Java ByteBuffer.rewind方法代码示例

import java.nio.ByteBuffer; //导入方法依赖的package包/类
private void growBuffer(int p_181670_1_)
{
    if (MathHelper.roundUp(p_181670_1_, 4) / 4 > this.rawIntBuffer.remaining() || this.vertexCount * this.vertexFormat.getNextOffset() + p_181670_1_ > this.byteBuffer.capacity())
    {
        int i = this.byteBuffer.capacity();
        int j = i + MathHelper.roundUp(p_181670_1_, 2097152);
        LOGGER.debug("Needed to grow BufferBuilder buffer: Old size {} bytes, new size {} bytes.", new Object[] {Integer.valueOf(i), Integer.valueOf(j)});
        int k = this.rawIntBuffer.position();
        ByteBuffer bytebuffer = GLAllocation.createDirectByteBuffer(j);
        this.byteBuffer.position(0);
        bytebuffer.put(this.byteBuffer);
        bytebuffer.rewind();
        this.byteBuffer = bytebuffer;
        this.rawFloatBuffer = this.byteBuffer.asFloatBuffer().asReadOnlyBuffer();
        this.rawIntBuffer = this.byteBuffer.asIntBuffer();
        this.rawIntBuffer.position(k);
        this.rawShortBuffer = this.byteBuffer.asShortBuffer();
        this.rawShortBuffer.position(k << 1);
    }
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
public byte[] serialize(String topic, ByteBuffer data) {
    if (data == null)
        return null;

    data.rewind();

    if (data.hasArray()) {
        byte[] arr = data.array();
        if (data.arrayOffset() == 0 && arr.length == data.remaining()) {
            return arr;
        }
    }

    byte[] ret = new byte[data.remaining()];
    data.get(ret, 0, ret.length);
    data.rewind();
    return ret;
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
/**
 * Calculate checkSum over the Page
 *
 * @param page
 */
private void calculateChecksumOverPage(ByteBuffer page)
{           
    //CRC should be zero before calculating it
    page.putInt(OggPageHeader.FIELD_PAGE_CHECKSUM_POS, 0);

    //Compute CRC over the  page  //TODO shouldnt really use array();
    byte[] crc = OggCRCFactory.computeCRC(page.array());
    for (int i = 0; i < crc.length; i++)
    {
        page.put(OggPageHeader.FIELD_PAGE_CHECKSUM_POS + i, crc[i]);
    }

    //Rewind to start of Page
    page.rewind();
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
/**
 * Verifies the given secp256k1 signature in native code. Calling when enabled == false is undefined (probably
 * library not loaded)
 *
 * @param data The data which was signed, must be exactly 32 bytes
 * @param signature The signature
 * @param pub The public key which did the signing
 */
public static boolean verify(byte[] data, byte[] signature, byte[] pub) throws AssertFailException {
    Preconditions.checkArgument(data.length == 32 && signature.length <= 520 && pub.length <= 520);

    ByteBuffer byteBuff = nativeECDSABuffer.get();
    if (byteBuff == null || byteBuff.capacity() < 520) {
        byteBuff = ByteBuffer.allocateDirect(520);
        byteBuff.order(ByteOrder.nativeOrder());
        nativeECDSABuffer.set(byteBuff);
    }
    byteBuff.rewind();
    byteBuff.put(data);
    byteBuff.put(signature);
    byteBuff.put(pub);

    r.lock();
    try {
        return secp256k1_ecdsa_verify(byteBuff, Secp256k1Context.getContext(), signature.length, pub.length) == 1;
    } finally {
        r.unlock();
    }
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
private static void createLargeFile(long filesize,
                                    File file) throws Exception {
    // Recreate a large file as a sparse file if possible
    Files.delete(file.toPath());

    try (FileChannel fc =
         FileChannel.open(file.toPath(),
                          CREATE_NEW, WRITE, SPARSE)) {
        ByteBuffer bb = ByteBuffer.allocate(1).put((byte)1);
        bb.rewind();
        System.out.println("  Writing large file...");
        long t0 = System.nanoTime();
        int rc = fc.write(bb, filesize - 1);
        long t1 = System.nanoTime();
        System.out.printf("  Wrote large file in %d ns (%d ms) %n",
            t1 - t0, TimeUnit.NANOSECONDS.toMillis(t1 - t0));

        if (rc != 1) {
            throw new RuntimeException("Failed to write 1 byte"
                                       + " to the large file");
        }
    }
    return;
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
public static void main(String[] args) {
    ByteBuffer bb=ByteBuffer.allocate(BSIZE);
    int i=0;
    while (i++<bb.limit()){
        if(bb.get()!=0){
            print("nonzero");
        }
        print("i="+i);
    }
    bb.rewind();

