com.google.devtools.kythe.platform.shared.FileDataCache.java Source code

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Here is the source code for com.google.devtools.kythe.platform.shared.FileDataCache.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.platform.shared;

import com.google.common.collect.ImmutableMap;
import com.google.common.util.concurrent.Futures;
import com.google.devtools.kythe.proto.Analysis.FileData;

import java.util.Map;
import java.util.concurrent.Future;

/**
 * {@link FileDataProvider} that looks up file data from a given {@link List} of {@link FileData}.
 */
public class FileDataCache implements FileDataProvider {
    private final Map<String, byte[]> fileContents;

    public FileDataCache(Iterable<FileData> fileData) {
        ImmutableMap.Builder<String, byte[]> builder = ImmutableMap.builder();
        for (FileData data : fileData) {
            builder.put(data.getInfo().getDigest(), data.getContent().toByteArray());
        }
        fileContents = builder.build();
    }

    @Override
    public Future<byte[]> startLookup(String path, String digest) {
        byte[] content = fileContents.get(digest);
        return content != null ? Futures.immediateFuture(content)
                : Futures.<byte[]>immediateFailedFuture(
                        new RuntimeException("Cache does not contain file for digest: " + digest));
    }
}