Small library for using circular buffers (forked from François Berder's implementation in order to add methods and fix problems)
Dependents: CircularBufferTest XBeeApi
Fork of CircularBuffer by
Test suite can be found in this application, CircularBufferTest
CircularBuffer.h
- Committer:
- johnb
- Date:
- 2014-01-18
- Revision:
- 5:abe8909f9603
- Parent:
- 4:e15dee1d59ee
- Child:
- 6:242d0e9f13d1
File content as of revision 5:abe8909f9603:
#ifndef CIRCULAR_BUFFER_H #define CIRCULAR_BUFFER_H #include <cstddef> #include <stdint.h> /** This class implements a static circular buffer. CirularBuffer class originally by François Berder ( see http://mbed.org/users/feb11/code/CircularBuffer/ ) Additions by John Bailey ( http://mbed.org/users/johnb/ ) */ template<size_t T> class CircularBuffer { public : /** Default constructor */ CircularBuffer(); /** Reads data from buffer (data is removed from the buffer as opposed to the peek method which allows inspection of the contents without modifying the buffer) \param data output buffer \param length Maximum number of bytes to read \return Number of bytes read \note The return value cannot exceed max(length,capacity) */ uint32_t read(uint8_t *data, uint32_t length); /** Reads data from buffer leaving the data in the buffer (as opposed to the read method which removed the returned data from the buffer) \param data output buffer \param length Maximum number of bytes to read \return Number of bytes read \note The return value cannot exceed max(length,capacity) */ uint32_t peek(uint8_t *data, uint32_t length) const; /** Writes data in buffer \param data input buffer \param length Maximum number of bytes to write \return Number of bytes wrote \note The return value cannot exceed max(length,capacity) */ uint32_t write(uint8_t *data, uint32_t length); /** Returns the total capacity of this buffer \return Capacity of buffer */ uint32_t getCapacity() const; /** Returns the number of bytes available in the buffer \return Number of bytes available in the buffer */ uint32_t getSize() const; /** Checks if this buffer is empty \return True if the buffer is empty, false otherwise */ bool isEmpty() const; /** Checks if this buffer is full \return True if the buffer is full, false otherwise */ bool isFull() const; private : typedef uint16_t CircularBufferIndex_t; CircularBufferIndex_t readIndex, writeIndex; uint8_t buffer[T]; }; template<size_t T> CircularBuffer<T>::CircularBuffer(): readIndex(T), writeIndex(0) { } template<size_t T> uint32_t CircularBuffer<T>::read(uint8_t *data, uint32_t length) { uint32_t n = 0; while(n < length && getSize() > 0) { if(readIndex == T) readIndex = 0; data[n++] = buffer[readIndex++]; } return n; } template<size_t T> uint32_t CircularBuffer<T>::peek(uint8_t *data, uint32_t length) const { uint32_t n = 0; CircularBufferIndex_t src = readIndex; while(n < length && getSize() > 0) { if(src == T) { src = 0; } data[n++] = buffer[src++]; } return n; } template<size_t T> uint32_t CircularBuffer<T>::write(uint8_t *data, uint32_t length) { uint32_t n = 0; while(n < length && getSize() < T) { if(writeIndex == T) writeIndex = 0; buffer[writeIndex++] = data[n++]; } return n; } template<size_t T> uint32_t CircularBuffer<T>::getCapacity() const { return T; } template<size_t T> uint32_t CircularBuffer<T>::getSize() const { return ((writeIndex > readIndex) ? (writeIndex - readIndex) : (T + writeIndex - readIndex)); } template<size_t T> bool CircularBuffer<T>::isEmpty() const { return getSize() == 0; } template<size_t T> bool CircularBuffer<T>::isFull() const { return getSize() == T; } typedef CircularBuffer<32> SmallCircularBuffer; typedef CircularBuffer<128> MediumCircularBuffer; typedef CircularBuffer<512> BigCircularBuffer; #endif