Support pagination when single index query

hugegraph-api/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <artifactId>hugegraph</artifactId>
         <groupId>com.baidu.hugegraph</groupId>
-        <version>0.9.1</version>
+        <version>0.9.2</version>
     </parent>
     <modelVersion>4.0.0</modelVersion>
 
@@ -86,7 +86,7 @@
                             </addDefaultSpecificationEntries>
                         </manifest>
                         <manifestEntries>
-                            <Implementation-Version>0.34.0.0</Implementation-Version>
+                            <Implementation-Version>0.35.0.0</Implementation-Version>
                         </manifestEntries>
                     </archive>
                 </configuration>

hugegraph-api/src/main/java/com/baidu/hugegraph/api/graph/EdgeAPI.java

@@ -222,17 +222,20 @@ public String list(@Context GraphManager manager,
         LOG.debug("Graph [{}] query edges by vertex: {}, direction: {}, " +
                   "label: {}, properties: {}, offset: {}, page: {}, limit: {}",
                   vertexId, direction, label, properties, offset, page, limit);
+
+        Map<String, Object> props = parseProperties(properties);
         if (page != null) {
             E.checkArgument(vertexId == null && direction == null &&
-                            label == null && properties == null && offset == 0,
-                            "Not support quering edges based on paging and " +
-                            "[vertex, direction, label, properties, offset] " +
-                            "together");
+                            offset == 0,
+                            "Not support querying edges based on paging " +
+                            "and [vertex, direction, offset] together");
+            E.checkArgument(props.size() <= 1,
+                            "Not support querying edges based on paging " +
+                            "and more than one property");
         }
 
         Id vertex = VertexAPI.checkAndParseVertexId(vertexId);
         Direction dir = parseDirection(direction);
-        Map<String, Object> props = parseProperties(properties);
 
         HugeGraph g = graph(manager, graph);
 

hugegraph-api/src/main/java/com/baidu/hugegraph/api/graph/VertexAPI.java

@@ -173,13 +173,16 @@ public String list(@Context GraphManager manager,
         LOG.debug("Graph [{}] query vertices by label: {}, properties: {}, " +
                   "offset: {}, page: {}, limit: {}",
                   graph, label, properties, offset, page, limit);
-        if (page != null) {
-            E.checkArgument(label == null && properties == null && offset == 0,
-                            "Not support quering vertices based on paging " +
-                            "and [label, properties, offset] together");
-        }
 
         Map<String, Object> props = parseProperties(properties);
+        if (page != null) {
+            E.checkArgument(offset == 0,
+                            "Not support querying vertices based on paging " +
+                            "and offset together");
+            E.checkArgument(props.size() <= 1,
+                            "Not support querying vertices based on paging " +
+                            "and more than one property");
+        }
 
         HugeGraph g = graph(manager, graph);
 

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

@@ -59,8 +59,7 @@
 import com.codahale.metrics.Histogram;
 import com.codahale.metrics.annotation.Timed;
 import com.fasterxml.jackson.annotation.JsonProperty;
-
-import jersey.repackaged.com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableMap;
 
 @Path("graphs/{graph}/jobs/gremlin")
 @Singleton

hugegraph-api/src/main/java/com/baidu/hugegraph/version/ApiVersion.java

@@ -78,10 +78,11 @@ public final class ApiVersion {
      * [0.32] Issue-250: Keep depth and degree consistent for traverser api
      * [0.33] Issue-305: Implement customized paths and crosspoints RESTful API
      * [0.34] Issue-307: Let VertexAPI use simplified property serializer
+     * [0.35] Issue-287: Support pagination when do index query
      */
 
     // The second parameter of Version.of() is for IDE running without JAR
-    public static final Version VERSION = Version.of(ApiVersion.class, "0.34");
+    public static final Version VERSION = Version.of(ApiVersion.class, "0.35");
 
     public static final void check() {
         // Check version of hugegraph-core. Firstly do check from version 0.3

hugegraph-cassandra/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <artifactId>hugegraph</artifactId>
         <groupId>com.baidu.hugegraph</groupId>
-        <version>0.9.1</version>
+        <version>0.9.2</version>
     </parent>
     <modelVersion>4.0.0</modelVersion>
 

hugegraph-cassandra/src/main/java/com/baidu/hugegraph/backend/store/cassandra/CassandraTable.java

@@ -127,25 +127,6 @@ protected List<Select> query2Select(String table, Query query) {
                       "currently, it will be replaced by [0, offset + limit)");
         }
 
-        // Set limit
-        if (query.limit() != Query.NO_LIMIT) {
-            long total = query.total();
-            String page = query.page();
-            if (page == null) {
-                select.limit((int) total);
-            } else {
-                select.setFetchSize((int) total);
-                // It's the first time if page is empty
-                if (!page.isEmpty()) {
-                    try {
-                        select.setPagingState(PagingState.fromString(page));
-                    } catch (PagingStateException e) {
-                        throw new BackendException(e.getMessage());
-                    }
-                }
-            }
-        }
-
         // Set order-by
         for (Map.Entry<HugeKeys, Order> order : query.orders().entrySet()) {
             String name = formatKey(order.getKey());
@@ -162,19 +143,45 @@ protected List<Select> query2Select(String table, Query query) {
 
         if (query.conditions().isEmpty()) {
             // Query only by id
+            this.setPageState(query, ids);
             LOG.debug("Query only by id(s): {}", ids);
             return ids;
         } else {
-            List<Select> conds = new ArrayList<Select>(ids.size());
+            List<Select> conds = new ArrayList<>(ids.size());
             for (Select selection : ids) {
                 // Query by condition
                 conds.addAll(this.queryCondition2Select(query, selection));
             }
+            this.setPageState(query, conds);
             LOG.debug("Query by conditions: {}", conds);
             return conds;
         }
     }
 
