added LazyEvaluator to evaluate a function lazily

AndroidOptionsInitializer.installDefaultIntegrations now evaluate cache dir lazily

Author: stefanosiano

sentry-android-core/src/main/java/io/sentry/android/core/AndroidOptionsInitializer.java

@@ -26,6 +26,7 @@
 import io.sentry.internal.gestures.GestureTargetLocator;
 import io.sentry.internal.viewhierarchy.ViewHierarchyExporter;
 import io.sentry.transport.NoOpEnvelopeCache;
+import io.sentry.util.LazyEvaluator;
 import io.sentry.util.Objects;
 import java.io.File;
 import java.util.ArrayList;
@@ -195,12 +196,13 @@ static void installDefaultIntegrations(
 
     // read the startup crash marker here to avoid doing double-IO for the SendCachedEnvelope
     // integrations below
-    final boolean hasStartupCrashMarker = AndroidEnvelopeCache.hasStartupCrashMarker(options);
+    LazyEvaluator<Boolean> startupCrashMarkerEvaluator =
+        new LazyEvaluator<>(() -> AndroidEnvelopeCache.hasStartupCrashMarker(options));
 
     options.addIntegration(
         new SendCachedEnvelopeIntegration(
             new SendFireAndForgetEnvelopeSender(() -> options.getCacheDirPath()),
-            hasStartupCrashMarker));
+            startupCrashMarkerEvaluator));
 
     // Integrations are registered in the same order. NDK before adding Watch outbox,
     // because sentry-native move files around and we don't want to watch that.
@@ -220,7 +222,7 @@ static void installDefaultIntegrations(
     options.addIntegration(
         new SendCachedEnvelopeIntegration(
             new SendFireAndForgetOutboxSender(() -> options.getOutboxPath()),
-            hasStartupCrashMarker));
+            startupCrashMarkerEvaluator));
 
     // AppLifecycleIntegration has to be installed before AnrIntegration, because AnrIntegration
     // relies on AppState set by it

sentry-android-core/src/main/java/io/sentry/android/core/SendCachedEnvelopeIntegration.java

@@ -5,6 +5,7 @@
 import io.sentry.SendCachedEnvelopeFireAndForgetIntegration;
 import io.sentry.SentryLevel;
 import io.sentry.SentryOptions;
+import io.sentry.util.LazyEvaluator;
 import io.sentry.util.Objects;
 import java.util.concurrent.Future;
 import java.util.concurrent.RejectedExecutionException;
@@ -16,13 +17,13 @@ final class SendCachedEnvelopeIntegration implements Integration {
 
   private final @NotNull SendCachedEnvelopeFireAndForgetIntegration.SendFireAndForgetFactory
       factory;
-  private final boolean hasStartupCrashMarker;
+  private final @NotNull LazyEvaluator<Boolean> startupCrashMarkerEvaluator;
 
   public SendCachedEnvelopeIntegration(
       final @NotNull SendCachedEnvelopeFireAndForgetIntegration.SendFireAndForgetFactory factory,
-      final boolean hasStartupCrashMarker) {
+      final @NotNull LazyEvaluator<Boolean> startupCrashMarkerEvaluator) {
     this.factory = Objects.requireNonNull(factory, "SendFireAndForgetFactory is required");
-    this.hasStartupCrashMarker = hasStartupCrashMarker;
+    this.startupCrashMarkerEvaluator = startupCrashMarkerEvaluator;
   }
 
   @Override
@@ -62,7 +63,7 @@ public void register(@NotNull IHub hub, @NotNull SentryOptions options) {
                     }
                   });
 
-      if (hasStartupCrashMarker) {
+      if (startupCrashMarkerEvaluator.getValue()) {
         androidOptions
             .getLogger()
             .log(SentryLevel.DEBUG, "Startup Crash marker exists, blocking flush.");

sentry-android-core/src/test/java/io/sentry/android/core/AndroidOptionsInitializerTest.kt

@@ -22,6 +22,9 @@ import org.junit.runner.RunWith
 import org.mockito.kotlin.any
 import org.mockito.kotlin.eq
 import org.mockito.kotlin.mock
+import org.mockito.kotlin.never
+import org.mockito.kotlin.spy
+import org.mockito.kotlin.verify
 import org.mockito.kotlin.whenever
 import org.robolectric.annotation.Config
 import java.io.File
@@ -599,6 +602,22 @@ class AndroidOptionsInitializerTest {
         assertFalse(fixture.sentryOptions.scopeObservers.any { it is PersistingScopeObserver })
     }
 
