com.facebook.buck.file.FileHash.java Source code

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Here is the source code for com.facebook.buck.file.FileHash.java

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/*
 * Copyright 2018-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.file;

import com.facebook.buck.util.types.Either;
import com.google.common.hash.HashCode;
import com.google.common.hash.HashFunction;
import com.google.common.hash.Hashing;

/** A small class that encapsulates a file hash that is either sha1, or sha256 */
public class FileHash {

    private final Either<HashCode, HashCode> sha1OrSha256;

    private FileHash(Either<HashCode, HashCode> sha1OrSha256) {
        this.sha1OrSha256 = sha1OrSha256;
    }

    /** Create a {@link FileHash} object with a sha1 hash */
    public static FileHash ofSha1(HashCode sha1) {
        return new FileHash(Either.ofLeft(sha1));
    }

    /** Create a {@link FileHash} object with a sha1 hash */
    public static FileHash ofSha256(HashCode sha256) {
        return new FileHash(Either.ofRight(sha256));
    }

    /** Get the hash function for this type of hash */
    public HashFunction getHashFunction() {
        if (sha1OrSha256.isLeft()) {
            return Hashing.sha1();
        } else {
            return Hashing.sha256();
        }
    }

    /** Get the original hash code object used to create this {@link FileHash} object */
    public HashCode getHashCode() {
        if (sha1OrSha256.isLeft()) {
            return sha1OrSha256.getLeft();
        } else {
            return sha1OrSha256.getRight();
        }
    }

    @Override
    public String toString() {
        return this.getHashCode().toString();
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }

        FileHash fileHash = (FileHash) o;

        return sha1OrSha256 != null ? sha1OrSha256.equals(fileHash.sha1OrSha256) : fileHash.sha1OrSha256 == null;
    }

    @Override
    public int hashCode() {
        return sha1OrSha256 != null ? sha1OrSha256.hashCode() : 0;
    }
}