turcsanyip commented on code in PR #10467:
URL: https://github.com/apache/nifi/pull/10467#discussion_r2817418539


##########
nifi-extension-bundles/nifi-couchbase-bundle/nifi-couchbase-services/src/main/java/org/apache/nifi/services/couchbase/CouchbaseMapCacheClient.java:
##########
@@ -0,0 +1,212 @@
+/*
+ * 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.nifi.services.couchbase;
+
+import org.apache.nifi.annotation.documentation.CapabilityDescription;
+import org.apache.nifi.annotation.documentation.Tags;
+import org.apache.nifi.components.PropertyDescriptor;
+import org.apache.nifi.distributed.cache.client.AtomicCacheEntry;
+import 
org.apache.nifi.distributed.cache.client.AtomicDistributedMapCacheClient;
+import org.apache.nifi.distributed.cache.client.Deserializer;
+import org.apache.nifi.distributed.cache.client.Serializer;
+import 
org.apache.nifi.services.couchbase.exception.CouchbaseCasMismatchException;
+import 
org.apache.nifi.services.couchbase.exception.CouchbaseDocExistsException;
+import 
org.apache.nifi.services.couchbase.exception.CouchbaseDocNotFoundException;
+import org.apache.nifi.services.couchbase.exception.CouchbaseException;
+import org.apache.nifi.services.couchbase.utils.CouchbaseGetResult;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.List;
+import java.util.Optional;
+
+@Tags({"distributed", "cache", "map", "cluster", "couchbase"})
+@CapabilityDescription("Provides the ability to communicate with a Couchbase 
Server cluster as a DistributedMapCacheServer." +
+        " This can be used in order to share a Map between nodes in a NiFi 
cluster." +
+        " Couchbase Server cluster can provide a high available and persistent 
cache storage.")
+public class CouchbaseMapCacheClient extends AbstractCouchbaseService 
implements AtomicDistributedMapCacheClient<Long> {
+
+    public static final PropertyDescriptor COUCHBASE_CONNECTION_SERVICE = new 
PropertyDescriptor.Builder()
+            .name("Couchbase Connection Service")
+            .description("A Couchbase Connection Service which manages 
connections to a Couchbase cluster.")
+            .required(true)
+            .identifiesControllerService(CouchbaseConnectionService.class)
+            .build();
+
+    private static final List<PropertyDescriptor> PROPERTIES = List.of(
+            COUCHBASE_CONNECTION_SERVICE,
+            BUCKET_NAME,
+            SCOPE_NAME,
+            COLLECTION_NAME
+    );
+
+    @Override
+    protected List<PropertyDescriptor> getSupportedPropertyDescriptors() {
+        return PROPERTIES;
+    }
+
+    @Override
+    public <K, V> AtomicCacheEntry<K, V, Long> fetch(K key, Serializer<K> 
keySerializer, Deserializer<V> valueDeserializer) throws IOException {
+        final String documentId = serializeDocumentKey(key, keySerializer);
+        try {
+            final CouchbaseGetResult result = 
couchbaseClient.getDocument(documentId);
+            return new AtomicCacheEntry<>(key, 
deserializeDocument(valueDeserializer, result.resultContent()), result.cas());
+        } catch (CouchbaseDocNotFoundException e) {
+            return null;
+        } catch (CouchbaseException e) {
+            throw new IOException("Failed to fetch cache entry [%s] from 
Couchbase".formatted(documentId), e);
+        }
+    }
+
+    @Override
+    public <K, V> boolean replace(AtomicCacheEntry<K, V, Long> entry, 
Serializer<K> keySerializer, Serializer<V> valueSerializer) throws IOException {
+        final String documentId = serializeDocumentKey(entry.getKey(), 
keySerializer);
+        final byte[] document = serializeDocument(entry.getValue(), 
valueSerializer);
+        final Optional<Long> revision = entry.getRevision();
+
+        if (revision.isEmpty()) {
+            try {
+                couchbaseClient.insertDocument(documentId, document);
+                return true;
+            } catch (CouchbaseDocExistsException e) {
+                return false;
+            } catch (CouchbaseException e) {
+                throw new IOException("Failed to insert cache entry [%s] into 
Couchbase".formatted(documentId), e);
+            }
+        }
+
+        try {
+            final long casValue = revision.get();
+            couchbaseClient.replaceDocument(documentId, document, casValue);
+            return true;
+        } catch (CouchbaseDocNotFoundException | CouchbaseCasMismatchException 
e) {
+            return false;
+        } catch (CouchbaseException e) {
+            throw new IOException("Failed to replace cache entry [%s] in 
Couchbase".formatted(documentId), e);
+        }
+    }
+
+    @Override
+    public <K, V> boolean putIfAbsent(K key, V value, Serializer<K> 
keySerializer, Serializer<V> valueSerializer) throws IOException {
+        final String documentId = serializeDocumentKey(key, keySerializer);
+        final byte[] document = serializeDocument(value, valueSerializer);
+
+        try {
+            couchbaseClient.insertDocument(documentId, document);
+            return true;
+        } catch (CouchbaseDocExistsException e) {
+            return false;
+        } catch (CouchbaseException e) {
+            throw new IOException("Failed to insert cache entry [%s] into 
Couchbase".formatted(documentId), e);
+        }
+    }
+
+    @Override
+    public <K, V> V getAndPutIfAbsent(K key, V value, Serializer<K> 
keySerializer, Serializer<V> valueSerializer, Deserializer<V> 
valueDeserializer) throws IOException {
+        final V document = get(key, keySerializer, valueDeserializer);
+        if (document != null) {
+            return document;
+        }
+
+        putIfAbsent(key, value, keySerializer, valueSerializer);
+        return value;

