Port changes from lttng-kt

[ust.git] / libust / header-inline.h

diff --git a/libust/header-inline.h b/libust/header-inline.h
new file mode 100644 (file)
index 0000000..1f1c6df
--- /dev/null
+++ b/libust/header-inline.h
@@ -0,0 +1,63 @@
+#ifndef UST_HEADER_INLINE_H
+#define UST_HEADER_INLINE_H
+
+#include "tracercore.h"
+
+/*
+ * ust_get_header_size
+ *
+ * Calculate alignment offset to 32-bits. This is the alignment offset of the
+ * event header.
+ *
+ * Important note :
+ * The event header must be 32-bits. The total offset calculated here :
+ *
+ * Alignment of header struct on 32 bits (min arch size, header size)
+ * + sizeof(header struct)  (32-bits)
+ * + (opt) u16 (ext. event id)
+ * + (opt) u16 (event_size) (if event_size == 0xFFFFUL, has ext. event size)
+ * + (opt) u32 (ext. event size)
+ * + (opt) u64 full TSC (aligned on min(64-bits, arch size))
+ *
+ * The payload must itself determine its own alignment from the biggest type it
+ * contains.
+ * */
+static __inline__ unsigned char ust_get_header_size(
+               struct ust_channel *channel,
+               size_t offset,
+               size_t data_size,
+               size_t *before_hdr_pad,
+               unsigned int rflags)
+{
+       size_t orig_offset = offset;
+       size_t padding;
+
+       padding = ltt_align(offset, sizeof(struct ltt_event_header));
+       offset += padding;
+       offset += sizeof(struct ltt_event_header);
+
+       if(unlikely(rflags)) {
+               switch (rflags) {
+               case LTT_RFLAG_ID_SIZE_TSC:
+                       offset += sizeof(u16) + sizeof(u16);
+                       if (data_size >= 0xFFFFU)
+                               offset += sizeof(u32);
+                       offset += ltt_align(offset, sizeof(u64));
+                       offset += sizeof(u64);
+                       break;
+               case LTT_RFLAG_ID_SIZE:
+                       offset += sizeof(u16) + sizeof(u16);
+                       if (data_size >= 0xFFFFU)
+                               offset += sizeof(u32);
+                       break;
+               case LTT_RFLAG_ID:
+                       offset += sizeof(u16);
+                       break;
+               }
+       }
+
+       *before_hdr_pad = padding;
+       return offset - orig_offset;
+}
+
+#endif /* UST_HEADER_INLINE_H */