summaryrefslogtreecommitdiff
path: root/protocol/lufa/midi/bytequeue/bytequeue.c
diff options
context:
space:
mode:
Diffstat (limited to 'protocol/lufa/midi/bytequeue/bytequeue.c')
-rwxr-xr-xprotocol/lufa/midi/bytequeue/bytequeue.c65
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);
+}
+