1 files changed, 167 insertions, 0 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/util/RegexFilter.java b/src/main/java/com/google/devtools/build/lib/util/RegexFilter.java
new file mode 100644
index 0000000000..d7c6834ad5
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+++ b/src/main/java/com/google/devtools/build/lib/util/RegexFilter.java
@@ -0,0 +1,167 @@
+// Copyright 2014 Google Inc. 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.common.options.Converter;
+import com.google.devtools.common.options.OptionsParsingException;
+
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+import java.util.regex.Pattern;
+import java.util.regex.PatternSyntaxException;
+
+/**
+ * Handles options that specify list of included/excluded regex expressions.
+ * Validates whether string is included in that filter.
+ *
+ * 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.
+ */
+public class RegexFilter implements Serializable {
+  private final Pattern inclusionPattern;
+  private final Pattern exclusionPattern;
+  private final int hashCode;
+
+  /**
+   * Converts from a colon-separated list of regex expressions with optional
+   * -/+ prefix into the RegexFilter. Colons prefixed with backslash are
+   * considered to be part of regex definition and not a delimiter between
+   * separate regex expressions.
+   *
+   * 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";
+    }
+
+  }
+
+  /**
+   * Creates new RegexFilter using provided inclusion and exclusion path lists.
+   */
+  public RegexFilter(List<String> inclusions, List<String> exclusions) {
+    inclusionPattern = convertRegexListToPattern(inclusions);
+    exclusionPattern = convertRegexListToPattern(exclusions);
+    hashCode = Objects.hash(inclusions, exclusions);
+  }
+
+  /**
+   * Converts list of regex expressions into one compiled regex expression.
+   */
+  private static Pattern convertRegexListToPattern(List<String> regexList) {
+    if (regexList.size() == 0) {
+      return null;
+    }
+    // Wrap each individual regex in the independent group, combine them using '|' and
+    // wrap in the non-capturing group.
+    return Pattern.compile("(?:(?>" + Joiner.on(")|(?>").join(regexList) + "))");
+  }
+
+  /**
+   * @return true iff given string is included (it is 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 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;
+  }
+}