Update timestamps by carrying the overflow

[babeltrace.git] / formats / ctf / ctf.c

diff --git a/formats/ctf/ctf.c b/formats/ctf/ctf.c
index 5e43d2fa867cce377f14cf9869929ef20afd79bd..29f95fec1bcae16ba7a8dcc53665c51d18d7729b 100644 (file)
--- a/formats/ctf/ctf.c
+++ b/formats/ctf/ctf.c
@@ -87,6 +87,32 @@ struct format ctf_format = {
        .close_trace = ctf_close_trace,
 };
 
+static
+void ctf_update_timestamp(struct ctf_stream *stream,
+                         struct definition_integer *integer_definition)
+{
+       struct declaration_integer *integer_declaration =
+               integer_definition->declaration;
+       uint64_t oldval, newval, updateval;
+
+       if (integer_declaration->len == 64) {
+               stream->timestamp = integer_definition->value._unsigned;
+               return;
+       }
+       /* keep low bits */
+       oldval = stream->timestamp;
+       oldval &= (1ULL << integer_declaration->len) - 1;
+       newval = integer_definition->value._unsigned;
+       /* Test for overflow by comparing low bits */
+       if (newval < oldval)
+               newval += 1ULL << integer_declaration->len;
+       /* updateval contains old high bits, and new low bits (sum) */
+       updateval = stream->timestamp;
+       updateval &= ~((1ULL << integer_declaration->len) - 1);
+       updateval += newval;
+       stream->timestamp = updateval;
+}
+
 static
 int ctf_read_event(struct stream_pos *ppos, struct ctf_stream *stream)
 {
@@ -132,12 +158,12 @@ int ctf_read_event(struct stream_pos *ppos, struct ctf_stream *stream)
                /* lookup timestamp */
                integer_definition = lookup_integer(&stream_class->event_header->p, "timestamp", FALSE);
                if (integer_definition) {
-                       stream->timestamp = integer_definition->value._unsigned;
+                       ctf_update_timestamp(stream, integer_definition);
                } else {
                        if (variant) {
                                integer_definition = lookup_integer(variant, "timestamp", FALSE);
                                if (integer_definition) {
-                                       stream->timestamp = integer_definition->value._unsigned;
+                                       ctf_update_timestamp(stream, integer_definition);
                                }
                        }
                }
@@ -381,7 +407,12 @@ void ctf_move_pos_slow(struct ctf_stream_pos *pos, size_t offset, int whence)
                /* Lookup context/packet size in index */
                pos->content_size = index->content_size;
                pos->packet_size = index->packet_size;
-               pos->offset = index->data_offset;
+               if (index->data_offset < index->content_size)
+                       pos->offset = index->data_offset;
+               else {
+                       pos->offset = EOF;
+                       return;
+               }
        }
        /* map new base. Need mapping length from header. */
        pos->base = mmap(NULL, pos->packet_size / CHAR_BIT, pos->prot,