Ensure prefix is correct module prefix

- Moved Prefix logic from RI to Service layer
- Prefix is no PREFIX propety, not the moduel name!
== RI (DB Layer) Changes
- Removed prefix logic incl hazelcast
- Added new basic ri-test for getDataNode and assert prefix is null
- Updated exsiting ri-test to us getDataNode
- Updated existing ri-test to only use " where really needed
== CPS Service Layer Changes
- Introduced PrefixResolver with clear and limited responsibility
- Use PrefixResolver where needed
- Cache prefix map per anchor, use cached entry when available
- Disabled SONAR on new Regex
== REST Layer
- Use PrefixResolver where needed

Issue-ID: CPS-1353
Signed-off-by: ToineSiebelink <toine.siebelink@est.tech>
Change-Id: Ie16f0e1ee1c280f3eb69c9e64fab69a780fb692a

15 files changed, 489 insertions, 23 deletions

diff --git a/cps-service/pom.xml b/cps-service/pom.xml
index f47a96315..4a98cc27d 100644
--- a/cps-service/pom.xml
+++ b/cps-service/pom.xml
@@ -110,6 +110,11 @@
       <groupId>org.codehaus.janino</groupId>
       <artifactId>janino</artifactId>
     </dependency>
+    <dependency>
+      <!-- Hazelcast provide Distributed Caches -->
+      <groupId>com.hazelcast</groupId>
+      <artifactId>hazelcast-spring</artifactId>
+    </dependency>
     <!-- T E S T   D E P E N D E N C I E S -->
     <dependency>
       <groupId>org.codehaus.groovy</groupId>
diff --git a/cps-service/src/main/java/org/onap/cps/cache/AnchorDataCacheConfig.java b/cps-service/src/main/java/org/onap/cps/cache/AnchorDataCacheConfig.java
new file mode 100644
index 000000000..54d6ff395
--- /dev/null
+++ b/cps-service/src/main/java/org/onap/cps/cache/AnchorDataCacheConfig.java
@@ -0,0 +1,70 @@
+/*
+ * ============LICENSE_START========================================================
+ *  Copyright (C) 2022 Nordix Foundation
+ *  ================================================================================
+ *  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.
+ *
+ *  SPDX-License-Identifier: Apache-2.0
+ *  ============LICENSE_END=========================================================
+ */
+
+package org.onap.cps.cache;
+
+import com.hazelcast.config.Config;
+import com.hazelcast.config.MapConfig;
+import com.hazelcast.config.NamedConfig;
+import com.hazelcast.core.Hazelcast;
+import com.hazelcast.core.HazelcastInstance;
+import com.hazelcast.map.IMap;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+/**
+ * Core infrastructure of the hazelcast distributed cache for anchor data config use cases.
+ */
+@Configuration
+public class AnchorDataCacheConfig {
+
+    private static final MapConfig anchorDataCacheMapConfig = createMapConfig("anchorDataCacheMapConfig");
+
+    /**
+     * Distributed instance of anchor data cache that contains module prefix by anchor name as properties.
+     *
+     * @return configured map of anchor data cache
+     */
+    @Bean
+    public IMap<String, AnchorDataCacheEntry> anchorDataCache() {
+        return createHazelcastInstance("hazelCastInstanceCpsCore", anchorDataCacheMapConfig)
+                .getMap("anchorDataCache");
+    }
+
+    private HazelcastInstance createHazelcastInstance(final String hazelcastInstanceName,
+            final NamedConfig namedConfig) {
+        return Hazelcast.newHazelcastInstance(initializeConfig(hazelcastInstanceName, namedConfig));
+    }
+
+    private Config initializeConfig(final String instanceName, final NamedConfig namedConfig) {
+        final Config config = new Config(instanceName);
+        config.addMapConfig((MapConfig) namedConfig);
+        config.setClusterName("cps-service-caches");
+        return config;
+    }
+
+    private static MapConfig createMapConfig(final String configName) {
+        final MapConfig mapConfig = new MapConfig(configName);
+        mapConfig.setBackupCount(3);
+        mapConfig.setAsyncBackupCount(3);
+        return mapConfig;
+    }
+
+}
diff --git a/cps-service/src/main/java/org/onap/cps/cache/AnchorDataCacheEntry.java b/cps-service/src/main/java/org/onap/cps/cache/AnchorDataCacheEntry.java
new file mode 100644
index 000000000..41adbdd5d
--- /dev/null
+++ b/cps-service/src/main/java/org/onap/cps/cache/AnchorDataCacheEntry.java
@@ -0,0 +1,44 @@
+/*
+ * ============LICENSE_START========================================================
+ *  Copyright (C) 2022 Nordix Foundation
+ *  ================================================================================
+ *  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.
+ *
+ *  SPDX-License-Identifier: Apache-2.0
+ *  ============LICENSE_END=========================================================
+ */
+
+package org.onap.cps.cache;
+
+import java.io.Serializable;
+import java.util.HashMap;
+import java.util.Map;
+
+public class AnchorDataCacheEntry implements Serializable {
+
+    private static final long serialVersionUID = 2111243947810370698L;
+
+    private Map<String, Serializable> properties = new HashMap<>();
+
+    public Object getProperty(final String propertyName) {
+        return properties.get(propertyName);
+    }
+
+    public void setProperty(final String propertyName, final Serializable value) {
+        properties.put(propertyName, value);
+    }
+
+    public boolean hasProperty(final String propertyName) {
+        return properties.containsKey(propertyName);
+    }
+}
diff --git a/cps-service/src/main/java/org/onap/cps/notification/CpsDataUpdatedEventFactory.java b/cps-service/src/main/java/org/onap/cps/notification/CpsDataUpdatedEventFactory.java
index 1013c13b7..f0cdaee8d 100644
--- a/cps-service/src/main/java/org/onap/cps/notification/CpsDataUpdatedEventFactory.java
+++ b/cps-service/src/main/java/org/onap/cps/notification/CpsDataUpdatedEventFactory.java
@@ -1,6 +1,7 @@
 /*
  * ============LICENSE_START=======================================================
  * Copyright (c) 2021-2022 Bell Canada.
+ * Modifications Copyright (c) 2022 Nordix Foundation
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -34,6 +35,7 @@ import org.onap.cps.spi.FetchDescendantsOption;
 import org.onap.cps.spi.model.Anchor;
 import org.onap.cps.spi.model.DataNode;
 import org.onap.cps.utils.DataMapUtils;
+import org.onap.cps.utils.PrefixResolver;
 import org.springframework.context.annotation.Lazy;
 import org.springframework.stereotype.Component;
 
