commit bbe311c0e56957cf2ae9cda634ee6907220859bd
author Jonathan Nguyen <jtnguyen@google.com> Thu Mar 14 20:44:52 2019 -0700
committer Tej Singh <singhtejinder@google.com> Fri Mar 15 00:26:32 2019 -0700
tree 0cd9bf77d363bb047979f8efbb7c05dd9ac7fd69
parent a3e9de112196e86bbafd36d70983fa7981f39295

Maintain existing train information

When sendBinaryPushStateChangedAtom is called with empty train
name/version/experiment ids, populate the empty fields from the
trainInfo previously stored on disk if possible.

If no train info is on disk (or read fails), the empty fields are passed
through.

Test: gts in ag/6731864
Test: testdrive 10051 with partially/completely missing train info
Bug: 128640419

Change-Id: Iea3c2db5c11d07f0b42b41aec7b2d7913a99ca03

cmds/statsd/src/StatsService.cpp

diff --git a/cmds/statsd/src/StatsService.cpp b/cmds/statsd/src/StatsService.cpp
index 1526d66..f78ae38 100644
--- a/cmds/statsd/src/StatsService.cpp
+++ b/cmds/statsd/src/StatsService.cpp
@@ -1198,30 +1198,48 @@
     }
     // TODO: add verifier permission
 
-    userid_t userId = multiuser_get_user_id(uid);
+    bool readTrainInfoSuccess = false;
+    InstallTrainInfo trainInfo;
+    if (trainVersionCode == -1 || experimentIds.empty() || trainName.size() == 0) {
+        readTrainInfoSuccess = StorageManager::readTrainInfo(trainInfo);
+    }
 
-    bool requiresStaging = options & IStatsManager::FLAG_REQUIRE_STAGING;
-    bool rollbackEnabled = options & IStatsManager::FLAG_ROLLBACK_ENABLED;
-    bool requiresLowLatencyMonitor = options & IStatsManager::FLAG_REQUIRE_LOW_LATENCY_MONITOR;
-
-    ProtoOutputStream proto;
-    for (const auto& expId : experimentIds) {
-        proto.write(FIELD_TYPE_INT64 | FIELD_COUNT_REPEATED | FIELD_ID_EXPERIMENT_ID,
-                    (long long)expId);
+    if (trainVersionCode == -1 && readTrainInfoSuccess) {
+        trainVersionCode = trainInfo.trainVersionCode;
     }
 
     vector<uint8_t> experimentIdsProtoBuffer;
-    experimentIdsProtoBuffer.resize(proto.size());
-    size_t pos = 0;
-    auto iter = proto.data();
-    while (iter.readBuffer() != NULL) {
-        size_t toRead = iter.currentToRead();
-        std::memcpy(&(experimentIdsProtoBuffer[pos]), iter.readBuffer(), toRead);
-        pos += toRead;
-        iter.rp()->move(toRead);
+    if (readTrainInfoSuccess && experimentIds.empty()) {
+        experimentIdsProtoBuffer = trainInfo.experimentIds;
+    } else {
+        ProtoOutputStream proto;
+        for (const auto& expId : experimentIds) {
+            proto.write(FIELD_TYPE_INT64 | FIELD_COUNT_REPEATED | FIELD_ID_EXPERIMENT_ID,
+                        (long long)expId);
+        }
+
+        experimentIdsProtoBuffer.resize(proto.size());
+        size_t pos = 0;
+        auto iter = proto.data();
+        while (iter.readBuffer() != NULL) {
+            size_t toRead = iter.currentToRead();
+            std::memcpy(&(experimentIdsProtoBuffer[pos]), iter.readBuffer(), toRead);
+            pos += toRead;
+            iter.rp()->move(toRead);
+        }
     }
 
-    std::string trainNameUtf8 = std::string(String8(trainName).string());
+    std::string trainNameUtf8;
+    if (readTrainInfoSuccess && trainName.size() == 0) {
+        trainNameUtf8 = trainInfo.trainName;
+    } else {
+        trainNameUtf8 = std::string(String8(trainName).string());
+    }
+
+    userid_t userId = multiuser_get_user_id(uid);
+    bool requiresStaging = options & IStatsManager::FLAG_REQUIRE_STAGING;
+    bool rollbackEnabled = options & IStatsManager::FLAG_ROLLBACK_ENABLED;
+    bool requiresLowLatencyMonitor = options & IStatsManager::FLAG_REQUIRE_LOW_LATENCY_MONITOR;
     LogEvent event(trainNameUtf8, trainVersionCode, requiresStaging, rollbackEnabled,
                    requiresLowLatencyMonitor, state, experimentIdsProtoBuffer, userId);
     mProcessor->OnLogEvent(&event);