fix: left index of system type can't be deleted (#675)

Change-Id: I654b2e4c69f8aebfc7ebed3225b2dd09da1720a0

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

@@ -366,11 +366,6 @@ public void rollbackTx() {
         }
     }
 
-    @Override
-    public String toString() {
-        return this.store;
-    }
-
     protected Cluster cluster() {
         return this.sessions.cluster();
     }

hugegraph-core/src/main/java/com/baidu/hugegraph/HugeGraph.java

@@ -263,6 +263,17 @@ private SchemaTransaction openSchemaTransaction() throws HugeException {
         }
     }
 
+    private GraphTransaction openSystemTransaction() throws HugeException {
+        this.checkGraphNotClosed();
+        try {
+            return new CachedGraphTransaction(this, this.loadSystemStore());
+        } catch (BackendException e) {
+            String message = "Failed to open system transaction";
+            LOG.error("{}", message, e);
+            throw new HugeException(message);
+        }
+    }
+
     private GraphTransaction openGraphTransaction() throws HugeException {
         this.checkGraphNotClosed();
         try {
@@ -309,6 +320,16 @@ public SchemaTransaction schemaTransaction() {
         return this.tx.schemaTransaction();
     }
 
+    public GraphTransaction systemTransaction() {
+        this.checkGraphNotClosed();
+        /*
+         * NOTE: system operations must be committed manually,
+         * Maybe users need to auto open tinkerpop tx by readWrite().
+         */
+        this.tx.readWrite();
+        return this.tx.systemTransaction();
+    }
+
     public GraphTransaction graphTransaction() {
         this.checkGraphNotClosed();
         /*
@@ -726,6 +747,10 @@ private SchemaTransaction schemaTransaction() {
             return this.getOrNewTransaction().schemaTx;
         }
 
+        private GraphTransaction systemTransaction() {
+            return this.getOrNewTransaction().systemTx;
+        }
+
         private GraphTransaction graphTransaction() {
             return this.getOrNewTransaction().graphTx;
         }
@@ -740,7 +765,8 @@ private Txs getOrNewTransaction() {
             Txs txs = this.transactions.get();
             if (txs == null) {
                 // TODO: close SchemaTransaction if GraphTransaction is error
-                txs = new Txs(openSchemaTransaction(), openGraphTransaction());
+                txs = new Txs(openSchemaTransaction(), openSystemTransaction(),
+                              openGraphTransaction());
                 this.transactions.set(txs);
             }
             return txs;
@@ -763,26 +789,24 @@ private void destroyTransaction() {
 
     private static final class Txs {
 
-        public final SchemaTransaction schemaTx;
-        public final GraphTransaction graphTx;
+        private final SchemaTransaction schemaTx;
+        private final GraphTransaction systemTx;
+        private final GraphTransaction graphTx;
 
-        public Txs(SchemaTransaction schemaTx, GraphTransaction graphTx) {
-            assert schemaTx != null && graphTx != null;
+        public Txs(SchemaTransaction schemaTx, GraphTransaction systemTx,
+                   GraphTransaction graphTx) {
+            assert schemaTx != null && systemTx != null && graphTx != null;
             this.schemaTx = schemaTx;
+            this.systemTx = systemTx;
             this.graphTx = graphTx;
         }
 
         public void commit() {
-            this.schemaTx.commit();
             this.graphTx.commit();
         }
 
         public void rollback() {
-            try {
-                this.schemaTx.rollback();
-            } finally {
-                this.graphTx.rollback();
-            }
+            this.graphTx.rollback();
         }
 
         public void close() {
@@ -792,6 +816,12 @@ public void close() {
                 LOG.error("Failed to close GraphTransaction", e);
             }
 
+            try {
+                this.systemTx.close();
+            } catch (Exception e) {
+                LOG.error("Failed to close SystemTransaction", e);
+            }
+
             try {
                 this.schemaTx.close();
             } catch (Exception e) {
@@ -801,8 +831,8 @@ public void close() {
 
