1 files changed, 86 insertions, 0 deletions
diff --git a/pd/portmidi_osx/pmutil.c b/pd/portmidi_osx/pmutil.c
new file mode 100644
index 00000000..f3582a42
--- /dev/null
+++ b/pd/portmidi_osx/pmutil.c
@@ -0,0 +1,86 @@
+/* pmutil.c -- some helpful utilities for building midi
+               applications that use PortMidi
+ */
+#include "stdlib.h"
+#include "memory.h"
+#include "portmidi.h"
+#include "pmutil.h"
+#include "pminternal.h"
+
+
+PmQueue *Pm_QueueCreate(long num_msgs, long bytes_per_msg)
+{
+    PmQueueRep *queue = (PmQueueRep *) malloc(sizeof(PmQueueRep));
+    if (!queue) return NULL;
+    queue->len = num_msgs * bytes_per_msg;
+    queue->buffer = malloc(queue->len);
+    if (!queue->buffer) {
+        free(queue);
+        return NULL;
+    }
+    queue->head = 0;
+    queue->tail = 0;
+    queue->msg_size = bytes_per_msg;
+    queue->overflow = FALSE;
+    return queue;
+}
+
+
+PmError Pm_QueueDestroy(PmQueue *q)
+{
+    PmQueueRep *queue = (PmQueueRep *) q;
+    if (!queue || !queue->buffer) return pmBadPtr;
+    free(queue->buffer);
+    free(queue);
+    return pmNoError;
+}
+
+
+PmError Pm_Dequeue(PmQueue *q, void *msg)
+{
+    long head;
+    PmQueueRep *queue = (PmQueueRep *) q;
+    if (queue->overflow) {
+        queue->overflow = FALSE;
+        return pmBufferOverflow;
+    }
+    head = queue->head; /* make sure this is written after access */
+    if (head == queue->tail) return 0;
+    memcpy(msg, queue->buffer + head, queue->msg_size);
+    head += queue->msg_size;
+    if (head == queue->len) head = 0;
+    queue->head = head;
+    return 1; /* success */
+}
+
+
+/* source should not enqueue data if overflow is set */
+/**/
+PmError Pm_Enqueue(PmQueue *q, void *msg)
+{
+    PmQueueRep *queue = (PmQueueRep *) q;
+    long tail = queue->tail;
+    memcpy(queue->buffer + tail, msg, queue->msg_size);
+    tail += queue->msg_size;
+    if (tail == queue->len) tail = 0;
+    if (tail == queue->head) {
+        queue->overflow = TRUE;
+        /* do not update tail, so message is lost */
+        return pmBufferOverflow;
+    }
+    queue->tail = tail;
+    return pmNoError;
+}
+
+
+int Pm_QueueFull(PmQueue *q)
+{
+    PmQueueRep *queue = (PmQueueRep *) q;
+    long tail = queue->tail;
+    tail += queue->msg_size;
+    if (tail == queue->len) {
+        tail = 0;
+    }
+    return (tail == queue->head);
+}
+