Java VertexIDAssigner類代碼示例

import com.thinkaurelius.titan.graphdb.database.idassigner.VertexIDAssigner; //導入依賴的package包/類
@Test
public void testKeybasedGraphPartitioning() {
    Object[] options = {option(GraphDatabaseConfiguration.IDS_FLUSH), false,
                        option(VertexIDAssigner.PLACEMENT_STRATEGY), PropertyPlacementStrategy.class.getName(),
            option(PropertyPlacementStrategy.PARTITION_KEY), "clusterId"};
    clopen(options);

    int[] groupDegrees = {5,5,5,5,5,5,5,5};
    int numVertices = setupGroupClusters(groupDegrees,CommitMode.PER_VERTEX);

    IntSet partitionIds = new IntHashSet(numVertices); //to track the "spread" of partition ids
    for (int i=0;i<groupDegrees.length;i++) {
        TitanVertex g = getOnlyVertex(tx.query().has("groupid","group"+i));
        int partitionId = -1;
        for (TitanVertex v : g.query().direction(Direction.IN).labels("member").vertices()) {
            if (partitionId<0) partitionId = getPartitionID(v);
            assertEquals(partitionId,getPartitionID(v));
            partitionIds.add(partitionId);
        }
    }
    assertTrue(partitionIds.size()>numPartitions/2); //This is a probabilistic test that might fail
}
 

import com.thinkaurelius.titan.graphdb.database.idassigner.VertexIDAssigner; //導入依賴的package包/類
/**
 *
 * @param numPartitionsBits The number of partitions bits to use. This means there are exactly (1<<numPartitionBits) partitions.
 * @param partitionMax The maxium number of ids that can be allocated per partition. This is artifically constraint by the MockIDAuthority
 * @param localPartitionDef This array contains three integers: 1+2) lower and upper bounds for the local partition range, and
 *                          3) the bit width of the local bounds. The bounds will be bitshifted forward to consume the bit width
 */
public VertexIDAssignerTest(int numPartitionsBits, int partitionMax, int[] localPartitionDef) {
    MockIDAuthority idAuthority = new MockIDAuthority(11, partitionMax);

    StandardStoreFeatures.Builder fb = new StandardStoreFeatures.Builder();

    if (null != localPartitionDef) {
        fb.localKeyPartition(true);
        idAuthority.setLocalPartition(PartitionIDRangeTest.convert(localPartitionDef[0],localPartitionDef[1],localPartitionDef[2]));
    }
    StoreFeatures features = fb.build();

    ModifiableConfiguration config = GraphDatabaseConfiguration.buildGraphConfiguration();
    config.set(GraphDatabaseConfiguration.CLUSTER_MAX_PARTITIONS,1<<numPartitionsBits);
    idAssigner = new VertexIDAssigner(config, idAuthority, features);
    System.out.println(String.format("Configuration [%s|%s|%s]",numPartitionsBits,partitionMax,Arrays.toString(localPartitionDef)));

    if (localPartitionDef!=null && localPartitionDef[0]<localPartitionDef[1] && localPartitionDef[2]<=numPartitionsBits) {
        this.maxIDAssignments = ((localPartitionDef[1]-localPartitionDef[0])<<(numPartitionsBits-localPartitionDef[2]))*((long)partitionMax);
    } else {
        this.maxIDAssignments = (1<<numPartitionsBits)*((long)partitionMax);
    }
}
 

import com.thinkaurelius.titan.graphdb.database.idassigner.VertexIDAssigner; //導入依賴的package包/類
public VertexIDAssignerTest(Boolean partition, int partitionMax, int[] localPartition) {
    MockIDAuthority idAuthority = new MockIDAuthority(11, partitionMax);

    StandardStoreFeatures.Builder fb = new StandardStoreFeatures.Builder();

    if (null != localPartition) {
        fb.localKeyPartition(true);
        idAuthority.setLocalPartition(localPartition);
    }
    StoreFeatures features = fb.build();

    ModifiableConfiguration config = GraphDatabaseConfiguration.buildConfiguration();
    config.set(GraphDatabaseConfiguration.CLUSTER_PARTITION,partition);
    config.set(GraphDatabaseConfiguration.CLUSTER_MAX_PARTITIONS,1024);
    idAssigner = new VertexIDAssigner(config, idAuthority, features);
    System.out.println("Partition: " + partition);
    System.out.println("partitionMax: " + partitionMax);
    System.out.println("localPartition: " + Arrays.toString(localPartition));
}
 

import com.thinkaurelius.titan.graphdb.database.idassigner.VertexIDAssigner; //導入依賴的package包/類
public VertexIDAssigner getIDAssigner(Backend backend) {
    return new VertexIDAssigner(configuration, backend.getIDAuthority(), backend.getStoreFeatures());
}