Review Comment:
   The method should return `null` if the key did not exist in the cache and 
has been inserted during this call.
   
   The method's [API 
doc](https://github.com/apache/nifi/blob/da8661d5ba4128a74a1a0a68937ad752c984ef09/nifi-extension-bundles/nifi-standard-services/nifi-distributed-cache-client-service-api/src/main/java/org/apache/nifi/distributed/cache/client/DistributedMapCacheClient.java#L70-L76)
 is not straightforward but the way the callers use `getAndPutIfAbsent()` 
([PutDistributedMapCache](https://github.com/apache/nifi/blob/da8661d5ba4128a74a1a0a68937ad752c984ef09/nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/java/org/apache/nifi/processors/standard/PutDistributedMapCache.java#L198-L200),
 
[DetectDuplicate](https://github.com/apache/nifi/blob/da8661d5ba4128a74a1a0a68937ad752c984ef09/nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/java/org/apache/nifi/processors/standard/DetectDuplicate.java#L177-L183))
 proves that the correct logic should be:
   
   - if the key exists in the cache => no update, return the value
   - if the key not exists in the cache => insert, return null



##########
nifi-extension-bundles/nifi-couchbase-bundle/nifi-couchbase-services/src/main/java/org/apache/nifi/services/couchbase/CouchbaseKeyValueLookupService.java:
##########
@@ -0,0 +1,81 @@
+/*
+ * 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.nifi.services.couchbase;
+
+import org.apache.nifi.annotation.documentation.CapabilityDescription;
+import org.apache.nifi.annotation.documentation.Tags;
+import org.apache.nifi.annotation.lifecycle.OnEnabled;
+import org.apache.nifi.components.PropertyDescriptor;
+import org.apache.nifi.controller.ConfigurationContext;
+import org.apache.nifi.expression.ExpressionLanguageScope;
+import org.apache.nifi.lookup.LookupFailureException;
+import org.apache.nifi.lookup.StringLookupService;
+import org.apache.nifi.processor.util.StandardValidators;
+import org.apache.nifi.services.couchbase.utils.CouchbaseLookupInResult;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+
+@Tags({"lookup", "enrich", "key", "value", "couchbase"})
+@CapabilityDescription("Lookup a string value from Couchbase Server associated 
with the specified key. The coordinates that are passed to the lookup must 
contain the key 'key'.")
+public class CouchbaseKeyValueLookupService extends AbstractCouchbaseService 
implements StringLookupService {
+
+    public static final PropertyDescriptor LOOKUP_SUB_DOC_PATH = new 
PropertyDescriptor.Builder()
+            .name("Lookup Sub-Document Path")
+            .description("The Sub-Document lookup path within the target JSON 
document.")
+            .addValidator(StandardValidators.NON_BLANK_VALIDATOR)
+            .expressionLanguageSupported(ExpressionLanguageScope.ENVIRONMENT)
+            .build();
+
+    private static final List<PropertyDescriptor> PROPERTIES = List.of(
+            COUCHBASE_CONNECTION_SERVICE,
+            BUCKET_NAME,
+            SCOPE_NAME,
+            COLLECTION_NAME,
+            LOOKUP_SUB_DOC_PATH
+    );
+
+    private volatile String subDocPath;
+
+    @Override
+    protected List<PropertyDescriptor> getSupportedPropertyDescriptors() {
+        return PROPERTIES;
+    }
+
+    @Override
+    @OnEnabled
+    public void onEnabled(final ConfigurationContext context) {
+        super.onEnabled(context);
+        subDocPath = 
context.getProperty(LOOKUP_SUB_DOC_PATH).evaluateAttributeExpressions().getValue();
+    }
+
+    @Override
+    public Optional<String> lookup(Map<String, Object> coordinates) throws 
LookupFailureException {
+        final Object documentId = coordinates.get(KEY);
+
+        if (documentId == null) {
+            return Optional.empty();
