X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=include%2Fbabeltrace%2Fctf%2Ftypes.h;h=c311b532738612fb2feeb31da1655755f610101a;hb=dd2544fde7500d15afb76f588009874cc577f0ac;hp=73288ef6681117bb8b8bd839f5bf5fc3f5f738fd;hpb=bbefb8dd3e1e198313e2eaf83f5451224ef8e27e;p=babeltrace.git

diff --git a/include/babeltrace/ctf/types.h b/include/babeltrace/ctf/types.h
index 73288ef6..c311b532 100644
--- a/include/babeltrace/ctf/types.h
+++ b/include/babeltrace/ctf/types.h
@@ -23,6 +23,59 @@
 #include <stdint.h>
 #include <glib.h>
 
+/*
+ * Always update stream_pos with move_pos and init_pos.
+ */
+struct stream_pos {
+	char *base;		/* Base address */
+	size_t offset;		/* Offset from base, in bits */
+	int dummy;		/* Dummy position, for length calculation */
+};
+
+static inline
+void init_pos(struct stream_pos *pos, char *base)
+{
+	pos->base = base;	/* initial base, page-aligned */
+	pos->offset = 0;
+	pos->dummy = false;
+}
+
+/*
+ * move_pos - move position of a relative bit offset
+ *
+ * TODO: allow larger files by updating base too.
+ */
+static inline
+void move_pos(struct stream_pos *pos, size_t offset)
+{
+	pos->offset = pos->offset + offset;
+}
+
+/*
+ * align_pos - align position on a bit offset (> 0)
+ *
+ * TODO: allow larger files by updating base too.
+ */
+static inline
+void align_pos(struct stream_pos *pos, size_t offset)
+{
+	pos->offset += offset_align(pos->offset, offset);
+}
+
+static inline
+void copy_pos(struct stream_pos *dest, struct stream_pos *src)
+{
+	memcpy(dest, src, sizeof(struct stream_pos));
+}
+
+static inline
+char *get_pos_addr(struct stream_pos *pos)
+{
+	/* Only makes sense to get the address after aligning on CHAR_BIT */
+	assert(!(pos->offset % CHAR_BIT));
+	return pos->base + (pos->offset / CHAR_BIT);
+}
+
 /*
  * IMPORTANT: All lengths (len) and offsets (start, end) are expressed in bits,
  *            *not* in bytes.