Add ring buffer recording for assessment

1 files changed, 64 insertions, 0 deletions

diff --git a/tools/gui/ring-buffer.c b/tools/gui/ring-buffer.c
new file mode 100644
index 0000000..56c7620
--- /dev/null
+++ b/tools/gui/ring-buffer.c
@@ -0,0 +1,64 @@
+
+#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->start_index = 0;
+    buffer->data = g_malloc0 (n_blocks * buffer->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->start_index = 0;
+}
+
+gpointer
+ring_buffer_get_current_pointer (RingBuffer *buffer)
+{
+    return ring_buffer_get_pointer (buffer, 0);
+}
+
+gpointer
+ring_buffer_get_pointer (RingBuffer *buffer,
+                         guint       index)
+{
+    g_assert (index < buffer->n_blocks_total);
+    return buffer->data + ((buffer->start_index + 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->start_index++;
+
+    if (buffer->n_blocks_used < buffer->n_blocks_total)
+        buffer->n_blocks_used++;
+    else
+        buffer->start_index = buffer->start_index % buffer->n_blocks_total;
+}