Differential D6953 Diff 25200 java/src/main/java/org/softwareheritage/graph/SwhGraphProperties.java

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java/src/main/java/org/softwareheritage/graph/SwhGraphProperties.java

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				package org.softwareheritage.graph;

				import org.softwareheritage.graph.maps.NodeIdMap;
				import org.softwareheritage.graph.maps.NodeTypesMap;

				import java.io.IOException;

				/**
				* This objects contains SWH graph properties such as node labels.
				*
				* Some property mappings are necessary because Software Heritage uses string based <a href=
				* "https://docs.softwareheritage.org/devel/swh-model/persistent-identifiers.html">persistent
				* identifiers</a> (SWHID) while WebGraph uses integers internally.
				*
				* The two node ID mappings (long id ↔ SWHID) are used for the input (users refer to the graph
				* using SWHID) and the output (convert back to SWHID for users results).
				*
				* Since graph traversal can be restricted depending on the node type (see {@link AllowedEdges}), a
				* long id → node type map is stored as well to avoid a full SWHID lookup.
				*
				* @see NodeIdMap
				* @see NodeTypesMap
				*/
				public class SwhGraphProperties {
				/** Path and basename of the compressed graph */
				String path;
				/** Mapping long id ↔ SWHIDs */
				NodeIdMap nodeIdMap;
				/** Mapping long id → node types */
				NodeTypesMap nodeTypesMap;

				protected SwhGraphProperties(String path, NodeIdMap nodeIdMap, NodeTypesMap nodeTypesMap) {
				this.path = path;
				this.nodeIdMap = nodeIdMap;
				this.nodeTypesMap = nodeTypesMap;
				}

				public static SwhGraphProperties load(String path) throws IOException {
				return new SwhGraphProperties(path, new NodeIdMap(path), new NodeTypesMap(path));
				}

				/**
				* Cleans up graph resources after use.
				*/
				public void close() throws IOException {
				this.nodeIdMap.close();
				}

				public String getPath() {
				return path;
				}

				/**
				* Converts {@link SWHID} node to long.
				*
				* @param swhid node specified as a {@link SWHID}
				* @return internal long node id
				* @see SWHID
				*/
				public long getNodeId(SWHID swhid) {
				return nodeIdMap.getNodeId(swhid);
				}

				/**
				* Converts long id node to {@link SWHID}.
				*
				* @param nodeId node specified as a long id
				* @return external SWHID
				* @see SWHID
				*/
				public SWHID getSWHID(long nodeId) {
				return nodeIdMap.getSWHID(nodeId);
				}

				/**
				* Returns node type.
				*
				* @param nodeId node specified as a long id
				* @return corresponding node type
				* @see Node.Type
				*/
				public Node.Type getNodeType(long nodeId) {
				return nodeTypesMap.getType(nodeId);
				}
				}