com.google.gitiles.RefServlet.java Source code

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// Copyright 2012 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 static com.google.common.base.Preconditions.checkNotNull;
import static javax.servlet.http.HttpServletResponse.SC_NOT_FOUND;

import com.google.common.base.Function;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.google.common.collect.Ordering;
import com.google.common.primitives.Ints;
import com.google.common.util.concurrent.UncheckedExecutionException;
import com.google.gson.reflect.TypeToken;

import org.eclipse.jgit.http.server.ServletUtils;
import org.eclipse.jgit.lib.AnyObjectId;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.RefComparator;
import org.eclipse.jgit.lib.RefDatabase;
import org.eclipse.jgit.revwalk.RevWalk;
import org.eclipse.jgit.transport.RefAdvertiser;

import java.io.IOException;
import java.io.Writer;
import java.util.Collection;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import javax.annotation.Nullable;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/** Serves an HTML page with all the refs in a repository. */
public class RefServlet extends BaseServlet {
    private static final long serialVersionUID = 1L;

    private final TimeCache timeCache;

    protected RefServlet(GitilesAccess.Factory accessFactory, Renderer renderer, TimeCache timeCache) {
        super(renderer, accessFactory);
        this.timeCache = checkNotNull(timeCache, "timeCache");
    }

    @Override
    protected void doGetHtml(HttpServletRequest req, HttpServletResponse res) throws IOException {
        if (!ViewFilter.getView(req).getPathPart().isEmpty()) {
            res.setStatus(SC_NOT_FOUND);
            return;
        }
        RevWalk walk = new RevWalk(ServletUtils.getRepository(req));
        List<Map<String, Object>> tags;
        try {
            tags = getTagsSoyData(req, timeCache, walk, 0);
        } finally {
            walk.release();
        }
        renderHtml(req, res, "gitiles.refsDetail",
                ImmutableMap.of("branches", getBranchesSoyData(req, 0), "tags", tags));
    }

    @Override
    protected void doGetText(HttpServletRequest req, HttpServletResponse res) throws IOException {
        GitilesView view = ViewFilter.getView(req);
        Map<String, Ref> refs = getRefs(ServletUtils.getRepository(req).getRefDatabase(), view.getPathPart());
        TextRefAdvertiser adv = new TextRefAdvertiser(startRenderText(req, res));
        adv.setDerefTags(true);
        adv.send(refs);
        adv.end();
    }

    @Override
    protected void doGetJson(HttpServletRequest req, HttpServletResponse res) throws IOException {
        GitilesView view = ViewFilter.getView(req);
        Map<String, Ref> refs = getRefs(ServletUtils.getRepository(req).getRefDatabase(), view.getPathPart());
        Map<String, RefJsonData> jsonRefs = new LinkedHashMap<>();
        for (Map.Entry<String, Ref> ref : refs.entrySet()) {
            jsonRefs.put(ref.getKey(), new RefJsonData(ref.getValue()));
        }
        renderJson(req, res, jsonRefs, new TypeToken<Map<String, RefJsonData>>() {
        }.getType());
    }

    static List<Map<String, Object>> getBranchesSoyData(HttpServletRequest req, int limit) throws IOException {
        RefDatabase refdb = ServletUtils.getRepository(req).getRefDatabase();
        Ref head = refdb.getRef(Constants.HEAD);
        Ref headLeaf = head != null && head.isSymbolic() ? head.getLeaf() : null;
        return getRefsSoyData(refdb, ViewFilter.getView(req), Constants.R_HEADS, branchComparator(headLeaf),
                headLeaf, limit);
    }

    private static Ordering<Ref> branchComparator(Ref headLeaf) {
        if (headLeaf == null) {
            return Ordering.from(RefComparator.INSTANCE);
        }
        final String headLeafName = headLeaf.getName();
        return new Ordering<Ref>() {
            @Override
            public int compare(@Nullable Ref left, @Nullable Ref right) {
                int l = isHead(left) ? 1 : 0;
                int r = isHead(right) ? 1 : 0;
                return r - l;
            }

            private final boolean isHead(Ref ref) {
                return ref != null && ref.getName().equals(headLeafName);
            }
        }.compound(RefComparator.INSTANCE);
    }

    static List<Map<String, Object>> getTagsSoyData(HttpServletRequest req, TimeCache timeCache, RevWalk walk,
            int limit) throws IOException {
        return getRefsSoyData(ServletUtils.getRepository(req).getRefDatabase(), ViewFilter.getView(req),
                Constants.R_TAGS, tagComparator(timeCache, walk), null, limit);
    }

    private static Ordering<Ref> tagComparator(final TimeCache timeCache, final RevWalk walk) {
        return Ordering.natural().onResultOf(new Function<Ref, Long>() {
            @Override
            public Long apply(Ref ref) {
                try {
                    return timeCache.getTime(walk, ref.getObjectId());
                } catch (IOException e) {
                    throw new UncheckedExecutionException(e);
                }
            }
        }).reverse().compound(RefComparator.INSTANCE);
    }

    private static List<Map<String, Object>> getRefsSoyData(RefDatabase refdb, GitilesView view, String prefix,
            Ordering<Ref> ordering, @Nullable Ref headLeaf, int limit) throws IOException {
        Collection<Ref> refs = refdb.getRefs(prefix).values();
        refs = ordering.leastOf(refs, limit > 0 ? Ints.saturatedCast(limit + 1L) : refs.size());
        List<Map<String, Object>> result = Lists.newArrayListWithCapacity(refs.size());

        for (Ref ref : refs) {
            String name = ref.getName().substring(prefix.length());
            boolean needPrefix = !ref.getName().equals(refdb.getRef(name).getName());
            Map<String, Object> value = Maps.newHashMapWithExpectedSize(3);
            value.put("url", GitilesView.revision().copyFrom(view)
                    .setRevision(Revision.unpeeled(needPrefix ? ref.getName() : name, ref.getObjectId())).toUrl());
            value.put("name", name);
            if (headLeaf != null) {
                value.put("isHead", headLeaf.equals(ref));
            }
            result.add(value);
        }
        return result;
    }

    static String sanitizeRefForText(String refName) {
        return refName.replace("&", "&amp;").replace("<", "&lt;").replace(">", "&gt;");
    }

    private static Map<String, Ref> getRefs(RefDatabase refdb, String path) throws IOException {
        path = GitilesView.maybeTrimLeadingAndTrailingSlash(path);
        if (path.isEmpty()) {
            return refdb.getRefs(RefDatabase.ALL);
        }
        path = Constants.R_REFS + path;
        Ref singleRef = refdb.getRef(path);
        if (singleRef != null) {
            return ImmutableMap.of(singleRef.getName(), singleRef);
        }
        return refdb.getRefs(path + '/');
    }

    private static class TextRefAdvertiser extends RefAdvertiser {
        private final Writer writer;

        private TextRefAdvertiser(Writer writer) {
            this.writer = writer;
        }

        @Override
        public void advertiseId(AnyObjectId id, String refName) throws IOException {
            super.advertiseId(id, sanitizeRefForText(refName));
        }

        @Override
        protected void writeOne(CharSequence line) throws IOException {
            writer.append(line);
        }

        @Override
        public void end() throws IOException {
            writer.close();
        }
    }

    static class RefJsonData {
        RefJsonData(Ref ref) {
            value = ref.getObjectId().getName();
            if (ref.getPeeledObjectId() != null) {
                peeled = ref.getPeeledObjectId().getName();
            }
            if (ref.isSymbolic()) {
                target = ref.getTarget().getName();
            }
        }

        String value;
        String peeled;
        String target;
    }
}