com.facebook.buck.android.resources.ResourceTable.java Source code

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Here is the source code for com.facebook.buck.android.resources.ResourceTable.java

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/*
 * Copyright 2017-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.resources;

import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSortedSet;
import com.google.common.collect.Maps;
import java.io.PrintStream;
import java.nio.ByteBuffer;
import java.util.Comparator;
import java.util.Map;
import java.util.stream.IntStream;

/**
 * A ResourceTable is the top-level representation of resources.arsc. It consists of a header:
 * ResTable_header u32 chunk_type u32 header_size u32 chunk_size u32 package_count
 *
 * <p>The header is followed by a StringPool and then package_count packages.
 *
 * <p>In practice, aapt always generates .arsc files with package_count == 1.
 */
public class ResourceTable extends ResChunk {
    public static final int HEADER_SIZE = 12;

    private final StringPool strings;
    private final ResTablePackage resPackage;

    public ResourceTable(StringPool strings, ResTablePackage resPackage) {
        super(CHUNK_RESOURCE_TABLE, HEADER_SIZE, HEADER_SIZE + strings.getChunkSize() + resPackage.getChunkSize());
        this.strings = strings;
        this.resPackage = resPackage;
    }

    public static ResourceTable get(ByteBuffer buf) {
        int type = buf.getShort();
        int headerSize = buf.getShort();
        int chunkSize = buf.getInt();
        int packageCount = buf.getInt();

        Preconditions.checkState(type == CHUNK_RESOURCE_TABLE);
        Preconditions.checkState(headerSize == HEADER_SIZE);
        Preconditions.checkState(packageCount == 1);

        StringPool strings = StringPool.get(slice(buf, buf.position()));
        ResTablePackage resPackage = ResTablePackage.get(slice(buf, HEADER_SIZE + strings.getChunkSize()));

        Preconditions.checkState(chunkSize == HEADER_SIZE + strings.getChunkSize() + resPackage.getChunkSize());

        return new ResourceTable(strings, resPackage);
    }

    @Override
    public void put(ByteBuffer buf) {
        putChunkHeader(buf);
        buf.putInt(1); // packageCount
        Preconditions.checkState(buf.position() == HEADER_SIZE);
        strings.put(buf);
        Preconditions.checkState(buf.position() == HEADER_SIZE + strings.getChunkSize());
        resPackage.put(buf);
    }

    public void reassignIds(ReferenceMapper refMapping) {
        resPackage.reassignIds(refMapping);
    }

    public static ResourceTable slice(ResourceTable table, Map<Integer, Integer> countsToExtract) {
        ResTablePackage newPackage = ResTablePackage.slice(table.resPackage, countsToExtract);

        StringPool strings = table.strings;
        // Figure out what strings are used by the retained references.
        ImmutableSortedSet.Builder<Integer> stringRefs = ImmutableSortedSet
                .orderedBy(Comparator.comparing(strings::getString).thenComparingInt(i -> i));
        newPackage.visitStringReferences(stringRefs::add);
        ImmutableList<Integer> stringsToExtract = stringRefs.build().asList();
        ImmutableMap<Integer, Integer> stringMapping = Maps
                .uniqueIndex(IntStream.range(0, stringsToExtract.size())::iterator, stringsToExtract::get);

        // Extract a StringPool that contains just the strings used by the new package.
        // This drops styles.
        StringPool newStrings = StringPool.create(stringsToExtract.stream().map(strings::getString)::iterator);

        // Adjust the string references.
        newPackage.transformStringReferences(stringMapping::get);

        return new ResourceTable(newStrings, newPackage);
    }

    public void dump(PrintStream out) {
        out.format("Package Groups (1)\n");
        resPackage.dump(strings, out);
    }

    public StringPool getStrings() {
        return strings;
    }

    public ResTablePackage getPackage() {
        return resPackage;
    }

    public void dumpStrings(PrintStream out) {
        strings.dump(out);
    }
}