/* * SonarQube * Copyright (C) 2009-2023 SonarSource SA * mailto:info AT sonarsource DOT com * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 3 of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this program; if not, write to the Free Software Foundation, * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ package org.sonar.scm.git; import java.io.OutputStream; import java.util.HashSet; import java.util.Set; import java.util.regex.Matcher; import java.util.regex.Pattern; class ChangedLinesComputer { private final Tracker tracker = new Tracker(); private final OutputStream receiver = new OutputStream() { StringBuilder sb = new StringBuilder(); @Override public void write(int b) { sb.append((char) b); if (b == '\n') { tracker.parseLine(sb.toString()); sb.setLength(0); } } }; /** * The OutputStream to pass to JGit's diff command. */ OutputStream receiver() { return receiver; } /** * From a stream of unified diff lines emitted by Git for a single file, * compute the line numbers that should be considered changed. * Example input: *
   * diff --git a/lao.txt b/lao.txt
   * index 635ef2c..7f050f2 100644
   * --- a/lao.txt
   * +++ b/lao.txt
   * @@ -1,7 +1,6 @@
   * -The Way that can be told of is not the eternal Way;
   * -The name that can be named is not the eternal name.
   *  The Nameless is the origin of Heaven and Earth;
   * -The Named is the mother of all things.
   * +The named is the mother of all things.
   * +
   *  Therefore let there always be non-being,
   *    so we may see their subtlety,
   *  And let there always be being,
   * @@ -9,3 +8,6 @@ And let there always be being,
   *  The two are the same,
   *  But after they are produced,
   *    they have different names.
   * +They both may be called deep and profound.
   * +Deeper and more profound,
   * +The door of all subtleties!names.
   * 
* See also: http://www.gnu.org/software/diffutils/manual/html_node/Example-Unified.html#Example-Unified */ Set changedLines() { return tracker.changedLines(); } private static class Tracker { private static final Pattern START_LINE_IN_TARGET = Pattern.compile(" \\+(\\d+)"); private final Set changedLines = new HashSet<>(); private boolean foundStart = false; private int lineNumInTarget; private void parseLine(String line) { if (line.startsWith("@@ ")) { Matcher matcher = START_LINE_IN_TARGET.matcher(line); if (!matcher.find()) { throw new IllegalStateException("Invalid block header on line " + line); } foundStart = true; lineNumInTarget = Integer.parseInt(matcher.group(1)); } else if (foundStart) { char firstChar = line.charAt(0); if (firstChar == ' ') { lineNumInTarget++; } else if (firstChar == '+') { changedLines.add(lineNumInTarget); lineNumInTarget++; } } } Set changedLines() { return changedLines; } } }