    bb.asCharBuffer().put("Howdy!");
    char c;
    while ((c=bb.getChar())!=0){
        printnb(c+"");
    }
    print();
    bb.rewind();
    bb.asShortBuffer().put((short)471142);
    print(bb.getShort());
    bb.rewind();

    bb.asIntBuffer().put(99471142);
    print(bb.getShort());
    bb.rewind();

    bb.asLongBuffer().put(99471142);
    print(bb.getLong());
    bb.rewind();

    bb.asFloatBuffer().put(99471142);
    print(bb.getFloat());
    bb.rewind();

    bb.asDoubleBuffer().put(99471142);
    print(bb.getDouble());
    bb.rewind();

}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
private void func_181670_b(int p_181670_1_)
{
    if (Config.isShaders())
    {
        p_181670_1_ *= 2;
    }

    if (p_181670_1_ > this.rawIntBuffer.remaining())
    {
        int i = this.byteBuffer.capacity();
        int j = i % 2097152;
        int k = j + (((this.rawIntBuffer.position() + p_181670_1_) * 4 - j) / 2097152 + 1) * 2097152;
        LogManager.getLogger().warn("Needed to grow BufferBuilder buffer: Old size " + i + " bytes, new size " + k + " bytes.");
        int l = this.rawIntBuffer.position();
        ByteBuffer bytebuffer = GLAllocation.createDirectByteBuffer(k);
        this.byteBuffer.position(0);
        bytebuffer.put(this.byteBuffer);
        bytebuffer.rewind();
        this.byteBuffer = bytebuffer;
        this.rawFloatBuffer = this.byteBuffer.asFloatBuffer();
        this.rawIntBuffer = this.byteBuffer.asIntBuffer();
        this.rawIntBuffer.position(l);
        this.field_181676_c = this.byteBuffer.asShortBuffer();
        this.field_181676_c.position(l << 1);

        if (this.quadSprites != null)
        {
            TextureAtlasSprite[] atextureatlassprite = this.quadSprites;
            int i1 = this.getBufferQuadSize();
            this.quadSprites = new TextureAtlasSprite[i1];
            System.arraycopy(atextureatlassprite, 0, this.quadSprites, 0, Math.min(atextureatlassprite.length, this.quadSprites.length));
            this.quadSpritesPrev = null;
        }
    }
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
@Test
public void decode() {
  final IntegerValue value = new IntegerValue(213);
  final EncodingRegistry reg = new EncodingRegistry(Optional.empty());
  final ByteBuffer buf = ByteBuffer.allocate(1000);
  (new IntegerEncoding()).encode(Format.BINARY, value, new TestBufferWriter(buf));
  buf.rewind();
  final Value<?> decoded = reg.decode(Oid.INT4, Format.BINARY, new TestBufferReader(buf));
  assertEquals(value, decoded);
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
public IPv4Packet(ByteBuffer raw) {
    this.raw = raw;
    raw.rewind();

    ipv4Header = new IPv4Header(raw.duplicate());
    if (!ipv4Header.isSupported()) {
        Log.d(TAG, "Unsupported IPv4 headers");
        transportHeader = null;
        return;
    }
    transportHeader = createTransportHeader();
    raw.limit(ipv4Header.getTotalLength());
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
private byte[] getBytes(CreateArkTransactionRequest createArkTransactionRequest, String senderPublicKey) {
    ByteBuffer buffer = ByteBuffer.allocate(1000);
    buffer.order(ByteOrder.LITTLE_ENDIAN);

    buffer.put(createArkTransactionRequest.getType());
    buffer.putInt((int) createArkTransactionRequest.getTimestamp()); // todo: fix downcast
    buffer.put(BaseEncoding.base16().lowerCase().decode(senderPublicKey));

    if(createArkTransactionRequest.getRecipientId() != null){
        buffer.put(Base58.decodeChecked(createArkTransactionRequest.getRecipientId()));
    } else {
        buffer.put(new byte[21]);
    }

    if (createArkTransactionRequest.getVendorField() != null) {
        byte[] vbytes = createArkTransactionRequest.getVendorField().getBytes();
        if(vbytes.length < 65){
            buffer.put(vbytes);
            buffer.put(new byte[64-vbytes.length]);
        }
    } else {
        buffer.put(new byte[64]);
    }

    buffer.putLong(createArkTransactionRequest.getAmount());
    buffer.putLong(createArkTransactionRequest.getFee());