@@ -60,6 +62,9 @@ public class CpsDataUpdatedEventFactory {
     @Lazy
     private final CpsDataService cpsDataService;
 
+    @Lazy
+    private final PrefixResolver prefixResolver;
+
     /**
      * Generates CPS Data Updated event. If observedTimestamp is not provided, then current timestamp is used.
      *
@@ -87,9 +92,9 @@ public class CpsDataUpdatedEventFactory {
         return cpsDataUpdatedEvent;
     }
 
-    private Data createData(final DataNode dataNode) {
-        final var data = new Data();
-        DataMapUtils.toDataMapWithIdentifier(dataNode).forEach(data::setAdditionalProperty);
+    private Data createData(final DataNode dataNode, final String prefix) {
+        final Data data = new Data();
+        DataMapUtils.toDataMapWithIdentifier(dataNode, prefix).forEach(data::setAdditionalProperty);
         return data;
     }
 
@@ -103,7 +108,8 @@ public class CpsDataUpdatedEventFactory {
         content.withObservedTimestamp(
             DATE_TIME_FORMATTER.format(observedTimestamp == null ? OffsetDateTime.now() : observedTimestamp));
         if (dataNode != null) {
-            content.withData(createData(dataNode));
+            final String prefix = prefixResolver.getPrefix(anchor, dataNode.getXpath());
+            content.withData(createData(dataNode, prefix));
         }
         return content;
     }
diff --git a/cps-service/src/main/java/org/onap/cps/spi/model/DataNode.java b/cps-service/src/main/java/org/onap/cps/spi/model/DataNode.java
index 19d5adef0..8170db3da 100644
--- a/cps-service/src/main/java/org/onap/cps/spi/model/DataNode.java
+++ b/cps-service/src/main/java/org/onap/cps/spi/model/DataNode.java
@@ -38,14 +38,13 @@ public class DataNode implements Serializable {
 
     private static final long serialVersionUID = 1482619410918597467L;
 
