Convert SynchronizedTypefaceHelper to Kotlin

Summary: as per title

Reviewed By: pengj

Differential Revision: D52999913

fbshipit-source-id: e6c586ecd3d0bc843f3e49c5aff7b0f94b1d11c1

Author: Andrew Wang

litho-rendercore/src/main/java/com/facebook/rendercore/utils/SynchronizedTypefaceHelper.java

@@ -0,0 +1,136 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.facebook.rendercore.utils
+
+import android.annotation.SuppressLint
+import android.annotation.TargetApi
+import android.graphics.Typeface
+import android.os.Build
+import android.util.LongSparseArray
+import android.util.SparseArray
+import androidx.core.util.forEach
+import java.util.concurrent.atomic.AtomicBoolean
+
+object SynchronizedTypefaceHelper {
+
+  private val isInitialized = AtomicBoolean(false)
+
+  /**
+   * Android doesn't expect typeface operations to occur off of the UI thread. To partially
+   * alleviate this issue, we override the typeface cache with a synchronized version.
+   */
+  @SuppressLint("PrivateApi")
+  @JvmStatic
+  fun setupSynchronizedTypeface() {
+    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) {
+      // sTypefaceCache was introduced in API level 16.
+      return
+    }
+    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
+      // sTypefaceCache was removed and Typeface is thread-safe since Android 9.
+      return
+    }
+    if (isInitialized.getAndSet(true)) {
+      return
+    }
+    try {
+      val typefaceCacheField = Typeface::class.java.getDeclaredField("sTypefaceCache")
+      typefaceCacheField.isAccessible = true
+      val lock = Any()
+      // This is nasty, but otherwise we have another race condition between
+      // typefaceCacheField.set and newCache.append if Typeface.create(...) is called elsewhere.
+      synchronized(lock) {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+          val oldCache = typefaceCacheField[null] as LongSparseArray<SparseArray<Typeface>>
+          val newCache = SynchronizedLongSparseArray(lock, oldCache.size())
+          typefaceCacheField[null] = newCache
+          oldCache.forEach { key, value ->
+            newCache.append(key, SynchronizedTypefaceSparseArray(value))
+          }
+        } else {
+          val oldCache = typefaceCacheField[null] as SparseArray<SparseArray<Typeface>>
+          val newCache = SynchronizedSparseArray(lock, oldCache.size())
+          typefaceCacheField[null] = newCache
+          oldCache.forEach { key, value ->
+            newCache.append(key, SynchronizedTypefaceSparseArray(value))
+          }
+        }
+      }
+    } catch (e: Exception) {
+      // We'll probably hit some thread-safety issues as we haven't managed to set a synchronized
+      // typefaceCache.
+    }
+  }
+
+  @TargetApi(Build.VERSION_CODES.LOLLIPOP)
+  internal class SynchronizedLongSparseArray(private val lock: Any, initialCapacity: Int) :
+      LongSparseArray<SparseArray<Typeface>?>(initialCapacity) {
+
+    override fun get(key: Long): SparseArray<Typeface>? {
+      synchronized(lock) {
+        val sparseArray = super.get(key)
+        if (sparseArray == null || sparseArray is SynchronizedTypefaceSparseArray) {
+          return sparseArray
+        }
+        val synchronizedSparseArray = SynchronizedTypefaceSparseArray(sparseArray)
+        put(key, synchronizedSparseArray)
+        return synchronizedSparseArray
+      }
+    }
+
+    override fun put(key: Long, value: SparseArray<Typeface>?) {
+      synchronized(lock) { super.put(key, value) }
+    }
+  }
+
+  @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
+  internal class SynchronizedSparseArray(private val lock: Any, initialCapacity: Int) :
+      SparseArray<SparseArray<Typeface>?>(initialCapacity) {
+
+    override fun get(key: Int): SparseArray<Typeface>? {
+      synchronized(lock) {
+        val sparseArray = super.get(key)
+        if (sparseArray == null || sparseArray is SynchronizedTypefaceSparseArray) {
+          return sparseArray
+        }
+        val synchronizedSparseArray = SynchronizedTypefaceSparseArray(sparseArray)
+        put(key, synchronizedSparseArray)
+        return synchronizedSparseArray
+      }
+    }
+
+    override fun put(key: Int, value: SparseArray<Typeface>?) {
+      synchronized(lock) { super.put(key, value) }
+    }
+  }
+
+  internal class SynchronizedTypefaceSparseArray(delegateSparseArray: SparseArray<Typeface>?) :
+      SparseArray<Typeface>() {
+    private val lock = Any()
+    private val delegateSparseArray: SparseArray<Typeface> = delegateSparseArray ?: SparseArray()
+
+    override fun get(key: Int): Typeface {
+      synchronized(lock) {
+        return delegateSparseArray[key]
+      }
+    }
+
+    override fun put(key: Int, value: Typeface) {
+      synchronized(lock) { delegateSparseArray.put(key, value) }
+    }
+  }
+}