Bump org.apache.zookeeper:zookeeper from 3.4.6 to 3.7.2

doc/eight-byte-id-structure.md

@@ -5,14 +5,14 @@ The eight byte IDs generated by the `LocalUniqueIDGenerator` and
 `SynchronizedUniqueIDGenerator` classes conform to the following structure:
 
 ```
-TTTTTTTT TTTTTTTT TTTTTTTT TTTTTTTT TTTTTTTT TTSSSSSS ...MGGGG GGGGCCCC
+TTTTTTTT TTTTTTTT TTTTTTTT TTTTTTTT TTTTTTTT TTSSSSSS GGGMGGGG GGGGCCCC
 |                                              |      |  ||        |
 v                                              |      |  |\        |
                                                |      v  \ \       |
 Date of ID creation, measured in milliseconds  |          \ \      |
-ellapsed since 1970-01-01T00:00:00.000,        | Reserved  \ \     |
-represented in reverse byte-order (in SPREAD   | for future | |    |
-mode) to guarantee an even spread of IDs.      | use.       | |    |
+ellapsed since 1970-01-01T00:00:00.000,        | Generator \ \     |
+represented in reverse byte-order (in SPREAD   | ID, see    | |    |
+mode) to guarantee an even spread of IDs.      | below.     | |    |
                                                |            | |    |
                                                v            | |    |
                                                             | |    |
@@ -27,13 +27,13 @@ mode) to guarantee an even spread of IDs.      | use.       | |    |
                                                               v    |
                                                                    |
                     Generator ID, manually assigned, or acquired   |
-                    through negotiation via a ZooKeeper-quorum.    |
-                                                                   |
+                    through negotiation via Etcd. Limited to 2048  |
+                    per Cluster ID.                                |
                                                                    v
 
                                      Cluster ID. Always manually assigned
                                      or statically configured. Limited to
-                                     16 (actieve) clusters.
+                                     16 (active) clusters.
 ```
 
 This approach offers a few useful features:

pom.xml

@@ -27,7 +27,7 @@
 
   <groupId>org.lable.oss.uniqueid</groupId>
   <artifactId>uniqueid</artifactId>
-  <version>3.2-SNAPSHOT</version>
+  <version>3.3-SNAPSHOT</version>
   <packaging>pom</packaging>
 
   <name>UniqueID</name>
@@ -45,12 +45,12 @@
     <java.language.level>1.8</java.language.level>
 
     <dynamicconfig.version>2.9-beta4</dynamicconfig.version>
-    <zookeeper.version>3.4.6</zookeeper.version>
+    <zookeeper.version>3.7.2</zookeeper.version>
     <jetcd-version>0.4.1</jetcd-version>
     <slf4j.version>1.7.21</slf4j.version>
 
     <!-- For testing only. -->
-    <log4j.version>2.7</log4j.version>
+    <log4j.version>2.17.1</log4j.version>
     <hamcrest.optional>1.0</hamcrest.optional>
   </properties>
 

uniqueid-core/pom.xml

@@ -20,7 +20,7 @@
   <parent>
     <artifactId>uniqueid</artifactId>
     <groupId>org.lable.oss.uniqueid</groupId>
-    <version>3.2-SNAPSHOT</version>
+    <version>3.3-SNAPSHOT</version>
   </parent>
   <modelVersion>4.0.0</modelVersion>
 

uniqueid-core/src/main/java/org/lable/oss/uniqueid/AutoRefillStack.java

@@ -15,7 +15,6 @@
  */
 package org.lable.oss.uniqueid;
 
-import javax.annotation.PreDestroy;
 import java.io.IOException;
 import java.util.ArrayDeque;
 import java.util.Deque;
@@ -63,7 +62,6 @@ public static IDGenerator decorate(IDGenerator generator, int batchSize) {
         return new AutoRefillStack(generator, batchSize);
     }
 
-    @PreDestroy
     @Override
     public void close() throws IOException {
         generator.close();

uniqueid-core/src/main/java/org/lable/oss/uniqueid/LocalUniqueIDGeneratorFactory.java

