sb_getc.cpp

00001 /*
00002     Copyright (c) 2010 Andy Kirkham
00003  
00004     Permission is hereby granted, free of charge, to any person obtaining a copy
00005     of this software and associated documentation files (the "Software"), to deal
00006     in the Software without restriction, including without limitation the rights
00007     to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00008     copies of the Software, and to permit persons to whom the Software is
00009     furnished to do so, subject to the following conditions:
00010  
00011     The above copyright notice and this permission notice shall be included in
00012     all copies or substantial portions of the Software.
00013  
00014     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00015     IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00016     FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00017     AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00018     LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00019     OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00020     THE SOFTWARE.
00021 */
00022 
00023 #include "../SerialBuffered.h"
00024 #include "../sb_globals.h"
00025 
00026 int SerialBuffered::getc(bool blocking) {
00027     char c;
00028     
00029     if (blocking) while (_rx_buffer_out[uart_number] == _rx_buffer_in[uart_number] && !_rx_buffer_full[uart_number]) ; /* Blocks! */    
00030     else if (_rx_buffer_in[uart_number] == _rx_buffer_out[uart_number] && !_rx_buffer_full[uart_number]) return -1;
00031     
00032     c = _rx_buffer[uart_number][_rx_buffer_out[uart_number]++];
00033     if (_rx_buffer_out[uart_number] >= _rx_buffer_size[uart_number]) {
00034         _rx_buffer_out[uart_number] = 0;
00035     } 
00036     if (_rx_buffer_full[uart_number]) _rx_buffer_full[uart_number] = false;     
00037     return (int)c;   
00038 }
00039 
00040 char SerialBuffered::getc(void) {
00041     return (char)getc(true);
00042 }
00043 
00044 int SerialBuffered::readable(void) {
00045     return (_rx_buffer_full[uart_number] || _rx_buffer_overflow[uart_number] || _rx_buffer_in[uart_number] != _rx_buffer_out[uart_number]) ? 1 : 0;
00046 }