com.google.devtools.kythe.extractors.shared.IndexInfoUtils.java Source code

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Here is the source code for com.google.devtools.kythe.extractors.shared.IndexInfoUtils.java

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/*
 * Copyright 2014 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.devtools.kythe.extractors.shared;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;

import com.google.common.base.Strings;
import com.google.common.collect.Lists;
import com.google.devtools.kythe.common.PathUtil;
import com.google.devtools.kythe.proto.Analysis.CompilationUnit;
import com.google.devtools.kythe.proto.Analysis.FileData;
import com.google.protobuf.CodedInputStream;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.List;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

/** Utilities to read and write compilation index information in .kindex files. */
public class IndexInfoUtils {
    public static final String INDEX_FILE_EXT = ".kindex";

    public static CompilationDescription readIndexInfoFromFile(String indexInfoFilename) throws IOException {
        checkArgument(!Strings.isNullOrEmpty(indexInfoFilename), "indexInfoFilename");

        InputStream indexInfoInputStream = new GZIPInputStream(new FileInputStream(indexInfoFilename));
        try {
            return readIndexInfoFromStream(indexInfoInputStream);
        } finally {
            indexInfoInputStream.close();
        }
    }

    public static CompilationDescription readIndexInfoFromStream(InputStream inputStream) throws IOException {
        checkNotNull(inputStream, "inputStream");

        // We do not use parseDelimitedFrom but use CodedInputStream manually,
        // as it allows us to control the size limit on each individual protobuf message read.
        CodedInputStream codedStream = CodedInputStream.newInstance(inputStream);
        codedStream.setSizeLimit(Integer.MAX_VALUE);

        CompilationUnit compilationUnit = CompilationUnit.parseFrom(codedStream.readBytes());
        List<FileData> fileContents = Lists.newArrayList();
        while (!codedStream.isAtEnd()) {
            fileContents.add(FileData.parseFrom(codedStream.readBytes()));
        }
        return new CompilationDescription(compilationUnit, fileContents);
    }

    public static void writeIndexInfoToStream(CompilationDescription description, OutputStream stream)
            throws IOException {
        OutputStream indexOutputStream = new GZIPOutputStream(stream);
        try {
            description.getCompilationUnit().writeDelimitedTo(indexOutputStream);
            for (FileData fileContent : description.getFileContents()) {
                fileContent.writeDelimitedTo(indexOutputStream);
            }
        } finally {
            indexOutputStream.close();
        }
    }

    public static void writeIndexInfoToFile(CompilationDescription description, String path) throws IOException {
        writeIndexInfoToStream(description, new FileOutputStream(path));
    }

    public static String getIndexFilename(String rootDirectory, String basename) {
        return PathUtil.join(rootDirectory, basename + INDEX_FILE_EXT);
    }
}