@@ -37,7 +37,7 @@ public class LocalUniqueIDGeneratorFactory {
      * Return the UniqueIDGenerator instance for this specific generator-ID, cluster-ID combination. If one was
      * already created, that is returned.
      *
-     * @param generatorId Generator ID to use (0 ≤ n ≤ 255).
+     * @param generatorId Generator ID to use (0 ≤ n ≤ 2047).
      * @param clusterId   Cluster ID to use (0 ≤ n ≤ 15).
      * @param clock       Clock implementation.
      * @param mode        Generator mode.
@@ -58,7 +58,7 @@ public synchronized static IDGenerator generatorFor(int generatorId, int cluster
      * Return the UniqueIDGenerator instance for this specific generator-ID, cluster-ID combination. If one was
      * already created, that is returned.
      *
-     * @param generatorId Generator ID to use (0 ≤ n ≤ 255).
+     * @param generatorId Generator ID to use (0 ≤ n ≤ 2047).
      * @param clusterId   Cluster ID to use (0 ≤ n ≤ 15).
      * @param mode        Generator mode.
      * @return A thread-safe UniqueIDGenerator instance.

uniqueid-core/src/main/java/org/lable/oss/uniqueid/bytes/Blueprint.java

@@ -34,7 +34,7 @@ public class Blueprint {
     /**
      * Upper bound (inclusive) of the generator-ID.
      */
-    public final static int MAX_GENERATOR_ID = 255;
+    public final static int MAX_GENERATOR_ID = 2047;
 
     /**
      * Upper bound (inclusive) of the cluster-ID.

uniqueid-core/src/main/java/org/lable/oss/uniqueid/bytes/IDBuilder.java

@@ -24,7 +24,7 @@
  * <p>
  * The eight byte ID is composed as follows:
  *
- * <pre>TTTTTTTT TTTTTTTT TTTTTTTT TTTTTTTT TTTTTTTT TTSSSSSS ...MGGGG GGGGCCCC</pre>
+ * <pre>TTTTTTTT TTTTTTTT TTTTTTTT TTTTTTTT TTTTTTTT TTSSSSSS GGGMGGGG GGGGCCCC</pre>
  *
  * <ul>
  * <li><code>T</code>: Timestamp (in milliseconds, bit order depends on mode)
@@ -67,8 +67,9 @@ public static byte[] build(Blueprint blueprint) {
         tsBytes[5] = (byte) or;
 
         // Last two bytes. The mode flag, generator ID, and cluster ID.
-        // [6] ...MGGGG  [7] GGGGCCCC
-        int flagGeneratorCluster = blueprint.getGeneratorId() << 4;
+        // [6] GGGMGGGG  [7] GGGGCCCC
+        int flagGeneratorCluster = (blueprint.getGeneratorId() << 5) & 0xE000;
+        flagGeneratorCluster += (blueprint.getGeneratorId() & 0x00FF) << 4;
         flagGeneratorCluster += blueprint.getClusterId();
         flagGeneratorCluster += blueprint.getMode().getModeMask() << 12;
 
@@ -160,8 +161,8 @@ private static int parseSequenceIdNoChecks(byte[] id) {
     }
 
     private static int parseGeneratorIdNoChecks(byte[] id) {
-        // [6] ....GGGG  [7] GGGG....
-        return (id[7] >> 4 & 0x0F) | (id[6] << 4 & 0xF0);
+        // [6] GGG.GGGG  [7] GGGG....
+        return (id[7] >> 4 & 0x0F) | (id[6] << 3 & 0x0700) | (id[6] << 4 & 0xF0);
     }
 
     private static int parseClusterIdNoChecks(byte[] id) {

uniqueid-core/src/test/java/org/lable/oss/uniqueid/LocalUniqueIDGeneratorFactoryTest.java

@@ -22,7 +22,7 @@ public class LocalUniqueIDGeneratorFactoryTest {
 
     @Test(expected = IllegalArgumentException.class)
     public void outOfBoundsGeneratorIDTest() {
-        LocalUniqueIDGeneratorFactory.generatorFor(256, 0, Mode.SPREAD);
+        LocalUniqueIDGeneratorFactory.generatorFor(2048, 0, Mode.SPREAD);
     }
 
