NIFI-4982 - Add a DistributedMapCacheLookupService

This closes #2558

Signed-off-by: zenfenan <zenfenan@apache.org>

nifi-nar-bundles/nifi-standard-services/nifi-lookup-services-bundle/nifi-lookup-services/pom.xml

@@ -32,6 +32,10 @@
             <groupId>org.apache.nifi</groupId>
             <artifactId>nifi-lookup-service-api</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.apache.nifi</groupId>
+            <artifactId>nifi-distributed-cache-client-service-api</artifactId>
+        </dependency>
         <dependency>
             <groupId>org.apache.nifi</groupId>
             <artifactId>nifi-utils</artifactId>

nifi-nar-bundles/nifi-standard-services/nifi-lookup-services-bundle/nifi-lookup-services/src/main/java/org/apache/nifi/lookup/DistributedMapCacheLookupService.java

@@ -0,0 +1,155 @@
+/*
+ * 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.lookup;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+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.components.Validator;
+import org.apache.nifi.controller.AbstractControllerService;
+import org.apache.nifi.controller.ConfigurationContext;
+import org.apache.nifi.distributed.cache.client.Deserializer;
+import org.apache.nifi.distributed.cache.client.DistributedMapCacheClient;
+import org.apache.nifi.distributed.cache.client.Serializer;
+import org.apache.nifi.distributed.cache.client.exception.DeserializationException;
+import org.apache.nifi.distributed.cache.client.exception.SerializationException;
+import org.apache.nifi.expression.ExpressionLanguageScope;
+
+@Tags({"lookup", "enrich", "key", "value", "map", "cache", "distributed"})
+@CapabilityDescription("Allows to choose a distributed map cache client to retrieve the value associated to a key. "
+    + "The coordinates that are passed to the lookup must contain the key 'key'.")
+public class DistributedMapCacheLookupService extends AbstractControllerService implements StringLookupService {
+
+    private static final List<Charset> STANDARD_CHARSETS = Arrays.asList(
+            StandardCharsets.UTF_8,
+            StandardCharsets.US_ASCII,
+            StandardCharsets.ISO_8859_1,
+            StandardCharsets.UTF_16,
+            StandardCharsets.UTF_16LE,
+            StandardCharsets.UTF_16BE);
+
+    private static final String KEY = "key";
+    private static final Set<String> REQUIRED_KEYS = Stream.of(KEY).collect(Collectors.toSet());
+
+    private volatile DistributedMapCacheClient cache;
+    private volatile static Charset charset;
+    private final Serializer<String> keySerializer = new StringSerializer();
+    private final Deserializer<String> valueDeserializer = new StringDeserializer();
+
+    public static final PropertyDescriptor PROP_DISTRIBUTED_CACHE_SERVICE = new PropertyDescriptor.Builder()
+            .name("distributed-map-cache-service")
+            .displayName("Distributed Cache Service")
+            .description("The Controller Service that is used to get the cached values.")
+            .required(true)
+            .identifiesControllerService(DistributedMapCacheClient.class)
+            .build();
+
+    public static final PropertyDescriptor CHARACTER_ENCODING = new PropertyDescriptor.Builder()
+            .name("character-encoding")
+            .displayName("Character Encoding")
+            .description("Specifies a character encoding to use.")
+            .required(true)
+            .allowableValues(getStandardCharsetNames())
+            .defaultValue(StandardCharsets.UTF_8.displayName())
+            .build();
+
+    private static Set<String> getStandardCharsetNames() {
+        return STANDARD_CHARSETS.stream().map(c -> c.displayName()).collect(Collectors.toSet());
+    }
+
+    @Override
+    protected PropertyDescriptor getSupportedDynamicPropertyDescriptor(final String propertyDescriptorName) {
+        return new PropertyDescriptor.Builder()
+            .name(propertyDescriptorName)
+            .required(false)
+            .dynamic(true)
+            .addValidator(Validator.VALID)
+            .expressionLanguageSupported(ExpressionLanguageScope.FLOWFILE_ATTRIBUTES)
+            .build();
+    }
+
+    @OnEnabled
+    public void onEnabled(final ConfigurationContext context) {
+        cache = context.getProperty(PROP_DISTRIBUTED_CACHE_SERVICE).asControllerService(DistributedMapCacheClient.class);
+        charset = Charset.forName(context.getProperty(CHARACTER_ENCODING).getValue());
+    }
+
+    @Override
+    protected List<PropertyDescriptor> getSupportedPropertyDescriptors() {
+        final List<PropertyDescriptor> descriptors = new ArrayList<>();
+        descriptors.add(PROP_DISTRIBUTED_CACHE_SERVICE);
+        descriptors.add(CHARACTER_ENCODING);
+        return descriptors;
+    }
+
+    @Override
+    public Optional<String> lookup(final Map<String, Object> coordinates) {
+        if (coordinates == null) {
+            return Optional.empty();
+        }
+
+        final String key = coordinates.get(KEY).toString();
+        if (key == null) {
+            return Optional.empty();
+        }
+
+        try {
+            return Optional.ofNullable(cache.get(key, keySerializer, valueDeserializer));
+        } catch (IOException e) {
+            getLogger().error("Error while trying to get the value from distributed map cache with key = " + key, e);
+            return Optional.empty();
+        }
+    }
+
+    @Override
+    public Set<String> getRequiredKeys() {
+        return REQUIRED_KEYS;
+    }
+
+    public static class StringDeserializer implements Deserializer<String> {
+        @Override
+        public String deserialize(final byte[] input) throws DeserializationException, IOException {
+            if (input == null || input.length == 0) {
+                return null;
+            }
+            return new String(input, 0, input.length, charset);
+        }
+    }
+
+    public static class StringSerializer implements Serializer<String> {
+        @Override
+        public void serialize(final String value, final OutputStream out) throws SerializationException, IOException {
+            out.write(value.getBytes(charset));
+        }
+    }
+
+}

nifi-nar-bundles/nifi-standard-services/nifi-lookup-services-bundle/nifi-lookup-services/src/main/resources/META-INF/services/org.apache.nifi.controller.ControllerService