-    DataNode() {    }
+    DataNode() {}
 
     private String dataspace;
     private String schemaSetName;
     private String anchorName;
     private ModuleReference moduleReference;
     private String xpath;
-    @Setter(AccessLevel.PUBLIC)
     private String moduleNamePrefix;
     private Map<String, Object> leaves = Collections.emptyMap();
     private Collection<String> xpathsChildren;
diff --git a/cps-service/src/main/java/org/onap/cps/utils/DataMapUtils.java b/cps-service/src/main/java/org/onap/cps/utils/DataMapUtils.java
index 4413c6b08..14641e05e 100644
--- a/cps-service/src/main/java/org/onap/cps/utils/DataMapUtils.java
+++ b/cps-service/src/main/java/org/onap/cps/utils/DataMapUtils.java
@@ -43,10 +43,9 @@ public class DataMapUtils {
      * @param dataNode data node object
      * @return a map representing same data with the root node identifier
      */
-    public static Map<String, Object> toDataMapWithIdentifier(final DataNode dataNode) {
-        return ImmutableMap.<String, Object>builder()
-            .put(getNodeIdentifierWithPrefix(dataNode.getXpath(), dataNode.getModuleNamePrefix()), toDataMap(dataNode))
-            .build();
+    public static Map<String, Object> toDataMapWithIdentifier(final DataNode dataNode, final String prefix) {
+        final String nodeIdentifierWithPrefix = getNodeIdentifierWithPrefix(dataNode.getXpath(), prefix);
+        return ImmutableMap.<String, Object>builder().put(nodeIdentifierWithPrefix, toDataMap(dataNode)).build();
     }
 
