Make the Trace object itself lazy

Make start optional and explicit.

3 files changed, 6 insertions, 5 deletions

diff --git a/searchcore/src/tests/proton/matching/match_phase_limiter/match_phase_limiter_test.cpp b/searchcore/src/tests/proton/matching/match_phase_limiter/match_phase_limiter_test.cpp
index be4bc159b1b..d05abac203e 100644
--- a/searchcore/src/tests/proton/matching/match_phase_limiter/match_phase_limiter_test.cpp
+++ b/searchcore/src/tests/proton/matching/match_phase_limiter/match_phase_limiter_test.cpp
@@ -291,6 +291,7 @@ TEST("require that the match phase limiter is able to pre-limit the query") {
     EXPECT_EQUAL(12u, limiter.sample_hits_per_thread(10));
     RelativeTime clock(std::make_unique<CountingClock>(fastos::TimeStamp::fromSec(1500000000), 1700000L));
     Trace trace(clock, 7);
+    trace.start(4);
     SearchIterator::UP search = limiter.maybe_limit(prepare(new MockSearch("search")), 0.1, 100000, trace.maybeCreateCursor(7, "limit"));
     limiter.updateDocIdSpaceEstimate(1000, 9000);
     EXPECT_EQUAL(1680u, limiter.getDocIdSpaceEstimate());
@@ -331,7 +332,7 @@ TEST("require that the match phase limiter is able to pre-limit the query") {
         "        }"
         "    ],"
         "    duration_ms: 3.4"
-        "}", trace.getSlime());
+        "}", *trace.getSlime());
 }
 
 TEST("require that the match phase limiter is able to post-limit the query") {
diff --git a/searchcore/src/vespa/searchcore/proton/matchengine/matchengine.cpp b/searchcore/src/vespa/searchcore/proton/matchengine/matchengine.cpp
index c7016d711cb..f887b5069cb 100644
--- a/searchcore/src/vespa/searchcore/proton/matchengine/matchengine.cpp
+++ b/searchcore/src/vespa/searchcore/proton/matchengine/matchengine.cpp
@@ -141,11 +141,11 @@ MatchEngine::performSearch(search::engine::SearchRequest::Source req,
     ret->request = req.release();
     ret->setDistributionKey(_distributionKey);
     if (ret->request->trace().getLevel() > 0) {
-        ret->request->trace().getRoot().setLong("distribution-key", _distributionKey);
+        ret->request->trace().getRoot()->setLong("distribution-key", _distributionKey);
         ret->request->trace().done();
         search::fef::Properties & trace = ret->propertiesMap.lookupCreate("trace");
         vespalib::SmartBuffer output(4096);
-        vespalib::slime::BinaryFormat::encode(ret->request->trace().getSlime(), output);
+        vespalib::slime::BinaryFormat::encode(*ret->request->trace().getSlime(), output);
         trace.add("slime", output.obtain().make_stringref());
     }
     client.searchDone(std::move(ret));
diff --git a/searchcore/src/vespa/searchcore/proton/matching/match_master.cpp b/searchcore/src/vespa/searchcore/proton/matching/match_master.cpp
index 7dd06038707..ed8900e0cac 100644
--- a/searchcore/src/vespa/searchcore/proton/matching/match_master.cpp
+++ b/searchcore/src/vespa/searchcore/proton/matching/match_master.cpp
@@ -99,8 +99,8 @@ MatchMaster::match(search::engine::Trace & trace,
         const MatchThread & matchThread = *threadState[i];
         match_time_s = std::max(match_time_s, matchThread.get_match_time());
         _stats.merge_partition(matchThread.get_thread_stats(), i);
-        if (inserter) {
-            vespalib::slime::inject(matchThread.getTrace().getRoot(), *inserter);
+        if (inserter && matchThread.getTrace().getRoot()) {
+            vespalib::slime::inject(*matchThread.getTrace().getRoot(), *inserter);
         }
     }
     _stats.queryLatency(query_time_s);