aniruddha Kanhere a4124602cc Merge changes to main.
This commit brings in the refactoring and restructuring changes
from IntegrationTesting1 branch to the main branch.
It also includes additional unit tests for 100% coverage.
The rationale behind not creating a PR is that the conflicts were too
huge to be resolved correctly. Thus, a force push to the main branch is
being done.
2022-05-26 12:42:45 -07:00

431 lines
14 KiB
C

/*
* FreeRTOS+TCP V2.3.4
* Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* SPDX-License-Identifier: MIT
*
* 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
*/
/**
* @file FreeRTOS_Stream_Buffer.c
* @brief Provides the API for managing/creating the stream buffers in the FreeRTOS+TCP network stack.
*/
/* Standard includes. */
#include <stdint.h>
/* FreeRTOS includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "semphr.h"
/* FreeRTOS+TCP includes. */
#include "FreeRTOS_IP.h"
#include "FreeRTOS_UDP_IP.h"
#include "FreeRTOS_Sockets.h"
#include "FreeRTOS_IP_Private.h"
/**
* @brief Get the space between lower and upper value provided to the function.
* @param[in] pxBuffer: The circular stream buffer.
* @param[in] uxLower: The lower value.
* @param[in] uxUpper: The upper value.
* @return The space between uxLower and uxUpper, which equals to the distance
* minus 1.
*/
size_t uxStreamBufferSpace( const StreamBuffer_t * pxBuffer,
const size_t uxLower,
const size_t uxUpper )
{
size_t uxCount;
uxCount = pxBuffer->LENGTH + uxUpper - uxLower - 1U;
if( uxCount >= pxBuffer->LENGTH )
{
uxCount -= pxBuffer->LENGTH;
}
return uxCount;
}
/**
* @brief Get the distance between lower and upper value provided to the function.
* @param[in] pxBuffer: The circular stream buffer.
* @param[in] uxLower: The lower value.
* @param[in] uxUpper: The upper value.
* @return The distance between uxLower and uxUpper.
*/
size_t uxStreamBufferDistance( const StreamBuffer_t * pxBuffer,
const size_t uxLower,
const size_t uxUpper )
{
size_t uxCount;
uxCount = pxBuffer->LENGTH + uxUpper - uxLower;
if( uxCount >= pxBuffer->LENGTH )
{
uxCount -= pxBuffer->LENGTH;
}
return uxCount;
}
/**
* @brief Get the number of items which can be added to the buffer at
* the head before reaching the tail.
* @param[in] pxBuffer: The circular stream buffer.
* @return The number of items which can still be added to uxHead
* before hitting on uxTail
*/
size_t uxStreamBufferGetSpace( const StreamBuffer_t * pxBuffer )
{
size_t uxHead = pxBuffer->uxHead;
size_t uxTail = pxBuffer->uxTail;
return uxStreamBufferSpace( pxBuffer, uxHead, uxTail );
}
/*-----------------------------------------------------------*/
/**
* @brief Get the distance between the pointer in free space and the tail.
* @param[in] pxBuffer: The circular stream buffer.
* @return Distance between uxFront and uxTail or the number of items
* which can still be added to uxFront, before hitting on uxTail.
*/
size_t uxStreamBufferFrontSpace( const StreamBuffer_t * pxBuffer )
{
size_t uxFront = pxBuffer->uxFront;
size_t uxTail = pxBuffer->uxTail;
return uxStreamBufferSpace( pxBuffer, uxFront, uxTail );
}
/*-----------------------------------------------------------*/
/**
* @brief Get the number of items which can be read from the tail before
* reaching the head.
* @param[in] pxBuffer: The circular stream buffer.
* @return The number of items which can be read from the tail before
* reaching the head.
*/
size_t uxStreamBufferGetSize( const StreamBuffer_t * pxBuffer )
{
size_t uxHead = pxBuffer->uxHead;
size_t uxTail = pxBuffer->uxTail;
return uxStreamBufferDistance( pxBuffer, uxTail, uxHead );
}
/*-----------------------------------------------------------*/
/**
* @brief Get the space between the mid pointer and the head in the stream
* buffer.
* @param[in] pxBuffer: The circular stream buffer.
* @return The space between the mid pointer and the head.
