Adding extension for timed logging (#537)

* Adding extension for timed logging

* Updating timed logging extension to avoid unnecessary allocations

Author: RamV13

api/current.txt

@@ -589,6 +589,12 @@ package androidx.core.util {
     method @RequiresApi(18) public static kotlin.collections.LongIterator valueIterator(android.util.SparseLongArray);
   }
 
+  public final class TimingLoggerKt {
+    ctor public TimingLoggerKt();
+    method public static void log(android.util.TimingLogger, kotlin.jvm.functions.Function1<? super android.util.TimingLogger,kotlin.Unit> work);
+    method public static void split(android.util.TimingLogger, String splitLabel, kotlin.jvm.functions.Function0<kotlin.Unit> work);
+  }
+
 }
 
 package androidx.core.view {

src/androidTest/java/androidx/core/util/TimingLoggerTest.kt

@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * 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 androidx.core.util
+
+import android.util.TimingLogger
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+class TimingLoggerTest {
+    @Test fun timingLogger() {
+        val called = arrayOf(false, false, false)
+
+        val timingLogger = TimingLogger("TAG", "methodA")
+        timingLogger.log {
+            split("work A") {
+                called[0] = true
+            }
+            split("work B") {
+                called[1] = true
+            }
+            split("work C") {
+                called[2] = true
+            }
+        }
+
+        assertTrue(called.reduce(Boolean::and))
+    }
+}

src/main/java/androidx/core/util/TimingLogger.kt

@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * 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 androidx.core.util
+
+import android.util.TimingLogger
+
+/**
+ * Resets the timing logger instance before timing each of the given splits and subsequently
+ * dumping the results to the log output.
+ */
+inline fun TimingLogger.log(work: TimingLogger.() -> Unit) {
+    this.reset()
+    work()
+    this.dumpToLog()
+}
+
+/**
+ * Times the given work and subsequently adds a split to the timing logger instance.
+ */
+inline fun TimingLogger.split(splitLabel: String, work: () -> Unit) {
+    work()
+    this.addSplit(splitLabel)
+}