Implement AerospikeGeneration annotation (#182)

- Added new annotation which can only on a field or property of type
Integer or int
- Only one such field can exist per class
- On read, mapped the generation value back to the field
- On write, if the field is set > 0, set the writePolicy.generation to
this value and writePolicy.generationPolicy to EXPECT_GEN_EQUAL
- Added appropriate configuration file
- Added code config: `.withFieldNamed("generation").asGenerationField()`
- Created unit tests for validation
- Updated the AeroMapperBaseTest class to honor `test.host` if set as a
system property instead of the default `localhost:3000`

* Fixed a couple of references to version instead of generation

* update Javadoc for AerospikeGeneration

* optimize annotation processing

---------

Co-authored-by: yrizhkov <yrizhkov@aerospike.com>

Author: tim-aero

src/main/java/com/aerospike/mapper/annotations/AerospikeGeneration.java

@@ -0,0 +1,38 @@
+package com.aerospike.mapper.annotations;
+
+import com.aerospike.client.policy.GenerationPolicy;
+import com.aerospike.client.policy.WritePolicy;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Mark a field or property to be used for optimistic concurrency control using Aerospike's generation field.
+ * <p/>
+ * The field or property must be of Integer or int type. When reading an object which has a field marked
+ * with @AerospikeGeneration, the returned record's generation field will be mapped into the @AerospikeGeneration field.
+ * When writing the record, if the @AerospikeGeneration field is non-zero, the generation will be set in the
+ * {@link WritePolicy#generation} field and the {@link WritePolicy#generationPolicy} will be set to
+ * {@link GenerationPolicy#EXPECT_GEN_EQUAL}.
+ * <p/>
+ * Example usage:
+ * <pre>
+ * &#64;AerospikeRecord(namespace = "test", set = "account")
+ * public class Account {
+ *     &#64;AerospikeKey
+ *     private int id;
+ *     &#64;AerospikeBin
+ *     private String name;
+ *     &#64;AerospikeGeneration
+ *     private int generation;
+ * }
+ * </pre>
+ *
+ * @author timfaulkes
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ElementType.FIELD, ElementType.METHOD})
+public @interface AerospikeGeneration {
+}

src/main/java/com/aerospike/mapper/tools/AeroMapper.java

@@ -9,6 +9,7 @@
 import com.aerospike.client.Record;
 import com.aerospike.client.Value;
 import com.aerospike.client.policy.BatchPolicy;
+import com.aerospike.client.policy.GenerationPolicy;
 import com.aerospike.client.policy.Policy;
 import com.aerospike.client.policy.QueryPolicy;
 import com.aerospike.client.policy.RecordExistsAction;
@@ -121,6 +122,14 @@ private <T> WritePolicy generateWritePolicyFromObject(T object) {
         if (sendKey != null) {
             writePolicy.sendKey = sendKey;
         }
+
+        // #181 Handle @AerospikeGeneration field for optimistic concurrency control
+        Integer generationValue = entry.getGenerationValue(object);
+        if (generationValue != null && generationValue > 0) {
+            writePolicy.generation = generationValue;
+            writePolicy.generationPolicy = GenerationPolicy.EXPECT_GEN_EQUAL;
+        }
+
         return writePolicy;
     }
 

src/main/java/com/aerospike/mapper/tools/ClassCacheEntry.java

@@ -6,6 +6,7 @@
 import com.aerospike.client.Operation;
 import com.aerospike.client.Value;
 import com.aerospike.client.policy.BatchPolicy;
+import com.aerospike.client.policy.GenerationPolicy;
 import com.aerospike.client.policy.Policy;
 import com.aerospike.client.policy.QueryPolicy;
 import com.aerospike.client.policy.RecordExistsAction;
@@ -107,6 +108,14 @@ private <T> WritePolicy generateWritePolicyFromObject(T object) {
         if (sendKey != null) {
             writePolicy.sendKey = sendKey;
         }
+
+        // #181 Handle @AerospikeGeneration field for optimistic concurrency control
+        Integer generationValue = entry.getGenerationValue(object);
+        if (generationValue != null && generationValue > 0) {
+            writePolicy.generation = generationValue;
+            writePolicy.generationPolicy = GenerationPolicy.EXPECT_GEN_EQUAL;
+        }
+
         return writePolicy;
     }
 

src/main/java/com/aerospike/mapper/tools/ReactiveAeroMapper.java

@@ -14,6 +14,7 @@ public class BinConfig {
     private Integer ordinal;
     private EmbedConfig embed;
     private ReferenceConfig reference;
+    private Boolean generation;
 
     public String getName() {
         return name;
@@ -51,7 +52,10 @@ public ReferenceConfig getReference() {
         return reference;
     }
 
-    
+    public Boolean isGeneration() {
+        return generation;
+    }
+
     public void setName(String name) {
         this.name = name;
     }
@@ -88,6 +92,10 @@ public void setReference(ReferenceConfig reference) {
         this.reference = reference;
     }
 
+    public void setGeneration(Boolean generation) {
+        this.generation = generation;
+    }
+
     public void validate(String className) {
         if (StringUtils.isBlank(this.name) && StringUtils.isBlank(this.field)) {
             throw new AerospikeException("Configuration for class " + className + " defines a bin which contains neither a name nor a field");
@@ -129,6 +137,9 @@ public BinConfig merge(BinConfig other) {
         if (this.reference == null && other.reference != null) {
             this.reference = other.reference;
         }
+        if (this.generation == null && other.generation != null) {
+            this.generation = other.generation;
+        }
         return this;
     }
 }

src/main/java/com/aerospike/mapper/tools/configuration/BinConfig.java

@@ -321,6 +321,11 @@ public Builder beingEmbeddedAs(AerospikeEmbed.EmbedType type, AerospikeEmbed.Emb
             return this.end();
         }
 
+        public Builder asGenerationField() {
+            this.binConfig.setGeneration(true);
+            return this.end();
+        }
+
         public Builder beingEmbeddedAs(AerospikeEmbed.EmbedType type, AerospikeEmbed.EmbedType elementType, boolean saveKey) {
             EmbedConfig embedConfig = new EmbedConfig();
             embedConfig.setType(type);

src/main/java/com/aerospike/mapper/tools/configuration/ClassConfig.java

@@ -6,6 +6,7 @@
 import com.aerospike.client.policy.ClientPolicy;
 
 import com.aerospike.client.AerospikeClient;
+import com.aerospike.client.Host;
 import com.aerospike.client.IAerospikeClient;
 import com.aerospike.mapper.tools.ClassCache;
 import com.fasterxml.jackson.core.JsonProcessingException;
@@ -25,7 +26,8 @@ public static void setupClass() {
         ClientPolicy policy = new ClientPolicy();
         // Set event loops to use in asynchronous commands.
         policy.eventLoops = new NioEventLoops(1);
-        client = new AerospikeClient(policy, "localhost", 3000);
+        Host[] hosts = Host.parseHosts(System.getProperty("test.host", "localhost:3000"), 3000);
+        client = new AerospikeClient(policy, hosts);
     }
 
     @AfterAll