fix(core): Reduce serialization log spam (#6255)

* fix(core): Reduce serialization log spam

Allow serializers to suppress debug logging for individual calls and disable it while calculating serialized byte sizes. Preserve compatibility for custom serializers through a default interface implementation.

Fixes #4946

Co-Authored-By: Claude <noreply@anthropic.com>

* changelog

---------

Co-authored-by: Claude <noreply@anthropic.com>

Author: adinauer

CHANGELOG.md

@@ -107,6 +107,10 @@
   - See the [Navigation for Android docs](https://docs.sentry.io/platforms/android/integrations/navigation/) for additional details.
 - Report the cellular network technology generation in `device.connection_effective_type`, for example `4g` or `5g` ([#6146](https://github.com/getsentry/sentry-java/pull/6146))
 
+### Fixes
+
+- Avoid duplicate serialization debug logs when calculating serialized object sizes ([#6255](https://github.com/getsentry/sentry-java/pull/6255))
+
 ### Dependencies
 
 - Bump Native SDK from v0.17.1 to v0.17.2 ([#6230](https://github.com/getsentry/sentry-java/pull/6230))

sentry/api/sentry.api

@@ -1229,6 +1229,7 @@ public abstract interface class io/sentry/ISerializer {
 	public abstract fun deserializeEnvelope (Ljava/io/InputStream;)Lio/sentry/SentryEnvelope;
 	public abstract fun serialize (Lio/sentry/SentryEnvelope;Ljava/io/OutputStream;)V
 	public abstract fun serialize (Ljava/lang/Object;Ljava/io/Writer;)V
+	public fun serialize (Ljava/lang/Object;Ljava/io/Writer;Z)V
 	public abstract fun serialize (Ljava/util/Map;)Ljava/lang/String;
 }
 
@@ -1446,6 +1447,7 @@ public final class io/sentry/JsonSerializer : io/sentry/ISerializer {
 	public fun deserializeEnvelope (Ljava/io/InputStream;)Lio/sentry/SentryEnvelope;
 	public fun serialize (Lio/sentry/SentryEnvelope;Ljava/io/OutputStream;)V
 	public fun serialize (Ljava/lang/Object;Ljava/io/Writer;)V
+	public fun serialize (Ljava/lang/Object;Ljava/io/Writer;Z)V
 	public fun serialize (Ljava/util/Map;)Ljava/lang/String;
 }
 

sentry/src/main/java/io/sentry/ISerializer.java

@@ -23,6 +23,20 @@ public interface ISerializer {
 
   <T> void serialize(@NotNull T entity, @NotNull Writer writer) throws IOException;
 
+  /**
+   * Serializes an entity to a writer with optional logging control.
+   *
+   * @param entity the entity to serialize
+   * @param writer the writer to serialize to
+   * @param enableLogging whether serializer logging is enabled, if supported
+   * @param <T> the type of entity
+   * @throws IOException if serialization fails
+   */
+  default <T> void serialize(@NotNull T entity, @NotNull Writer writer, boolean enableLogging)
+      throws IOException {
+    serialize(entity, writer);
+  }
+
   /**
    * Serializes an envelope
    *

sentry/src/main/java/io/sentry/JsonSerializer.java

@@ -207,10 +207,16 @@ public JsonSerializer(@NotNull SentryOptions options) {
 
   @Override
   public <T> void serialize(@NotNull T entity, @NotNull Writer writer) throws IOException {
+    serialize(entity, writer, true);
+  }
+
+  @Override
+  public <T> void serialize(@NotNull T entity, @NotNull Writer writer, boolean enableLogging)
+      throws IOException {
     Objects.requireNonNull(entity, "The entity is required.");
     Objects.requireNonNull(writer, "The Writer object is required.");
 
-    if (options.getLogger().isEnabled(SentryLevel.DEBUG)) {
+    if (enableLogging && options.getLogger().isEnabled(SentryLevel.DEBUG)) {
       String serialized = serializeToString(entity, options.isEnablePrettySerializationOutput());
       options.getLogger().log(SentryLevel.DEBUG, "Serializing object: %s", serialized);
     }

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

@@ -85,7 +85,7 @@ public static long byteSizeOf(
     }
     try {
       final ByteCountingWriter writer = new ByteCountingWriter();
-      serializer.serialize(serializable, writer);
+      serializer.serialize(serializable, writer, false);
       return writer.getByteCount();
     } catch (Throwable t) {
       logger.log(SentryLevel.ERROR, "Could not calculate size of serializable", t);

sentry/src/test/java/io/sentry/JsonSerializerTest.kt

@@ -1525,6 +1525,20 @@ class JsonSerializerTest {
       .log(any(), check { assertTrue(it.startsWith("Serializing object:")) }, any<Any>())
   }
 
+  @Test
+  fun `json serializer can disable serialization logging`() {
+    val logger = mock<ILogger>()
+    val options = SentryOptions()
+    options.setLogger(logger)
+    options.setDebug(true)
+    whenever(logger.isEnabled(any())).thenReturn(true)
+
+    (options.serializer as JsonSerializer).serialize(mapOf("key" to "val"), StringWriter(), false)
+
+    verify(logger, never())
+      .log(any(), check { assertTrue(it.startsWith("Serializing object:")) }, any<Any>())
+  }
+
   @Test
   fun `json serializer does not close the stream that is passed in`() {
     val stream = mock<OutputStream>()

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

@@ -1,6 +1,7 @@
 package io.sentry.util
 
 import io.sentry.ILogger
+import io.sentry.ISerializer
 import io.sentry.JsonSerializable
 import io.sentry.JsonSerializer
 import io.sentry.ObjectWriter
@@ -18,7 +19,9 @@ import kotlin.test.assertNull
 import kotlin.test.assertTrue
 import org.mockito.invocation.InvocationOnMock
 import org.mockito.kotlin.any
+import org.mockito.kotlin.eq
 import org.mockito.kotlin.mock
+import org.mockito.kotlin.verify
 
 class JsonSerializationUtilsTest {
 
@@ -117,6 +120,16 @@ class JsonSerializationUtilsTest {
     assertTrue(byteSize > 0, "byteSize should be positive")
   }
 
+  @Test
+  fun `byteSizeOf disables serialization logging`() {
+    val mockSerializer: ISerializer = mock()
+    val serializable: JsonSerializable = mock()
+
+    JsonSerializationUtils.byteSizeOf(mockSerializer, logger, serializable)
+
+    verify(mockSerializer).serialize(eq(serializable), any(), eq(false))
+  }
+
   @Test
   fun `byteSizeOf returns 0 on serialization error`() {
     val serializable =