* specific length.
   *
   * <p>For example, if you need 1024-bit hash codes, you could join two {@link Hashing#sha512} hash
   * functions together: {@code Hashing.concatenating(Hashing.sha512(), Hashing.sha512())}.
   *
   * @since 19.0
   */
  public static HashFunction concatenating(
      HashFunction first, HashFunction second, HashFunction... rest) {

import static org.gradle.internal.hash.HashCode.Usage.SAFE_TO_REUSE_BYTES;

/**
 * Some popular hash functions. Replacement for Guava's hashing utilities.
 * Inspired by the Google Guava project – https://github.com/google/guava.
 */
public class Hashing {
    private Hashing() {
    }

    private static final HashFunction MD5 = MessageDigestHashFunction.of("MD5");

   * specific length.
   *
   * <p>For example, if you need 1024-bit hash codes, you could join two {@link Hashing#sha512} hash
   * functions together: {@code Hashing.concatenating(Hashing.sha512(), Hashing.sha512())}.
   *
   * @since 19.0
   */
  public static HashFunction concatenating(
      HashFunction first, HashFunction second, HashFunction... rest) {

    assertEquals("Hashing.md5()", Hashing.md5().toString());
    assertEquals("Hashing.sha1()", Hashing.sha1().toString());
    assertEquals("Hashing.sha256()", Hashing.sha256().toString());
    assertEquals("Hashing.sha512()", Hashing.sha512().toString());
  }

  private static void assertMessageDigestHashing(byte[] input, String algorithmName) {
    try {
      MessageDigest digest = MessageDigest.getInstance(algorithmName);

    assertEquals(
        "Hashing.hmacMd5(Key[algorithm=HmacMD5, format=RAW])", Hashing.hmacMd5(MD5_KEY).toString());
    assertEquals(
        "Hashing.hmacMd5(Key[algorithm=HmacMD5, format=RAW])", Hashing.hmacMd5(keyData).toString());

    assertEquals(
        "Hashing.hmacSha1(Key[algorithm=HmacSHA1, format=RAW])",
        Hashing.hmacSha1(SHA1_KEY).toString());
    assertEquals(

    assertEquals(
        "Hashing.hmacMd5(Key[algorithm=HmacMD5, format=RAW])", Hashing.hmacMd5(MD5_KEY).toString());
    assertEquals(
        "Hashing.hmacMd5(Key[algorithm=HmacMD5, format=RAW])", Hashing.hmacMd5(keyData).toString());

    assertEquals(
        "Hashing.hmacSha1(Key[algorithm=HmacSHA1, format=RAW])",
        Hashing.hmacSha1(SHA1_KEY).toString());
    assertEquals(

        given:
        def hasher = Hashing.newHasher()
        hasher.putInt(1)
        hasher.hash()

        when:
        hasher.hash()

        then:
        thrown(IllegalStateException)
    }

    def 'hashers can overlap'() {
        when:
        def hasher1 = Hashing.newHasher()
        hasher1.putInt(1)

        and:
        def hasher2 = Hashing.newHasher()
        hasher2.putInt(1)

import org.gradle.internal.fingerprint.hashing.ConfigurableNormalizer;
import org.gradle.internal.fingerprint.hashing.RegularFileSnapshotContext;
import org.gradle.internal.fingerprint.hashing.RegularFileSnapshotContextHasher;
import org.gradle.internal.fingerprint.hashing.ResourceHasher;
import org.gradle.internal.fingerprint.hashing.ZipEntryContext;

    byte result = 0x01;
    // Trick the JVM to prevent it from using the hash function non-polymorphically
    result ^= Hashing.crc32().hashInt(reps).asBytes()[0];
    result ^= Hashing.adler32().hashInt(reps).asBytes()[0];
    for (int i = 0; i < reps; i++) {
      result ^= hashFunction.hashBytes(testBytes).asBytes()[0];
    }
    return result;
  }

import org.gradle.api.internal.file.archive.ZipEntry;
import org.gradle.internal.fingerprint.hashing.RegularFileSnapshotContext;
import org.gradle.internal.fingerprint.hashing.ResourceHasher;
import org.gradle.internal.fingerprint.hashing.ZipEntryContext;
import org.gradle.internal.hash.HashCode;
import org.gradle.internal.hash.Hasher;
import org.gradle.internal.hash.Hashing;

import javax.annotation.Nullable;
import java.io.IOException;

/**