com.facebook.buck.android.dalvik.DalvikAwareOutputStreamHelper.java Source code

Introduction

Here is the source code for com.facebook.buck.android.dalvik.DalvikAwareOutputStreamHelper.java

Source

/*
 * Copyright 2013-present Facebook, Inc.
 *
 * 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.facebook.buck.android.dalvik;

import com.facebook.buck.jvm.java.classes.FileLike;
import com.facebook.buck.util.zip.DeterministicZipBuilder;
import com.google.common.base.Charsets;
import com.google.common.base.Preconditions;
import com.google.common.collect.Sets;
import com.google.common.io.ByteStreams;
import java.io.IOException;
import java.io.InputStream;
import java.io.Writer;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.HashSet;
import java.util.Set;
import java.util.zip.Deflater;

/** Helper to write a Zip file used by {@link DalvikAwareZipSplitter}. */
public class DalvikAwareOutputStreamHelper implements ZipOutputStreamHelper {

    private static final int MAX_METHOD_REFERENCES = 64 * 1024;
    private static final int MAX_FIELD_REFERENCES = 64 * 1024;

    private final DeterministicZipBuilder zipBuilder;
    private final Set<String> entryNames = new HashSet<>();
    private final long linearAllocLimit;
    private final Writer reportFileWriter;
    private final DalvikStatsCache dalvikStatsCache;

    private final Set<DalvikMemberReference> currentMethodReferences = new HashSet<>();
    private final Set<DalvikMemberReference> currentFieldReferences = new HashSet<>();
    private long currentLinearAllocSize;

    DalvikAwareOutputStreamHelper(Path outputFile, long linearAllocLimit, Path reportDir,
            DalvikStatsCache dalvikStatsCache) throws IOException {
        Preconditions.checkState(Files.exists(outputFile.getParent()));
        this.zipBuilder = new DeterministicZipBuilder(outputFile);
        this.linearAllocLimit = linearAllocLimit;
        Path reportFile = reportDir.resolve(outputFile.getFileName() + ".txt");
        this.reportFileWriter = Files.newBufferedWriter(reportFile, Charsets.UTF_8);
        this.dalvikStatsCache = dalvikStatsCache;
    }

    private boolean isEntryTooBig(FileLike entry) {
        DalvikStatsTool.Stats stats = dalvikStatsCache.getStats(entry);
        if (currentLinearAllocSize + stats.estimatedLinearAllocSize > linearAllocLimit) {
            return true;
        }
        int newMethodRefs = Sets.difference(stats.methodReferences, currentMethodReferences).size();
        if (currentMethodReferences.size() + newMethodRefs > MAX_METHOD_REFERENCES) {
            return true;
        }
        int newFieldRefs = Sets.difference(stats.fieldReferences, currentFieldReferences).size();
        return currentFieldReferences.size() + newFieldRefs > MAX_FIELD_REFERENCES;
    }

    @Override
    public boolean canPutEntry(FileLike fileLike) {
        return !isEntryTooBig(fileLike);
    }

    @Override
    public boolean containsEntry(FileLike fileLike) {
        return entryNames.contains(fileLike.getRelativePath());
    }

    @Override
    public void putEntry(FileLike fileLike) throws IOException {
        String name = fileLike.getRelativePath();
        // Tracks unique entry names and avoids duplicates.  This is, believe it or not, how
        // proguard seems to handle merging multiple -injars into a single -outjar.
        if (!containsEntry(fileLike)) {
            entryNames.add(name);
            try (InputStream in = fileLike.getInput()) {
                byte[] bytes = ByteStreams.toByteArray(in);
                zipBuilder.addEntry(bytes, name, Deflater.NO_COMPRESSION);
            }

            // Make sure FileLike#getSize didn't lie (or we forgot to call canPutEntry).
            DalvikStatsTool.Stats stats = dalvikStatsCache.getStats(fileLike);
            Preconditions.checkState(!isEntryTooBig(fileLike), "Putting entry %s (%s) exceeded maximum size of %s",
                    name, stats.estimatedLinearAllocSize, linearAllocLimit);
            currentLinearAllocSize += stats.estimatedLinearAllocSize;
            currentMethodReferences.addAll(stats.methodReferences);
            currentFieldReferences.addAll(stats.fieldReferences);
            String report = String.format("%d %d %d %s\n", stats.estimatedLinearAllocSize,
                    stats.methodReferences.size(), stats.fieldReferences.size(), name);
            reportFileWriter.append(report);
        }
    }

    @Override
    public void close() throws IOException {
        zipBuilder.close();
        reportFileWriter.close();
    }
}