Stats traversal algorithm added.
This is part of the work to add a selector argument to getStats().
Changes:
- TakeReferencedStats() added, which traverses the stats graph and takes
any stats from the report that are directly or indirectly accessible
from the starting stats objects in the stats graph. The result is
returned as a stats report.
- GetStatsReferencedIds(), an efficient helper function for getting
neighbor stats object IDs.
- RTCStatsReport::Take(), removed the stats object with the given ID and
returns ownership of it (so that it can be added to another report).
TakeReferencedStats() is tested with a bunch of sample stats graphs.
GetStatsReferencedIds() is tested in the rtcstats_integrationttest.cc,
making sure the expected IDs are returned. The expected IDs are the
values of the stats object members with the "Id" or "Ids" suffix.
Design doc:
https://docs.google.com/document/d/18BywbtXgHCjsbR5nWBedpzqDjAfXrFSTJNiADnzoK0w/edit?usp=sharing
Bug: chromium:680172
Change-Id: I5da9da8250da0cb05adb864015901393a4290776
Reviewed-on: https://webrtc-review.googlesource.com/60869
Commit-Queue: Henrik Boström <hbos@webrtc.org>
Reviewed-by: Taylor Brandstetter <deadbeef@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22381}diff --git a/pc/BUILD.gn b/pc/BUILD.gn
index 334d1af..54bf0c7 100644
--- a/pc/BUILD.gn
+++ b/pc/BUILD.gn
@@ -150,6 +150,8 @@
"remoteaudiosource.h",
"rtcstatscollector.cc",
"rtcstatscollector.h",
+ "rtcstatstraversal.cc",
+ "rtcstatstraversal.h",
"rtpreceiver.cc",
"rtpreceiver.h",
"rtpsender.cc",
@@ -436,6 +438,7 @@
"proxy_unittest.cc",
"rtcstats_integrationtest.cc",
"rtcstatscollector_unittest.cc",
+ "rtcstatstraversal_unittest.cc",
"rtpmediautils_unittest.cc",
"rtpsenderreceiver_unittest.cc",
"sctputils_unittest.cc",
diff --git a/pc/rtcstats_integrationtest.cc b/pc/rtcstats_integrationtest.cc
index 374c048..40d07f7 100644
--- a/pc/rtcstats_integrationtest.cc
+++ b/pc/rtcstats_integrationtest.cc
@@ -8,6 +8,7 @@
* be found in the AUTHORS file in the root of the source tree.
*/
+#include <algorithm>
#include <set>
#include <vector>
@@ -17,6 +18,7 @@
#include "api/peerconnectioninterface.h"
#include "api/stats/rtcstats_objects.h"
#include "api/stats/rtcstatsreport.h"
+#include "pc/rtcstatstraversal.h"
#include "pc/test/peerconnectiontestwrapper.h"
#include "pc/test/rtcstatsobtainer.h"
#include "rtc_base/checks.h"
@@ -24,6 +26,7 @@
#include "rtc_base/gunit.h"
#include "rtc_base/refcountedobject.h"
#include "rtc_base/scoped_ref_ptr.h"
+#include "rtc_base/stringutils.h"
#include "rtc_base/trace_event.h"
#include "rtc_base/virtualsocketserver.h"
@@ -741,6 +744,52 @@
EXPECT_EQ(stats_obtainer->report()->ToJson(),
RTCStatsReportTraceListener::last_trace());
}
+
+// GetStatsReferencedIds() is optimized to recognize what is or isn't a
+// referenced ID based on dictionary type information and knowing what members
+// are used as references, as opposed to iterating all members to find the ones
+// with the "Id" or "Ids" suffix. As such, GetStatsReferencedIds() is tested as
+// an integration test instead of a unit test in order to guard against adding
+// new references and forgetting to update GetStatsReferencedIds().
+TEST_F(RTCStatsIntegrationTest, GetStatsReferencedIds) {
+ StartCall();
+
+ rtc::scoped_refptr<const RTCStatsReport> report = GetStatsFromCallee();
+ for (const RTCStats& stats : *report) {
+ // Find all references by looking at all string members with the "Id" or
+ // "Ids" suffix.