*/
size_t uxStreamBufferMidSpace( const StreamBuffer_t * pxBuffer )
{
size_t uxHead = pxBuffer->uxHead;
size_t uxMid = pxBuffer->uxMid;
return uxStreamBufferDistance( pxBuffer, uxMid, uxHead );
}
/*-----------------------------------------------------------*/
/**
* @brief Move Clear the stream buffer.
* @param[in] pxBuffer: The circular stream buffer.
*/
void vStreamBufferClear( StreamBuffer_t * pxBuffer )
{
/* Make the circular buffer empty */
pxBuffer->uxHead = 0U;
pxBuffer->uxTail = 0U;
pxBuffer->uxFront = 0U;
pxBuffer->uxMid = 0U;
}
/*-----------------------------------------------------------*/
/**
* @brief Move the mid pointer forward by given byte count
* @param[in] pxBuffer: The circular stream buffer.
* @param[in] uxCount: The byte count by which the mid pointer is to be moved.
*/
void vStreamBufferMoveMid( StreamBuffer_t * pxBuffer,
size_t uxCount )
{
/* Increment uxMid, but no further than uxHead */
size_t uxSize = uxStreamBufferMidSpace( pxBuffer );
size_t uxMid = pxBuffer->uxMid;
size_t uxMoveCount = uxCount;
if( uxMoveCount > uxSize )
{
uxMoveCount = uxSize;
}
uxMid += uxMoveCount;
if( uxMid >= pxBuffer->LENGTH )
{
uxMid -= pxBuffer->LENGTH;
}
pxBuffer->uxMid = uxMid;
}
/*-----------------------------------------------------------*/
/**
* @brief Check whether the value in left is less than or equal to the
* value in right from the perspective of the circular stream
* buffer.
* @param[in] pxBuffer: The circular stream buffer.
* @param[in] uxLeft: The left pointer in the stream buffer.
* @param[in] uxRight: The right value pointer in the stream buffer.
* @return pdTRUE if uxLeft <= uxRight, else pdFALSE.
*/
BaseType_t xStreamBufferLessThenEqual( const StreamBuffer_t * pxBuffer,
const size_t uxLeft,
const size_t uxRight )
{
BaseType_t xReturn = pdFALSE;
size_t uxTail = pxBuffer->uxTail;
/* Returns true if ( uxLeft <= uxRight ) */
if( ( uxLeft - uxTail ) <= ( uxRight - uxTail ) )
{
xReturn = pdTRUE;
}
return xReturn;
}
/*-----------------------------------------------------------*/
/**
* @brief Get the pointer to data and the amount of data which can be read in one go.
*
* @param[in] pxBuffer: The circular stream buffer.
* @param[out] ppucData: Pointer to the data pointer which will point to the
* data which can be read.
*
* @return The number of bytes which can be read in one go (which might be less than
* actual number of available bytes since this is a circular buffer and tail
* can loop back to the start of the buffer).
*/
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_size_t( uxSize, pxBuffer->LENGTH - uxNextTail );
}
/*-----------------------------------------------------------*/
/**
* @brief Adds data to a stream buffer.
*
* @param[in,out] pxBuffer: The buffer to which the bytes will be added.
* @param[in] uxOffset: If uxOffset > 0, data will be written at an offset from uxHead
* while uxHead will not be moved yet.
* @param[in,out] pucData: A pointer to the data to be added. If 'pucData' equals NULL,
* the function is called to advance the 'Head' only.
* @param[in] uxByteCount: The number of bytes to add.
*
* @return The number of bytes added to the buffer.
