IgnoreNode.java

/*
 * Copyright (C) 2010, 2021 Red Hat Inc. and others
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Distribution License v. 1.0 which is available at
 * https://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */
package org.eclipse.jgit.ignore;

import static java.nio.charset.StandardCharsets.UTF_8;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import org.eclipse.jgit.annotations.Nullable;
import org.eclipse.jgit.errors.InvalidPatternException;
import org.eclipse.jgit.internal.JGitText;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Represents a bundle of ignore rules inherited from a base directory.
 *
 * This class is not thread safe, it maintains state about the last match.
 */
public class IgnoreNode {

    private static final Logger LOG = LoggerFactory.getLogger(IgnoreNode.class);

    /** Result from {@link IgnoreNode#isIgnored(String, boolean)}. */
    public enum MatchResult {
        /** The file is not ignored, due to a rule saying its not ignored. */
        NOT_IGNORED,

        /** The file is ignored due to a rule in this node. */
        IGNORED,

        /** The ignore status is unknown, check inherited rules. */
        CHECK_PARENT,

        /**
         * The first previous (parent) ignore rule match (if any) should be
         * negated, and then inherited rules applied.
         *
         * @since 3.6
         */
        CHECK_PARENT_NEGATE_FIRST_MATCH;
    }

    /** The rules that have been parsed into this node. */
    private final List<FastIgnoreRule> rules;

    /**
     * Create an empty ignore node with no rules.
     */
    public IgnoreNode() {
        this(new ArrayList<>());
    }

    /**
     * Create an ignore node with given rules.
     *
     * @param rules
     *            list of rules.
     */
    public IgnoreNode(List<FastIgnoreRule> rules) {
        this.rules = rules;
    }

    /**
     * Parse files according to gitignore standards.
     *
     * @param in
     *            input stream holding the standard ignore format. The caller is
     *            responsible for closing the stream.
     * @throws java.io.IOException
     *             Error thrown when reading an ignore file.
     */
    public void parse(InputStream in) throws IOException {
        parse(null, in);
    }

    /**
     * Parse files according to gitignore standards.
     *
     * @param sourceName
     *            identifying the source of the stream
     * @param in
     *            input stream holding the standard ignore format. The caller is
     *            responsible for closing the stream.
     * @throws java.io.IOException
     *             Error thrown when reading an ignore file.
     * @since 5.11
     */
    public void parse(String sourceName, InputStream in) throws IOException {
        BufferedReader br = asReader(in);
        String txt;
        int lineNumber = 1;
        while ((txt = br.readLine()) != null) {
            if (txt.length() > 0 && !txt.startsWith("#") && !txt.equals("/")) { //$NON-NLS-1$ //$NON-NLS-2$
                FastIgnoreRule rule = new FastIgnoreRule();
                try {
                    rule.parse(txt);
                } catch (InvalidPatternException e) {
                    if (sourceName != null) {
                        LOG.error(MessageFormat.format(
                                JGitText.get().badIgnorePatternFull, sourceName,
                                Integer.toString(lineNumber), e.getPattern(),
                                e.getLocalizedMessage()), e);
                    } else {
                        LOG.error(MessageFormat.format(
                                JGitText.get().badIgnorePattern,
                                e.getPattern()), e);
                    }
                }
                if (!rule.isEmpty()) {
                    rules.add(rule);
                }
            }
            lineNumber++;
        }
    }

    private static BufferedReader asReader(InputStream in) {
        return new BufferedReader(new InputStreamReader(in, UTF_8));
    }

    /**
     * Get list of all ignore rules held by this node
     *
     * @return list of all ignore rules held by this node
     */
    public List<FastIgnoreRule> getRules() {
        return Collections.unmodifiableList(rules);
    }

    /**
     * Determine if an entry path matches an ignore rule.
     *
     * @param entryPath
     *            the path to test. The path must be relative to this ignore
     *            node's own repository path, and in repository path format
     *            (uses '/' and not '\').
     * @param isDirectory
     *            true if the target item is a directory.
     * @return status of the path.
     */
    public MatchResult isIgnored(String entryPath, boolean isDirectory) {
        final Boolean result = checkIgnored(entryPath, isDirectory);
        if (result == null) {
            return MatchResult.CHECK_PARENT;
        }

        return result.booleanValue() ? MatchResult.IGNORED
                : MatchResult.NOT_IGNORED;
    }

    /**
     * Determine if an entry path matches an ignore rule.
     *
     * @param entryPath
     *            the path to test. The path must be relative to this ignore
     *            node's own repository path, and in repository path format
     *            (uses '/' and not '\').
     * @param isDirectory
     *            true if the target item is a directory.
     * @return Boolean.TRUE, if the entry is ignored; Boolean.FALSE, if the
     *         entry is forced to be not ignored (negated match); or null, if
     *         undetermined
     * @since 4.11
     */
    public @Nullable Boolean checkIgnored(String entryPath,
            boolean isDirectory) {
        // Parse rules in the reverse order that they were read because later
        // rules have higher priority
        for (int i = rules.size() - 1; i > -1; i--) {
            FastIgnoreRule rule = rules.get(i);
            if (rule.isMatch(entryPath, isDirectory, true)) {
                return Boolean.valueOf(rule.getResult());
            }
        }
        return null;
    }

    /** {@inheritDoc} */
    @Override
    public String toString() {
        return rules.toString();
    }
}