+        }
+        try {
+            final CouchbaseLookupInResult result = 
couchbaseClient.lookupIn(documentId.toString(), subDocPath);
+            return 
Optional.ofNullable(result.resultContent()).map(Object::toString);
+        } catch (Exception e) {
+            throw new LookupFailureException("Key-value lookup from Couchbase 
failed", e);
+        }

Review Comment:
   `LookupService.lookup()` should return `Optional.empty()` if the key is not 
found (instead of throwing an exception).
   The [API 
doc](https://github.com/apache/nifi/blob/da8661d5ba4128a74a1a0a68937ad752c984ef09/nifi-extension-bundles/nifi-standard-services/nifi-lookup-service-api/src/main/java/org/apache/nifi/lookup/LookupService.java#L28-L36)
 is not really clear but the `Optional` return type indicates the intent. Also, 
`LookupAttribute` processor should transfer a non-existing key to the 
`unmatched` relationship but now it goes to `failure` due to the exception.



##########
nifi-extension-bundles/nifi-couchbase-bundle/nifi-couchbase-services/src/test/java/org/apache/nifi/services/couchbase/CouchbaseMapCacheClientTest.java:
##########
@@ -0,0 +1,143 @@
+/*
+ * 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.nifi.services.couchbase;
+
+import org.apache.nifi.components.PropertyDescriptor;
+import org.apache.nifi.distributed.cache.client.Deserializer;
+import org.apache.nifi.distributed.cache.client.Serializer;
+import 
org.apache.nifi.services.couchbase.exception.CouchbaseDocNotFoundException;
+import org.apache.nifi.services.couchbase.exception.CouchbaseException;
+import org.apache.nifi.services.couchbase.utils.CouchbaseGetResult;
+import org.apache.nifi.services.couchbase.utils.CouchbaseUpsertResult;
+import org.apache.nifi.util.MockConfigurationContext;
+import org.apache.nifi.util.MockControllerServiceInitializationContext;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+import static 
org.apache.nifi.services.couchbase.AbstractCouchbaseService.COUCHBASE_CONNECTION_SERVICE;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+public class CouchbaseMapCacheClientTest extends AbstractCouchbaseServiceTest {
+
+    private final Serializer<String> stringSerializer = (value, output) -> 
output.write(value.getBytes(StandardCharsets.UTF_8));
+    private final Deserializer<String> stringDeserializer = input -> new 
String(input, StandardCharsets.UTF_8);
+    private CouchbaseMapCacheClient mapCacheClient;
+
+    @BeforeEach
+    public void init() {
+        mapCacheClient = new CouchbaseMapCacheClient();
+    }
+
+    @Test
+    public void testCacheGet() throws CouchbaseException, IOException {
+        final CouchbaseClient client = mock(CouchbaseClient.class);
+        when(client.getDocument(anyString())).thenReturn(new 
CouchbaseGetResult(TEST_DOCUMENT_CONTENT.getBytes(), TEST_CAS));
+
+        final CouchbaseConnectionService connectionService = 
mockConnectionService(client);
+
+        final MockControllerServiceInitializationContext 
serviceInitializationContext = new 
MockControllerServiceInitializationContext(connectionService, 
CONNECTION_SERVICE_ID);
+        final Map<PropertyDescriptor, String> properties = 
Collections.singletonMap(COUCHBASE_CONNECTION_SERVICE, CONNECTION_SERVICE_ID);
+        final MockConfigurationContext context = new 
MockConfigurationContext(properties, serviceInitializationContext, new 
HashMap<>());
+
+        mapCacheClient.onEnabled(context);
+
+        final String result = mapCacheClient.get(TEST_DOCUMENT_ID, 
stringSerializer, stringDeserializer);
+
+        assertEquals(TEST_DOCUMENT_CONTENT, result);
+    }
+
+    @Test
+    public void testCacheGetFailure() throws CouchbaseException, IOException {

