This is an Australian 915Mhz edition of 1.0.8v libDot. Library for LoRa communication using MultiTech MDOT.
Diff: MTSCircularBuffer.h
- Revision:
- 1:9f30fbe9e9c1
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/MTSCircularBuffer.h Wed Jun 24 17:03:08 2015 -0500 @@ -0,0 +1,165 @@ +/************************************************ + * MultiTech MTDOT Library + * Copyright (c) 2015 MultiTech Systems + * + * See LICENSE file for license information + ***********************************************/ + +#ifndef MTSCIRCULARBUFFER_H +#define MTSCIRCULARBUFFER_H + +#include "Utils.h" + +namespace mts +{ + +/** This class provides a circular byte buffer meant for temporary storage +* during IO transactions. It contains many of the common methods you +* would expect from a circular buffer like read, write, and various +* methods for checking the size or status. It should be noted that +* this class does not include any special code for thread safety like +* a lock. In most cases this is not problematic, but is something +* to be aware of. +*/ +class MTSCircularBuffer +{ +public: + /** Creates an MTSCircularBuffer object with the specified static size. + * + * @prarm bufferSize size of the buffer in bytes. + */ + MTSCircularBuffer(int bufferSize); + + /** Destructs an MTSCircularBuffer object and frees all related resources. + */ + ~MTSCircularBuffer(); + + /** This method enables bulk reads from the buffer. If more data is + * requested then available it simply returns all remaining data within the + * buffer. + * + * @param data the buffer where data read will be added to. + * @param length the amount of data in bytes to be read into the buffer. + * @returns the total number of bytes that were read. + */ + int read(char* data, int length); + + /** This method reads a single byte from the buffer. + * + * @param data char where the read byte will be stored. + * @returns 1 if byte is read or 0 if no bytes available. + */ + int read(char& data); + + /** This method enables bulk writes to the buffer. If more data + * is requested to be written then space available the method writes + * as much data as possible and returns the actual amount written. + * + * @param data the byte array to be written. + * @param length the length of data to be written from the data paramter. + * @returns the number of bytes written to the buffer, which is 0 if + * the buffer is full. + */ + int write(const char* data, int length); + + /** This method writes a signle byte as a char to the buffer. + * + * @param data the byte to be written as a char. + * @returns 1 if the byte was written or 0 if the buffer was full. + */ + int write(char data); + + /** This method is used to setup a callback funtion when the buffer reaches + * a certain threshold. The threshold condition is checked after every read + * and write call is completed. The condition is made up of both a threshold + * value and operator. An example that would trigger a callback is if the + * threshold was 10, the operator GREATER, and there were 12 bytes added to an + * empty buffer. + * + * @param tptr a pointer to the object to be called when the condition is met. + * @param mptr a pointer to the function within the object to be called when + * the condition is met. + * @param threshold the value in bytes to be used as part of the condition. + * @param op the operator to be used in conjunction with the threshold + * as part of the condition. + */ + template<typename T> + void attach(T *tptr, void( T::*mptr)(void), int threshold, RelationalOperator op) { + _threshold = threshold; + _op = op; + notify.attach(tptr, mptr); + } + + /** This method is used to setup a callback funtion when the buffer reaches + * a certain threshold. The threshold condition is checked after every read + * and write call is completed. The condition is made up of both a threshold + * value and operator. An example that would trigger a callback is if the + * threshold was 10, the operator GREATER, and there were 12 bytes added to an + * empty buffer. + * + * @param fptr a pointer to the static function to be called when the condition + * is met. + * @param threshold the value in bytes to be used as part of the condition. + * @param op the operator to be used in conjunction with the threshold + * as part of the condition. + */ + void attach(void(*fptr)(void), int threshold, RelationalOperator op) { + _threshold = threshold; + _op = op; + notify.attach(fptr); + } + + /** This method returns the size of the storage space currently allocated for + * the buffer. This value is equivalent to the one passed into the constructor. + * This value is equal or greater than the size() of the buffer. + * + * @returns the allocated size of the buffer in bytes. + */ + int capacity(); + + /** This method returns the amount of space left for writing. + * + * @returns numbers of unused bytes in buffer. + */ + int remaining(); + + /** This method returns the number of bytes available for reading. + * + * @returns number of bytes currently in buffer. + */ + int size(); + + /** This method returns whether the buffer is full. + * + * @returns true if full, otherwise false. + */ + bool isFull(); + + /** This method returns whether the buffer is empty. + * + * @returns true if empty, otherwise false. + */ + bool isEmpty(); + + /** This method clears the buffer. This is done through + * setting the internal read and write indexes to the same + * value and is therefore not an expensive operation. + */ + void clear(); + + +private: + int bufferSize; // total size of the buffer + char* buffer; // internal byte buffer as a character buffer + int readIndex; // read index for circular buffer + int writeIndex; // write index for circular buffer + int bytes; // available data + FunctionPointer notify; // function pointer used for the internal callback notification + int _threshold; // threshold for the notification + RelationalOperator _op; // operator that determines the direction of the threshold + void checkThreshold(); // private function that checks thresholds and processes notifications +}; + +} + +#endif /* MTSCIRCULARBUFFER_H */