2 files changed, 99 insertions, 0 deletions
diff --git a/bin/common/ring-buffer.c b/bin/common/ring-buffer.c
new file mode 100644
index 0000000..039024f
--- /dev/null
+++ b/bin/common/ring-buffer.c
@@ -0,0 +1,70 @@
+
+#include <math.h>
+#include "ring-buffer.h"
+
+RingBuffer *
+ring_buffer_new (gsize block_size,
+                 gsize n_blocks)
+{
+    RingBuffer *buffer;
+
+    buffer = g_new0 (RingBuffer, 1);
+    buffer->block_size = block_size;
+    buffer->n_blocks_total = n_blocks;
+    buffer->n_blocks_used = 0;
+    buffer->current_index = 0;
+    buffer->data = g_malloc0_n (n_blocks, block_size);
+
+    return buffer;
+}
+
+void
+ring_buffer_free (RingBuffer *buffer)
+{
+    g_free (buffer->data);
+    g_free (buffer);
+}
+
+void
+ring_buffer_reset (RingBuffer *buffer)
+{
+    buffer->n_blocks_used = 0;
+    buffer->current_index = 0;
+}
+
+gsize
+ring_buffer_get_block_size (RingBuffer *buffer)
+{
+    return buffer->block_size;
+}
+
+gpointer
+ring_buffer_get_current_pointer (RingBuffer *buffer)
+{
+    return buffer->data + (buffer->current_index % buffer->n_blocks_total) * buffer->block_size;
+}
+
+gpointer
+ring_buffer_get_pointer (RingBuffer *buffer,
+                         guint       index)
+{
+    g_assert (index < buffer->n_blocks_total);
+    return buffer->data + ((buffer->current_index - buffer->n_blocks_used + index) % buffer->n_blocks_total) * buffer->block_size;
+}
+
+guint
+ring_buffer_get_num_blocks (RingBuffer *buffer)
+{
+    return buffer->n_blocks_used;
+}
+
+void
+ring_buffer_proceed (RingBuffer *buffer)
+{
+    buffer->current_index++;
+
+    if (buffer->n_blocks_used < buffer->n_blocks_total)
+        buffer->n_blocks_used++;
+    else
+        buffer->current_index = buffer->current_index % buffer->n_blocks_total;
+}
diff --git a/bin/common/ring-buffer.h b/bin/common/ring-buffer.h
new file mode 100644
index 0000000..a3758cb
--- /dev/null
+++ b/bin/common/ring-buffer.h
@@ -0,0 +1,29 @@
+#ifndef RING_BUFFER_H
+#define RING_BUFFER_H
+
+#include <glib.h>
+
+G_BEGIN_DECLS
+
+typedef struct {
+    guchar  *data;
+    gsize    block_size;
+    guint    n_blocks_total;
+    guint    n_blocks_used;
+    guint    current_index;
+} RingBuffer;
+
+RingBuffer * ring_buffer_new                  (gsize       block_size,
+                                               gsize       n_blocks);
+void         ring_buffer_free                 (RingBuffer *buffer);
+void         ring_buffer_reset                (RingBuffer *buffer);
+gsize        ring_buffer_get_block_size       (RingBuffer *buffer);
+gpointer     ring_buffer_get_current_pointer  (RingBuffer *buffer);
+gpointer     ring_buffer_get_pointer          (RingBuffer *buffer,
+                                               guint       index);
+guint        ring_buffer_get_num_blocks       (RingBuffer *buffer);
+void         ring_buffer_proceed              (RingBuffer *buffer);
+
+G_END_DECLS
+
+#endif