com.google.gitiles.ReadmeHelper.java Source code

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Here is the source code for com.google.gitiles.ReadmeHelper.java

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// Copyright 2015 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.gitiles;

import com.google.gitiles.doc.GitilesMarkdown;
import com.google.gitiles.doc.ImageLoader;
import com.google.gitiles.doc.MarkdownToHtml;
import com.google.template.soy.data.SanitizedContent;

import org.eclipse.jgit.errors.CorruptObjectException;
import org.eclipse.jgit.errors.IncorrectObjectTypeException;
import org.eclipse.jgit.errors.LargeObjectException;
import org.eclipse.jgit.errors.MissingObjectException;
import org.eclipse.jgit.lib.Config;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.FileMode;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.ObjectReader;
import org.eclipse.jgit.revwalk.RevTree;
import org.eclipse.jgit.treewalk.TreeWalk;
import org.eclipse.jgit.util.RawParseUtils;
import org.pegdown.ast.RootNode;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;

class ReadmeHelper {
    private static final Logger log = LoggerFactory.getLogger(ReadmeHelper.class);

    private final ObjectReader reader;
    private final GitilesView view;
    private final Config cfg;
    private final RevTree rootTree;
    private final boolean render;

    private String readmePath;
    private ObjectId readmeId;

    ReadmeHelper(ObjectReader reader, GitilesView view, Config cfg, RevTree rootTree) {
        this.reader = reader;
        this.view = view;
        this.cfg = cfg;
        this.rootTree = rootTree;
        render = cfg.getBoolean("markdown", "render", true);
    }

    void scanTree(RevTree tree)
            throws MissingObjectException, IncorrectObjectTypeException, CorruptObjectException, IOException {
        if (render) {
            TreeWalk tw = new TreeWalk(reader);
            tw.setRecursive(false);
            tw.addTree(tree);
            while (tw.next() && !isPresent()) {
                considerEntry(tw);
            }
        }
    }

    void considerEntry(TreeWalk tw) {
        if (render && FileMode.REGULAR_FILE.equals(tw.getRawMode(0)) && isReadmeFile(tw.getNameString())) {
            readmePath = tw.getPathString();
            readmeId = tw.getObjectId(0);
        }
    }

    boolean isPresent() {
        return readmeId != null;
    }

    String getPath() {
        return readmePath;
    }

    SanitizedContent render() {
        try {
            int inputLimit = cfg.getInt("markdown", "inputLimit", 5 << 20);
            byte[] raw = reader.open(readmeId, Constants.OBJ_BLOB).getCachedBytes(inputLimit);
            String md = RawParseUtils.decode(raw);
            RootNode root = GitilesMarkdown.parseFile(view, readmePath, md);
            if (root == null) {
                return null;
            }

            int imageLimit = cfg.getInt("markdown", "imageLimit", 256 << 10);
            ImageLoader img = null;
            if (imageLimit > 0) {
                img = new ImageLoader(reader, view, rootTree, readmePath, imageLimit);
            }

            return new MarkdownToHtml(view, cfg).setImageLoader(img).setReadme(true).toSoyHtml(root);
        } catch (LargeObjectException | IOException e) {
            log.error(String.format("error rendering %s/%s", view.getRepositoryName(), readmePath), e);
            return null;
        }
    }

    /** True if the file is the default markdown file to render in tree view. */
    private static boolean isReadmeFile(String name) {
        return name.equalsIgnoreCase("README.md");
    }
}