[iotdb] 01/04: Add deviceMergeOperator

[xi...@apache.org]

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xiangweiwei pushed a commit to branch deviceMergeOperator1
in repository https://gitbox.apache.org/repos/asf/iotdb.git

commit 087f4204985aaac1f661ad2f52ff912a2ca05d2d
Author: Alima777 <wx...@gmail.com>
AuthorDate: Tue May 3 20:14:12 2022 +0800

    Add deviceMergeOperator
---
 .../operator/process/DeviceMergeOperator.java      | 50 ++++++++++++++++++++++
 .../operator/process/DeviceViewOperator.java       |  8 ++--
 .../operator/process/merge/ColumnMerger.java       |  2 +-
 3 files changed, 55 insertions(+), 5 deletions(-)

diff --git a/server/src/main/java/org/apache/iotdb/db/mpp/execution/operator/process/DeviceMergeOperator.java b/server/src/main/java/org/apache/iotdb/db/mpp/execution/operator/process/DeviceMergeOperator.java
new file mode 100644
index 0000000000..4122015cb5
--- /dev/null
+++ b/server/src/main/java/org/apache/iotdb/db/mpp/execution/operator/process/DeviceMergeOperator.java
@@ -0,0 +1,50 @@
+/*
+ * 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 org.apache.iotdb.db.mpp.execution.operator.process;
+
+import org.apache.iotdb.db.mpp.execution.operator.Operator;
+import org.apache.iotdb.db.mpp.execution.operator.OperatorContext;
+
+import java.util.List;
+
+/**
+ * DeviceMergeOperator is responsible for merging tsBlock coming from DeviceViewOperators.
+ *
+ * <p>If the devices in different dataNodes are different, we need to output tsBlocks of each node
+ * in order of device. If the same device exists in different nodes, the tsBlocks need to be merged
+ * by time within the device.
+ *
+ * <p>The form of tsBlocks from input operators should be the same strictly, which is transferred by
+ * DeviceViewOperator.
+ */
+public class DeviceMergeOperator {
+
+  private final OperatorContext operatorContext;
+  // The size devices and deviceOperators should be the same.
+  private final List<String> devices;
+  private final List<Operator> deviceOperators;
+
+  public DeviceMergeOperator(
+      OperatorContext operatorContext, List<String> devices, List<Operator> deviceOperators) {
+    this.operatorContext = operatorContext;
+    this.devices = devices;
+    this.deviceOperators = deviceOperators;
+  }
+}
diff --git a/server/src/main/java/org/apache/iotdb/db/mpp/execution/operator/process/DeviceViewOperator.java b/server/src/main/java/org/apache/iotdb/db/mpp/execution/operator/process/DeviceViewOperator.java
index a90dcfd0bb..d3165042a6 100644
--- a/server/src/main/java/org/apache/iotdb/db/mpp/execution/operator/process/DeviceViewOperator.java
+++ b/server/src/main/java/org/apache/iotdb/db/mpp/execution/operator/process/DeviceViewOperator.java
@@ -34,10 +34,10 @@ import com.google.common.util.concurrent.ListenableFuture;
 import java.util.List;
 
 /**
- * Since devices have been sorted by the merge order as expected, what DeviceMergeOperator need to
- * do is traversing the device child operators, get all tsBlocks of one device and transform it to
- * the form we need, adding the device column and allocating value column to its expected location,
- * then get the next device operator until no next device.
+ * Since devices have been sorted by the merge order as expected, what DeviceViewOperator need to do
+ * is traversing the device child operators, get all tsBlocks of one device and transform it to the
+ * form we need, adding the device column and allocating value column to its expected location, then
+ * get the next device operator until no next device.
  *
  * <p>The deviceOperators can be timeJoinOperator or seriesScanOperator that have not transformed
  * the result form.
diff --git a/server/src/main/java/org/apache/iotdb/db/mpp/execution/operator/process/merge/ColumnMerger.java b/server/src/main/java/org/apache/iotdb/db/mpp/execution/operator/process/merge/ColumnMerger.java
index 4d301c8e8a..731827aea5 100644
--- a/server/src/main/java/org/apache/iotdb/db/mpp/execution/operator/process/merge/ColumnMerger.java
+++ b/server/src/main/java/org/apache/iotdb/db/mpp/execution/operator/process/merge/ColumnMerger.java
@@ -40,7 +40,7 @@ public interface ColumnMerger {
   /**
    * merge columns belonging to same series into one column
    *
-   * @param inputTsBlocks all source TsBlocks, some of which will cantain source column
+   * @param inputTsBlocks all source TsBlocks, some of which will contain source column
    * @param inputIndex start index for each source TsBlock and size of it is equal to inputTsBlocks,
    *     we should only read from this array and not update it because others will use the start
    *     index value in inputIndex array