implement 8 olap algorithms (#4)

* add olap algo api
* improve source filter
* fix louvain shaking with limit degree
* catch exception for lpa and louvain
* add 3 params for lpa: label,source_label,percision
* improve louvain node store
* remove vertices from class Community
* move showCommunity to AbstractCommAlgorithm
* add some parameters to AbstractAlgorithm
* improve louvain log
* improve clearPass and communities check
* split louvain cache
* fix degreeCentrality bug: degree is always < 500

Change-Id: I2341b981dab44f43ac50ae0f8fa5e51b7acc1b5a

hugegraph-api/src/main/java/com/baidu/hugegraph/api/job/AlgorithmAPI.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright 2017 HugeGraph Authors
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with this
+ * work for additional information regarding copyright ownership. The ASF
+ * licenses this file to You 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.
+ */
+
+package com.baidu.hugegraph.api.job;
+
+import java.util.Map;
+
+import javax.inject.Singleton;
+import javax.ws.rs.Consumes;
+import javax.ws.rs.NotFoundException;
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+import javax.ws.rs.PathParam;
+import javax.ws.rs.Produces;
+import javax.ws.rs.core.Context;
+
+import org.slf4j.Logger;
+
+import com.baidu.hugegraph.HugeGraph;
+import com.baidu.hugegraph.api.API;
+import com.baidu.hugegraph.api.filter.StatusFilter.Status;
+import com.baidu.hugegraph.backend.id.Id;
+import com.baidu.hugegraph.core.GraphManager;
+import com.baidu.hugegraph.job.AlgorithmJob;
+import com.baidu.hugegraph.job.JobBuilder;
+import com.baidu.hugegraph.server.RestServer;
+import com.baidu.hugegraph.util.E;
+import com.baidu.hugegraph.util.JsonUtil;
+import com.baidu.hugegraph.util.Log;
+import com.codahale.metrics.annotation.Timed;
+import com.google.common.collect.ImmutableMap;
+
+@Path("graphs/{graph}/jobs/algorithm")
+@Singleton
+public class AlgorithmAPI extends API {
+
+    private static final Logger LOG = Log.logger(RestServer.class);
+
+    @POST
+    @Timed
+    @Path("/{name}")
+    @Status(Status.CREATED)
+    @Consumes(APPLICATION_JSON)
+    @Produces(APPLICATION_JSON_WITH_CHARSET)
+    public Map<String, Id> post(@Context GraphManager manager,
+                                @PathParam("graph") String graph,
+                                @PathParam("name") String algorithm,
+                                Map<String, Object> parameters) {
+        LOG.debug("Graph [{}] schedule algorithm job: {}", graph, parameters);
+        E.checkArgument(algorithm != null && !algorithm.isEmpty(),
+                        "The algorithm name can't be empty");
+        if (parameters == null) {
+            parameters = ImmutableMap.of();
+        }
+        if (!AlgorithmJob.check(algorithm, parameters)) {
+            throw new NotFoundException("Not found algorithm: " + algorithm);
+        }
+
+        HugeGraph g = graph(manager, graph);
+        Map<String, Object> input = ImmutableMap.of("algorithm", algorithm,
+                                                    "parameters", parameters);
+        JobBuilder<Object> builder = JobBuilder.of(g);
+        builder.name("algorithm:" + algorithm)
+               .input(JsonUtil.toJson(input))
+               .job(new AlgorithmJob());
+        return ImmutableMap.of("task_id", builder.schedule().id());
+    }
+}

hugegraph-core/src/main/java/com/baidu/hugegraph/job/AlgorithmJob.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2017 HugeGraph Authors
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with this
+ * work for additional information regarding copyright ownership. The ASF
+ * licenses this file to You 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.
+ */
+
+package com.baidu.hugegraph.job;
+
+import java.util.Map;
+
+import com.baidu.hugegraph.job.algorithm.Algorithm;
+import com.baidu.hugegraph.job.algorithm.AlgorithmPool;
+import com.baidu.hugegraph.util.E;
+import com.baidu.hugegraph.util.JsonUtil;
+
+public class AlgorithmJob extends Job<Object> {
+
+    public static final String TASK_TYPE = "algorithm";
+
+    public static boolean check(String name, Map<String, Object> parameters) {
+        Algorithm algorithm = AlgorithmPool.instance().find(name);
+        if (algorithm == null) {
+            return false;
+        }
+        algorithm.checkParameters(parameters);
+        return true;
+    }
+
+    @Override
+    public String type() {
+        return TASK_TYPE;
+    }
+
+    @Override
+    public Object execute() throws Exception {
+        String input = this.task().input();
+        E.checkArgumentNotNull(input, "The input can't be null");
+        @SuppressWarnings("unchecked")
+        Map<String, Object> map = JsonUtil.fromJson(input, Map.class);
+
+        Object value = map.get("algorithm");
+        E.checkArgument(value instanceof String,
+                        "Invalid algorithm name '%s'", value);
+        String name = (String) value;
+
+        value = map.get("parameters");
+        E.checkArgument(value instanceof Map,
+                        "Invalid algorithm parameters '%s'", value);
+        @SuppressWarnings("unchecked")
+        Map<String, Object> parameters = (Map<String, Object>) value;
+
+        AlgorithmPool pool = AlgorithmPool.instance();
+        Algorithm algorithm = pool.find(name);
+        E.checkArgument(algorithm != null,
+                        "There is no algorithm named '%s'", name);
+        return algorithm.call(this, parameters);
+    }
+}