| /* |
| * 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.calcite.rex; |
| |
| import org.apache.calcite.rel.type.RelDataType; |
| import org.apache.calcite.sql.SqlAggFunction; |
| import org.apache.calcite.sql.SqlWindow; |
| import org.apache.calcite.util.ControlFlowException; |
| import org.apache.calcite.util.Util; |
| |
| import org.checkerframework.checker.nullness.qual.Nullable; |
| |
| import java.util.List; |
| import java.util.Objects; |
| |
| import static com.google.common.base.Preconditions.checkArgument; |
| |
| /** |
| * Call to an aggregate function over a window. |
| */ |
| public class RexOver extends RexCall { |
| private static final Finder FINDER = new Finder(); |
| |
| //~ Instance fields -------------------------------------------------------- |
| |
| private final RexWindow window; |
| private final boolean distinct; |
| private final boolean ignoreNulls; |
| |
| //~ Constructors ----------------------------------------------------------- |
| |
| /** |
| * Creates a RexOver. |
| * |
| * <p>For example, "SUM(DISTINCT x) OVER (ROWS 3 PRECEDING)" is represented |
| * as: |
| * |
| * <ul> |
| * <li>type = Integer, |
| * <li>op = {@link org.apache.calcite.sql.fun.SqlStdOperatorTable#SUM}, |
| * <li>operands = { {@link RexFieldAccess}("x") } |
| * <li>window = {@link SqlWindow}(ROWS 3 PRECEDING) |
| * </ul> |
| * |
| * @param type Result type |
| * @param op Aggregate operator |
| * @param operands Operands list |
| * @param window Window specification |
| * @param distinct Aggregate operator is applied on distinct elements |
| */ |
| RexOver( |
| RelDataType type, |
| SqlAggFunction op, |
| List<RexNode> operands, |
| RexWindow window, |
| boolean distinct, |
| boolean ignoreNulls) { |
| super(type, op, operands); |
| checkArgument(op.isAggregator()); |
| this.window = Objects.requireNonNull(window, "window"); |
| this.distinct = distinct; |
| this.ignoreNulls = ignoreNulls; |
| } |
| |
| //~ Methods ---------------------------------------------------------------- |
| |
| /** |
| * Returns the aggregate operator for this expression. |
| */ |
| public SqlAggFunction getAggOperator() { |
| return (SqlAggFunction) getOperator(); |
| } |
| |
| public RexWindow getWindow() { |
| return window; |
| } |
| |
| public boolean isDistinct() { |
| return distinct; |
| } |
| |
| public boolean ignoreNulls() { |
| return ignoreNulls; |
| } |
| |
| @Override protected String computeDigest(boolean withType) { |
| final StringBuilder sb = new StringBuilder(op.getName()); |
| sb.append("("); |
| if (distinct) { |
| sb.append("DISTINCT "); |
| } |
| appendOperands(sb); |
| sb.append(")"); |
| if (ignoreNulls) { |
| sb.append(" IGNORE NULLS"); |
| } |
| if (withType) { |
| sb.append(":"); |
| sb.append(type.getFullTypeString()); |
| } |
| sb.append(" OVER ("); |
| window.appendDigest(sb, op.allowsFraming()) |
| .append(")"); |
| return sb.toString(); |
| } |
| |
| @Override public <R> R accept(RexVisitor<R> visitor) { |
| return visitor.visitOver(this); |
| } |
| |
| @Override public <R, P> R accept(RexBiVisitor<R, P> visitor, P arg) { |
| return visitor.visitOver(this, arg); |
| } |
| |
| @Override public int nodeCount() { |
| return super.nodeCount() + window.nodeCount; |
| } |
| |
| /** |
| * Returns whether an expression contains an OVER clause. |
| */ |
| public static boolean containsOver(RexNode expr) { |
| try { |
| expr.accept(FINDER); |
| return false; |
| } catch (OverFound e) { |
| Util.swallow(e, null); |
| return true; |
| } |
| } |
| |
| /** |
| * Returns whether a program contains an OVER clause. |
| */ |
| public static boolean containsOver(RexProgram program) { |
| try { |
| RexUtil.apply(FINDER, program.getExprList(), null); |
| return false; |
| } catch (OverFound e) { |
| Util.swallow(e, null); |
| return true; |
| } |
| } |
| |
| /** |
| * Returns whether an expression list contains an OVER clause. |
| */ |
| public static boolean containsOver(List<? extends RexNode> exprs, |
| @Nullable RexNode condition) { |
| try { |
| RexUtil.apply(FINDER, exprs, condition); |
| return false; |
| } catch (OverFound e) { |
| Util.swallow(e, null); |
| return true; |
| } |
| } |
| |
| @Override public RexCall clone(RelDataType type, List<RexNode> operands) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| //~ Inner Classes ---------------------------------------------------------- |
| |
| /** Exception thrown when an OVER is found. */ |
| private static class OverFound extends ControlFlowException { |
| public static final OverFound INSTANCE = new OverFound(); |
| } |
| |
| /** |
| * Visitor which detects a {@link RexOver} inside a {@link RexNode} |
| * expression. |
| * |
| * <p>It is re-entrant (two threads can use an instance at the same time) |
| * and it can be re-used for multiple visits. |
| */ |
| private static class Finder extends RexVisitorImpl<Void> { |
| Finder() { |
| super(true); |
| } |
| |
| @Override public Void visitOver(RexOver over) { |
| throw OverFound.INSTANCE; |
| } |
| } |
| |
| @Override public boolean equals(@Nullable Object o) { |
| if (this == o) { |
| return true; |
| } |
| if (o == null || getClass() != o.getClass()) { |
| return false; |
| } |
| if (!super.equals(o)) { |
| return false; |
| } |
| RexOver rexOver = (RexOver) o; |
| return distinct == rexOver.distinct |
| && ignoreNulls == rexOver.ignoreNulls |
| && window.equals(rexOver.window) |
| && op.allowsFraming() == rexOver.op.allowsFraming(); |
| } |
| |
| @Override public int hashCode() { |
| if (hash == 0) { |
| hash = |
| Objects.hash(super.hashCode(), window, distinct, ignoreNulls, |
| op.allowsFraming()); |
| } |
| return hash; |
| } |
| } |