commit 361e767146d1a105ce76028a29ed010686a4735b
author Ryan Zuklie <rzuklie@google.com> Fri Mar 10 14:33:04 2023 -0800
committer Ryan Zuklie <rzuklie@google.com> Tue Mar 14 14:53:19 2023 -0700
tree 4b7897723b67d8ed7f136d2869dd80a6b50b98cb
parent e0cd64066ac36d452ec4b78018692d1a925766d0

Add support for NetworkTrace aggregation threshold

The aggregation threshold determines the number of packets a particular
bundle has to hit before recording only aggregate results. This allows
individual high-throughput streams to be recorded at a significantly
reduced trace buffer cost.

Bug: 246985031
Test: atest libnetworkstats_test
Change-Id: I9e3c6f013db91919be541860364764e913726cf1

service-t/native/libs/libnetworkstats/NetworkTraceHandler.cpp

diff --git a/service-t/native/libs/libnetworkstats/NetworkTraceHandler.cpp b/service-t/native/libs/libnetworkstats/NetworkTraceHandler.cpp
index 33bc9f2..a9550b5 100644
--- a/service-t/native/libs/libnetworkstats/NetworkTraceHandler.cpp
+++ b/service-t/native/libs/libnetworkstats/NetworkTraceHandler.cpp
@@ -182,15 +182,22 @@
     auto* event = dst->set_network_packet_bundle();
     Fill(key, event->set_ctx());
 
-    protozero::PackedVarInt offsets;
-    protozero::PackedVarInt lengths;
-    for (const auto& kv : details.time_and_len) {
-      offsets.Append(kv.first - details.minTs);
-      lengths.Append(kv.second);
-    }
+    int count = details.time_and_len.size();
+    if (!mAggregationThreshold || count < mAggregationThreshold) {
+      protozero::PackedVarInt offsets;
+      protozero::PackedVarInt lengths;
+      for (const auto& kv : details.time_and_len) {
+        offsets.Append(kv.first - details.minTs);
+        lengths.Append(kv.second);
+      }
 
-    event->set_packet_timestamps(offsets);
-    event->set_packet_lengths(lengths);
+      event->set_packet_timestamps(offsets);
+      event->set_packet_lengths(lengths);
+    } else {
+      event->set_total_duration(details.maxTs - details.minTs);
+      event->set_total_length(details.bytes);
+      event->set_total_packets(count);
+    }
   }
 }
 

service-t/native/libs/libnetworkstats/NetworkTraceHandlerTest.cpp

diff --git a/service-t/native/libs/libnetworkstats/NetworkTraceHandlerTest.cpp b/service-t/native/libs/libnetworkstats/NetworkTraceHandlerTest.cpp
index e92c5f0..6756fb0 100644
--- a/service-t/native/libs/libnetworkstats/NetworkTraceHandlerTest.cpp
+++ b/service-t/native/libs/libnetworkstats/NetworkTraceHandlerTest.cpp
@@ -203,5 +203,39 @@
               testing::ElementsAre(0, 2));
 }
 
+TEST_F(NetworkTraceHandlerTest, AggregationThreshold) {
+  // With an aggregation threshold of 3, the set of packets with uid=123 will
+  // be aggregated (3>=3) whereas packets with uid=456 get per-packet info.
+  NetworkPacketTraceConfig config;
+  config.set_aggregation_threshold(3);
+
+  std::vector<PacketTrace> input = {
+      PacketTrace{.uid = 123, .timestampNs = 2, .length = 200},
+      PacketTrace{.uid = 123, .timestampNs = 1, .length = 100},
+      PacketTrace{.uid = 123, .timestampNs = 4, .length = 300},
+
+      PacketTrace{.uid = 456, .timestampNs = 2, .length = 400},
+      PacketTrace{.uid = 456, .timestampNs = 4, .length = 100},
+  };
+
+  std::vector<TracePacket> events;
+  ASSERT_TRUE(TraceAndSortPackets(input, &events, config));
+
+  ASSERT_EQ(events.size(), 2);
+
+  EXPECT_EQ(events[0].timestamp(), 1);
+  EXPECT_EQ(events[0].network_packet_bundle().ctx().uid(), 123);
+  EXPECT_EQ(events[0].network_packet_bundle().total_duration(), 3);
+  EXPECT_EQ(events[0].network_packet_bundle().total_packets(), 3);
+  EXPECT_EQ(events[0].network_packet_bundle().total_length(), 600);
+
+  EXPECT_EQ(events[1].timestamp(), 2);
+  EXPECT_EQ(events[1].network_packet_bundle().ctx().uid(), 456);
+  EXPECT_THAT(events[1].network_packet_bundle().packet_lengths(),
+              testing::ElementsAre(400, 100));
+  EXPECT_THAT(events[1].network_packet_bundle().packet_timestamps(),
+              testing::ElementsAre(0, 2));
+}
+
 }  // namespace bpf
 }  // namespace android