    byte[] outBuffer = new byte[buffer.position()];
    buffer.rewind();
    buffer.get(outBuffer);

    return outBuffer;
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
private void addTimelineDelegationToken(
    ContainerLaunchContext clc) throws YarnException, IOException {
  Credentials credentials = new Credentials();
  DataInputByteBuffer dibb = new DataInputByteBuffer();
  ByteBuffer tokens = clc.getTokens();
  if (tokens != null) {
    dibb.reset(tokens);
    credentials.readTokenStorageStream(dibb);
    tokens.rewind();
  }
  // If the timeline delegation token is already in the CLC, no need to add
  // one more
  for (org.apache.hadoop.security.token.Token<? extends TokenIdentifier> token : credentials
      .getAllTokens()) {
    if (token.getKind().equals(TimelineDelegationTokenIdentifier.KIND_NAME)) {
      return;
    }
  }
  org.apache.hadoop.security.token.Token<TimelineDelegationTokenIdentifier>
      timelineDelegationToken = getTimelineDelegationToken();
  if (timelineDelegationToken == null) {
    return;
  }
  credentials.addToken(timelineService, timelineDelegationToken);
  if (LOG.isDebugEnabled()) {
    LOG.debug("Add timline delegation token into credentials: "
        + timelineDelegationToken);
  }
  DataOutputBuffer dob = new DataOutputBuffer();
  credentials.writeTokenStorageToStream(dob);
  tokens = ByteBuffer.wrap(dob.getData(), 0, dob.getLength());
  clc.setTokens(tokens);
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
static ByteBuffer getBuffer(long size) {
    if (size < 0 || Integer.MAX_VALUE < size) {
        throw new IndexOutOfBoundsException("size");
    }

    ByteBuffer result = null;

    if (size > LARGE_BUFFER) {
        result = allocateBuffer(size);
    } else {
        BufferReference[] cache = CACHE.get();

        // buffers are ordered by decreasing capacity
        // cache[MAX_CACHED_BUFFERS] is always null
        for (int i = MAX_CACHED_BUFFERS - 1; i >= 0; i--) {
            BufferReference reference = cache[i];

            if (reference != null) {
                ByteBuffer buffer = reference.get();

                if (buffer != null && size <= buffer.capacity()) {
                    cache[i] = null;
                    result = buffer;
                    result.rewind();
                    break;
                }
            }
        }

        if (result == null) {
            result = allocateBuffer(size);
        }
    }

    result.limit((int)size);

    return result;
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
/**
 * Read the VBRI Properties from the buffer
 */
private VbriFrame(ByteBuffer header)
{
    this.header=header;
    //Go to start of Buffer
    header.rewind();
    header.position(10);
    setAudioSize();
    setFrameCount();
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
/**
 * libsecp256k1 Create an ECDSA signature.
 *
 * @param data Message hash, 32 bytes
 * @param key Secret key, 32 bytes
 * @return sig byte array of signature
 */
public static byte[] sign(byte[] data, byte[] sec) throws AssertFailException {
    Preconditions.checkArgument(data.length == 32 && sec.length <= 32);

    ByteBuffer byteBuff = nativeECDSABuffer.get();
    if (byteBuff == null || byteBuff.capacity() < 32 + 32) {
        byteBuff = ByteBuffer.allocateDirect(32 + 32);
        byteBuff.order(ByteOrder.nativeOrder());
        nativeECDSABuffer.set(byteBuff);
    }
    byteBuff.rewind();
    byteBuff.put(data);
    byteBuff.put(sec);

    byte[][] retByteArray;

    r.lock();
    try {
        retByteArray = secp256k1_ecdsa_sign(byteBuff, Secp256k1Context.getContext());
    } finally {
        r.unlock();
    }

    byte[] sigArr = retByteArray[0];
    int sigLen = new BigInteger(new byte[] { retByteArray[1][0] }).intValue();
    int retVal = new BigInteger(new byte[] { retByteArray[1][1] }).intValue();

    assertEquals(sigArr.length, sigLen, "Got bad signature length.");

    return retVal == 0 ? new byte[0] : sigArr;
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
private ByteBuffer subscriptionUserData() {
    final UUID uuid = UUID.randomUUID();
    final ByteBuffer buf = ByteBuffer.allocate(4 + 16 + 4 + 4);
    // version
    buf.putInt(1);
    // encode client processId
    buf.putLong(uuid.getMostSignificantBits());
    buf.putLong(uuid.getLeastSignificantBits());
    // previously running tasks
    buf.putInt(0);
    // cached tasks
    buf.putInt(0);
    buf.rewind();
    return buf;
}