Review Comment:
   This is a valid case, not a real failure, so I would rename the test method 
to `testCacheGetNotFound()` or similar.
   The failure (exception) case can be tested separately.



##########
nifi-extension-bundles/nifi-couchbase-bundle/nifi-couchbase-services/src/main/java/org/apache/nifi/services/couchbase/CouchbaseMapCacheClient.java:
##########
@@ -0,0 +1,212 @@
+/*
+ * 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.nifi.services.couchbase;
+
+import org.apache.nifi.annotation.documentation.CapabilityDescription;
+import org.apache.nifi.annotation.documentation.Tags;
+import org.apache.nifi.components.PropertyDescriptor;
+import org.apache.nifi.distributed.cache.client.AtomicCacheEntry;
+import 
org.apache.nifi.distributed.cache.client.AtomicDistributedMapCacheClient;
+import org.apache.nifi.distributed.cache.client.Deserializer;
+import org.apache.nifi.distributed.cache.client.Serializer;
+import 
org.apache.nifi.services.couchbase.exception.CouchbaseCasMismatchException;
+import 
org.apache.nifi.services.couchbase.exception.CouchbaseDocExistsException;
+import 
org.apache.nifi.services.couchbase.exception.CouchbaseDocNotFoundException;
+import org.apache.nifi.services.couchbase.exception.CouchbaseException;
+import org.apache.nifi.services.couchbase.utils.CouchbaseGetResult;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.List;
+import java.util.Optional;
+
+@Tags({"distributed", "cache", "map", "cluster", "couchbase"})
+@CapabilityDescription("Provides the ability to communicate with a Couchbase 
Server cluster as a DistributedMapCacheServer." +
+        " This can be used in order to share a Map between nodes in a NiFi 
cluster." +
+        " Couchbase Server cluster can provide a high available and persistent 
cache storage.")
+public class CouchbaseMapCacheClient extends AbstractCouchbaseService 
implements AtomicDistributedMapCacheClient<Long> {
+
+    public static final PropertyDescriptor COUCHBASE_CONNECTION_SERVICE = new 
PropertyDescriptor.Builder()
+            .name("Couchbase Connection Service")
+            .description("A Couchbase Connection Service which manages 
connections to a Couchbase cluster.")
+            .required(true)
+            .identifiesControllerService(CouchbaseConnectionService.class)
+            .build();

Review Comment:
   The property is already defined in the parent class. So it can be deleted.



