perf session: Add perf_session__peek_event()
Add a function to peek at other events in the event stream.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1406786474-9306-15-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 7e27f1e..1b383bd 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -897,6 +897,61 @@
swap(event, sample_id_all);
}
+int perf_session__peek_event(struct perf_session *session, off_t file_offset,
+ void *buf, size_t buf_sz,
+ union perf_event **event_ptr,
+ struct perf_sample *sample)
+{
+ union perf_event *event;
+ size_t hdr_sz, rest;
+ int fd;
+
+ if (session->one_mmap && !session->header.needs_swap) {
+ event = file_offset - session->one_mmap_offset +
+ session->one_mmap_addr;
+ goto out_parse_sample;
+ }
+
+ if (perf_data_file__is_pipe(session->file))
+ return -1;
+
+ fd = perf_data_file__fd(session->file);
+ hdr_sz = sizeof(struct perf_event_header);
+
+ if (buf_sz < hdr_sz)
+ return -1;
+
+ if (lseek(fd, file_offset, SEEK_SET) == (off_t)-1 ||
+ readn(fd, &buf, hdr_sz) != (ssize_t)hdr_sz)
+ return -1;
+
+ event = (union perf_event *)buf;
+
+ if (session->header.needs_swap)
+ perf_event_header__bswap(&event->header);
+
+ if (event->header.size < hdr_sz)
+ return -1;
+
+ rest = event->header.size - hdr_sz;
+
+ if (readn(fd, &buf, rest) != (ssize_t)rest)
+ return -1;
+
+ if (session->header.needs_swap)
+ event_swap(event, perf_evlist__sample_id_all(session->evlist));
+
+out_parse_sample:
+
+ if (sample && event->header.type < PERF_RECORD_USER_TYPE_START &&
+ perf_evlist__parse_sample(session->evlist, event, sample))
+ return -1;
+
+ *event_ptr = event;
+
+ return 0;
+}
+
static s64 perf_session__process_event(struct perf_session *session,
union perf_event *event,
struct perf_tool *tool,