+    protected void setPageState(Query query, List<Select> selects) {
+        if (query.limit() == Query.NO_LIMIT) {
+            return;
+        }
+        for (Select select : selects) {
+            long total = query.total();
+            String page = query.page();
+            if (page == null) {
+                // Set limit
+                select.limit((int) total);
+            } else {
+                select.setFetchSize((int) total);
+                // It's the first time if page is empty
+                if (!page.isEmpty()) {
+                    try {
+                        select.setPagingState(PagingState.fromString(page));
+                    } catch (PagingStateException e) {
+                        throw new BackendException(e);
+                    }
+                }
+            }
+        }
+    }
+
     protected List<Select> queryId2Select(Query query, Select select) {
         // Query by id(s)
         if (query.ids().isEmpty()) {

hugegraph-core/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>com.baidu.hugegraph</groupId>
         <artifactId>hugegraph</artifactId>
-        <version>0.9.1</version>
+        <version>0.9.2</version>
         <relativePath>../pom.xml</relativePath>
     </parent>
     <artifactId>hugegraph-core</artifactId>
@@ -157,7 +157,7 @@
                             </addDefaultSpecificationEntries>
                         </manifest>
                         <manifestEntries>
-                            <Implementation-Version>0.9.1.0</Implementation-Version>
+                            <Implementation-Version>0.9.2.0</Implementation-Version>
                         </manifestEntries>
                     </archive>
                 </configuration>

hugegraph-core/src/main/java/com/baidu/hugegraph/backend/page/IdHolder.java

@@ -0,0 +1,103 @@
+/*
+ * 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.backend.page;
+
+import java.util.Set;
+import java.util.function.Function;
+
+import com.baidu.hugegraph.backend.id.Id;
+import com.baidu.hugegraph.backend.query.ConditionQuery;
+import com.baidu.hugegraph.util.E;
+import com.baidu.hugegraph.util.InsertionOrderUtil;
+import com.google.common.collect.ImmutableSet;
+
+public final class IdHolder {
+
+    private final ConditionQuery query;
+    private final Function<ConditionQuery, PageIds> idsFetcher;
+    private boolean exhausted;
+
+    private Set<Id> ids;
+
+    /**
+     * For non-paging situation
+     */
+    public IdHolder(Set<Id> ids) {
+        this.query = null;
+        this.idsFetcher = null;
+        this.exhausted = false;
+        if (ids instanceof ImmutableSet) {
+            this.ids = InsertionOrderUtil.newSet(ids);
+        } else {
+            this.ids = ids;
+        }
+    }
+
+    /**
+     * For paging situation
+     */
+    public IdHolder(ConditionQuery query,
+                    Function<ConditionQuery, PageIds> idsFetcher) {
+        E.checkArgument(query.paging(),
+                        "Query '%s' must include page info", query);
+        this.query = query.copy();
+        this.idsFetcher = idsFetcher;
+        this.exhausted = false;
+        this.ids = null;
+    }
+
+    public void merge(Set<Id> ids) {
+        this.ids.addAll(ids);
+    }
+
+    public Set<Id> ids() {
+        E.checkNotNull(this.ids, "ids");
+        return this.ids;
+    }
+
+    public int size() {
+        if (this.ids == null) {
+            return 0;
+        }
+        return this.ids.size();
+    }
+
+    public boolean paging() {
+        return this.idsFetcher != null;
+    }
+
+    public PageIds fetchNext(String page, long pageSize) {
+        if (this.exhausted) {
+            return PageIds.EMPTY;
+        }
+
+        this.query.page(page);
+        this.query.limit(pageSize);
+
+        PageIds result = this.idsFetcher.apply(this.query);
+
+        assert result != null;
+        this.ids = result.ids();
+        if (this.ids.size() != this.query.limit() || result.page() == null) {
+            this.exhausted = true;
+        }
+        return result;
+    }
+}

hugegraph-core/src/main/java/com/baidu/hugegraph/backend/page/IdHolderList.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.backend.page;
+
+import java.util.ArrayList;
+import java.util.Collection;
+
+import com.baidu.hugegraph.util.E;
+
+public final class IdHolderList extends ArrayList<IdHolder> {
+
+    private final boolean paging;
+
+    public IdHolderList(boolean paging) {
+        this.paging = paging;
+    }
+
+    public boolean paging() {
+        return this.paging;
+    }
+
+    @Override
+    public boolean add(IdHolder holder) {
+        E.checkArgument(this.paging == holder.paging(),
+                        "The IdHolder to be linked must be " +
+                        "in same paging mode");
+        if (this.paging || this.isEmpty()) {
+            super.add(holder);
+        } else {
+            assert this.size() == 1;
+            IdHolder self = this.get(0);
+            assert !self.paging();
+            self.merge(holder.ids());
+        }
+        return true;
+    }
+
+    @Override
+    public boolean addAll(Collection<? extends IdHolder> idHolders) {
+        for (IdHolder idHolder : idHolders) {
+            this.add(idHolder);
+        }
+        return true;
+    }
+
+    public int idsSize() {
+        if (this.paging || this.isEmpty()) {
+            return 0;
+        } else {
+            assert this.size() == 1;
+            return this.get(0).size();
+        }
+    }
+}