##########
nifi-extension-bundles/nifi-couchbase-bundle/nifi-couchbase-services/src/test/java/org/apache/nifi/services/couchbase/CouchbaseMapCacheClientTest.java:
##########
@@ -0,0 +1,143 @@
+/*
+ * 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.nifi.services.couchbase;
+
+import org.apache.nifi.components.PropertyDescriptor;
+import org.apache.nifi.distributed.cache.client.Deserializer;
+import org.apache.nifi.distributed.cache.client.Serializer;
+import 
org.apache.nifi.services.couchbase.exception.CouchbaseDocNotFoundException;
+import org.apache.nifi.services.couchbase.exception.CouchbaseException;
+import org.apache.nifi.services.couchbase.utils.CouchbaseGetResult;
+import org.apache.nifi.services.couchbase.utils.CouchbaseUpsertResult;
+import org.apache.nifi.util.MockConfigurationContext;
+import org.apache.nifi.util.MockControllerServiceInitializationContext;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+import static 
org.apache.nifi.services.couchbase.AbstractCouchbaseService.COUCHBASE_CONNECTION_SERVICE;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+public class CouchbaseMapCacheClientTest extends AbstractCouchbaseServiceTest {
+
+    private final Serializer<String> stringSerializer = (value, output) -> 
output.write(value.getBytes(StandardCharsets.UTF_8));
+    private final Deserializer<String> stringDeserializer = input -> new 
String(input, StandardCharsets.UTF_8);
+    private CouchbaseMapCacheClient mapCacheClient;
+
+    @BeforeEach
+    public void init() {
+        mapCacheClient = new CouchbaseMapCacheClient();
+    }
+
+    @Test
+    public void testCacheGet() throws CouchbaseException, IOException {
+        final CouchbaseClient client = mock(CouchbaseClient.class);
+        when(client.getDocument(anyString())).thenReturn(new 
CouchbaseGetResult(TEST_DOCUMENT_CONTENT.getBytes(), TEST_CAS));
+
+        final CouchbaseConnectionService connectionService = 
mockConnectionService(client);
+
+        final MockControllerServiceInitializationContext 
serviceInitializationContext = new 
MockControllerServiceInitializationContext(connectionService, 
CONNECTION_SERVICE_ID);
+        final Map<PropertyDescriptor, String> properties = 
Collections.singletonMap(COUCHBASE_CONNECTION_SERVICE, CONNECTION_SERVICE_ID);
+        final MockConfigurationContext context = new 
MockConfigurationContext(properties, serviceInitializationContext, new 
HashMap<>());
+
+        mapCacheClient.onEnabled(context);
+
+        final String result = mapCacheClient.get(TEST_DOCUMENT_ID, 
stringSerializer, stringDeserializer);
+
+        assertEquals(TEST_DOCUMENT_CONTENT, result);
+    }
+
+    @Test
+    public void testCacheGetFailure() throws CouchbaseException, IOException {
+        final CouchbaseClient client = mock(CouchbaseClient.class);
+        when(client.getDocument(anyString())).thenThrow(new 
CouchbaseDocNotFoundException("Test exception", null));
+
+        final CouchbaseConnectionService connectionService = 
mockConnectionService(client);
+
+        final MockControllerServiceInitializationContext 
serviceInitializationContext = new 
MockControllerServiceInitializationContext(connectionService, 
CONNECTION_SERVICE_ID);
+        final Map<PropertyDescriptor, String> properties = 
Collections.singletonMap(COUCHBASE_CONNECTION_SERVICE, CONNECTION_SERVICE_ID);
+        final MockConfigurationContext context = new 
MockConfigurationContext(properties, serviceInitializationContext, new 
HashMap<>());

Review Comment:
   This block could be extracted into a `BeforeEach` method in the abstract 
class in order to avoid copy-paste.