     @Test(expected = IllegalArgumentException.class)

uniqueid-core/src/test/java/org/lable/oss/uniqueid/bytes/IDBuilderTest.java

@@ -17,6 +17,10 @@
 
 import org.apache.commons.codec.binary.Hex;
 import org.junit.Test;
+import org.lable.oss.uniqueid.ByteArray;
+
+import java.util.HashSet;
+import java.util.Set;
 
 import static org.hamcrest.CoreMatchers.is;
 import static org.junit.Assert.assertThat;
@@ -41,8 +45,7 @@ public void buildMostlyOnes() {
                 Blueprint.MAX_CLUSTER_ID,
                 Mode.SPREAD
         ));
-        // The "0f" for the 7th byte is due to the reserved bits that are always zero for the SPREAD mode.
-        final String expected = "ffffffffffff0fff";
+        final String expected = "ffffffffffffefff";
 
         // Baseline check, if all ID parts are all ones so is the result (except for the reserved bytes).
         assertThat(Hex.encodeHexString(result), is(expected));
@@ -234,4 +237,31 @@ public void parseIllegalArgument() {
     public void parseIllegalArgumentNull() {
         IDBuilder.parse(null);
     }
+
+    @Test
+    public void fullGeneratorSpace() {
+        // Verify that bitwise operations in IDBuilder work.
+        Set<ByteArray> results = new HashSet<>();
+        for (int generatorId = 0; generatorId <= Blueprint.MAX_GENERATOR_ID; generatorId++) {
+            byte[] result = IDBuilder.build(new Blueprint(
+                    Blueprint.MAX_TIMESTAMP,
+                    Blueprint.MAX_SEQUENCE_COUNTER,
+                    generatorId,
+                    Blueprint.MAX_CLUSTER_ID,
+                    Mode.SPREAD
+            ));
+            results.add(new ByteArray(result));
+
+            result = IDBuilder.build(new Blueprint(
+                    Blueprint.MAX_TIMESTAMP,
+                    Blueprint.MAX_SEQUENCE_COUNTER,
+                    generatorId,
+                    Blueprint.MAX_CLUSTER_ID,
+                    Mode.TIME_SEQUENTIAL
+            ));
+            results.add(new ByteArray(result));
+        }
+
+        assertThat(results.size(), is(2 *(Blueprint.MAX_GENERATOR_ID + 1)));
+    }
 }

uniqueid-etcd/pom.xml

@@ -20,7 +20,7 @@
   <parent>
     <artifactId>uniqueid</artifactId>
     <groupId>org.lable.oss.uniqueid</groupId>
-    <version>3.2-SNAPSHOT</version>
+    <version>3.3-SNAPSHOT</version>
   </parent>
   <modelVersion>4.0.0</modelVersion>
 

uniqueid-etcd/src/main/java/org/lable/oss/uniqueid/etcd/EtcdHelper.java

@@ -45,10 +45,22 @@ public static Optional<Integer> getInt(Client etcd, String key) throws Execution
         }
     }
 
+    public static Optional<String> get(Client etcd, String key) throws ExecutionException, InterruptedException {
+        GetResponse getResponse = etcd.getKVClient().get(asByteSequence(key)).get();
+
+        if (getResponse.getCount() == 0) return Optional.empty();
+
+        return Optional.of(getResponse.getKvs().get(0).getValue().toString(StandardCharsets.UTF_8));
+    }
+
     public static void put(Client etcd, String key, int value) throws ExecutionException, InterruptedException {
         etcd.getKVClient().put(asByteSequence(key), asByteSequence(value)).get();
     }
 
+    public static void put(Client etcd, String key) throws ExecutionException, InterruptedException {
+        etcd.getKVClient().put(asByteSequence(key),ByteSequence.EMPTY).get();
+    }
+
     public static void delete(Client etcd, String key) throws ExecutionException, InterruptedException {
         etcd.getKVClient().delete(asByteSequence(key)).get();
     }

uniqueid-etcd/src/main/java/org/lable/oss/uniqueid/etcd/RegistryBasedGeneratorIdentity.java

