usrlib.cpp

00001 //******************************************************************************
00002 //*
00003 //*     FULLNAME:  Single-Chip Microcontroller Real-Time Operating System
00004 //*
00005 //*     NICKNAME:  scmRTOS
00006 //*               
00007 //*     PURPOSE:  User Suport Library Source
00008 //*               
00009 //*     Version: 3.10
00010 //*
00011 //*     $Revision: 256 $
00012 //*     $Date:: 2010-01-22 #$
00013 //*
00014 //*     Copyright (c) 2003-2010, Harry E. Zhurov
00015 //*
00016 //*     Permission is hereby granted, free of charge, to any person 
00017 //*     obtaining  a copy of this software and associated documentation 
00018 //*     files (the "Software"), to deal in the Software without restriction, 
00019 //*     including without limitation the rights to use, copy, modify, merge, 
00020 //*     publish, distribute, sublicense, and/or sell copies of the Software, 
00021 //*     and to permit persons to whom the Software is furnished to do so, 
00022 //*     subject to the following conditions:
00023 //*
00024 //*     The above copyright notice and this permission notice shall be included 
00025 //*     in all copies or substantial portions of the Software.
00026 //*
00027 //*     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
00028 //*     EXPRESS  OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 
00029 //*     MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
00030 //*     IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY 
00031 //*     CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, 
00032 //*     TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH 
00033 //*     THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
00034 //*
00035 //*     =================================================================
00036 //*     See http://scmrtos.sourceforge.net for documentation, latest
00037 //*     information, license and contact details.
00038 //*     =================================================================
00039 //*
00040 //******************************************************************************
00041 
00042 #include <usrlib.h>
00043 #include <commdefs.h>
00044 
00045 using namespace usr;
00046 
00047 //------------------------------------------------------------------------------
00048 //
00049 ///   Circular buffer function-member description
00050 //
00051 //
00052 //
00053 TCbuf::TCbuf(byte* const Address, const byte Size) :
00054         buf(Address),
00055         size(Size),
00056         count(0),
00057         first(0),
00058         last(0)
00059 {
00060 }
00061 //------------------------------------------------------------------------------
00062 bool TCbuf::write(const byte* data, const byte Count)
00063 {
00064     if( Count > (size - count) )
00065         return false;
00066 
00067     for(byte i = 0; i < Count; i++)
00068         push(*(data++));
00069 
00070     return true;
00071 }
00072 //------------------------------------------------------------------------------
00073 void TCbuf::read(byte* data, const byte Count)
00074 {
00075     byte N = Count <= count ? Count : count;
00076 
00077     for(byte i = 0; i < N; i++)
00078         data[i] = pop();
00079 }
00080 //------------------------------------------------------------------------------
00081 byte TCbuf::get_byte(const byte index) const
00082 {
00083     byte x = first + index;
00084 
00085     if(x < size)
00086         return buf[x];
00087     else
00088         return buf[x - size];
00089 }
00090 
00091 //------------------------------------------------------------------------------
00092 bool TCbuf::put(const byte item)
00093 {
00094     if(count == size)
00095         return false;
00096 
00097     push(item);
00098     return true;
00099 }
00100 //------------------------------------------------------------------------------
00101 byte TCbuf::get()
00102 {
00103     if(count)
00104         return pop();
00105     else
00106         return 0;
00107 }
00108 //------------------------------------------------------------------------------
00109 //
00110 /// \note
00111 /// For internal purposes.
00112 /// Use this function with care - it doesn't perform free size check.
00113 //
00114 void TCbuf::push(const byte item)
00115 {
00116     buf[last] = item;
00117     last++;
00118     count++;
00119 
00120     if(last == size)
00121         last = 0;
00122 }
00123 //------------------------------------------------------------------------------
00124 //
00125 /// \note
00126 /// For internal purposes.
00127 /// Use this function with care - it doesn't perform free size check.
00128 //
00129 byte TCbuf::pop()
00130 {
00131     byte item = buf[first];
00132 
00133     count--;
00134     first++;
00135     if(first == size)
00136         first = 0;
00137 
00138     return item;
00139 }
00140 //------------------------------------------------------------------------------