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new 23abc02191 Refactor abstract class Expression (#5793)
23abc02191 is described below
commit 23abc0219177de83b5b6e8df607570be37ada621
Author: Steve Yurong Su <[email protected]>
AuthorDate: Wed May 4 19:37:35 2022 +0800
Refactor abstract class Expression (#5793)
Make every method and every field clearer.
---
.../iotdb/db/query/expression/Expression.java | 80 ++++++++++++++++------
1 file changed, 60 insertions(+), 20 deletions(-)
diff --git
a/server/src/main/java/org/apache/iotdb/db/query/expression/Expression.java
b/server/src/main/java/org/apache/iotdb/db/query/expression/Expression.java
index 2a56a4974f..2779a735e9 100644
--- a/server/src/main/java/org/apache/iotdb/db/query/expression/Expression.java
+++ b/server/src/main/java/org/apache/iotdb/db/query/expression/Expression.java
@@ -69,11 +69,9 @@ import java.util.Set;
/** A skeleton class for expression */
public abstract class Expression {
- private String expressionStringCache;
-
- protected Boolean isConstantOperandCache = null;
-
- protected Integer inputColumnIndex = null;
+
/////////////////////////////////////////////////////////////////////////////////////////////////
+ // Expression type inferring for execution plan generation
+
/////////////////////////////////////////////////////////////////////////////////////////////////
public boolean isBuiltInAggregationFunctionExpression() {
return false;
@@ -87,6 +85,10 @@ public abstract class Expression {
return false;
}
+
/////////////////////////////////////////////////////////////////////////////////////////////////
+ // Operations for time series paths
+
/////////////////////////////////////////////////////////////////////////////////////////////////
+
public abstract void concat(
List<PartialPath> prefixPaths,
List<Expression> resultExpressions,
@@ -107,9 +109,19 @@ public abstract class Expression {
public abstract void collectPaths(Set<PartialPath> pathSet);
+
/////////////////////////////////////////////////////////////////////////////////////////////////
+ // For UDF instances initialization
+
/////////////////////////////////////////////////////////////////////////////////////////////////
+
public abstract void constructUdfExecutors(
Map<String, UDTFExecutor> expressionName2Executor, ZoneId zoneId);
+
/////////////////////////////////////////////////////////////////////////////////////////////////
+ // For expression evaluation DAG building
+
/////////////////////////////////////////////////////////////////////////////////////////////////
+
+ protected Integer inputColumnIndex = null;
+
public abstract void bindInputLayerColumnIndexWithExpression(UDTFPlan
udtfPlan);
public abstract void updateStatisticsForMemoryAssigner(LayerMemoryAssigner
memoryAssigner);
@@ -123,14 +135,21 @@ public abstract class Expression {
LayerMemoryAssigner memoryAssigner)
throws QueryProcessException, IOException;
- /** Sub-classes should override this method indicating if the expression is
a constant operand */
- protected abstract boolean isConstantOperandInternal();
+
/////////////////////////////////////////////////////////////////////////////////////////////////
+ // getExpressions: returning DIRECT children expressions
+
/////////////////////////////////////////////////////////////////////////////////////////////////
/**
* returns the DIRECT children expressions if it has any, otherwise an EMPTY
list will be returned
*/
public abstract List<Expression> getExpressions();
+
/////////////////////////////////////////////////////////////////////////////////////////////////
+ // isConstantOperand
+
/////////////////////////////////////////////////////////////////////////////////////////////////
+
+ protected Boolean isConstantOperandCache = null;
+
/** If this expression and all of its sub-expressions are {@link
ConstantOperand}. */
public final boolean isConstantOperand() {
if (isConstantOperandCache == null) {
@@ -139,11 +158,20 @@ public abstract class Expression {
return isConstantOperandCache;
}
- /**
- * Sub-classes should override this method to provide valid string
representation of this object.
- * See {@link #getExpressionString()}
- */
- protected abstract String getExpressionStringInternal();
+ /** Sub-classes should override this method indicating if the expression is
a constant operand */
+ protected abstract boolean isConstantOperandInternal();
+
+
/////////////////////////////////////////////////////////////////////////////////////////////////
+ // toString
+
/////////////////////////////////////////////////////////////////////////////////////////////////
+
+ private String expressionStringCache;
+
+ /** Sub-classes must not override this method. */
+ @Override
+ public final String toString() {
+ return getExpressionString();
+ }
/**
* Get the representation of the expression in string. The hash code of the
returned value will be
@@ -158,6 +186,16 @@ public abstract class Expression {
return expressionStringCache;
}
+ /**
+ * Sub-classes should override this method to provide valid string
representation of this object.
+ * See {@link #getExpressionString()}
+ */
+ protected abstract String getExpressionStringInternal();
+
+
/////////////////////////////////////////////////////////////////////////////////////////////////
+ // hashCode & equals
+
/////////////////////////////////////////////////////////////////////////////////////////////////
+
/** Sub-classes must not override this method. */
@Override
public final int hashCode() {
@@ -178,11 +216,9 @@ public abstract class Expression {
return getExpressionString().equals(((Expression)
o).getExpressionString());
}
- /** Sub-classes must not override this method. */
- @Override
- public final String toString() {
- return getExpressionString();
- }
+
/////////////////////////////////////////////////////////////////////////////////////////////////
+ // iterator: level-order traversal iterator
+
/////////////////////////////////////////////////////////////////////////////////////////////////
/** returns an iterator to traverse all the successor expressions in a
level-order */
public final Iterator<Expression> iterator() {
@@ -218,7 +254,9 @@ public abstract class Expression {
}
}
- public abstract ExpressionType getExpressionType();
+
/////////////////////////////////////////////////////////////////////////////////////////////////
+ // serialize & deserialize
+
/////////////////////////////////////////////////////////////////////////////////////////////////
public static void serialize(Expression expression, ByteBuffer byteBuffer) {
ReadWriteIOUtils.write(
@@ -232,8 +270,6 @@ public abstract class Expression {
}
}
- protected abstract void serialize(ByteBuffer byteBuffer);
-
public static Expression deserialize(ByteBuffer byteBuffer) {
short type = ReadWriteIOUtils.readShort(byteBuffer);
@@ -325,4 +361,8 @@ public abstract class Expression {
return expression;
}
+
+ public abstract ExpressionType getExpressionType();
+
+ protected abstract void serialize(ByteBuffer byteBuffer);
}
