perf(core): [SDK Overhead Reduction 11] Replace ISO8601 timestamp handling

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## Unreleased
+
+### Internal
+
+- Reduce timestamp parsing and formatting overhead with Sentry-specific ISO-8601 handling. ([#5602](https://github.com/getsentry/sentry-java/pull/5602))
+
 ## 8.45.0
 
 ### Features

THIRD_PARTY_NOTICES.md

@@ -62,6 +62,22 @@ limitations under the License.
 
 ---
 
+## Howard Hinnant — Date Algorithms (Public Domain)
+
+**Source:** https://howardhinnant.github.io/date_algorithms.html<br>
+**License:** Public Domain<br>
+**Copyright:** None; public domain dedication by Howard Hinnant
+
+### Scope
+
+The Sentry Java SDK includes adapted civil date conversion algorithms from Howard Hinnant's date algorithms for UTC ISO 8601 timestamp parsing and formatting. The code resides in `io.sentry.vendor.SentryIso8601Utils`.
+
+```
+Consider these donated to the public domain.
+```
+
+---
+
 ## Android Open Source Project — Base64 (Apache 2.0)
 
 **Source:** https://cs.android.com/android/platform/superproject/main/+/main:frameworks/base/core/java/android/util/Base64.java<br>

sentry/api/sentry.api

@@ -8076,6 +8076,11 @@ public class io/sentry/vendor/Base64 {
 	public static fun encodeToString ([BIII)Ljava/lang/String;
 }
 
+public final class io/sentry/vendor/SentryIso8601Utils {
+	public static fun formatTimestamp (J)Ljava/lang/String;
+	public static fun parseTimestamp (Ljava/lang/String;)J
+}
+
 public class io/sentry/vendor/gson/internal/bind/util/ISO8601Utils {
 	public static final field TIMEZONE_UTC Ljava/util/TimeZone;
 	public fun <init> ()V

sentry/src/main/java/io/sentry/Breadcrumb.java

@@ -823,7 +823,12 @@ public static final class JsonKeys {
   public void serialize(final @NotNull ObjectWriter writer, final @NotNull ILogger logger)
       throws IOException {
     writer.beginObject();
-    writer.name(JsonKeys.TIMESTAMP).value(logger, getTimestamp());
+    writer
+        .name(JsonKeys.TIMESTAMP)
+        .value(
+            timestampMs != null
+                ? DateUtils.getTimestampFromMillis(timestampMs)
+                : DateUtils.getTimestamp(getTimestamp()));
     if (message != null) {
       writer.name(JsonKeys.MESSAGE).value(message);
     }

sentry/src/main/java/io/sentry/DateUtils.java

@@ -2,11 +2,9 @@
 
 import static io.sentry.vendor.gson.internal.bind.util.ISO8601Utils.TIMEZONE_UTC;
 
-import io.sentry.vendor.gson.internal.bind.util.ISO8601Utils;
+import io.sentry.vendor.SentryIso8601Utils;
 import java.math.BigDecimal;
 import java.math.RoundingMode;
-import java.text.ParseException;
-import java.text.ParsePosition;
 import java.util.Calendar;
 import java.util.Date;
 import org.jetbrains.annotations.ApiStatus;
@@ -15,6 +13,7 @@
 
 /** Utilities to deal with dates */
 @ApiStatus.Internal
+@SuppressWarnings("JavaUtilDate")
 public final class DateUtils {
 
   private DateUtils() {}
@@ -39,8 +38,8 @@ private DateUtils() {}
   public static @NotNull Date getDateTime(final @NotNull String timestamp)
       throws IllegalArgumentException {
     try {
-      return ISO8601Utils.parse(timestamp, new ParsePosition(0));
-    } catch (ParseException e) {
+      return getDateTime(SentryIso8601Utils.parseTimestamp(timestamp));
+    } catch (IllegalArgumentException e) {
       throw new IllegalArgumentException("timestamp is not ISO format " + timestamp);
     }
   }
@@ -51,7 +50,6 @@ private DateUtils() {}
    * @param timestamp millis eg 1581410911.988 (1581410911 seconds and 988 millis)
    * @return the UTC Date
    */
-  @SuppressWarnings("JdkObsolete")
   public static @NotNull Date getDateTimeWithMillisPrecision(final @NotNull String timestamp)
       throws IllegalArgumentException {
     try {
@@ -69,7 +67,17 @@ private DateUtils() {}
    * @return the UTC/ISO 8601 timestamp
    */
   public static @NotNull String getTimestamp(final @NotNull Date date) {
-    return ISO8601Utils.format(date, true);
+    return getTimestampFromMillis(date.getTime());
+  }
+
+  /**
+   * Get the UTC/ISO 8601 timestamp from millis.
+   *
+   * @param millis the UTC millis from the epoch
+   * @return the UTC/ISO 8601 timestamp
+   */
+  static @NotNull String getTimestampFromMillis(final long millis) {
+    return SentryIso8601Utils.formatTimestamp(millis);
   }
 
   /**