| // Copyright 2014 The Bazel Authors. All rights reserved. |
| // |
| // Licensed 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 com.google.devtools.build.lib.util; |
| |
| import com.google.common.base.Joiner; |
| import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable; |
| import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec; |
| import com.google.devtools.common.options.Converter; |
| import com.google.devtools.common.options.OptionsParsingException; |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.Objects; |
| import java.util.function.Predicate; |
| import java.util.regex.Pattern; |
| import java.util.regex.PatternSyntaxException; |
| import javax.annotation.Nullable; |
| |
| /** |
| * Handles options that specify list of included/excluded regex expressions. Validates whether |
| * string is included in that filter. |
| * |
| * <p>String is considered to be included into the filter if it does not match any of the excluded |
| * regex expressions and if it matches at least one included regex expression. |
| */ |
| @AutoCodec |
| @Immutable |
| public final class RegexFilter implements Predicate<String> { |
| // Null inclusion or exclusion pattern means those patterns are not used. |
| @Nullable private final Pattern inclusionPattern; |
| @Nullable private final Pattern exclusionPattern; |
| private final int hashCode; |
| |
| /** |
| * Converts from a comma-separated list of regex expressions with optional -/+ prefix into the |
| * RegexFilter. Commas prefixed with backslash are considered to be part of regex definition and |
| * not a delimiter between separate regex expressions. |
| * |
| * <p>Order of expressions is not important. Empty entries are ignored. '-' marks an excluded |
| * expression. |
| */ |
| public static class RegexFilterConverter implements Converter<RegexFilter> { |
| |
| @Override |
| public RegexFilter convert(String input) throws OptionsParsingException { |
| List<String> inclusionList = new ArrayList<>(); |
| List<String> exclusionList = new ArrayList<>(); |
| |
| for (String piece : input.split("(?<!\\\\),")) { // Split on ',' but not on '\,' |
| piece = piece.replace("\\,", ","); |
| boolean isExcluded = piece.startsWith("-"); |
| if (isExcluded || piece.startsWith("+")) { |
| piece = piece.substring(1); |
| } |
| if (piece.length() > 0) { |
| (isExcluded ? exclusionList : inclusionList).add(piece); |
| } |
| } |
| |
| try { |
| return new RegexFilter(inclusionList, exclusionList); |
| } catch (PatternSyntaxException e) { |
| throw new OptionsParsingException("Failed to build valid regular expression: " |
| + e.getMessage()); |
| } |
| } |
| |
| @Override |
| public String getTypeDescription() { |
| return "a comma-separated list of regex expressions with prefix '-' specifying" |
| + " excluded paths"; |
| } |
| } |
| |
| /** |
| * Constructor taking regexes directly. |
| * |
| * <p>Null {@code inclusionPattern} or {@code exclusionPattern} means that inclusion or exclusion |
| * matching will not be applied, respectively. |
| */ |
| @AutoCodec.Instantiator |
| RegexFilter(@Nullable Pattern inclusionPattern, @Nullable Pattern exclusionPattern) { |
| this.inclusionPattern = inclusionPattern; |
| this.exclusionPattern = exclusionPattern; |
| this.hashCode = |
| Objects.hash( |
| inclusionPattern == null ? null : inclusionPattern.pattern(), |
| exclusionPattern == null ? null : exclusionPattern.pattern()); |
| } |
| |
| /** Creates new RegexFilter using provided inclusion and exclusion path lists. */ |
| public RegexFilter(List<String> inclusions, List<String> exclusions) { |
| this(takeUnionOfRegexes(inclusions), takeUnionOfRegexes(exclusions)); |
| } |
| |
| /** |
| * Converts a list of regex expressions into a single regex representing its union or null when |
| * the list is empty. |
| */ |
| private static Pattern takeUnionOfRegexes(List<String> regexList) { |
| if (regexList.isEmpty()) { |
| return null; |
| } |
| // Wraps each individual regex into an independent group, then combines them using '|' and |
| // wraps the result in a non-capturing group. |
| return Pattern.compile("(?:(?>" + Joiner.on(")|(?>").join(regexList) + "))"); |
| } |
| |
| /** |
| * @return true iff given string is included (it does not match exclusion pattern (if any) and |
| * matches inclusionPatter (if any)). |
| */ |
| public boolean isIncluded(String value) { |
| if (exclusionPattern != null && exclusionPattern.matcher(value).find()) { |
| return false; |
| } |
| if (inclusionPattern == null) { |
| return true; |
| } |
| return inclusionPattern.matcher(value).find(); |
| } |
| |
| @Override |
| public boolean test(String value) { |
| return isIncluded(value); |
| } |
| |
| @Nullable |
| public String getInclusionRegex() { |
| return inclusionPattern == null ? null : inclusionPattern.pattern(); |
| } |
| |
| @Nullable |
| public String getExclusionRegex() { |
| return exclusionPattern == null ? null : exclusionPattern.pattern(); |
| } |
| |
| @Override |
| public String toString() { |
| StringBuilder builder = new StringBuilder(); |
| if (inclusionPattern != null) { |
| builder.append(inclusionPattern.pattern().replace(",", "\\,")); |
| if (exclusionPattern != null) { |
| builder.append(","); |
| } |
| } |
| if (exclusionPattern != null) { |
| builder.append("-"); |
| builder.append(exclusionPattern.pattern().replace(",", "\\,")); |
| } |
| return builder.toString(); |
| } |
| |
| @Override |
| public boolean equals(Object other) { |
| if (this == other) { |
| return true; |
| } |
| if (!(other instanceof RegexFilter)) { |
| return false; |
| } |
| |
| RegexFilter otherFilter = (RegexFilter) other; |
| if (this.exclusionPattern == null ^ otherFilter.exclusionPattern == null) { |
| return false; |
| } |
| if (this.inclusionPattern == null ^ otherFilter.inclusionPattern == null) { |
| return false; |
| } |
| if (this.exclusionPattern != null && !this.exclusionPattern.pattern().equals( |
| otherFilter.exclusionPattern.pattern())) { |
| return false; |
| } |
| if (this.inclusionPattern != null && !this.inclusionPattern.pattern().equals( |
| otherFilter.inclusionPattern.pattern())) { |
| return false; |
| } |
| return true; |
| } |
| |
| @Override |
| public int hashCode() { |
| return hashCode; |
| } |
| } |