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The following commit(s) were added to refs/heads/main by this push:
new 16e84356da Core: Add UUIDv7 generator (#14700)
16e84356da is described below
commit 16e84356dae1975fa04d8c3ecce30a90df18ca9f
Author: Huaxin Gao <[email protected]>
AuthorDate: Tue Dec 2 00:46:37 2025 -0800
Core: Add UUIDv7 generator (#14700)
---
.../java/org/apache/iceberg/util/UUIDUtil.java | 31 ++++++++++++++++++++
.../java/org/apache/iceberg/util/TestUUIDUtil.java | 34 ++++++++++++++++++++++
2 files changed, 65 insertions(+)
diff --git a/api/src/main/java/org/apache/iceberg/util/UUIDUtil.java
b/api/src/main/java/org/apache/iceberg/util/UUIDUtil.java
index b72feec00b..3146a3763c 100644
--- a/api/src/main/java/org/apache/iceberg/util/UUIDUtil.java
+++ b/api/src/main/java/org/apache/iceberg/util/UUIDUtil.java
@@ -20,10 +20,13 @@ package org.apache.iceberg.util;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
+import java.security.SecureRandom;
import java.util.UUID;
import org.apache.iceberg.relocated.com.google.common.base.Preconditions;
public class UUIDUtil {
+ private static final SecureRandom SECURE_RANDOM = new SecureRandom();
+
private UUIDUtil() {}
public static UUID convert(byte[] buf) {
@@ -78,4 +81,32 @@ public class UUIDUtil {
buffer.putLong(8, value.getLeastSignificantBits());
return buffer;
}
+
+ /**
+ * Generate a RFC 9562 UUIDv7.
+ *
+ * <p>Layout: - 48-bit Unix epoch milliseconds - 4-bit version (0b0111) -
12-bit random (rand_a) -
+ * 2-bit variant (RFC 4122, 0b10) - 62-bit random (rand_b)
+ */
+ public static UUID generateUuidV7() {
+ long epochMs = System.currentTimeMillis();
+ Preconditions.checkState(
+ (epochMs >>> 48) == 0, "Invalid timestamp: does not fit within 48
bits: %s", epochMs);
+
+ // Draw 10 random bytes once: 2 bytes for rand_a (12 bits) and 8 bytes for
rand_b (62 bits)
+ byte[] randomBytes = new byte[10];
+ SECURE_RANDOM.nextBytes(randomBytes);
+ ByteBuffer rb = ByteBuffer.wrap(randomBytes).order(ByteOrder.BIG_ENDIAN);
+ long randMSB = ((long) rb.getShort()) & 0x0FFFL; // 12 bits
+ long randLSB = rb.getLong() & 0x3FFFFFFFFFFFFFFFL; // 62 bits
+
+ long msb = (epochMs << 16); // place timestamp in the top 48 bits
+ msb |= 0x7000L; // version 7 (UUID bits 48..51)
+ msb |= randMSB; // low 12 bits of MSB
+
+ long lsb = 0x8000000000000000L; // RFC 4122 variant '10'
+ lsb |= randLSB;
+
+ return new UUID(msb, lsb);
+ }
}
diff --git a/api/src/test/java/org/apache/iceberg/util/TestUUIDUtil.java
b/api/src/test/java/org/apache/iceberg/util/TestUUIDUtil.java
new file mode 100644
index 0000000000..c5f85c2f20
--- /dev/null
+++ b/api/src/test/java/org/apache/iceberg/util/TestUUIDUtil.java
@@ -0,0 +1,34 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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 org.apache.iceberg.util;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.UUID;
+import org.junit.jupiter.api.Test;
+
+public class TestUUIDUtil {
+
+ @Test
+ public void uuidV7HasVersionAndVariant() {
+ UUID uuid = UUIDUtil.generateUuidV7();
+ assertThat(uuid.version()).isEqualTo(7);
+ assertThat(uuid.variant()).isEqualTo(2);
+ }
+}
