CircBuffer.h

00001 /* Copyright (c) 2010-2011 mbed.org, MIT License
00002 *
00003 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
00004 * and associated documentation files (the "Software"), to deal in the Software without
00005 * restriction, including without limitation the rights to use, copy, modify, merge, publish,
00006 * distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
00007 * Software is furnished to do so, subject to the following conditions:
00008 *
00009 * The above copyright notice and this permission notice shall be included in all copies or
00010 * substantial portions of the Software.
00011 *
00012 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
00013 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
00014 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
00015 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00016 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
00017 */
00018 
00019 #ifndef CIRCBUFFER_H
00020 #define CIRCBUFFER_H
00021 
00022 template <class T>
00023 class CircBuffer
00024 {
00025 public:
00026     CircBuffer( int length )
00027     {
00028         write = 0;
00029         read = 0;
00030         size = length + 1;
00031         buf = ( T * )malloc( size * sizeof( T ) );
00032     };
00033 
00034     bool isFull()
00035     {
00036         return ( ( write + 1 ) % size == read );
00037     };
00038 
00039     bool isEmpty()
00040     {
00041         return ( read == write );
00042     };
00043 
00044     void queue( T k )
00045     {
00046         if ( isFull() )
00047         {
00048             read++;
00049             read %= size;
00050         }
00051 
00052         buf[write++] = k;
00053         write %= size;
00054     }
00055 
00056     uint16_t available()
00057     {
00058         return ( write >= read ) ? write - read : size - read + write;
00059     };
00060 
00061     bool dequeue( T *c )
00062     {
00063         bool empty = isEmpty();
00064 
00065         if ( !empty )
00066         {
00067             *c = buf[read++];
00068             read %= size;
00069         }
00070 
00071         return( !empty );
00072     };
00073 
00074 private:
00075     volatile uint16_t write;
00076     volatile uint16_t read;
00077     uint16_t size;
00078     T *buf;
00079 };
00080 
00081 #endif
00082