Diff: utils/MTSCircularBuffer.h

Revision:

0:563b70517320

Child:

2:8d3ea0dfce39

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/utils/MTSCircularBuffer.h	Mon Dec 09 15:29:35 2013 +0000
@@ -0,0 +1,120 @@
+#ifndef MTSCIRCULARBUFFER_H
+#define MTSCIRCULARBUFFER_H
+
+#include "mbed.h"
+#include "Vars.h"
+
+/** 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.
+    *
+    * @returns the byte or -1 if no byte was available. 
+    */
+    int read();
+
+    /** This method enables bulk writes to the buffer. If more data
+    * is requested to be written then space available no data is written
+    * and an error value returned.
+    *
+    * @param data the byte array to be written.
+    * @param length the length of data to be written from the data paramter.
+    * @returns the capacity in the buffer or -1 if the write failed
+    * because the buffer was full.
+    */
+    int write(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 the capacity in the buffer or -1 if the write failed
+    * because the buffer was full.
+    */
+    int write(char data);
+
+    /**
+    *
+    */
+    template<typename T>
+    void attach(T *tptr, void(T::*mptr)(void), int threshold, Vars::RelationalOperator op);
+
+    void attach(void(*fptr)(void), int threshold, Vars::RelationalOperator op);
+
+    /** This method returns the static size of the buffer. This value
+    * is equivalent to the one passed into the constructor.
+    *
+    * @returns the static size of the buffer in bytes.
+    */
+    int getSize();
+
+    /** This method returns the amount of space left for writing.
+    *
+    * @returns numbers of unused bytes in buffer.
+    */
+    int capacity();
+
+    /** This method returns the number of bytes available for reading.
+    *
+    * @returns number of bytes currently in buffer.
+    */
+    int available();
+
+    /** This method returns whether the buffer is empty.
+    *
+    * @returns true if empty, otherwise false.
+    */
+    bool isEmpty();
+
+    /** This method returns whether the buffer is full.
+    *
+    * @returns true if full, otherwise false.
+    */
+    bool isFull();
+    
+    /** 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
+    FunctionPointer notify; // function pointer used for the internal callback notification 
+    int threshold; // threshold for the notification
+    Vars::RelationalOperator op; // operator that determines the direction of the threshold
+    void checkThreshold(); // private function that checks thresholds and processes notifications
+};
+
+#endif /* MTSCIRCULARBUFFER_H */
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