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package org.openjdk.bench.javax.crypto.full;

import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.Param;
import org.openjdk.jmh.annotations.Setup;

import java.security.spec.AlgorithmParameterSpec;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.nio.ByteBuffer;

/**
 * This is the common code for the AES/GCM and ChaCha20-Poly1305 performance
 * tests.  Encryption and decryption are run with input and output
 * ByteBuffers, direct and heap, for single and multi-part testing.
 *
 * The IV rotates through a set buffer and creates a new AlgorithmParameterSpec
 * for each encrypt benchmark operation.
 */

public abstract class ByteBufferBase extends CryptoBase {
    // Defined by the test
    String algorithm;
    int keyLength = 256;

    @Param({"1024", "1500", "4096", "16384"})
    int dataSize;

    @Param({"direct", "heap"})
    String dataMethod;

    static final int IV_BUFFER_SIZE = 36;
    public byte[] iv;
    public int iv_index = 0;
    private int updateLen = 0;

    private Cipher encryptCipher, decryptCipher;
    private ByteBuffer encryptedData, in, out;
    private SecretKeySpec ks;
    // Used for decryption to avoid repeated getParameter() calls
    private AlgorithmParameterSpec spec;

    abstract AlgorithmParameterSpec getNewSpec();

    // Configure setup with particular test parameters
    public void init(String algorithm, int keyLength) throws Exception {
        this.algorithm = algorithm;
        this.keyLength = keyLength;
        init();
    }

    // Configure setup with particular test parameters
    public void init(String algorithm, int keyLength, int dataSize)
        throws Exception {
        this.dataSize = dataSize;
        init(algorithm, keyLength);
    }

    // Initalize test setup
    private void init() throws Exception {
        setupProvider();

        // Setup key material
        iv = fillSecureRandom(new byte[IV_BUFFER_SIZE]);
        spec = getNewSpec();
        // CC20 doesn't care about the algorithm name on the key, but AES does.
        ks = new SecretKeySpec(fillSecureRandom(new byte[keyLength / 8]),
            "AES");

        // Setup Cipher classes
        encryptCipher = makeCipher(prov, algorithm);
        encryptCipher.init(Cipher.ENCRYPT_MODE, ks, spec);
        decryptCipher = makeCipher(prov, algorithm);
        decryptCipher.init(Cipher.DECRYPT_MODE, ks, spec);

        // Setup input/output buffers
        byte[] data = fillRandom(new byte[dataSize]);
        if (dataMethod.equalsIgnoreCase("direct")) {
            in = ByteBuffer.allocateDirect(data.length);
            in.put(data);
            in.flip();
            encryptedData = ByteBuffer.allocateDirect(
                encryptCipher.getOutputSize(data.length));
            out = ByteBuffer.allocateDirect(encryptedData.capacity());
        } else if (dataMethod.equalsIgnoreCase("heap")) {
            in = ByteBuffer.wrap(data);
            encryptedData = ByteBuffer.allocate(
                encryptCipher.getOutputSize(data.length));
            out = ByteBuffer.allocate(encryptedData.capacity());
        }

        encryptCipher.doFinal(in, encryptedData);
        encryptedData.flip();
        in.flip();
        updateLen = in.remaining() / 2;
    }

    @Benchmark
    public void encrypt() throws Exception {
        encryptCipher.init(Cipher.ENCRYPT_MODE, ks, getNewSpec());
        encryptCipher.doFinal(in, out);
        out.flip();
        in.flip();
    }

    @Benchmark
    public void encryptMultiPart() throws Exception {
        encryptCipher.init(Cipher.ENCRYPT_MODE, ks, getNewSpec());
        in.limit(updateLen);
        encryptCipher.update(in, out);
        in.limit(in.capacity());
        encryptCipher.doFinal(in, out);
        out.flip();
        in.flip();
    }

    @Benchmark
    public void decrypt() throws Exception {
        decryptCipher.init(Cipher.DECRYPT_MODE, ks, spec);
        decryptCipher.doFinal(encryptedData, out);
        encryptedData.flip();
        out.flip();
    }

    @Benchmark
    public void decryptMultiPart() throws Exception {
        decryptCipher.init(Cipher.DECRYPT_MODE, ks, spec);

        int len = encryptedData.remaining();
        encryptedData.limit(updateLen);
        decryptCipher.update(encryptedData, out);
        encryptedData.limit(len);

        decryptCipher.doFinal(encryptedData, out);
        encryptedData.flip();
        out.flip();
    }
}