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Posted to commits@iotdb.apache.org by xi...@apache.org on 2022/03/01 12:07:05 UTC
[iotdb] branch xingtanzjr/operator-design created (now ded718f)
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xingtanzjr pushed a change to branch xingtanzjr/operator-design
in repository https://gitbox.apache.org/repos/asf/iotdb.git.
at ded718f add basic operators
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new ded718f add basic operators
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[iotdb] 01/01: add basic operators
Posted by xi...@apache.org.
This is an automated email from the ASF dual-hosted git repository.
xingtanzjr pushed a commit to branch xingtanzjr/operator-design
in repository https://gitbox.apache.org/repos/asf/iotdb.git
commit ded718f31b6e541db6c2cd45efe2057b4bfaa9b5
Author: Jinrui.Zhang <xi...@gmail.com>
AuthorDate: Tue Mar 1 20:06:07 2022 +0800
add basic operators
---
.../query/distribution/common/SeriesBatchData.java | 14 +++++++
.../query/distribution/common/TraversalOrder.java | 9 +++++
.../db/query/distribution/common/TreeNode.java | 23 +++++++++++
.../query/distribution/operator/ExecOperator.java | 18 +++++++++
.../distribution/operator/SeriesScanOperator.java | 46 ++++++++++++++++++++++
.../distribution/operator/TimeJoinOperator.java | 23 +++++++++++
6 files changed, 133 insertions(+)
diff --git a/server/src/main/java/org/apache/iotdb/db/query/distribution/common/SeriesBatchData.java b/server/src/main/java/org/apache/iotdb/db/query/distribution/common/SeriesBatchData.java
new file mode 100644
index 0000000..7a9ae65
--- /dev/null
+++ b/server/src/main/java/org/apache/iotdb/db/query/distribution/common/SeriesBatchData.java
@@ -0,0 +1,14 @@
+package org.apache.iotdb.db.query.distribution.common;
+
+import org.apache.iotdb.tsfile.read.common.BatchData;
+
+/**
+ * @author xingtanzjr
+ * TODO: currently we only use it to describe the result set of SeriesScanOperator
+ * The BatchData is suitable as the encapsulation of part of result set of SeriesScanOperator
+ * BatchData is the class defined and generally used in single-node IoTDB
+ * We leverage it as the `batch` here. We can consider a more general name or make some modifications for it.
+ */
+public class SeriesBatchData extends BatchData {
+
+}
diff --git a/server/src/main/java/org/apache/iotdb/db/query/distribution/common/TraversalOrder.java b/server/src/main/java/org/apache/iotdb/db/query/distribution/common/TraversalOrder.java
new file mode 100644
index 0000000..6b00372
--- /dev/null
+++ b/server/src/main/java/org/apache/iotdb/db/query/distribution/common/TraversalOrder.java
@@ -0,0 +1,9 @@
+package org.apache.iotdb.db.query.distribution.common;
+
+/**
+ * The traversal order for operators by timestamp
+ */
+public enum TraversalOrder {
+ ASC,
+ DESC
+}
diff --git a/server/src/main/java/org/apache/iotdb/db/query/distribution/common/TreeNode.java b/server/src/main/java/org/apache/iotdb/db/query/distribution/common/TreeNode.java
new file mode 100644
index 0000000..9cf2dd3
--- /dev/null
+++ b/server/src/main/java/org/apache/iotdb/db/query/distribution/common/TreeNode.java
@@ -0,0 +1,23 @@
+package org.apache.iotdb.db.query.distribution.common;
+
+import java.util.List;
+
+/**
+ * @author A simple class to describe the tree style structure of query executable operators
+ * @param <T>
+ */
+public class TreeNode<T extends TreeNode<T>> {
+ protected List<T> children;
+
+ public T getChild(int i) {
+ return hasChild(i) ? children.get(i) : null;
+ }
+
+ public boolean hasChild(int i) {
+ return children.size() > i;
+ }
+
+ public void addChild(T n) {
+ children.add(n);
+ }
+}
diff --git a/server/src/main/java/org/apache/iotdb/db/query/distribution/operator/ExecOperator.java b/server/src/main/java/org/apache/iotdb/db/query/distribution/operator/ExecOperator.java
new file mode 100644
index 0000000..b9a1691
--- /dev/null
+++ b/server/src/main/java/org/apache/iotdb/db/query/distribution/operator/ExecOperator.java
@@ -0,0 +1,18 @@
+package org.apache.iotdb.db.query.distribution.operator;
+
+import org.apache.iotdb.db.query.distribution.common.TreeNode;
+
+/**
+ * @author xingtanzjr
+ * The base class of query executable operators, which is used to compose logical query plan.
