1 files changed, 64 insertions, 0 deletions
diff --git a/quantum/midi/bytequeue/bytequeue.c b/quantum/midi/bytequeue/bytequeue.c
new file mode 100644
index 0000000000..0dd18680f0
--- /dev/null
+++ b/quantum/midi/bytequeue/bytequeue.c
@@ -0,0 +1,64 @@
+// 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);
+}