Java Code Examples for com.google.common.hash.HashFunction#hashBytes()

@Test
public void testEditingPrimaryDexClassForcesRebuildForSimplePackage() throws IOException {
  BuildTarget buildTarget = BuildTargetFactory.newInstance(SIMPLE_TARGET);
  Path outputPath = BuildTargetPaths.getGenPath(filesystem, buildTarget, "%s.apk");
  HashFunction hashFunction = Hashing.sha1();
  String dexFileName = "classes.dex";

  workspace.runBuckdCommand("build", SIMPLE_TARGET).assertSuccess();
  ZipInspector zipInspector = new ZipInspector(workspace.getPath(outputPath));
  HashCode originalHash = hashFunction.hashBytes(zipInspector.getFileContents(dexFileName));

  workspace.replaceFileContents(
      "java/com/sample/app/MyApplication.java", "MyReplaceableName", "ChangedValue");

  workspace.resetBuildLogFile();
  ProcessResult result = workspace.runBuckdCommand("build", SIMPLE_TARGET);
  result.assertSuccess();
  BuckBuildLog buildLog = workspace.getBuildLog();
  buildLog.assertTargetBuiltLocally(SIMPLE_TARGET);

  HashCode hashAfterChange = hashFunction.hashBytes(zipInspector.getFileContents(dexFileName));
  assertThat(
      "MyApplication.java file has been edited. Final artifact hash must change as well",
      originalHash,
      is(not(equalTo(hashAfterChange))));
}
 

static Slice computeHash(HashFunction hash, Slice data)
{
    HashCode result;
    if (data.hasByteArray()) {
        result = hash.hashBytes(data.byteArray(), data.byteArrayOffset(), data.length());
    }
    else {
        result = hash.hashBytes(data.getBytes());
    }
    return wrappedBuffer(result.asBytes());
}
 

private String getHashFor(File inputFile) {
    String retval = alreadyChecked.get(inputFile.getAbsolutePath());
    if (retval != null) return retval;
    // add a hash of the original file path
    try {
        HashFunction hashFunction = Hashing.md5();
        HashCode hashCode = hashFunction.hashBytes(Files.readAllBytes(inputFile.toPath()));
        retval = hashCode.toString();
        alreadyChecked.put(inputFile.getAbsolutePath(), retval);
        return retval;
    } catch (IOException e) {
        e.printStackTrace();
        return "ERROR";
    }
}
 

private HashCode hash(ByteBuffer buf) {
    HashFunction hashFn = Hashing.murmur3_128();
    if (buf.hasArray()) {
        return hashFn.hashBytes(buf.array(), buf.arrayOffset() + buf.position(), buf.remaining());
    } else {
        return hashFn.hashBytes(ByteBufferUtil.getArray(buf));
    }
}
 

public static void main(String[] args) {
	final int seed = 42;
	HashFunction guava = Hashing.murmur3_128(seed);

	String uuid = UUID.randomUUID().toString();
	byte[] bytes = uuid.getBytes();
	
	HashCode guavaCode = guava.hashBytes(bytes);
	long[] myCodes = Murmur3.hash_x64_128(bytes, bytes.length, seed);
	
	System.out.println("Hash from guava: " + guavaCode);
	System.out.println("Hash from murmur: " + display(myCodes[0]) + " " + display(myCodes[1]));
}
 

public byte[] acquireData(Serializer serializer, HashFunction hasher) throws IOException {
  // We should only ever need the data once.
  byte[] current = dataRef.get();
  if (current != null) {
    dropData();
    return current;
  }

  byte[] reserialized = serializer.reserialize(instance);
  HashCode recomputedHash = hasher.hashBytes(reserialized);
  Verify.verify(recomputedHash.toString().equals(hash));
  this.dataRef = new WeakReference<>(reserialized);
  return reserialized;
}
 

/**
 * Verify if the expected checksum is equal to the checksum of the given file.
 *
 * @param function the checksum function like MD5, SHA256 used to generate the checksum from the file
 * @param file the file we want to calculate the checksum from
 * @param expectedChecksum the expected checksum
 * @throws IOException on I/O error reading the file or the checksum verification failed
 */
private void verifyChecksum(HashFunction function, Path file, String expectedChecksum) throws IOException {
    HashCode actualHash = function.hashBytes(Files.readAllBytes(file));
    HashCode expectedHash = HashCode.fromString(expectedChecksum);
    if (!Objects.equals(actualHash, expectedHash)) {
        throw new IOException("GEO IP Checksum verification failed. "
            + "Expected: " + expectedChecksum + "Actual:" + actualHash);
    }
}
 

@Override
public HashCode hash(HashFunction hashFunction) throws IOException {
  return hashFunction.hashBytes(bytes, offset, length);
}
 

@Override
public HashCode hash(HashFunction hashFunction) throws IOException {
  return hashFunction.hashBytes(bytes, offset, length);
}
 

@Override
public HashCode hash(HashFunction hashFunction) throws IOException {
  return hashFunction.hashBytes(bytes, offset, length);
}
 

@Override
public HashCode hash(HashFunction hashFunction) throws IOException {
  return hashFunction.hashBytes(bytes, offset, length);
}
 

@Override
public HashCode hash(HashFunction hashFunction) throws IOException {
  return hashFunction.hashBytes(bytes, offset, length);
}
 

@Override
public HashCode hash(HashFunction hashFunction) {
  // overridden to use array directly for performance
  return hashFunction.hashBytes(array);
}
 

public static String getMD5Checksum(final InputStream is) throws IOException {
    final HashFunction hf = Hashing.md5();

    final HashCode hashCode = hf.hashBytes(getBytesFromInputStream(is));

    return hashCode.toString();
}