Bluetooth UART support for the Adafruit BluefruitLE SPI, for the University of York Engineering Stage 1 project
utility/Adafruit_FIFO.cpp
- Committer:
- ajp109
- Date:
- 2021-03-12
- Revision:
- 3:bdfd15be7b82
- Parent:
- 0:a80552d32b80
File content as of revision 3:bdfd15be7b82:
/**************************************************************************/ /*! @file Adafruit_FIFO.cpp @author hathach @section LICENSE Software License Agreement (BSD License) Copyright (c) 2015, Adafruit Industries (adafruit.com) All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. 3. Neither the name of the copyright holders nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /**************************************************************************/ #include "Adafruit_FIFO.h" #include <string.h> /******************************************************************************/ /*! @brief Constructor @param[in] buffer Memory location to store data @param[in] depth Maximum number of items can be hold in buffer @param[in] item_size Number of bytes of each item @param[in] overwrite Should the buffer is overwitten to the first item when it is full */ /******************************************************************************/ Adafruit_FIFO::Adafruit_FIFO(void* buffer, uint16_t depth, uint8_t item_size, bool overwrite) { m_buffer = (uint8_t*) buffer; m_depth = depth; m_item_size = item_size; m_overwritable = overwrite; m_count = m_wr_idx = m_rd_idx = 0; } /******************************************************************************/ /*! @brief Clear the FIFO */ /******************************************************************************/ void Adafruit_FIFO::clear(void) { m_rd_idx = m_wr_idx = m_count = 0; } /******************************************************************************/ /*! @brief Write an item to the FIFO @param[in] item Memory address of the item */ /******************************************************************************/ bool Adafruit_FIFO::write(void const* item) { if ( full() && !m_overwritable ) return false; memcpy( m_buffer + (m_wr_idx * m_item_size), item, m_item_size); m_wr_idx = (m_wr_idx + 1) % m_depth; if ( full() ) { m_rd_idx = m_wr_idx; // keep the full state (rd == wr && len = size) } else { m_count++; } return true; } /******************************************************************************/ /*! @brief Write array of items to the FIFO @param[in] data Memory address of the item's array @param[in] n Number of items to write @return Number of written items */ /******************************************************************************/ uint16_t Adafruit_FIFO::write_n(void const * data, uint16_t n) { if ( n == 0 ) return 0; uint8_t* buf = (uint8_t*) data; uint16_t len = 0; while( (len < n) && write(buf) ) { len++; buf += m_item_size; } return len; } /******************************************************************************/ /*! @brief Read an item from FIFO @param[in] buffer Memory address to store item */ /******************************************************************************/ bool Adafruit_FIFO::read(void* buffer) { if( empty() ) return false; memcpy(buffer, m_buffer + (m_rd_idx * m_item_size), m_item_size); m_rd_idx = (m_rd_idx + 1) % m_depth; m_count--; return true; } /******************************************************************************/ /*! @brief Read multiple items to an array @param[in] buffer Memory address of the item's array @param[in] n Number of items to read @return Number of read items */ /******************************************************************************/ uint16_t Adafruit_FIFO::read_n (void * buffer, uint16_t n) { if( n == 0 ) return 0; uint8_t* buf = (uint8_t*) buffer; uint16_t len = 0; while( (len < n) && read(buf) ) { len++; buf += m_item_size; } return len; } /******************************************************************************/ /*! @brief Read an item without removing it from the FIFO @param[in] buffer Memory address to store item */ /******************************************************************************/ bool Adafruit_FIFO::peek(void* buffer) { if( empty() ) return false; memcpy(buffer, m_buffer + (m_rd_idx * m_item_size), m_item_size); return true; } /******************************************************************************/ /*! @brief Read an item without removing it from the FIFO at the specific index @param[in] position Position to read from in the FIFO buffer @param[in] buffer Memory address to store item */ /******************************************************************************/ bool Adafruit_FIFO::peekAt(uint16_t position, void * p_buffer) { if( empty() || (position >= m_count) ) return false; uint16_t index = (m_rd_idx + position) % m_depth; // rd_idx is position=0 memcpy(p_buffer, m_buffer + (index * m_item_size), m_item_size); return true; }