| /* |
| * 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.druid.query.expression; |
| |
| import com.google.common.annotations.VisibleForTesting; |
| import com.google.common.collect.ImmutableSet; |
| import org.apache.druid.java.util.common.IAE; |
| import org.apache.druid.java.util.common.StringUtils; |
| import org.apache.druid.math.expr.Expr; |
| import org.apache.druid.math.expr.ExprEval; |
| import org.apache.druid.math.expr.ExprMacroTable; |
| |
| import javax.annotation.Nonnull; |
| import java.util.Arrays; |
| import java.util.List; |
| import java.util.Objects; |
| |
| public abstract class TrimExprMacro implements ExprMacroTable.ExprMacro |
| { |
| private static final char[] EMPTY_CHARS = new char[0]; |
| private static final char[] DEFAULT_CHARS = new char[]{' '}; |
| |
| enum TrimMode |
| { |
| BOTH("trim", true, true), |
| LEFT("ltrim", true, false), |
| RIGHT("rtrim", false, true); |
| |
| private final String name; |
| private final boolean left; |
| private final boolean right; |
| |
| TrimMode(final String name, final boolean left, final boolean right) |
| { |
| this.name = name; |
| this.left = left; |
| this.right = right; |
| } |
| |
| public String getFnName() |
| { |
| return name; |
| } |
| |
| public boolean isLeft() |
| { |
| return left; |
| } |
| |
| public boolean isRight() |
| { |
| return right; |
| } |
| } |
| |
| private final TrimMode mode; |
| |
| public TrimExprMacro(final TrimMode mode) |
| { |
| this.mode = mode; |
| } |
| |
| @Override |
| public String name() |
| { |
| return mode.getFnName(); |
| } |
| |
| @Override |
| public Expr apply(final List<Expr> args) |
| { |
| if (args.size() < 1 || args.size() > 2) { |
| throw new IAE("Function[%s] must have 1 or 2 arguments", name()); |
| } |
| |
| if (args.size() == 1) { |
| return new TrimStaticCharsExpr(mode, args.get(0), DEFAULT_CHARS, null); |
| } else { |
| final Expr charsArg = args.get(1); |
| if (charsArg.isLiteral()) { |
| final String charsString = charsArg.eval(ExprUtils.nilBindings()).asString(); |
| final char[] chars = charsString == null ? EMPTY_CHARS : charsString.toCharArray(); |
| return new TrimStaticCharsExpr(mode, args.get(0), chars, charsArg); |
| } else { |
| return new TrimDynamicCharsExpr(mode, args.get(0), args.get(1)); |
| } |
| } |
| } |
| |
| @VisibleForTesting |
| static class TrimStaticCharsExpr extends ExprMacroTable.BaseScalarUnivariateMacroFunctionExpr |
| { |
| private final TrimMode mode; |
| private final char[] chars; |
| private final Expr charsExpr; |
| |
| public TrimStaticCharsExpr(final TrimMode mode, final Expr stringExpr, final char[] chars, final Expr charsExpr) |
| { |
| super(mode.getFnName(), stringExpr); |
| this.mode = mode; |
| this.chars = chars; |
| this.charsExpr = charsExpr; |
| } |
| |
| @Nonnull |
| @Override |
| public ExprEval eval(final ObjectBinding bindings) |
| { |
| final ExprEval stringEval = arg.eval(bindings); |
| |
| if (chars.length == 0 || stringEval.value() == null) { |
| return stringEval; |
| } |
| |
| final String s = stringEval.asString(); |
| |
| int start = 0; |
| int end = s.length(); |
| |
| if (mode.isLeft()) { |
| while (start < s.length()) { |
| if (arrayContains(chars, s.charAt(start))) { |
| start++; |
| } else { |
| break; |
| } |
| } |
| } |
| |
| if (mode.isRight()) { |
| while (end > start) { |
| if (arrayContains(chars, s.charAt(end - 1))) { |
| end--; |
| } else { |
| break; |
| } |
| } |
| } |
| |
| if (start == 0 && end == s.length()) { |
| return stringEval; |
| } else { |
| return ExprEval.of(s.substring(start, end)); |
| } |
| } |
| |
| @Override |
| public Expr visit(Shuttle shuttle) |
| { |
| Expr newStringExpr = arg.visit(shuttle); |
| return shuttle.visit(new TrimStaticCharsExpr(mode, newStringExpr, chars, charsExpr)); |
| } |
| |
| @Override |
| public String stringify() |
| { |
| if (charsExpr != null) { |
| return StringUtils.format("%s(%s, %s)", mode.getFnName(), arg.stringify(), charsExpr.stringify()); |
| } |
| return super.stringify(); |
| } |
| |
| @Override |
| public boolean equals(Object o) |
