Merge changes from topic "cherrypicker-L60200030001118132:N13600030018110596" into main

* changes:
  Pass in a new instance supplier for creating RingBuffer.
  Update RingBuffer to take Supplier<T> for creating new instances.

3 files changed, 37 insertions, 31 deletions

diff --git a/core/java/com/android/internal/util/RingBuffer.java b/core/java/com/android/internal/util/RingBuffer.java
index 8fc4c30e54ab..7f8c8a1cae04 100644
--- a/core/java/com/android/internal/util/RingBuffer.java
+++ b/core/java/com/android/internal/util/RingBuffer.java
@@ -19,7 +19,10 @@ package com.android.internal.util;
 import static com.android.internal.util.Preconditions.checkArgumentPositive;
 
 import java.lang.reflect.Array;
+import java.lang.reflect.InvocationTargetException;
 import java.util.Arrays;
+import java.util.function.IntFunction;
+import java.util.function.Supplier;
 
 /**
  * A simple ring buffer structure with bounded capacity backed by an array.
@@ -29,16 +32,35 @@ import java.util.Arrays;
  */
 public class RingBuffer<T> {
 
+    private final Supplier<T> mNewItem;
     // Array for storing events.
     private final T[] mBuffer;
     // Cursor keeping track of the logical end of the array. This cursor never
     // wraps and instead keeps track of the total number of append() operations.
     private long mCursor = 0;
 
+    /**
+     * @deprecated This uses reflection to create new instances.
+     *             Use {@link #RingBuffer(Supplier, IntFunction, int)}} instead.
+     */
+    @Deprecated
     public RingBuffer(Class<T> c, int capacity) {
+        this(() -> (T) createNewItem(c), cap -> (T[]) Array.newInstance(c, cap), capacity);
+    }
+
+    private static Object createNewItem(Class c) {
+        try {
+            return c.getDeclaredConstructor().newInstance();
+        } catch (IllegalAccessException | InstantiationException | NoSuchMethodException
+                 | InvocationTargetException e) {
+            return null;
+        }
+    }
+
+    public RingBuffer(Supplier<T> newItem, IntFunction<T[]> newBacking, int capacity) {
         checkArgumentPositive(capacity, "A RingBuffer cannot have 0 capacity");
-        // Java cannot create generic arrays without a runtime hint.
-        mBuffer = (T[]) Array.newInstance(c, capacity);
+        mBuffer = newBacking.apply(capacity);
+        mNewItem = newItem;
     }
 
     public int size() {
@@ -68,22 +90,11 @@ public class RingBuffer<T> {
     public T getNextSlot() {
         final int nextSlotIdx = indexOf(mCursor++);
         if (mBuffer[nextSlotIdx] == null) {
-            mBuffer[nextSlotIdx] = createNewItem();
+            mBuffer[nextSlotIdx] = mNewItem.get();
         }
         return mBuffer[nextSlotIdx];
     }
 
-    /**
-     * @return a new object of type <T> or null if a new object could not be created.
-     */
-    protected T createNewItem() {
-        try {
-            return (T) mBuffer.getClass().getComponentType().newInstance();
-        } catch (IllegalAccessException | InstantiationException e) {
-            return null;
-        }
-    }
-
     public T[] toArray() {
         // Only generic way to create a T[] from another T[]
         T[] out = Arrays.copyOf(mBuffer, size(), (Class<T[]>) mBuffer.getClass());
diff --git a/services/core/java/com/android/server/net/NetworkPolicyLogger.java b/services/core/java/com/android/server/net/NetworkPolicyLogger.java
index 4d19eade5a05..d7188c7f10c6 100644
--- a/services/core/java/com/android/server/net/NetworkPolicyLogger.java
+++ b/services/core/java/com/android/server/net/NetworkPolicyLogger.java
@@ -42,7 +42,6 @@ import android.util.ArraySet;
 import android.util.Log;
 import android.util.Slog;
 