+ * TODO: consider how to restrict the children type for each type of ExecOperator
+ */
+public abstract class ExecOperator<T> extends TreeNode<ExecOperator<?>> {
+
+ // Judge whether current operator has more result
+ public abstract boolean hasNext();
+
+ // Get next result batch of this operator
+ // Return null if there is no more result to return
+ public abstract T getNextBatch();
+}
diff --git a/server/src/main/java/org/apache/iotdb/db/query/distribution/operator/SeriesScanOperator.java b/server/src/main/java/org/apache/iotdb/db/query/distribution/operator/SeriesScanOperator.java
new file mode 100644
index 0000000..ebbc03d
--- /dev/null
+++ b/server/src/main/java/org/apache/iotdb/db/query/distribution/operator/SeriesScanOperator.java
@@ -0,0 +1,46 @@
+package org.apache.iotdb.db.query.distribution.operator;
+
+import org.apache.iotdb.db.query.distribution.common.SeriesBatchData;
+import org.apache.iotdb.db.query.distribution.common.TraversalOrder;
+import org.apache.iotdb.tsfile.read.common.Path;
+import org.apache.iotdb.tsfile.read.filter.basic.Filter;
+
+/**
+ * SeriesScanOperator is responsible for read data and pre-aggregated statistic for a specific series.
+ * When reading data, the SeriesScanOperator can read the raw data batch by batch. And also, it can leverage
+ * the filter and other info to decrease the result set.
+ * Besides, the SeriesScanOperator can read the pre-aggregated statistic in TsFile. And return the statistic with
+ * a fix time range one by one. If the time range is narrower than the smallest pre-aggregated statistic or has overlap
+ * with pre-aggregated statistic, the SeriesScanOperator will read the raw data and calculate the aggregation result for
+ * specific time range.
+ *
+ * Children type: []
+ */
+public class SeriesScanOperator extends ExecOperator<SeriesBatchData> {
+
+ // The path of the target series which will be scanned.
+ private Path seriesPath;
+
+ // The order to traverse the series by timestamp.
+ // The default order is ASC, which means "order by timestamp asc"
+ private TraversalOrder scanOrder = TraversalOrder.ASC;
+
+ // Filter data in current series.
+ private Filter filter;
+
+ // Limit for result set. The default value is -1, which means no limit
+ private int limit = -1;
+
+ // offset for result set. The default value is 0
+ private int offset;
+
+ @Override
+ public boolean hasNext() {
+ return false;
+ }
+
+ @Override
+ public SeriesBatchData getNextBatch() {
+ return null;
+ }
+}
diff --git a/server/src/main/java/org/apache/iotdb/db/query/distribution/operator/TimeJoinOperator.java b/server/src/main/java/org/apache/iotdb/db/query/distribution/operator/TimeJoinOperator.java
new file mode 100644
index 0000000..8361276
--- /dev/null
+++ b/server/src/main/java/org/apache/iotdb/db/query/distribution/operator/TimeJoinOperator.java
@@ -0,0 +1,23 @@
+package org.apache.iotdb.db.query.distribution.operator;
+
+import org.apache.iotdb.tsfile.read.common.RowRecord;
+
+/**
+ * TimeJoinOperator is responsible for join two or more series.
+ * The join algorithm is like outer join by timestamp column.
+ * The output result of TimeJoinOperator is sorted by timestamp
+ *
+ * Children type: [SeriesScanOperator]
+ */
+public class TimeJoinOperator extends ExecOperator<RowRecord> {
+
+ @Override
+ public boolean hasNext() {
+ return false;
+ }
+
+ @Override
+ public RowRecord getNextBatch() {
+ return null;
+ }
+}