+ std::set<const std::string*> expected_ids;
+ for (const auto* member : stats.Members()) {
+ if (!member->is_defined())
+ continue;
+ if (member->type() == RTCStatsMemberInterface::kString) {
+ if (rtc::ends_with(member->name(), "Id")) {
+ const auto& id = member->cast_to<const RTCStatsMember<std::string>>();
+ expected_ids.insert(&(*id));
+ }
+ } else if (member->type() == RTCStatsMemberInterface::kSequenceString) {
+ if (rtc::ends_with(member->name(), "Ids")) {
+ const auto& ids =
+ member->cast_to<const RTCStatsMember<std::vector<std::string>>>();
+ for (const std::string& id : *ids)
+ expected_ids.insert(&id);
+ }
+ }
+ }
+
+ std::vector<const std::string*> neighbor_ids = GetStatsReferencedIds(stats);
+ EXPECT_EQ(neighbor_ids.size(), expected_ids.size());
+ for (const std::string* neighbor_id : neighbor_ids) {
+ EXPECT_TRUE(expected_ids.find(neighbor_id) != expected_ids.end())
+ << "Unexpected neighbor ID: " << *neighbor_id;
+ }
+ for (const std::string* expected_id : expected_ids) {
+ EXPECT_TRUE(std::find(neighbor_ids.begin(), neighbor_ids.end(),
+ expected_id) != neighbor_ids.end())
+ << "Missing expected neighbor ID: " << *expected_id;
+ }
+ }
+}
#endif // HAVE_SCTP
} // namespace
diff --git a/pc/rtcstatstraversal.cc b/pc/rtcstatstraversal.cc
new file mode 100644
index 0000000..2b74bee
--- /dev/null
+++ b/pc/rtcstatstraversal.cc
@@ -0,0 +1,119 @@
+/*
+ * Copyright 2018 The WebRTC Project Authors. All rights reserved.
+ *
+ * Use of this source code is governed by a BSD-style license
+ * that can be found in the LICENSE file in the root of the source
+ * tree. An additional intellectual property rights grant can be found
+ * in the file PATENTS. All contributing project authors may
+ * be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "pc/rtcstatstraversal.h"
+
+#include <memory>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "api/stats/rtcstats_objects.h"
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+
+namespace {
+
+void TraverseAndTakeVisitedStats(RTCStatsReport* report,
+ RTCStatsReport* visited_report,
+ const std::string& current_id) {
+ // Mark current stats object as visited by moving it |report| to
+ // |visited_report|.
+ std::unique_ptr<const RTCStats> current = report->Take(current_id);
+ if (!current) {
+ // This node has already been visited (or it is an invalid id).
+ return;
+ }
+ std::vector<const std::string*> neighbor_ids =
+ GetStatsReferencedIds(*current);
+ visited_report->AddStats(std::move(current));
+
+ // Recursively traverse all neighbors.
+ for (const auto* neighbor_id : neighbor_ids) {
+ TraverseAndTakeVisitedStats(report, visited_report, *neighbor_id);
+ }
+}
+
+void AddIdIfDefined(const RTCStatsMember<std::string>& id,
+ std::vector<const std::string*>* neighbor_ids) {
+ if (id.is_defined())
+ neighbor_ids->push_back(&(*id));
+}
+
+void AddIdsIfDefined(const RTCStatsMember<std::vector<std::string>>& ids,
+ std::vector<const std::string*>* neighbor_ids) {
+ if (ids.is_defined()) {
+ for (const std::string& id : *ids)
+ neighbor_ids->push_back(&id);
+ }
+}
+
+} // namespace
+
+rtc::scoped_refptr<RTCStatsReport> TakeReferencedStats(
+ rtc::scoped_refptr<RTCStatsReport> report,
+ const std::vector<std::string>& ids) {
+ rtc::scoped_refptr<RTCStatsReport> result = RTCStatsReport::Create();
+ for (const auto& id : ids) {
+ TraverseAndTakeVisitedStats(report.get(), result.get(), id);
+ }
+ return result;
+}
+
+std::vector<const std::string*> GetStatsReferencedIds(const RTCStats& stats) {
+ std::vector<const std::string*> neighbor_ids;
+ const char* type = stats.type();
+ if (type == RTCCertificateStats::kType) {
+ const auto& certificate = static_cast<const RTCCertificateStats&>(stats);
+ AddIdIfDefined(certificate.issuer_certificate_id, &neighbor_ids);
+ } else if (type == RTCCodecStats::kType) {
+ // RTCCodecStats does not have any neighbor references.
+ } else if (type == RTCDataChannelStats::kType) {
+ // RTCDataChannelStats does not have any neighbor references.