*/
size_t uxStreamBufferAdd( StreamBuffer_t * pxBuffer,
size_t uxOffset,
const uint8_t * pucData,
size_t uxByteCount )
{
size_t uxSpace, uxNextHead, uxFirst;
size_t uxCount = uxByteCount;
uxSpace = uxStreamBufferGetSpace( pxBuffer );
/* If uxOffset > 0, items can be placed in front of uxHead */
if( uxSpace > uxOffset )
{
uxSpace -= uxOffset;
}
else
{
uxSpace = 0U;
}
/* The number of bytes that can be written is the minimum of the number of
* bytes requested and the number available. */
uxCount = FreeRTOS_min_size_t( uxSpace, uxCount );
if( uxCount != 0U )
{
uxNextHead = pxBuffer->uxHead;
if( uxOffset != 0U )
{
/* ( uxOffset > 0 ) means: write in front if the uxHead marker */
uxNextHead += uxOffset;
if( uxNextHead >= pxBuffer->LENGTH )
{
uxNextHead -= pxBuffer->LENGTH;
}
}
if( pucData != NULL )
{
/* Calculate the number of bytes that can be added in the first
* write - which may be less than the total number of bytes that need
* to be added if the buffer will wrap back to the beginning. */
uxFirst = FreeRTOS_min_size_t( pxBuffer->LENGTH - uxNextHead, uxCount );
/* Write as many bytes as can be written in the first write. */
( void ) memcpy( &( pxBuffer->ucArray[ uxNextHead ] ), pucData, uxFirst );
/* If the number of bytes written was less than the number that
* could be written in the first write... */
if( uxCount > uxFirst )
{
/* ...then write the remaining bytes to the start of the
* buffer. */
( void ) memcpy( pxBuffer->ucArray, &( pucData[ uxFirst ] ), uxCount - uxFirst );
}
}
if( uxOffset == 0U )
{
/* ( uxOffset == 0 ) means: write at uxHead position */
uxNextHead += uxCount;
if( uxNextHead >= pxBuffer->LENGTH )
{
uxNextHead -= pxBuffer->LENGTH;
}
pxBuffer->uxHead = uxNextHead;
}
if( xStreamBufferLessThenEqual( pxBuffer, pxBuffer->uxFront, uxNextHead ) != pdFALSE )
{
/* Advance the front pointer */
pxBuffer->uxFront = uxNextHead;
}
}
return uxCount;
}
/*-----------------------------------------------------------*/
/**
* @brief Read bytes from stream buffer.
*
* @param[in] pxBuffer: The buffer from which the bytes will be read.
* @param[in] uxOffset: can be used to read data located at a certain offset from 'lTail'.
* @param[in,out] pucData: If 'pucData' equals NULL, the function is called to advance 'lTail' only.
* @param[in] uxMaxCount: The number of bytes to read.
* @param[in] xPeek: if 'xPeek' is pdTRUE, or if 'uxOffset' is non-zero, the 'lTail' pointer will
* not be advanced.
*
* @return The count of the bytes read.
*/
size_t uxStreamBufferGet( StreamBuffer_t * pxBuffer,
size_t uxOffset,
uint8_t * pucData,
size_t uxMaxCount,
BaseType_t xPeek )
{
size_t uxSize, uxCount, uxFirst, uxNextTail;
/* How much data is available? */
uxSize = uxStreamBufferGetSize( pxBuffer );
if( uxSize > uxOffset )
{
uxSize -= uxOffset;
}
else
{
uxSize = 0U;
}
/* Use the minimum of the wanted bytes and the available bytes. */
uxCount = FreeRTOS_min_size_t( uxSize, uxMaxCount );
if( uxCount > 0U )
{
uxNextTail = pxBuffer->uxTail;
if( uxOffset != 0U )
{
uxNextTail += uxOffset;
if( uxNextTail >= pxBuffer->LENGTH )
{
uxNextTail -= pxBuffer->LENGTH;
}
}
if( pucData != NULL )
{
/* Calculate the number of bytes that can be read - which may be
* less than the number wanted if the data wraps around to the start of
* the buffer. */
uxFirst = FreeRTOS_min_size_t( pxBuffer->LENGTH - uxNextTail, uxCount );
/* Obtain the number of bytes it is possible to obtain in the first
* read. */
( void ) memcpy( pucData, &( pxBuffer->ucArray[ uxNextTail ] ), uxFirst );
/* If the total number of wanted bytes is greater than the number
* that could be read in the first read... */
if( uxCount > uxFirst )
{
/*...then read the remaining bytes from the start of the buffer. */
( void ) memcpy( &( pucData[ uxFirst ] ), pxBuffer->ucArray, uxCount - uxFirst );
}
}
if( ( xPeek == pdFALSE ) && ( uxOffset == 0U ) )
{
/* Move the tail pointer to effectively remove the data read from
* the buffer. */
uxNextTail += uxCount;
if( uxNextTail >= pxBuffer->LENGTH )
{
uxNextTail -= pxBuffer->LENGTH;
}
pxBuffer->uxTail = uxNextTail;
}
}
return uxCount;
}