     /**
diff --git a/cps-service/src/main/java/org/onap/cps/utils/PrefixResolver.java b/cps-service/src/main/java/org/onap/cps/utils/PrefixResolver.java
new file mode 100644
index 000000000..58b239c34
--- /dev/null
+++ b/cps-service/src/main/java/org/onap/cps/utils/PrefixResolver.java
@@ -0,0 +1,133 @@
+/*
+ *  ============LICENSE_START=======================================================
+ *  Copyright (C) 2022 Nordix Foundation.
+ *  ================================================================================
+ *  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.
+ *
+ *  SPDX-License-Identifier: Apache-2.0
+ *  ============LICENSE_END=========================================================
+ */
+
+package org.onap.cps.utils;
+
+import com.hazelcast.map.IMap;
+import java.io.Serializable;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import lombok.RequiredArgsConstructor;
+import org.onap.cps.api.CpsAdminService;
+import org.onap.cps.api.impl.YangTextSchemaSourceSetCache;
+import org.onap.cps.cache.AnchorDataCacheEntry;
+import org.onap.cps.spi.model.Anchor;
+import org.onap.cps.yang.YangTextSchemaSourceSet;
+import org.opendaylight.yangtools.yang.common.QNameModule;
+import org.opendaylight.yangtools.yang.model.api.DataNodeContainer;
+import org.opendaylight.yangtools.yang.model.api.DataSchemaNode;
+import org.opendaylight.yangtools.yang.model.api.Module;
+import org.opendaylight.yangtools.yang.model.api.SchemaContext;
+import org.springframework.stereotype.Component;
+
+@Component
+@RequiredArgsConstructor
+public class PrefixResolver {
+    private static final long ANCHOR_DATA_CACHE_TTL_SECS = TimeUnit.HOURS.toSeconds(1);
+
+    private static final String CACHE_ENTRY_PROPERTY_NAME = "prefixPerContainerName";
+
+    private final CpsAdminService cpsAdminService;
+
+    private final YangTextSchemaSourceSetCache yangTextSchemaSourceSetCache;
+
+    private final IMap<String, AnchorDataCacheEntry> anchorDataCache;
+
+    private static final Pattern TOP_LEVEL_NODE_NAME_FINDER
+        = Pattern.compile("\\/([\\w-]*)(\\[@(?!.*\\[).*?])?(\\/.*)?");  //NOSONAR
+
+    /**
+     * Get the module prefix for the given xpath for a dataspace and anchor name.
+     *
+     * @param dataspaceName the name of the dataspace
+     * @param anchorName the name of the anchor the xpath belongs to
+     * @param xpath the xpath to prefix a prefix for
+     * @return the prefix of the module the top level element of given xpath
+     */
+    public String getPrefix(final String dataspaceName, final String anchorName, final String xpath) {
+        final Anchor anchor = cpsAdminService.getAnchor(dataspaceName, anchorName);
+        return getPrefix(anchor, xpath);
+    }
+
+    /**
+     * Get the module prefix for the given xpath under the given anchor.
+     *
+     * @param anchor the anchor the xpath belong to
+     * @param xpath the xpath to prefix a prefix for
+     * @return the prefix of the module the top level element of given xpath
+     */
+    public String getPrefix(final Anchor anchor, final String xpath) {
+        final Map<String, String> prefixPerContainerName = getPrefixPerContainerName(anchor);
+        return getPrefixForTopContainer(prefixPerContainerName, xpath);
+    }
+
+    private Map<String, String> getPrefixPerContainerName(final Anchor anchor) {
+        if (anchorDataCache.containsKey(anchor.getName())) {