+ } else if (type == RTCIceCandidatePairStats::kType) {
+ const auto& candidate_pair =
+ static_cast<const RTCIceCandidatePairStats&>(stats);
+ AddIdIfDefined(candidate_pair.transport_id, &neighbor_ids);
+ AddIdIfDefined(candidate_pair.local_candidate_id, &neighbor_ids);
+ AddIdIfDefined(candidate_pair.remote_candidate_id, &neighbor_ids);
+ } else if (type == RTCLocalIceCandidateStats::kType ||
+ type == RTCRemoteIceCandidateStats::kType) {
+ const auto& local_or_remote_candidate =
+ static_cast<const RTCIceCandidateStats&>(stats);
+ AddIdIfDefined(local_or_remote_candidate.transport_id, &neighbor_ids);
+ } else if (type == RTCMediaStreamStats::kType) {
+ const auto& stream = static_cast<const RTCMediaStreamStats&>(stats);
+ AddIdsIfDefined(stream.track_ids, &neighbor_ids);
+ } else if (type == RTCMediaStreamTrackStats::kType) {
+ // RTCMediaStreamTrackStats does not have any neighbor references.
+ } else if (type == RTCPeerConnectionStats::kType) {
+ // RTCPeerConnectionStats does not have any neighbor references.
+ } else if (type == RTCInboundRTPStreamStats::kType ||
+ type == RTCOutboundRTPStreamStats::kType) {
+ const auto& rtp = static_cast<const RTCRTPStreamStats&>(stats);
+ AddIdIfDefined(rtp.associate_stats_id, &neighbor_ids);
+ AddIdIfDefined(rtp.track_id, &neighbor_ids);
+ AddIdIfDefined(rtp.transport_id, &neighbor_ids);
+ AddIdIfDefined(rtp.codec_id, &neighbor_ids);
+ } else if (type == RTCTransportStats::kType) {
+ // RTCTransportStats does not have any neighbor references.
+ const auto& transport = static_cast<const RTCTransportStats&>(stats);
+ AddIdIfDefined(transport.rtcp_transport_stats_id, &neighbor_ids);
+ AddIdIfDefined(transport.selected_candidate_pair_id, &neighbor_ids);
+ AddIdIfDefined(transport.local_certificate_id, &neighbor_ids);
+ AddIdIfDefined(transport.remote_certificate_id, &neighbor_ids);
+ } else {
+ RTC_NOTREACHED() << "Unrecognized type: " << type;
+ }
+ return neighbor_ids;
+}
+
+} // namespace webrtc
diff --git a/pc/rtcstatstraversal.h b/pc/rtcstatstraversal.h
new file mode 100644
index 0000000..1c50ae4
--- /dev/null
+++ b/pc/rtcstatstraversal.h
@@ -0,0 +1,43 @@
+/*
+ * Copyright 2018 The WebRTC Project Authors. All rights reserved.
+ *
+ * Use of this source code is governed by a BSD-style license
+ * that can be found in the LICENSE file in the root of the source
+ * tree. An additional intellectual property rights grant can be found
+ * in the file PATENTS. All contributing project authors may
+ * be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef PC_RTCSTATSTRAVERSAL_H_
+#define PC_RTCSTATSTRAVERSAL_H_
+
+#include <string>
+#include <vector>
+
+#include "api/stats/rtcstatsreport.h"
+#include "rtc_base/scoped_ref_ptr.h"
+
+namespace webrtc {
+
+// Traverses the stats graph, taking all stats objects that are directly or
+// indirectly accessible from and including the stats objects identified by
+// |ids|, returning them as a new stats report.
+// This is meant to be used to implement the stats selection algorithm.
+// https://w3c.github.io/webrtc-pc/#dfn-stats-selection-algorithm
+rtc::scoped_refptr<RTCStatsReport> TakeReferencedStats(
+ rtc::scoped_refptr<RTCStatsReport> report,
+ const std::vector<std::string>& ids);
+
+// Gets pointers to the string values of any members in |stats| that are used as
+// references for looking up other stats objects in the same report by ID. The
+// pointers are valid for the lifetime of |stats| assumings its members are not
+// modified.
+//
+// For example, RTCCodecStats contains "transportId"
+// (RTCCodecStats::transport_id) referencing an RTCTransportStats.