@@ -0,0 +1,130 @@
+/*
+ * Copyright (C) 2014 Lable ([email protected])
+ *
+ * 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 org.lable.oss.uniqueid.etcd;
+
+import io.etcd.jetcd.ByteSequence;
+import io.etcd.jetcd.Client;
+import org.lable.oss.uniqueid.GeneratorException;
+import org.lable.oss.uniqueid.GeneratorIdentityHolder;
+import org.lable.oss.uniqueid.bytes.Blueprint;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.time.Duration;
+
+/**
+ * Holder for a claimed cluster-id and generator-id that once claimed remains claimed without an active connection to
+ * an Etcd cluster. The claim is relinquished upon calling {@link #close()} (where a new connection to Etcd will be
+ * set up briefly).
+ */
+public class RegistryBasedGeneratorIdentity implements GeneratorIdentityHolder {
+    private static final Logger logger = LoggerFactory.getLogger(RegistryBasedGeneratorIdentity.class);
+
+    private final String endpoints;
+    private final String namespace;
+    private final Duration acquisitionTimeout;
+    private final boolean waitWhenNoResourcesAvailable;
+    private final RegistryBasedResourceClaim resourceClaim;
+
+    public RegistryBasedGeneratorIdentity(String endpoints,
+                                          String namespace,
+                                          String registryEntry,
+                                          Duration acquisitionTimeout,
+                                          boolean waitWhenNoResourcesAvailable) {
+        this.endpoints = endpoints;
+        this.namespace = namespace;
+        this.acquisitionTimeout = acquisitionTimeout;
+        this.waitWhenNoResourcesAvailable = waitWhenNoResourcesAvailable;
+
+        try {
+            resourceClaim = acquireResourceClaim(registryEntry, 0);
+        } catch (GeneratorException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    public static RegistryBasedGeneratorIdentity basedOn(String endpoints, String namespace, String registryEntry)
+            throws IOException {
+        return new RegistryBasedGeneratorIdentity(
+                endpoints, namespace, registryEntry, Duration.ofMinutes(5), true
+        );
+    }
+
+    public static RegistryBasedGeneratorIdentity basedOn(String endpoints,
+                                                         String namespace,
+                                                         String registryEntry,
+                                                         Duration acquisitionTimeout,
+                                                         boolean waitWhenNoResourcesAvailable)
+            throws IOException {
+        return new RegistryBasedGeneratorIdentity(
+                endpoints, namespace, registryEntry, acquisitionTimeout, waitWhenNoResourcesAvailable
+        );
+    }
+
+    @Override
+    public int getClusterId() throws GeneratorException {
+        return resourceClaim.getClusterId();
+    }
+
+    @Override
+    public int getGeneratorId() throws GeneratorException {
+        return resourceClaim.getGeneratorId();
+    }
+
+    public String getRegistryEntry() {
+        return resourceClaim.getRegistryEntry();
+    }
+
+    private RegistryBasedResourceClaim acquireResourceClaim(String registryEntry, int retries)
+            throws GeneratorException {
+        try {
+            return RegistryBasedResourceClaim.claim(
+                    this::getEtcdConnection,
+                    Blueprint.MAX_GENERATOR_ID + 1,
+                    registryEntry,
+                    acquisitionTimeout,
+                    waitWhenNoResourcesAvailable
+            );
+        } catch (IOException e) {
+            if (retries < 3) {
+                logger.warn(
+                        "Connection to Etcd failed, retrying claim acquisition, attempt " + (retries + 1) + ".",
+                        e
+                );
+                return acquireResourceClaim(registryEntry, retries + 1);
+            } else {
+                logger.error("Failed to acquire resource claim after attempt " + (retries + 1) + ".", e);
+                throw new GeneratorException(e);
+            }
+        }
+    }
+
+    Client getEtcdConnection() {
+        return Client.builder()
+                .endpoints(endpoints.split(","))
+                .namespace(ByteSequence.from(namespace, StandardCharsets.UTF_8))
+                .build();
+    }
+
+    @Override
+    public void close() throws IOException {
+        if (resourceClaim != null) {
+            resourceClaim.close();
+        }
+    }
+}