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 <[email protected]> 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; + } +}
