X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=libust%2Fbuffer.h;fp=libust%2Fbuffer.h;h=c974a0b6ba0f0d6211e2e9f489f7ee544269b2bb;hb=a6de76185dd1e98838d6801e34356f012df7544c;hp=0000000000000000000000000000000000000000;hpb=fd2fb4f99b55b49eab921fd5ef174fcbb539d2cf;p=ust.git

diff --git a/libust/buffer.h b/libust/buffer.h
new file mode 100644
index 0000000..c974a0b
--- /dev/null
+++ b/libust/buffer.h
@@ -0,0 +1,22 @@
+#ifndef UST_BUFFER_H
+#define UST_BUFFER_H
+
+/* Buffer offset macros */
+
+/*
+ * BUFFER_TRUNC zeroes the subbuffer offset and the subbuffer number parts of
+ * the offset, which leaves only the buffer number.
+ */
+#define BUFFER_TRUNC(offset, chan) \
+	((offset) & (~((chan)->alloc_size-1)))
+#define BUFFER_OFFSET(offset, chan) ((offset) & ((chan)->alloc_size - 1))
+#define SUBBUF_OFFSET(offset, chan) ((offset) & ((chan)->subbuf_size - 1))
+#define SUBBUF_ALIGN(offset, chan) \
+	(((offset) + (chan)->subbuf_size) & (~((chan)->subbuf_size - 1)))
+#define SUBBUF_TRUNC(offset, chan) \
+	((offset) & (~((chan)->subbuf_size - 1)))
+#define SUBBUF_INDEX(offset, chan) \
+	(BUFFER_OFFSET((offset), chan) >> (chan)->subbuf_size_order)
+
+
+#endif /* UST_BUFFER_H */