+// https://w3c.github.io/webrtc-stats/#dom-rtccodecstats-transportid
+std::vector<const std::string*> GetStatsReferencedIds(const RTCStats& stats);
+
+} // namespace webrtc
+
+#endif // PC_RTCSTATSTRAVERSAL_H_
diff --git a/pc/rtcstatstraversal_unittest.cc b/pc/rtcstatstraversal_unittest.cc
new file mode 100644
index 0000000..0552964
--- /dev/null
+++ b/pc/rtcstatstraversal_unittest.cc
@@ -0,0 +1,208 @@
+/*
+ * Copyright 2018 The WebRTC Project Authors. All rights reserved.
+ *
+ * Use of this source code is governed by a BSD-style license
+ * that can be found in the LICENSE file in the root of the source
+ * tree. An additional intellectual property rights grant can be found
+ * in the file PATENTS. All contributing project authors may
+ * be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "pc/rtcstatstraversal.h"
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "api/stats/rtcstats_objects.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/gunit.h"
+
+// This file contains tests for TakeReferencedStats().
+// GetStatsNeighborIds() is tested in rtcstats_integrationtest.cc.
+
+namespace webrtc {
+
+class RTCStatsTraversalTest : public testing::Test {
+ public:
+ RTCStatsTraversalTest() {
+ transport_ = new RTCTransportStats("transport", 0);
+ candidate_pair_ = new RTCIceCandidatePairStats("candidate-pair", 0);
+ local_candidate_ = new RTCLocalIceCandidateStats("local-candidate", 0);
+ remote_candidate_ = new RTCRemoteIceCandidateStats("remote-candidate", 0);
+ initial_report_ = RTCStatsReport::Create(0);
+ initial_report_->AddStats(std::unique_ptr<const RTCStats>(transport_));
+ initial_report_->AddStats(std::unique_ptr<const RTCStats>(candidate_pair_));
+ initial_report_->AddStats(
+ std::unique_ptr<const RTCStats>(local_candidate_));
+ initial_report_->AddStats(
+ std::unique_ptr<const RTCStats>(remote_candidate_));
+ result_ = RTCStatsReport::Create(0);
+ }
+
+ void TakeReferencedStats(std::vector<const RTCStats*> start_nodes) {
+ std::vector<std::string> start_ids;
+ for (const RTCStats* start_node : start_nodes) {
+ start_ids.push_back(start_node->id());
+ }
+ result_ = webrtc::TakeReferencedStats(initial_report_, start_ids);
+ }
+
+ void EXPECT_VISITED(const RTCStats* stats) {
+ EXPECT_FALSE(initial_report_->Get(stats->id()))
+ << '"' << stats->id()
+ << "\" should be visited but it was not removed from initial report.";
+ EXPECT_TRUE(result_->Get(stats->id()))
+ << '"' << stats->id()
+ << "\" should be visited but it was not added to the resulting report.";
+ }
+
+ void EXPECT_UNVISITED(const RTCStats* stats) {
+ EXPECT_TRUE(initial_report_->Get(stats->id()))
+ << '"' << stats->id()
+ << "\" should not be visited but it was removed from initial report.";
+ EXPECT_FALSE(result_->Get(stats->id()))
+ << '"' << stats->id()
+ << "\" should not be visited but it was added to the resulting report.";
+ }
+
+ protected:
+ rtc::scoped_refptr<RTCStatsReport> initial_report_;
+ rtc::scoped_refptr<RTCStatsReport> result_;
+ // Raw pointers to stats owned by the reports.
+ RTCTransportStats* transport_;
+ RTCIceCandidatePairStats* candidate_pair_;
+ RTCIceCandidateStats* local_candidate_;
+ RTCIceCandidateStats* remote_candidate_;
+};
+
+TEST_F(RTCStatsTraversalTest, NoReachableConnections) {
+ // Everything references transport but transport doesn't reference anything.