+            final AnchorDataCacheEntry anchorDataCacheEntry = anchorDataCache.get(anchor.getName());
+            if (anchorDataCacheEntry.hasProperty(CACHE_ENTRY_PROPERTY_NAME)) {
+                return (Map) anchorDataCacheEntry.getProperty(CACHE_ENTRY_PROPERTY_NAME);
+            }
+        }
+        return createAndCachePrefixPerContainerNameMap(anchor);
+    }
+
+    private String getPrefixForTopContainer(final Map<String, String> prefixPerContainerName,
+                                            final String xpath) {
+        final Matcher matcher = TOP_LEVEL_NODE_NAME_FINDER.matcher(xpath);
+        if (matcher.matches()) {
+            final String topLevelContainerName = matcher.group(1);
+            if (prefixPerContainerName.containsKey(topLevelContainerName)) {
+                return prefixPerContainerName.get(topLevelContainerName);
+            }
+        }
+        return "";
+    }
+
+    private Map<String, String> createAndCachePrefixPerContainerNameMap(final Anchor anchor) {
+        final YangTextSchemaSourceSet yangTextSchemaSourceSet =
+            yangTextSchemaSourceSetCache.get(anchor.getDataspaceName(), anchor.getSchemaSetName());
+        final SchemaContext schemaContext = yangTextSchemaSourceSet.getSchemaContext();
+        final Map<QNameModule, String> prefixPerQNameModule = new HashMap<>(schemaContext.getModules().size());
+        for (final Module module : schemaContext.getModules()) {
+            prefixPerQNameModule.put(module.getQNameModule(), module.getPrefix());
+        }
+        final HashMap<String, String> prefixPerContainerName = new HashMap<>();
+        for (final DataSchemaNode dataSchemaNode : schemaContext.getChildNodes()) {
+            if (dataSchemaNode instanceof DataNodeContainer) {
+                final String containerName = dataSchemaNode.getQName().getLocalName();
+                final String prefix = prefixPerQNameModule.get(dataSchemaNode.getQName().getModule());
+                prefixPerContainerName.put(containerName, prefix);
+            }
+        }
+        cachePrefixPerContainerNameMap(anchor.getName(), prefixPerContainerName);
+        return prefixPerContainerName;
+    }
+
+    private void cachePrefixPerContainerNameMap(final String anchorName,
+                                                final Serializable prefixPerContainerName) {
+        final AnchorDataCacheEntry anchorDataCacheEntry = new AnchorDataCacheEntry();
+        anchorDataCacheEntry.setProperty(CACHE_ENTRY_PROPERTY_NAME, prefixPerContainerName);
+        anchorDataCache.put(anchorName, anchorDataCacheEntry, ANCHOR_DATA_CACHE_TTL_SECS, TimeUnit.SECONDS);
+    }
+
+}
diff --git a/cps-service/src/main/java/org/onap/cps/utils/YangUtils.java b/cps-service/src/main/java/org/onap/cps/utils/YangUtils.java
index 5e1b486aa..8fcdc4ebd 100644
--- a/cps-service/src/main/java/org/onap/cps/utils/YangUtils.java
+++ b/cps-service/src/main/java/org/onap/cps/utils/YangUtils.java
@@ -1,6 +1,6 @@
 /*
  *  ============LICENSE_START=======================================================
- *  Copyright (C) 2020-2021 Nordix Foundation
+ *  Copyright (C) 2020-2022 Nordix Foundation
  *  Modifications Copyright (C) 2021 Bell Canada.
  *  Modifications Copyright (C) 2021 Pantheon.tech
  *  ================================================================================
@@ -53,7 +53,6 @@ public class YangUtils {
 