##########
nifi-extension-bundles/nifi-couchbase-bundle/nifi-couchbase-services/src/main/java/org/apache/nifi/services/couchbase/CouchbaseMapCacheClient.java:
##########
@@ -0,0 +1,212 @@
+/*
+ * 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.nifi.services.couchbase;
+
+import org.apache.nifi.annotation.documentation.CapabilityDescription;
+import org.apache.nifi.annotation.documentation.Tags;
+import org.apache.nifi.components.PropertyDescriptor;
+import org.apache.nifi.distributed.cache.client.AtomicCacheEntry;
+import 
org.apache.nifi.distributed.cache.client.AtomicDistributedMapCacheClient;
+import org.apache.nifi.distributed.cache.client.Deserializer;
+import org.apache.nifi.distributed.cache.client.Serializer;
+import 
org.apache.nifi.services.couchbase.exception.CouchbaseCasMismatchException;
+import 
org.apache.nifi.services.couchbase.exception.CouchbaseDocExistsException;
+import 
org.apache.nifi.services.couchbase.exception.CouchbaseDocNotFoundException;
+import org.apache.nifi.services.couchbase.exception.CouchbaseException;
+import org.apache.nifi.services.couchbase.utils.CouchbaseGetResult;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.List;
+import java.util.Optional;
+
+@Tags({"distributed", "cache", "map", "cluster", "couchbase"})
+@CapabilityDescription("Provides the ability to communicate with a Couchbase 
Server cluster as a DistributedMapCacheServer." +
+        " This can be used in order to share a Map between nodes in a NiFi 
cluster." +
+        " Couchbase Server cluster can provide a high available and persistent 
cache storage.")
+public class CouchbaseMapCacheClient extends AbstractCouchbaseService 
implements AtomicDistributedMapCacheClient<Long> {
+
+    public static final PropertyDescriptor COUCHBASE_CONNECTION_SERVICE = new 
PropertyDescriptor.Builder()
+            .name("Couchbase Connection Service")
+            .description("A Couchbase Connection Service which manages 
connections to a Couchbase cluster.")
+            .required(true)
+            .identifiesControllerService(CouchbaseConnectionService.class)
+            .build();
+
+    private static final List<PropertyDescriptor> PROPERTIES = List.of(
+            COUCHBASE_CONNECTION_SERVICE,
+            BUCKET_NAME,
+            SCOPE_NAME,
+            COLLECTION_NAME
+    );
+
+    @Override
+    protected List<PropertyDescriptor> getSupportedPropertyDescriptors() {
+        return PROPERTIES;
+    }
+
+    @Override
+    public <K, V> AtomicCacheEntry<K, V, Long> fetch(K key, Serializer<K> 
keySerializer, Deserializer<V> valueDeserializer) throws IOException {
+        final String documentId = serializeDocumentKey(key, keySerializer);
+        try {
+            final CouchbaseGetResult result = 
couchbaseClient.getDocument(documentId);
+            return new AtomicCacheEntry<>(key, 
deserializeDocument(valueDeserializer, result.resultContent()), result.cas());
+        } catch (CouchbaseDocNotFoundException e) {
+            return null;
+        } catch (CouchbaseException e) {
+            throw new IOException("Failed to fetch cache entry [%s] from 
Couchbase".formatted(documentId), e);
+        }
+    }
+
+    @Override
+    public <K, V> boolean replace(AtomicCacheEntry<K, V, Long> entry, 
Serializer<K> keySerializer, Serializer<V> valueSerializer) throws IOException {
+        final String documentId = serializeDocumentKey(entry.getKey(), 
keySerializer);
+        final byte[] document = serializeDocument(entry.getValue(), 
valueSerializer);
+        final Optional<Long> revision = entry.getRevision();
+
+        if (revision.isEmpty()) {
+            try {
+                couchbaseClient.insertDocument(documentId, document);
+                return true;
+            } catch (CouchbaseDocExistsException e) {
+                return false;
+            } catch (CouchbaseException e) {
+                throw new IOException("Failed to insert cache entry [%s] into 
Couchbase".formatted(documentId), e);
+            }
+        }
+
+        try {
+            final long casValue = revision.get();
+            couchbaseClient.replaceDocument(documentId, document, casValue);
+            return true;
+        } catch (CouchbaseDocNotFoundException | CouchbaseCasMismatchException 
e) {
+            return false;
+        } catch (CouchbaseException e) {
+            throw new IOException("Failed to replace cache entry [%s] in 
Couchbase".formatted(documentId), e);
+        }
+    }
+
+    @Override
+    public <K, V> boolean putIfAbsent(K key, V value, Serializer<K> 
keySerializer, Serializer<V> valueSerializer) throws IOException {
+        final String documentId = serializeDocumentKey(key, keySerializer);
+        final byte[] document = serializeDocument(value, valueSerializer);
+
+        try {
+            couchbaseClient.insertDocument(documentId, document);
+            return true;
+        } catch (CouchbaseDocExistsException e) {
+            return false;
+        } catch (CouchbaseException e) {
+            throw new IOException("Failed to insert cache entry [%s] into 
Couchbase".formatted(documentId), e);
+        }
+    }
+
+    @Override
+    public <K, V> V getAndPutIfAbsent(K key, V value, Serializer<K> 
keySerializer, Serializer<V> valueSerializer, Deserializer<V> 
valueDeserializer) throws IOException {
+        final V document = get(key, keySerializer, valueDeserializer);
+        if (document != null) {
+            return document;
+        }
+
+        putIfAbsent(key, value, keySerializer, valueSerializer);