-import com.android.internal.annotations.Keep;
 import com.android.internal.util.IndentingPrintWriter;
 import com.android.internal.util.RingBuffer;
 import com.android.server.am.ProcessList;
@@ -414,7 +413,7 @@ public class NetworkPolicyLogger {
         private static final Date sDate = new Date();
 
         public LogBuffer(int capacity) {
-            super(Data.class, capacity);
+            super(Data::new, Data[]::new, capacity);
         }
 
         public void uidStateChanged(int uid, int procState, long procStateSeq,
@@ -690,12 +689,8 @@ public class NetworkPolicyLogger {
 
     /**
      * Container class for all networkpolicy events data.
-     *
-     * Note: This class needs to be public for RingBuffer class to be able to create
-     * new instances of this.
      */
-    @Keep
-    public static final class Data {
+    private static final class Data {
         public int type;
         public long timeStamp;
 
diff --git a/services/usage/java/com/android/server/usage/BroadcastResponseStatsLogger.java b/services/usage/java/com/android/server/usage/BroadcastResponseStatsLogger.java
index 336bfdd0fb14..a8fd6f29f862 100644
--- a/services/usage/java/com/android/server/usage/BroadcastResponseStatsLogger.java
+++ b/services/usage/java/com/android/server/usage/BroadcastResponseStatsLogger.java
@@ -35,11 +35,13 @@ import android.util.Slog;
 import android.util.TimeUtils;
 
 import com.android.internal.annotations.GuardedBy;
-import com.android.internal.annotations.Keep;
 import com.android.internal.util.IndentingPrintWriter;
 import com.android.internal.util.RingBuffer;
 import com.android.server.usage.BroadcastResponseStatsTracker.NotificationEventType;
 
+import java.util.function.IntFunction;
+import java.util.function.Supplier;
+
 public class BroadcastResponseStatsLogger {
 
     private static final int MAX_LOG_SIZE =
@@ -49,10 +51,10 @@ public class BroadcastResponseStatsLogger {
 
     @GuardedBy("mLock")
     private final LogBuffer mBroadcastEventsBuffer = new LogBuffer(
-            BroadcastEvent.class, MAX_LOG_SIZE);
+            BroadcastEvent::new, BroadcastEvent[]::new, MAX_LOG_SIZE);
     @GuardedBy("mLock")
     private final LogBuffer mNotificationEventsBuffer = new LogBuffer(
-            NotificationEvent.class, MAX_LOG_SIZE);
+            NotificationEvent::new, NotificationEvent[]::new, MAX_LOG_SIZE);
 
     void logBroadcastDispatchEvent(int sourceUid, @NonNull String targetPackage,
             UserHandle targetUser, long idForResponseEvent,
@@ -96,8 +98,8 @@ public class BroadcastResponseStatsLogger {
 
     private static final class LogBuffer<T extends Data> extends RingBuffer<T> {
 
-        LogBuffer(Class<T> classType, int capacity) {
-            super(classType, capacity);
+        LogBuffer(Supplier<T> newItem, IntFunction<T[]> newBacking, int capacity) {
+            super(newItem, newBacking, capacity);
         }
 
         void logBroadcastDispatchEvent(int sourceUid, @NonNull String targetPackage,
@@ -179,8 +181,7 @@ public class BroadcastResponseStatsLogger {
         }
     }
 
-    @Keep
-    public static final class BroadcastEvent implements Data {
+    private static final class BroadcastEvent implements Data {
         public int sourceUid;
         public int targetUserId;
         public int targetUidProcessState;
@@ -200,8 +201,7 @@ public class BroadcastResponseStatsLogger {
         }
     }
 
-    @Keep
-    public static final class NotificationEvent implements Data {
+    private static final class NotificationEvent implements Data {
         public int type;
         public String packageName;
         public int userId;
@@ -218,7 +218,7 @@ public class BroadcastResponseStatsLogger {
         }
     }
 
-    public interface Data {
+    private interface Data {
         void reset();
     }
 }