+ //
+ // candidate-pair
+ // | | |
+ // v | v
+ // local-candidate | remote-candidate
+ // | | |
+ // v v v
+ // start:transport
+ candidate_pair_->transport_id = "transport";
+ candidate_pair_->local_candidate_id = "local-candidate";
+ candidate_pair_->remote_candidate_id = "remote-candidate";
+ local_candidate_->transport_id = "transport";
+ remote_candidate_->transport_id = "transport";
+ TakeReferencedStats({transport_});
+ EXPECT_VISITED(transport_);
+ EXPECT_UNVISITED(candidate_pair_);
+ EXPECT_UNVISITED(local_candidate_);
+ EXPECT_UNVISITED(remote_candidate_);
+}
+
+TEST_F(RTCStatsTraversalTest, SelfReference) {
+ transport_->rtcp_transport_stats_id = "transport";
+ TakeReferencedStats({transport_});
+ EXPECT_VISITED(transport_);
+ EXPECT_UNVISITED(candidate_pair_);
+ EXPECT_UNVISITED(local_candidate_);
+ EXPECT_UNVISITED(remote_candidate_);
+}
+
+TEST_F(RTCStatsTraversalTest, BogusReference) {
+ transport_->rtcp_transport_stats_id = "bogus-reference";
+ TakeReferencedStats({transport_});
+ EXPECT_VISITED(transport_);
+ EXPECT_UNVISITED(candidate_pair_);
+ EXPECT_UNVISITED(local_candidate_);
+ EXPECT_UNVISITED(remote_candidate_);
+}
+
+TEST_F(RTCStatsTraversalTest, Tree) {
+ // start:candidate-pair
+ // | |
+ // v v
+ // local-candidate remote-candidate
+ // |
+ // v
+ // transport
+ candidate_pair_->local_candidate_id = "local-candidate";
+ candidate_pair_->remote_candidate_id = "remote-candidate";
+ local_candidate_->transport_id = "transport";
+ TakeReferencedStats({candidate_pair_});
+ EXPECT_VISITED(transport_);
+ EXPECT_VISITED(candidate_pair_);
+ EXPECT_VISITED(local_candidate_);
+ EXPECT_VISITED(remote_candidate_);
+}
+
+TEST_F(RTCStatsTraversalTest, MultiplePathsToSameNode) {
+ // start:candidate-pair
+ // | |
+ // v v
+ // local-candidate remote-candidate
+ // | |
+ // v v
+ // transport
+ candidate_pair_->local_candidate_id = "local-candidate";
+ candidate_pair_->remote_candidate_id = "remote-candidate";
+ local_candidate_->transport_id = "transport";
+ remote_candidate_->transport_id = "transport";
+ TakeReferencedStats({candidate_pair_});
+ EXPECT_VISITED(transport_);
+ EXPECT_VISITED(candidate_pair_);
+ EXPECT_VISITED(local_candidate_);
+ EXPECT_VISITED(remote_candidate_);
+}
+
+TEST_F(RTCStatsTraversalTest, CyclicGraph) {
+ // candidate-pair
+ // | ^
+ // v |
+ // start:local-candidate | remote-candidate
+ // | |
+ // v |
+ // transport
+ local_candidate_->transport_id = "transport";
+ transport_->selected_candidate_pair_id = "candidate-pair";
+ candidate_pair_->local_candidate_id = "local-candidate";
+ TakeReferencedStats({local_candidate_});
+ EXPECT_VISITED(transport_);
+ EXPECT_VISITED(candidate_pair_);
+ EXPECT_VISITED(local_candidate_);
+ EXPECT_UNVISITED(remote_candidate_);
+}
+
+TEST_F(RTCStatsTraversalTest, MultipleStarts) {
+ // start:candidate-pair
+ // |
+ // v
+ // local-candidate remote-candidate
+ // |
+ // v
+ // start:transport
+ candidate_pair_->remote_candidate_id = "remote-candidate";
+ local_candidate_->transport_id = "transport";
+ TakeReferencedStats({candidate_pair_, transport_});
+ EXPECT_VISITED(transport_);
+ EXPECT_VISITED(candidate_pair_);
+ EXPECT_UNVISITED(local_candidate_);
+ EXPECT_VISITED(remote_candidate_);
+}
+
+TEST_F(RTCStatsTraversalTest, MultipleStartsLeadingToSameNode) {
+ // candidate-pair
+ //
+ //
+ // start:local-candidate start:remote-candidate
+ // | |
+ // v v
+ // transport
+ local_candidate_->transport_id = "transport";
+ remote_candidate_->transport_id = "transport";
+ TakeReferencedStats({local_candidate_, remote_candidate_});
+ EXPECT_VISITED(transport_);
+ EXPECT_UNVISITED(candidate_pair_);
+ EXPECT_VISITED(local_candidate_);
+ EXPECT_VISITED(remote_candidate_);
+}
+
+} // namespace webrtc