     private static final String XPATH_DELIMITER_REGEX = "\\/";
     private static final String XPATH_NODE_KEY_ATTRIBUTES_REGEX = "\\[.*?\\]";
-    //Might cause an issue with [] inside [] in key-values
 
     /**
      * Parses jsonData into NormalizedNode according to given schema context.
@@ -125,6 +124,7 @@ public class YangUtils {
         return xpathBuilder.toString();
     }
 
+
     private static String getKeyAttributesStatement(
         final YangInstanceIdentifier.NodeIdentifierWithPredicates nodeIdentifier) {
         final List<String> keyAttributes = nodeIdentifier.entrySet().stream().map(
diff --git a/cps-service/src/test/groovy/org/onap/cps/cache/AnchorDataCacheConfigSpec.groovy b/cps-service/src/test/groovy/org/onap/cps/cache/AnchorDataCacheConfigSpec.groovy
new file mode 100644
index 000000000..839444b68
--- /dev/null
+++ b/cps-service/src/test/groovy/org/onap/cps/cache/AnchorDataCacheConfigSpec.groovy
@@ -0,0 +1,52 @@
+/*
+ *  ============LICENSE_START=======================================================
+ *  Copyright (C) 2022 Nordix Foundation
+ *  ================================================================================
+ *  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.
+ *
+ *  SPDX-License-Identifier: Apache-2.0
+ *  ============LICENSE_END=========================================================
+ */
+
+package org.onap.cps.cache
+import com.hazelcast.core.Hazelcast
+import com.hazelcast.map.IMap
+import org.springframework.beans.factory.annotation.Autowired
+import org.springframework.boot.test.context.SpringBootTest
+import org.springframework.test.context.ContextConfiguration
+import spock.lang.Specification
+
+@SpringBootTest
+@ContextConfiguration(classes = [AnchorDataCacheConfig])
+class AnchorDataCacheConfigSpec extends Specification {
+
+    @Autowired
+    private IMap<String, AnchorDataCacheEntry> anchorDataCache
+
+    def 'Embedded (hazelcast) cache for Anchor Data.'() {
+        expect: 'system is able to create an instance of the Anchor data cache'
+            assert null != anchorDataCache
+        and: 'there is at least 1 instance'
+            assert Hazelcast.allHazelcastInstances.size() > 0
+        and: 'anchorDataCache is present'
+            assert Hazelcast.allHazelcastInstances.name.contains('hazelCastInstanceCpsCore')
+    }
+
+    def 'Verify configs for Distributed Caches'(){
+        given: 'the Anchor Data Cache config'
+            def anchorDataCacheConfig =  Hazelcast.getHazelcastInstanceByName('hazelCastInstanceCpsCore').config.mapConfigs.get('anchorDataCacheMapConfig')
+        expect: 'system created instance with correct config'
+            assert anchorDataCacheConfig.backupCount == 3
+            assert anchorDataCacheConfig.asyncBackupCount == 3
+    }
+}
diff --git a/cps-service/src/test/groovy/org/onap/cps/cache/AnchorDataCacheEntrySpec.groovy b/cps-service/src/test/groovy/org/onap/cps/cache/AnchorDataCacheEntrySpec.groovy
new file mode 100644
index 000000000..f38b45d17
--- /dev/null
+++ b/cps-service/src/test/groovy/org/onap/cps/cache/AnchorDataCacheEntrySpec.groovy
@@ -0,0 +1,40 @@
+/*
+ *  ============LICENSE_START=======================================================
+ *  Copyright (C) 2022 Nordix Foundation
+ *  ================================================================================
+ *  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.
+ *
+ *  SPDX-License-Identifier: Apache-2.0
+ *  ============LICENSE_END=========================================================
+ */
+
+package org.onap.cps.cache
+
+
+import spock.lang.Specification
+
+class AnchorDataCacheEntrySpec extends Specification {
+
+    def objectUnderTest = new AnchorDataCacheEntry()
+
+    def 'Anchor Data Cache Properties Management.'() {
+        when: 'a property named "sample" is added to the cache'
+            objectUnderTest.setProperty('sample', 123)
+        then: 'the cache has that property'
+            assert objectUnderTest.hasProperty('sample')
+        and: 'the value is correct'
+            assert objectUnderTest.getProperty('sample') == 123
+        and: 'the cache does not have an an object called "something else"'
+            assert objectUnderTest.hasProperty('something else') == false
+    }
+}
diff --git a/cps-service/src/test/groovy/org/onap/cps/notification/CpsDataUpdateEventFactorySpec.groovy b/cps-service/src/test/groovy/org/onap/cps/notification/CpsDataUpdateEventFactorySpec.groovy
index 682197d51..6f9a148eb 100644
--- a/cps-service/src/test/groovy/org/onap/cps/notification/CpsDataUpdateEventFactorySpec.groovy
+++ b/cps-service/src/test/groovy/org/onap/cps/notification/CpsDataUpdateEventFactorySpec.groovy
@@ -1,6 +1,7 @@
 /*
- * ============LICENSE_START=======================================================
- * Copyright (c) 2021-2022 Bell Canada.
+ *  ============LICENSE_START=======================================================
+ *  Copyright (c) 2021-2022 Bell Canada.
+ *  Modifications Copyright (c) 2022 Nordix Foundation
  *  ================================================================================
  *  Licensed under the Apache License, Version 2.0 (the "License");
  *  you may not use this file except in compliance with the License.
@@ -23,7 +24,7 @@ package org.onap.cps.notification
 import java.time.OffsetDateTime
 import java.time.format.DateTimeFormatter
 import org.onap.cps.utils.DateTimeUtility
-import org.onap.cps.api.CpsAdminService
+import org.onap.cps.utils.PrefixResolver
 import org.onap.cps.api.CpsDataService
 import org.onap.cps.event.model.Content
 import org.onap.cps.event.model.Data
@@ -37,7 +38,9 @@ class CpsDataUpdateEventFactorySpec extends Specification {
 
     def mockCpsDataService = Mock(CpsDataService)
 
-    def objectUnderTest = new CpsDataUpdatedEventFactory(mockCpsDataService)
+    def mockPrefixResolver = Mock(PrefixResolver)
+
+    def objectUnderTest = new CpsDataUpdatedEventFactory(mockCpsDataService, mockPrefixResolver)
 
     def dateTimeFormat = 'yyyy-MM-dd\'T\'HH:mm:ss.SSSZ'
 
