diff options
Diffstat (limited to 'protocol/lufa/midi/bytequeue/bytequeue.c')
-rwxr-xr-x | protocol/lufa/midi/bytequeue/bytequeue.c | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/protocol/lufa/midi/bytequeue/bytequeue.c b/protocol/lufa/midi/bytequeue/bytequeue.c new file mode 100755 index 0000000000..e434956328 --- /dev/null +++ b/protocol/lufa/midi/bytequeue/bytequeue.c @@ -0,0 +1,65 @@ +//this is a single reader [maybe multiple writer?] byte queue +//Copyright 2008 Alex Norman +//writen by Alex Norman +// +//This file is part of avr-bytequeue. +// +//avr-bytequeue is free software: you can redistribute it and/or modify +//it under the terms of the GNU General Public License as published by +//the Free Software Foundation, either version 3 of the License, or +//(at your option) any later version. +// +//avr-bytequeue is distributed in the hope that it will be useful, +//but WITHOUT ANY WARRANTY; without even the implied warranty of +//MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +//GNU General Public License for more details. +// +//You should have received a copy of the GNU General Public License +//along with avr-bytequeue. If not, see <http://www.gnu.org/licenses/>. + +#include "bytequeue.h" +#include "interrupt_setting.h" + +void bytequeue_init(byteQueue_t * queue, uint8_t * dataArray, byteQueueIndex_t arrayLen){ + queue->length = arrayLen; + queue->data = dataArray; + queue->start = queue->end = 0; +} + +bool bytequeue_enqueue(byteQueue_t * queue, uint8_t item){ + interrupt_setting_t setting = store_and_clear_interrupt(); + //full + if(((queue->end + 1) % queue->length) == queue->start){ + restore_interrupt_setting(setting); + return false; + } else { + queue->data[queue->end] = item; + queue->end = (queue->end + 1) % queue->length; + restore_interrupt_setting(setting); + return true; + } +} + +byteQueueIndex_t bytequeue_length(byteQueue_t * queue){ + byteQueueIndex_t len; + interrupt_setting_t setting = store_and_clear_interrupt(); + if(queue->end >= queue->start) + len = queue->end - queue->start; + else + len = (queue->length - queue->start) + queue->end; + restore_interrupt_setting(setting); + return len; +} + +//we don't need to avoid interrupts if there is only one reader +uint8_t bytequeue_get(byteQueue_t * queue, byteQueueIndex_t index){ + return queue->data[(queue->start + index) % queue->length]; +} + +//we just update the start index to remove elements +void bytequeue_remove(byteQueue_t * queue, byteQueueIndex_t numToRemove){ + interrupt_setting_t setting = store_and_clear_interrupt(); + queue->start = (queue->start + numToRemove) % queue->length; + restore_interrupt_setting(setting); +} + |