Very simple ring buffer implementation (not tested yet)

git-svn-id: http://svn.xiph.org/trunk/speex@14022 0101bb08-14d6-0310-b084-bc0e0c8e3800

1 files changed, 92 insertions, 0 deletions

diff --git a/libspeex/buffer.c b/libspeex/buffer.c
new file mode 100644
index 0000000..274137b
--- /dev/null
+++ b/libspeex/buffer.c
@@ -0,0 +1,92 @@
+
+#include "os_support.h"
+#include "misc.h"
+
+struct SpeexBuffer_;
+typedef struct SpeexBuffer_ SpeexBuffer;
+
+
+struct SpeexBuffer_ {
+   void *data;
+   int   size;
+   int   read_ptr;
+   int   write_ptr;
+   int   available;
+};
+
+SpeexBuffer *speex_buffer_init(int size)
+{
+   SpeexBuffer *st = speex_alloc(sizeof(SpeexBuffer));
+   st->data = speex_alloc(size);
+   st->size = size;
+   st->read_ptr = 0;
+   st->write_ptr = 0;
+   st->available = 0;
+   return st;
+}
+
+int speex_buffer_write(SpeexBuffer *st, void *data, int len)
+{
+   int end;
+   int end1;
+   if (len > st->size)
+   {
+      data += len-st->size;
+      len = st->size;
+   }
+   end = st->write_ptr + len;
+   end1 = end;
+   if (end1 > st->size)
+      end1 = st->size;
+   speex_move(st->data + st->write_ptr, data, end1 - st->write_ptr);
+   if (end > st->size)
+   {
+      end -= st->size;
+      speex_move(st->data, data+end1 - st->write_ptr, end);
+   }
+   st->available += len;
+   if (st->available > st->size)
+   {
+      st->available = st->size;
+      st->read_ptr = st->write_ptr;
+   }
+   return len;
+}
+
+/*int speex_buffer_writezeros(SpeexBuffer *st, int len)
+{
+   return len;
+}*/
+
+int speex_buffer_read(SpeexBuffer *st, void *data, int len)
+{
+   int end, end1;
+   if (len > st->available)
+   {
+      speex_memset(data+st->available, 0, st->size-st->available);
+      len = st->available;
+   }
+   end = st->read_ptr + len;
+   end1 = end;
+   if (end1 > st->size)
+      end1 = st->size;
+   speex_move(data, st->data + st->read_ptr, end1 - st->read_ptr);
+
+   if (end > st->size)
+   {
+      end -= st->size;
+      speex_move(data+end1 - st->read_ptr, st->data, end);
+   }
+   st->available -= len;
+   return len;
+}
+
+int speex_buffer_get_available(SpeexBuffer *st)
+{
+   return st->available;
+}
+
+int speex_buffer_resize(SpeexBuffer *st, void *data, int len)
+{
+   return len;
+}