diff --git a/cps-service/src/test/groovy/org/onap/cps/spi/model/DataNodeBuilderSpec.groovy b/cps-service/src/test/groovy/org/onap/cps/spi/model/DataNodeBuilderSpec.groovy
index 16d4efc27..fcfb4826d 100644
--- a/cps-service/src/test/groovy/org/onap/cps/spi/model/DataNodeBuilderSpec.groovy
+++ b/cps-service/src/test/groovy/org/onap/cps/spi/model/DataNodeBuilderSpec.groovy
@@ -176,12 +176,11 @@ class DataNodeBuilderSpec extends Specification {
     def 'Use of adding the module name prefix attribute of data node.'() {
         when: 'data node is built with a prefix'
             def testDataNode = new DataNodeBuilder()
-                    .withModuleNamePrefix('sampleModuleNamePrefix')
                     .withXpath(xPath)
                     .withLeaves(sampleLeaves)
                     .build()
         then: 'the result when node request is a #scenario includes the correct prefix'
-            def result = new DataMapUtils().toDataMapWithIdentifier(testDataNode)
+            def result = new DataMapUtils().toDataMapWithIdentifier(testDataNode, 'sampleModuleNamePrefix')
             result.toString() == expectedResult
         where: 'the following parameters are used'
             scenario          | xPath                                       | sampleLeaves                   | expectedResult
diff --git a/cps-service/src/test/groovy/org/onap/cps/utils/DataMapUtilsSpec.groovy b/cps-service/src/test/groovy/org/onap/cps/utils/DataMapUtilsSpec.groovy
index 7f2c638ff..84dddeb60 100644
--- a/cps-service/src/test/groovy/org/onap/cps/utils/DataMapUtilsSpec.groovy
+++ b/cps-service/src/test/groovy/org/onap/cps/utils/DataMapUtilsSpec.groovy
@@ -65,11 +65,7 @@ class DataMapUtilsSpec extends Specification {
 