| { |
| if (this == o) { |
| return true; |
| } |
| if (o == null || getClass() != o.getClass()) { |
| return false; |
| } |
| if (!super.equals(o)) { |
| return false; |
| } |
| TrimStaticCharsExpr that = (TrimStaticCharsExpr) o; |
| return mode == that.mode && |
| Arrays.equals(chars, that.chars) && |
| Objects.equals(charsExpr, that.charsExpr); |
| } |
| |
| @Override |
| public int hashCode() |
| { |
| int result = Objects.hash(super.hashCode(), mode, charsExpr); |
| result = 31 * result + Arrays.hashCode(chars); |
| return result; |
| } |
| } |
| |
| @VisibleForTesting |
| static class TrimDynamicCharsExpr implements Expr |
| { |
| private final TrimMode mode; |
| private final Expr stringExpr; |
| private final Expr charsExpr; |
| |
| public TrimDynamicCharsExpr(final TrimMode mode, final Expr stringExpr, final Expr charsExpr) |
| { |
| this.mode = mode; |
| this.stringExpr = stringExpr; |
| this.charsExpr = charsExpr; |
| } |
| |
| @Nonnull |
| @Override |
| public ExprEval eval(final ObjectBinding bindings) |
| { |
| final ExprEval stringEval = stringExpr.eval(bindings); |
| |
| if (stringEval.value() == null) { |
| return stringEval; |
| } |
| |
| final ExprEval charsEval = charsExpr.eval(bindings); |
| |
| if (charsEval.value() == null) { |
| return stringEval; |
| } |
| |
| final String s = stringEval.asString(); |
| final String chars = charsEval.asString(); |
| |
| int start = 0; |
| int end = s.length(); |
| |
| if (mode.isLeft()) { |
| while (start < s.length()) { |
| if (stringContains(chars, s.charAt(start))) { |
| start++; |
| } else { |
| break; |
| } |
| } |
| } |
| |
| if (mode.isRight()) { |
| while (end > start) { |
| if (stringContains(chars, s.charAt(end - 1))) { |
| end--; |
| } else { |
| break; |
| } |
| } |
| } |
| |
| if (start == 0 && end == s.length()) { |
| return stringEval; |
| } else { |
| return ExprEval.of(s.substring(start, end)); |
| } |
| } |
| |
| @Override |
| public String stringify() |
| { |
| return StringUtils.format("%s(%s, %s)", mode.getFnName(), stringExpr.stringify(), charsExpr.stringify()); |
| } |
| |
| @Override |
| public void visit(final Visitor visitor) |
| { |
| stringExpr.visit(visitor); |
| charsExpr.visit(visitor); |
| visitor.visit(this); |
| } |
| |
| @Override |
| public Expr visit(Shuttle shuttle) |
| { |
| Expr newStringExpr = stringExpr.visit(shuttle); |
| Expr newCharsExpr = charsExpr.visit(shuttle); |
| return shuttle.visit(new TrimDynamicCharsExpr(mode, newStringExpr, newCharsExpr)); |
| } |
| |
| @Override |
| public BindingDetails analyzeInputs() |
| { |
| return stringExpr.analyzeInputs() |
| .with(charsExpr) |
| .withScalarArguments(ImmutableSet.of(stringExpr, charsExpr)); |
| } |
| |
| @Override |
| public boolean equals(Object o) |
| { |
| if (this == o) { |
| return true; |
| } |
| if (o == null || getClass() != o.getClass()) { |
| return false; |
| } |
| TrimDynamicCharsExpr that = (TrimDynamicCharsExpr) o; |
| return mode == that.mode && |
| Objects.equals(stringExpr, that.stringExpr) && |
| Objects.equals(charsExpr, that.charsExpr); |
| } |
| |
| @Override |
| public int hashCode() |
| { |
| return Objects.hash(mode, stringExpr, charsExpr); |
| } |
| } |
| |
| private static boolean arrayContains(char[] array, char c) |
| { |
| for (final char arrayChar : array) { |
| if (arrayChar == c) { |
| return true; |
| } |
| } |
| |
| return false; |
| } |
| |
| private static boolean stringContains(String string, char c) |
| { |
| for (int i = 0; i < string.length(); i++) { |
| if (string.charAt(i) == c) { |
| return true; |
| } |
| } |
| |
| return false; |
| } |
| |
| public static class BothTrimExprMacro extends TrimExprMacro |
| { |
| public BothTrimExprMacro() |
| { |
| super(TrimMode.BOTH); |
| } |
| } |
| |
| public static class LeftTrimExprMacro extends TrimExprMacro |
| { |
| public LeftTrimExprMacro() |
| { |
| super(TrimMode.LEFT); |
| } |
| } |
| |
| public static class RightTrimExprMacro extends TrimExprMacro |
| { |
| public RightTrimExprMacro() |
| { |
| super(TrimMode.RIGHT); |
| } |
| } |
| } |