From 8c9e4b68f09c92f7f1d26916bbac7014c45f5d49 Mon Sep 17 00:00:00 2001
From: Hugo Benichi <hugobenichi@google.com>
Date: Wed, 19 Oct 2016 11:17:28 +0900
Subject: [PATCH] DO NOT MERGE: IpConnectivityMetrics reads buffer size in
 settings

Test: IpConnectivityMetricsTest passes. Also manually changed the new
setting and verified the buffer size is as expected after flushing the
buffer.
Bug: 32198637

(cherry picked from commit 05686dbb6b965eb1a54591d2ed2334337886c6ee)

Change-Id: Iefbeac3a688b260fb3f92dfe0bfd9db28e26749d
---
 core/java/android/provider/Settings.java      |  7 ++++++
 .../connectivity/IpConnectivityMetrics.java   | 24 +++++++++++++++++--
 .../IpConnectivityMetricsTest.java            |  2 +-
 3 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
index db7baac7fdd77..e52983e995dfc 100755
--- a/core/java/android/provider/Settings.java
+++ b/core/java/android/provider/Settings.java
@@ -7172,6 +7172,13 @@ public final class Settings {
         */
        public static final String MOBILE_DATA_ALWAYS_ON = "mobile_data_always_on";
 
+        /**
+         * Size of the event buffer for IP connectivity metrics.
+         * @hide
+         */
+        public static final String CONNECTIVITY_METRICS_BUFFER_SIZE =
+              "connectivity_metrics_buffer_size";
+
        /** {@hide} */
        public static final String NETSTATS_ENABLED = "netstats_enabled";
        /** {@hide} */
diff --git a/services/core/java/com/android/server/connectivity/IpConnectivityMetrics.java b/services/core/java/com/android/server/connectivity/IpConnectivityMetrics.java
index e176fe1575c10..642f2e01987bf 100644
--- a/services/core/java/com/android/server/connectivity/IpConnectivityMetrics.java
+++ b/services/core/java/com/android/server/connectivity/IpConnectivityMetrics.java
@@ -22,6 +22,7 @@ import android.net.IIpConnectivityMetrics;
 import android.net.metrics.IpConnectivityLog;
 import android.os.IBinder;
 import android.os.Parcelable;
+import android.provider.Settings;
 import android.text.TextUtils;
 import android.util.Base64;
 import android.util.Log;
@@ -32,6 +33,7 @@ import java.io.FileDescriptor;
 import java.io.IOException;
 import java.io.PrintWriter;
 import java.util.ArrayList;
+import java.util.function.ToIntFunction;
 
 import static com.android.server.connectivity.metrics.IpConnectivityLogClass.IpConnectivityEvent;
 
@@ -51,6 +53,8 @@ final public class IpConnectivityMetrics extends SystemService {
 
     // Default size of the event buffer. Once the buffer is full, incoming events are dropped.
     private static final int DEFAULT_BUFFER_SIZE = 2000;
+    // Maximum size of the event buffer.
+    private static final int MAXIMUM_BUFFER_SIZE = DEFAULT_BUFFER_SIZE * 10;
 
     // Lock ensuring that concurrent manipulations of the event buffer are correct.
     // There are three concurrent operations to synchronize:
@@ -70,11 +74,18 @@ final public class IpConnectivityMetrics extends SystemService {
     @GuardedBy("mLock")
     private int mCapacity;
 
-    public IpConnectivityMetrics(Context ctx) {
+    private final ToIntFunction<Context> mCapacityGetter;
+
+    public IpConnectivityMetrics(Context ctx, ToIntFunction<Context> capacityGetter) {
         super(ctx);
+        mCapacityGetter = capacityGetter;
         initBuffer();
     }
 
+    public IpConnectivityMetrics(Context ctx) {
+        this(ctx, READ_BUFFER_SIZE);
+    }
+
     @Override
     public void onStart() {
         if (DBG) Log.d(TAG, "onStart");
@@ -93,7 +104,7 @@ final public class IpConnectivityMetrics extends SystemService {
 
     @VisibleForTesting
     public int bufferCapacity() {
-        return DEFAULT_BUFFER_SIZE; // TODO: read from config
+        return mCapacityGetter.applyAsInt(getContext());
     }
 
     private void initBuffer() {
@@ -236,4 +247,13 @@ final public class IpConnectivityMetrics extends SystemService {
             getContext().enforceCallingOrSelfPermission(what, "IpConnectivityMetrics");
         }
     };
+
+    private static final ToIntFunction<Context> READ_BUFFER_SIZE = (ctx) -> {
+        int size = Settings.Global.getInt(ctx.getContentResolver(),
+                Settings.Global.CONNECTIVITY_METRICS_BUFFER_SIZE, DEFAULT_BUFFER_SIZE);
+        if (size <= 0) {
+            return DEFAULT_BUFFER_SIZE;
+        }
+        return Math.min(size, MAXIMUM_BUFFER_SIZE);
+    };
 }
diff --git a/tests/net/java/com/android/server/connectivity/IpConnectivityMetricsTest.java b/tests/net/java/com/android/server/connectivity/IpConnectivityMetricsTest.java
index 8bdc829f7bfa3..14b5cbeb9276d 100644
--- a/tests/net/java/com/android/server/connectivity/IpConnectivityMetricsTest.java
+++ b/tests/net/java/com/android/server/connectivity/IpConnectivityMetricsTest.java
@@ -57,7 +57,7 @@ public class IpConnectivityMetricsTest extends TestCase {
 
     public void setUp() {
         MockitoAnnotations.initMocks(this);
-        mService = new IpConnectivityMetrics(mCtx);
+        mService = new IpConnectivityMetrics(mCtx, (ctx) -> 2000);
     }
 
     public void testLoggingEvents() throws Exception {