     def 'Data node structure conversion to map with root node identifier.'() {
         when: 'data node structure is converted to a map with root node identifier'
-            def result = DataMapUtils.toDataMapWithIdentifier(dataNode)
-
-        then: 'root node identifier is not null'
-            result.parent != null
-
+            def result = DataMapUtils.toDataMapWithIdentifier(dataNode,dataNode.moduleNamePrefix)
         then: 'root node leaves are populated under its node identifier'
             def parentNode = result.parent
             parentNode.parentLeaf == 'parentLeafValue'
diff --git a/cps-service/src/test/groovy/org/onap/cps/utils/PrefixResolverSpec.groovy b/cps-service/src/test/groovy/org/onap/cps/utils/PrefixResolverSpec.groovy
new file mode 100644
index 000000000..4c1b89116
--- /dev/null
+++ b/cps-service/src/test/groovy/org/onap/cps/utils/PrefixResolverSpec.groovy
@@ -0,0 +1,117 @@
+/*
+ *  ============LICENSE_START=======================================================
+ *  Copyright (C) 2021-2022 Nordix Foundation
+ *  Modifications Copyright (C) 2021 Pantheon.tech
+ *  Modifications Copyright (C) 2021-2022 Bell Canada.
+ *  ================================================================================
+ *  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.
+ *
+ *  SPDX-License-Identifier: Apache-2.0
+ *  ============LICENSE_END=========================================================
+ */
+
+package org.onap.cps.utils
+
+import com.hazelcast.map.IMap
+import org.onap.cps.TestUtils
+import org.onap.cps.api.CpsAdminService
+import org.onap.cps.api.impl.YangTextSchemaSourceSetCache
+import org.onap.cps.cache.AnchorDataCacheEntry
+import org.onap.cps.spi.model.Anchor
+import org.onap.cps.yang.YangTextSchemaSourceSet
+import org.onap.cps.yang.YangTextSchemaSourceSetBuilder
+import spock.lang.Specification
+
+class PrefixResolverSpec extends Specification {
+
+    def mockCpsAdminService = Mock(CpsAdminService)
+
+    def mockYangTextSchemaSourceSetCache = Mock(YangTextSchemaSourceSetCache)
+
+    def mockAnchorDataCache = Mock(IMap<String, AnchorDataCacheEntry>)
+
+    def objectUnderTest = new PrefixResolver(mockCpsAdminService, mockYangTextSchemaSourceSetCache, mockAnchorDataCache)
+
+    def mockYangTextSchemaSourceSet = Mock(YangTextSchemaSourceSet)
+
+    def yangResourceNameToContent = TestUtils.getYangResourcesAsMap('test-tree.yang')
+
+    def schemaContext = YangTextSchemaSourceSetBuilder.of(yangResourceNameToContent).getSchemaContext()
+
+    def setup() {
+        given: 'an anchor for the test-tree model'
+            def anchor = new Anchor(dataspaceName: 'testDataspace', name: 'testAnchor')
+        and: 'the system can get this anchor'
+            mockCpsAdminService.getAnchor('testDataspace', 'testAnchor') >> anchor
+        and: 'the schema source cache contains the schema context for the test-tree module'
+            mockYangTextSchemaSourceSet.getSchemaContext() >> schemaContext
+    }
+
+    def 'get xpath prefix using node schema context'() {
+        when: 'the prefix of the yang module is retrieved'
+            def result = objectUnderTest.getPrefix('testDataspace', 'testAnchor', xpath)
+        then: 'the expected prefix is returned'
+            result == expectedPrefix
+        and: 'the cache is updated for the given anchor with a map of prefixes per top level container (just one one this case)'
+            1 * mockAnchorDataCache.put('testAnchor',_ , _ ,_) >> { args -> {
+                def prefixPerContainerName = args[1].getProperty("prefixPerContainerName")
+                assert prefixPerContainerName.size() == 1
+                assert prefixPerContainerName.get('test-tree') == 'tree'
+                }
+            }
+        and: 'schema source cache is used (i.e. need to build schema context)'
+            1 * mockYangTextSchemaSourceSetCache.get(*_) >> mockYangTextSchemaSourceSet
+        where: 'the following scenarios are applied'
+            xpath                         || expectedPrefix
+            '/test-tree'                  || 'tree'
+            '/test-tree/with/descendants' || 'tree'
+            '/test-tree[@id=1]'           || 'tree'
+            '/test-tree[@id=1]/child'     || 'tree'
+            '/not-defined'                || ''
+            'invalid-xpath'               || ''
+    }
+
+    def 'get prefix with populated anchor data cache with #scenario cache entry'() {
+        given: 'anchor data cache is populated for the anchor with a prefix for top level container named #cachedTopLevelContainerName'
+            def anchorDataCacheEntry = new AnchorDataCacheEntry()
+            def prefixPerContainerName = [(cachedTopLevelContainerName): 'cachedPrefix']
+            anchorDataCacheEntry.setProperty('prefixPerContainerName',prefixPerContainerName)
+            mockAnchorDataCache.containsKey('testAnchor') >> true
+            mockAnchorDataCache.get('testAnchor') >> anchorDataCacheEntry
+        when: 'the prefix of the yang module is retrieved'
+            def result = objectUnderTest.getPrefix('testDataspace', 'testAnchor', '/test-tree')
+        then: 'the expected prefix is returned'
+            result == expectedPrefix
+        and: 'schema source cache is not used (i.e. no need to build schema context)'
+            0 * mockYangTextSchemaSourceSetCache.get(*_)
+        where: 'the following scenarios are applied'
+            scenario       | cachedTopLevelContainerName || expectedPrefix
+            'matching'     | 'test-tree'                 || 'cachedPrefix'
+            'non-matching' | 'other'                     || ''
+    }
+
+    def 'get prefix with other (non relevant) data in anchor data cache'() {
+        given: 'anchor data cache is populated with non relevant other property'
+            def anchorDataCacheEntry = new AnchorDataCacheEntry()
+            anchorDataCacheEntry.setProperty('something else', 'does not matter')
+            mockAnchorDataCache.containsKey('testAnchor') >> true
+            mockAnchorDataCache.get('testAnchor') >> anchorDataCacheEntry
+        when: 'the prefix of the yang module is retrieved'
+            def result = objectUnderTest.getPrefix('testDataspace', 'testAnchor', '/test-tree')
+        then: 'the expected prefix is returned'
+            result == 'tree'
+        and: 'schema source cache is used (i.e. need to build schema context)'
+            1 * mockYangTextSchemaSourceSetCache.get(*_) >> mockYangTextSchemaSourceSet
+    }
+
+}
diff --git a/cps-service/src/test/resources/test-tree.yang b/cps-service/src/test/resources/test-tree.yang
index 63100657e..a9f7e224b 100644
--- a/cps-service/src/test/resources/test-tree.yang
+++ b/cps-service/src/test/resources/test-tree.yang
@@ -33,4 +33,7 @@ module test-tree {
 
         }
     }
+    leaf topLevelLeafAddedForBranchCoverageInPrefixResolverSpec {
+        type string;
+    }
 }