Review Comment:
   Due to concurrent updates, `get()` may return `null` but `putIfAbsent()` 
cannot insert the item because the key has been added between the two calls. I 
suggest checking the return value of `putIfAbsent()` and if it is `false`, try 
to retrieve the existing value from the cache again.



##########
nifi-extension-bundles/nifi-couchbase-bundle/nifi-couchbase-services/src/main/java/org/apache/nifi/services/couchbase/CouchbaseMapCacheClient.java:
##########
@@ -0,0 +1,184 @@
+/*
+ * 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.nifi.services.couchbase;
+
+import org.apache.nifi.annotation.documentation.CapabilityDescription;
+import org.apache.nifi.annotation.documentation.Tags;
+import org.apache.nifi.components.PropertyDescriptor;
+import org.apache.nifi.distributed.cache.client.AtomicCacheEntry;
+import 
org.apache.nifi.distributed.cache.client.AtomicDistributedMapCacheClient;
+import org.apache.nifi.distributed.cache.client.Deserializer;
+import org.apache.nifi.distributed.cache.client.Serializer;
+import org.apache.nifi.services.couchbase.exception.CouchbaseException;
+import org.apache.nifi.services.couchbase.utils.CouchbaseGetResult;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.List;
+
+@Tags({"distributed", "cache", "map", "cluster", "couchbase"})
+@CapabilityDescription("Provides the ability to communicate with a Couchbase 
Server cluster as a DistributedMapCacheServer." +
+        " This can be used in order to share a Map between nodes in a NiFi 
cluster." +
+        " Couchbase Server cluster can provide a high available and persistent 
cache storage.")
+public class CouchbaseMapCacheClient extends AbstractCouchbaseService 
implements AtomicDistributedMapCacheClient<Long> {
+
+    public static final PropertyDescriptor COUCHBASE_CONNECTION_SERVICE = new 
PropertyDescriptor.Builder()
+            .name("Couchbase Connection Service")
+            .description("A Couchbase Connection Service which manages 
connections to a Couchbase cluster.")
+            .required(true)
+            .identifiesControllerService(CouchbaseConnectionService.class)
+            .build();
+
+    private static final List<PropertyDescriptor> PROPERTIES = List.of(
+            COUCHBASE_CONNECTION_SERVICE,
+            BUCKET_NAME,
+            SCOPE_NAME,
+            COLLECTION_NAME
+    );
+
+    @Override
+    protected List<PropertyDescriptor> getSupportedPropertyDescriptors() {
+        return PROPERTIES;
+    }
+
+    @Override
+    public <K, V> AtomicCacheEntry<K, V, Long> fetch(K key, Serializer<K> 
keySerializer, Deserializer<V> valueDeserializer) throws IOException {
+        final String documentId = serializeDocumentKey(key, keySerializer);
+        try {
+            final CouchbaseGetResult result = 
couchbaseClient.getDocument(documentId);
+            return new AtomicCacheEntry<>(key, 
deserializeDocument(valueDeserializer, result.resultContent()), result.cas());
+        } catch (CouchbaseException e) {
+            return null;
+        }
+    }
+
+    @Override
+    public <K, V> boolean replace(AtomicCacheEntry<K, V, Long> entry, 
Serializer<K> keySerializer, Serializer<V> valueSerializer) throws IOException {
+        final String documentId = serializeDocumentKey(entry.getKey(), 
keySerializer);
+        final byte[] document = serializeDocument(entry.getValue(), 
valueSerializer);
+
+        try {
+            couchbaseClient.replaceDocument(documentId, document);

Review Comment:
   The method has been extended with the insert step. Tested with Wait/Notify 
processors and it works correctly. 



-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: [email protected]

For queries about this service, please contact Infrastructure at:
[email protected]


Reply via email to