@@ -19,3 +19,4 @@ org.apache.nifi.lookup.RestLookupService
 org.apache.nifi.lookup.SimpleKeyValueLookupService
 org.apache.nifi.lookup.SimpleCsvFileLookupService
 org.apache.nifi.lookup.XMLFileLookupService
+org.apache.nifi.lookup.DistributedMapCacheLookupService

nifi-nar-bundles/nifi-standard-services/nifi-lookup-services-bundle/nifi-lookup-services/src/test/java/org/apache/nifi/lookup/TestDistributedMapCacheLookupService.java

@@ -0,0 +1,130 @@
+/*
+ * 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.lookup;
+
+import static org.hamcrest.CoreMatchers.instanceOf;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThat;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+
+import org.apache.nifi.annotation.lifecycle.OnEnabled;
+import org.apache.nifi.components.PropertyDescriptor;
+import org.apache.nifi.controller.AbstractControllerService;
+import org.apache.nifi.controller.ConfigurationContext;
+import org.apache.nifi.distributed.cache.client.Deserializer;
+import org.apache.nifi.distributed.cache.client.DistributedMapCacheClient;
+import org.apache.nifi.distributed.cache.client.Serializer;
+import org.apache.nifi.reporting.InitializationException;
+import org.apache.nifi.util.TestRunner;
+import org.apache.nifi.util.TestRunners;
+import org.junit.Test;
+
+public class TestDistributedMapCacheLookupService {
+
+    final static Optional<String> EMPTY_STRING = Optional.empty();
+
+    @Test
+    public void testDistributedMapCacheLookupService() throws InitializationException {
+        final TestRunner runner = TestRunners.newTestRunner(TestProcessor.class);
+        final DistributedMapCacheLookupService service = new DistributedMapCacheLookupService();
+        final DistributedMapCacheClient client = new DistributedMapCacheClientImpl();
+
+        runner.addControllerService("client", client);
+        runner.addControllerService("lookup-service", service);
+        runner.setProperty(service, DistributedMapCacheLookupService.PROP_DISTRIBUTED_CACHE_SERVICE, "client");
+
+        runner.enableControllerService(client);
+        runner.enableControllerService(service);
+
+        runner.assertValid(service);
+
+        assertThat(service, instanceOf(LookupService.class));
+
+        final Optional<String> get = service.lookup(Collections.singletonMap("key", "myKey"));
+        assertEquals(Optional.of("myValue"), get);
+
+        final Optional<String> absent = service.lookup(Collections.singletonMap("key", "absentKey"));
+        assertEquals(EMPTY_STRING, absent);
+    }
+
+    static final class DistributedMapCacheClientImpl extends AbstractControllerService implements DistributedMapCacheClient {
+
+        private Map<String, String> map = new HashMap<String, String>();
+
+        @OnEnabled
+        public void onEnabled(final ConfigurationContext context) {
+            map.put("myKey", "myValue");
+        }
+
+        @Override
+        public void close() throws IOException {
+        }
+
+        @Override
+        public void onPropertyModified(final PropertyDescriptor descriptor, final String oldValue, final String newValue) {
+        }
+
+        @Override
+        protected java.util.List<PropertyDescriptor> getSupportedPropertyDescriptors() {
+            return new ArrayList<>();
+        }
+
+        @Override
+        public <K, V> boolean putIfAbsent(final K key, final V value, final Serializer<K> keySerializer, final Serializer<V> valueSerializer) throws IOException {
+            throw new UnsupportedOperationException("not implemented");
+        }
+
+        @Override
+        public <K, V> V getAndPutIfAbsent(final K key, final V value, final Serializer<K> keySerializer, final Serializer<V> valueSerializer,
+                final Deserializer<V> valueDeserializer) throws IOException {
+            throw new UnsupportedOperationException("not implemented");
+        }
+
+        @Override
+        public <K> boolean containsKey(final K key, final Serializer<K> keySerializer) throws IOException {
+            throw new UnsupportedOperationException("not implemented");
+        }
+
+        @Override
+        @SuppressWarnings("unchecked")
+        public <K, V> V get(final K key, final Serializer<K> keySerializer, final Deserializer<V> valueDeserializer) throws IOException {
+            return (V) map.get(key);
+        }
+
+        @Override
+        public <K> boolean remove(final K key, final Serializer<K> serializer) throws IOException {
+            throw new UnsupportedOperationException("not implemented");
+        }
+
+        @Override
+        public long removeByPattern(String regex) throws IOException {
+            throw new UnsupportedOperationException("not implemented");
+        }
+
+        @Override
+        public <K, V> void put(final K key, final V value, final Serializer<K> keySerializer, final Serializer<V> valueSerializer) throws IOException {
+            throw new UnsupportedOperationException("not implemented");
+        }
+    }
+
+}