Reduce anchor lookups related to PrefixResolver (CPS-2417 #1)

Instead of looking up same Anchor many times inside a for-loop,
do it once outside the loop.

This greatly improves performance in some cases, such as v2 GET API:
- /cps/api/v2/dataspaces/{dataspace}/anchors/{anchor}/node
Testing shows 3x faster response time.

Issue-ID: CPS-2417
Signed-off-by: danielhanrahan <daniel.hanrahan@est.tech>
Change-Id: I80d97d8cc24372eed70626ed840cad985cbe0a4b

3 files changed, 7 insertions, 21 deletions

diff --git a/cps-service/src/main/java/org/onap/cps/api/impl/CpsDataServiceImpl.java b/cps-service/src/main/java/org/onap/cps/api/impl/CpsDataServiceImpl.java
index 951770b053..eed4f09bf0 100644
--- a/cps-service/src/main/java/org/onap/cps/api/impl/CpsDataServiceImpl.java
+++ b/cps-service/src/main/java/org/onap/cps/api/impl/CpsDataServiceImpl.java
@@ -400,8 +400,7 @@ public class CpsDataServiceImpl implements CpsDataService {
     private List<Map<String, Object>> prefixResolver(final Anchor anchor, final Collection<DataNode> dataNodes) {
         final List<Map<String, Object>> prefixToDataNodes = new ArrayList<>(dataNodes.size());
         for (final DataNode dataNode: dataNodes) {
-            final String prefix = prefixResolver
-                    .getPrefix(anchor.getDataspaceName(), anchor.getName(), dataNode.getXpath());
+            final String prefix = prefixResolver.getPrefix(anchor, dataNode.getXpath());
             final Map<String, Object> prefixToDataNode = DataMapUtils.toDataMapWithIdentifier(dataNode, prefix);
             prefixToDataNodes.add(prefixToDataNode);
         }
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
index 35dc7347b2..93fb72864f 100644
--- a/cps-service/src/main/java/org/onap/cps/utils/PrefixResolver.java
+++ b/cps-service/src/main/java/org/onap/cps/utils/PrefixResolver.java
@@ -55,19 +55,6 @@ public class PrefixResolver {
     private final IMap<String, AnchorDataCacheEntry> anchorDataCache;
 
     /**
-     * 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 = cpsAnchorService.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
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
index b975de6555..5ef584a0b8 100644
--- a/cps-service/src/test/groovy/org/onap/cps/utils/PrefixResolverSpec.groovy
+++ b/cps-service/src/test/groovy/org/onap/cps/utils/PrefixResolverSpec.groovy
@@ -48,10 +48,10 @@ class PrefixResolverSpec extends Specification {
 
     def schemaContext = YangTextSchemaSourceSetBuilder.of(yangResourceNameToContent).getSchemaContext()
 
+    def anchor = new Anchor(dataspaceName: 'testDataspace', name: 'testAnchor')
+
     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'
+        given: 'the system can get the anchor'
             mockCpsAnchorService.getAnchor('testDataspace', 'testAnchor') >> anchor
         and: 'the schema source cache contains the schema context for the test-tree module'
             mockYangTextSchemaSourceSet.getSchemaContext() >> schemaContext
@@ -59,7 +59,7 @@ class PrefixResolverSpec extends Specification {
 
     def 'get xpath prefix using node schema context'() {
         when: 'the prefix of the yang module is retrieved'
-            def result = objectUnderTest.getPrefix('testDataspace', 'testAnchor', xpath)
+            def result = objectUnderTest.getPrefix(anchor, 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)'
@@ -90,7 +90,7 @@ class PrefixResolverSpec extends Specification {
             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')
+            def result = objectUnderTest.getPrefix(anchor, '/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)'
@@ -108,7 +108,7 @@ class PrefixResolverSpec extends Specification {
             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')
+            def result = objectUnderTest.getPrefix(anchor, '/test-tree')
         then: 'the expected prefix is returned'
             result == 'tree'
         and: 'schema source cache is used (i.e. need to build schema context)'