From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36238) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1blzso-00070i-Vp for qemu-devel@nongnu.org; Mon, 19 Sep 2016 10:49:24 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1blzsj-0005mT-UO for qemu-devel@nongnu.org; Mon, 19 Sep 2016 10:49:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37970) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1blzsj-0005m5-O5 for qemu-devel@nongnu.org; Mon, 19 Sep 2016 10:49:17 -0400 From: "Daniel P. Berrange" Date: Mon, 19 Sep 2016 15:48:52 +0100 Message-Id: <1474296549-29171-2-git-send-email-berrange@redhat.com> In-Reply-To: <1474296549-29171-1-git-send-email-berrange@redhat.com> References: <1474296549-29171-1-git-send-email-berrange@redhat.com> Subject: [Qemu-devel] [PATCH v3 01/18] trace: add trace event iterator APIs List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Stefan Hajnoczi , =?UTF-8?q?Llu=C3=ADs=20Vilanova?= , "Daniel P. Berrange" Currently methods which want to iterate over trace events, do so using the trace_event_count() and trace_event_id() methods. This leaks the concept of a single ID enum to the callers. There is an alternative trace_event_pattern() method which can be used in an iteration context, but its design is stateless, so is not easy to expand it in the future. This defines a formal iterator API will provide an future proof way of iterating over events. The iterator is also able to apply a pattern match filter to events, further removing the need for the pattern Signed-off-by: Daniel P. Berrange --- trace/control.c | 21 +++++++++++++++++++++ trace/control.h | 27 +++++++++++++++++++++++++++ 2 files changed, 48 insertions(+) diff --git a/trace/control.c b/trace/control.c index 05d85ac..1a96049 100644 --- a/trace/control.c +++ b/trace/control.c @@ -125,6 +125,27 @@ TraceEvent *trace_event_pattern(const char *pat, TraceEvent *ev) return NULL; } +void trace_event_iter_init(TraceEventIter *iter, const char *pattern) +{ + iter->event = 0; + iter->pattern = pattern; +} + +TraceEvent *trace_event_iter_next(TraceEventIter *iter) +{ + while (iter->event < TRACE_EVENT_COUNT) { + TraceEvent *ev = &(trace_events[iter->event]); + iter->event++; + if (!iter->pattern || + pattern_glob(iter->pattern, + trace_event_get_name(ev))) { + return ev; + } + } + + return NULL; +} + void trace_list_events(void) { int i; diff --git a/trace/control.h b/trace/control.h index 27a16fc..c71b405 100644 --- a/trace/control.h +++ b/trace/control.h @@ -13,6 +13,10 @@ #include "qemu-common.h" #include "trace/generated-events.h" +typedef struct TraceEventIter { + size_t event; + const char *pattern; +} TraceEventIter; /** * TraceEventID: @@ -25,6 +29,29 @@ */ enum TraceEventID; + +/** + * trace_event_iter_init: + * @iter: the event iterator struct + * @pattern: optional pattern to filter events on name + * + * Initialize the event iterator struct @iter, + * optionally using @pattern to filter out events + * with non-matching names. + */ +void trace_event_iter_init(TraceEventIter *iter, const char *pattern); + +/** + * trace_event_iter_next: + * @iter: the event iterator struct + * + * Get the next event, if any. When this returns NULL, + * the iterator should no longer be used. + * + * Returns: the next event, or NULL if no more events exist + */ +TraceEvent *trace_event_iter_next(TraceEventIter *iter); + /** * trace_event_id: * @id: Event identifier. -- 2.7.4