Query data nodes with limit

  - added new methods to java interfaces
  - added integration test
  - removed unused methods

Issue-ID: CPS-2394
Change-Id: Iac4094a5daedbf593d17f55928136a80391c6d23
Signed-off-by: leventecsanyi <levente.csanyi@est.tech>

3 files changed, 49 insertions, 2 deletions

diff --git a/cps-service/src/main/java/org/onap/cps/api/CpsQueryService.java b/cps-service/src/main/java/org/onap/cps/api/CpsQueryService.java
index d783b9ed0e..3044fe0a90 100644
--- a/cps-service/src/main/java/org/onap/cps/api/CpsQueryService.java
+++ b/cps-service/src/main/java/org/onap/cps/api/CpsQueryService.java
@@ -32,6 +32,8 @@ import org.onap.cps.api.parameters.PaginationOption;
  */
 public interface CpsQueryService {
 
+    public static int NO_LIMIT = 0;
+
     /**
      * Get data nodes for the given dataspace and anchor by cps path.
      *
@@ -45,6 +47,20 @@ public interface CpsQueryService {
     Collection<DataNode> queryDataNodes(String dataspaceName, String anchorName,
                                         String cpsPath, FetchDescendantsOption fetchDescendantsOption);
 
+    /**
+     * Retrieves a collection of data nodes based on the specified CPS path query.
+     *
+     * @param dataspaceName the name of the dataspace (must not be null or empty)
+     * @param anchorName the name of the anchor (must not be null or empty)
+     * @param cpsPath the CPS path used for querying (must not be null or empty)
+     * @param fetchDescendantsOption specifies whether to include descendant nodes in the output
+     * @param queryResultLimit the maximum number of data nodes to return; if less than 1, returns all matching nodes
+     *
+     * @return a collection of matching {@link DataNode} instances (can be empty if no nodes are found)
+     */
+    Collection<DataNode> queryDataNodes(String dataspaceName, String anchorName,
+                                        String cpsPath, FetchDescendantsOption fetchDescendantsOption,
+                                        int queryResultLimit);
 
     /**
      * Get data leaf for the given dataspace and anchor by cps path.
diff --git a/cps-service/src/main/java/org/onap/cps/impl/CpsQueryServiceImpl.java b/cps-service/src/main/java/org/onap/cps/impl/CpsQueryServiceImpl.java
index 508a1b2449..f27445f7c9 100644
--- a/cps-service/src/main/java/org/onap/cps/impl/CpsQueryServiceImpl.java
+++ b/cps-service/src/main/java/org/onap/cps/impl/CpsQueryServiceImpl.java
@@ -46,8 +46,22 @@ public class CpsQueryServiceImpl implements CpsQueryService {
     public Collection<DataNode> queryDataNodes(final String dataspaceName, final String anchorName,
                                                final String cpsPath,
                                                final FetchDescendantsOption fetchDescendantsOption) {
-        cpsValidator.validateNameCharacters(dataspaceName, anchorName);
-        return cpsDataPersistenceService.queryDataNodes(dataspaceName, anchorName, cpsPath, fetchDescendantsOption);
+        return queryDataNodes(dataspaceName, anchorName, cpsPath, fetchDescendantsOption, NO_LIMIT);
+    }
+
+    @Override
+    @Timed(value = "cps.data.service.datanode.query",
+            description = "Time taken to query data nodes with a limit on results")
+    public Collection<DataNode> queryDataNodes(final String dataSpaceName, final String anchorName,
+                                               final String cpsPath,
+                                               final FetchDescendantsOption fetchDescendantsOption,
+                                               final int queryResultLimit) {
+        cpsValidator.validateNameCharacters(dataSpaceName, anchorName);
+        return cpsDataPersistenceService.queryDataNodes(dataSpaceName,
+                                                        anchorName,
+                                                        cpsPath,
+                                                        fetchDescendantsOption,
+                                                        queryResultLimit);
     }
 
     @Override
diff --git a/cps-service/src/main/java/org/onap/cps/spi/CpsDataPersistenceService.java b/cps-service/src/main/java/org/onap/cps/spi/CpsDataPersistenceService.java
index a4f05cdb53..5be5fb0481 100644
--- a/cps-service/src/main/java/org/onap/cps/spi/CpsDataPersistenceService.java
+++ b/cps-service/src/main/java/org/onap/cps/spi/CpsDataPersistenceService.java
@@ -186,6 +186,23 @@ public interface CpsDataPersistenceService {
                                   String cpsPath, FetchDescendantsOption fetchDescendantsOption);
 
     /**
+     * Get a datanode by cps path.
+     *
+     * @param dataspaceName          dataspace name
+     * @param anchorName             anchor name
+     * @param cpsPath                cps path
+     * @param fetchDescendantsOption defines whether the descendants of the node(s) found by the query should be
+     *                               included in the output
+     * @param queryResultLimit       limits the number of returned entities (if less than 1 returns all)
+     *
+     * @return the data nodes found i.e. 0 or more data nodes
+     */
+    List<DataNode> queryDataNodes(String dataspaceName,
+                                  String anchorName,
+                                  String cpsPath, FetchDescendantsOption fetchDescendantsOption,
+                                  int queryResultLimit);
+
+    /**
      * Get data leaf for the given dataspace and anchor by cps path.
      *
      * @param dataspaceName          dataspace name