+    @Test
+    fun `installDefaultIntegrations does not evaluate cacheDir or outboxPath when called`() {
+        val mockOptions = spy(fixture.sentryOptions)
+        AndroidOptionsInitializer.installDefaultIntegrations(
+            fixture.context,
+            mockOptions,
+            mock(),
+            mock(),
+            mock(),
+            false,
+            false
+        )
+        verify(mockOptions, never()).outboxPath
+        verify(mockOptions, never()).cacheDirPath
+    }
+
     @Config(sdk = [30])
     @Test
     fun `AnrV2Integration added to integrations list for API 30 and above`() {

sentry-android-core/src/test/java/io/sentry/android/core/SendCachedEnvelopeIntegrationTest.kt

@@ -5,6 +5,7 @@ import io.sentry.ILogger
 import io.sentry.SendCachedEnvelopeFireAndForgetIntegration.SendFireAndForget
 import io.sentry.SendCachedEnvelopeFireAndForgetIntegration.SendFireAndForgetFactory
 import io.sentry.SentryLevel.DEBUG
+import io.sentry.util.LazyEvaluator
 import org.awaitility.kotlin.await
 import org.mockito.kotlin.any
 import org.mockito.kotlin.eq
@@ -53,7 +54,7 @@ class SendCachedEnvelopeIntegrationTest {
                 }
             )
 
-            return SendCachedEnvelopeIntegration(factory, hasStartupCrashMarker)
+            return SendCachedEnvelopeIntegration(factory, LazyEvaluator { hasStartupCrashMarker })
         }
     }
 

sentry/api/sentry.api

@@ -4151,6 +4151,15 @@ public final class io/sentry/util/JsonSerializationUtils {
 	public static fun calendarToMap (Ljava/util/Calendar;)Ljava/util/Map;
 }
 
+public final class io/sentry/util/LazyEvaluator {
+	public fun <init> (Lio/sentry/util/LazyEvaluator$Evaluator;)V
+	public fun getValue ()Ljava/lang/Object;
+}
+
+public abstract interface class io/sentry/util/LazyEvaluator$Evaluator {
+	public abstract fun evaluate ()Ljava/lang/Object;
+}
+
 public final class io/sentry/util/LogUtils {
 	public fun <init> ()V
 	public static fun logNotInstanceOf (Ljava/lang/Class;Ljava/lang/Object;Lio/sentry/ILogger;)V

sentry/src/main/java/io/sentry/util/LazyEvaluator.java

@@ -0,0 +1,42 @@
+package io.sentry.util;
+
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * Class that evaluates a function lazily. It means the evaluator function is called only when
+ * getValue is called, and it's cached.
+ */
+@ApiStatus.Internal
+public final class LazyEvaluator<T> {
+  private @Nullable T value = null;
+  private final @NotNull Evaluator<T> evaluator;
+
+  /**
+   * Class that evaluates a function lazily. It means the evaluator function is called only when
+   * getValue is called, and it's cached.
+   *
+   * @param evaluator The function to evaluate.
+   */
+  public LazyEvaluator(final @NotNull Evaluator<T> evaluator) {
+    this.evaluator = evaluator;
+  }
+
+  /**
+   * Executes the evaluator function and caches its result, so that it's called only once.
+   *
+   * @return The result of the evaluator function.
+   */
+  public synchronized @NotNull T getValue() {
+    if (value == null) {
+      value = evaluator.evaluate();
+    }
+    return value;
+  }
+
+  public interface Evaluator<T> {
+    @NotNull
+    T evaluate();
+  }
+}

sentry/src/test/java/io/sentry/util/LazyEvaluatorTest.kt

@@ -0,0 +1,41 @@
+package io.sentry.util
+
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class LazyEvaluatorTest {
+
+    class Fixture {
+        var count = 0
+
+        fun getSut(): LazyEvaluator<Int> {
+            count = 0
+            return LazyEvaluator<Int> { ++count }
+        }
+    }
+
+    private val fixture = Fixture()
+
+    @Test
+    fun `does not evaluate on instantiation`() {
+        fixture.getSut()
+        assertEquals(0, fixture.count)
+    }
+
+    @Test
+    fun `evaluator is called on getValue`() {
+        val evaluator = fixture.getSut()
+        assertEquals(0, fixture.count)
+        assertEquals(1, evaluator.value)
+        assertEquals(1, fixture.count)
+    }
+
+    @Test
+    fun `evaluates only once`() {
+        val evaluator = fixture.getSut()
+        assertEquals(0, fixture.count)
+        assertEquals(1, evaluator.value)
+        assertEquals(1, evaluator.value)
+        assertEquals(1, fixture.count)
+    }
+}