1 files changed, 94 insertions, 0 deletions
diff --git a/src/queue.c b/src/queue.c
new file mode 100644
index 0000000..1b52a8c
--- /dev/null
+++ b/src/queue.c
@@ -0,0 +1,94 @@
+/*
+ * queue.c
+ *
+ */
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "queue.h"
+
+void
+clonequeue(Queue *t, Queue *s)
+{
+  t->alloc = t->elements = malloc((s->count + 8) * sizeof(Id));
+  if (s->count)
+    memcpy(t->alloc, s->elements, s->count * sizeof(Id));
+  t->count = s->count;
+  t->left = 8;
+}
+
+void
+queueinit(Queue *q)
+{
+  q->alloc = q->elements = 0;
+  q->count = q->left = 0;
+}
+
+void
+queueinit_buffer(Queue *q, Id *buf, int size)
+{
+  q->alloc = 0;
+  q->elements = buf;
+  q->count = 0;
+  q->left = size;
+}
+
+void
+queuefree(Queue *q)
+{
+  if (q->alloc)
+    free(q->alloc);
+  q->alloc = q->elements = 0;
+  q->count = q->left = 0;
+}
+
+Id
+queueshift(Queue *q)
+{
+  if (!q->count)
+    return 0;
+  q->count--;
+  return *q->elements++;
+}
+
+void
+queuepush(Queue *q, Id id)
+{
+  if (!q->left)
+    {
+      if (q->alloc && q->alloc != q->elements)
+	{
+	  memmove(q->alloc, q->elements, q->count * sizeof(Id));
+	  q->left += q->elements - q->alloc;
+	  q->elements = q->alloc;
+	}
+      else if (q->alloc)
+	{
+	  q->elements = q->alloc = realloc(q->alloc, (q->count + 8) * sizeof(Id));
+	  q->left += 8;
+	}
+      else
+	{
+	  q->alloc = malloc((q->count + 8) * sizeof(Id));
+	  if (q->count)
+	    memcpy(q->alloc, q->elements, q->count * sizeof(Id));
+	  q->elements = q->alloc;
+	  q->left += 8;
+	}
+    }
+  q->elements[q->count++] = id;
+  q->left--;
+}
+
+void
+queuepushunique(Queue *q, Id id)
+{
+  int i;
+  for (i = q->count; i > 0; )
+    if (q->elements[--i] == id)
+      return;
+  queuepush(q, id);
+}
+
+