MediaMetrics: Retain previous audio state a limited time.
Clears after 1 hour to reduce memory footprint.
Only one previous state is kept at any time.
Test: reboot, wait, mediametrics dumpsys/logcat
Bug: 159410113
Change-Id: I1bce419a69dc14699e70ac481354c1121477b194
diff --git a/services/mediametrics/AudioAnalytics.cpp b/services/mediametrics/AudioAnalytics.cpp
index 78e2c89..29801a4 100644
--- a/services/mediametrics/AudioAnalytics.cpp
+++ b/services/mediametrics/AudioAnalytics.cpp
@@ -64,6 +64,8 @@
static constexpr const auto LOG_LEVEL = android::base::VERBOSE;
+static constexpr int PREVIOUS_STATE_EXPIRE_SEC = 60 * 60; // 1 hour.
+
/*
* For logging purposes, we list all of the MediaMetrics atom fields,
* which can then be associated with consecutive arguments to the statsd write.
@@ -173,6 +175,19 @@
// to end of full expression.
mAnalyticsState->clear(); // TODO: filter the analytics state.
// Perhaps report this.
+
+ // Set up a timer to expire the previous audio state to save space.
+ // Use the transaction log size as a cookie to see if it is the
+ // same as before. A benign race is possible where a state is cleared early.
+ const size_t size = mPreviousAnalyticsState->transactionLog().size();
+ mTimedAction.postIn(
+ std::chrono::seconds(PREVIOUS_STATE_EXPIRE_SEC), [this, size](){
+ if (mPreviousAnalyticsState->transactionLog().size() == size) {
+ ALOGD("expiring previous audio state after %d seconds.",
+ PREVIOUS_STATE_EXPIRE_SEC);
+ mPreviousAnalyticsState->clear(); // removes data from the state.
+ }
+ });
}));
// Handle device use record statistics
diff --git a/services/mediametrics/AudioAnalytics.h b/services/mediametrics/AudioAnalytics.h
index 809de19..df097b1 100644
--- a/services/mediametrics/AudioAnalytics.h
+++ b/services/mediametrics/AudioAnalytics.h
@@ -117,7 +117,7 @@
// AnalyticsState is individually locked, and we use SharedPtrWrap
// to allow safe access even if the shared pointer changes underneath.
-
+ // These wrap pointers always point to a valid state object.
SharedPtrWrap<AnalyticsState> mAnalyticsState;
SharedPtrWrap<AnalyticsState> mPreviousAnalyticsState;