         @Override
         public String toString() {
-            return String.format("{schemaTx=%s,graphTx=%s}",
-                                 this.schemaTx, this.graphTx);
+            return String.format("{schemaTx=%s,systemTx=%s,graphTx=%s}",
+                                 this.schemaTx, this.systemTx, this.graphTx);
         }
     }
 }

hugegraph-core/src/main/java/com/baidu/hugegraph/backend/store/AbstractBackendStore.java

@@ -52,6 +52,11 @@ public <R> R metadata(HugeType type, String meta, Object[] args) {
         return dispatcher.dispatchMetaHandler(session, meta, args);
     }
 
+    @Override
+    public String toString() {
+        return String.format("%s/%s", this.database(), this.store());
+    }
+
     protected abstract BackendTable<Session, ?> table(HugeType type);
 
     // NOTE: Need to support passing null

hugegraph-core/src/main/java/com/baidu/hugegraph/backend/store/memory/InMemoryDBStore.java

@@ -215,11 +215,6 @@ public BackendFeatures features() {
         return FEATURES;
     }
 
-    @Override
-    public String toString() {
-        return this.store;
-    }
-
     /***************************** Store defines *****************************/
 
     public static class InMemorySchemaStore extends InMemoryDBStore {

hugegraph-core/src/main/java/com/baidu/hugegraph/backend/tx/GraphIndexTransaction.java

@@ -101,10 +101,10 @@ public GraphIndexTransaction(HugeGraph graph, BackendStore store) {
 
     protected Id asyncRemoveIndexLeft(ConditionQuery query,
                                       HugeElement element) {
-        RemoveLeftIndexJob callable = new RemoveLeftIndexJob(query, element);
+        RemoveLeftIndexJob job = new RemoveLeftIndexJob(query, element);
         HugeTask<?> task = EphemeralJobBuilder.of(this.graph())
                                               .name(element.id().asString())
-                                              .job(callable)
+                                              .job(job)
                                               .schedule();
         return task.id();
     }
@@ -1291,16 +1291,16 @@ public static class RemoveLeftIndexJob extends EphemeralJob<Object> {
 
         private static final String REMOVE_LEFT_INDEX = "remove_left_index";
 
-        private ConditionQuery query;
-        private HugeElement element;
+        private final ConditionQuery query;
+        private final HugeElement element;
         private GraphIndexTransaction tx;
 
-        private RemoveLeftIndexJob(ConditionQuery query,
-                                   HugeElement element) {
+        private RemoveLeftIndexJob(ConditionQuery query, HugeElement element) {
             E.checkArgumentNotNull(query, "query");
             E.checkArgumentNotNull(element, "element");
             this.query = query;
             this.element = element;
+            this.tx = null;
         }
 
         @Override
@@ -1310,7 +1310,9 @@ public String type() {
 
         @Override
         public Object execute() {
-            this.tx = this.graph().graphTransaction().indexTransaction();
+            this.tx = this.element.schemaLabel().system() ?
+                      this.graph().systemTransaction().indexTransaction() :
+                      this.graph().graphTransaction().indexTransaction();
             return this.removeIndexLeft(this.query, this.element);
         }
 

hugegraph-core/src/main/java/com/baidu/hugegraph/schema/SchemaElement.java

@@ -99,8 +99,13 @@ public void status(SchemaStatus status) {
         this.status = status;
     }
 
+    public boolean system() {
+        return this.longId() < 0L;
+    }
+
     public boolean primitive() {
-        return false;
+        long id = this.longId();
+        return -MAX_PRIMITIVE_SYS_ID <= id && id < 0L;
     }
 
     public boolean hidden() {

hugegraph-mysql/src/main/java/com/baidu/hugegraph/backend/store/mysql/MysqlStore.java

@@ -263,11 +263,6 @@ public BackendFeatures features() {
         return FEATURES;
     }
 
-    @Override
-    public String toString() {
-        return this.store;
-    }
-
     protected void initTables() {
         Session session = this.sessions.session();
         for (MysqlTable table : this.tables()) {