Java ByteBuffer.capacity方法代码示例

import java.nio.ByteBuffer; //导入方法依赖的package包/类
/**
 * Retrieve a dependency table and send it via the connection. If
 * no table is available send a response code indicating such.
 * The message is prepended with two lengths. One length is for
 * the network layer and is the size of the whole message not including
 * the length prefix.
 * @param dependencyId ID of the dependency table to send to the client
 */
private void sendDependencyTable(final int dependencyId) throws IOException{
    final byte[] dependencyBytes = nextDependencyAsBytes(dependencyId);
    if (dependencyBytes == null) {
        m_connection.m_socket.getOutputStream().write(Connection.kErrorCode_DependencyNotFound);
        return;
    }
    // 1 for response code + 4 for dependency length prefix + dependencyBytes.length
    final ByteBuffer message = ByteBuffer.allocate(1 + 4 + dependencyBytes.length);

    // write the response code
    message.put((byte)Connection.kErrorCode_DependencyFound);

    // write the dependency's length prefix
    message.putInt(dependencyBytes.length);

    // finally, write dependency table itself
    message.put(dependencyBytes);
    message.rewind();
    if (m_connection.m_socketChannel.write(message) != message.capacity()) {
        throw new IOException("Unable to send dependency table to client. Attempted blocking write of " +
                message.capacity() + " but not all of it was written");
    }
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
private void setCJKSupport(ByteBuffer os2Table) {
    /* required info is in ulong at offset 46 */
    if (os2Table == null || os2Table.capacity() < 50) {
        return;
    }
    int range2 = os2Table.getInt(46); /* ulUnicodeRange2 */

    /* Any of these bits set in the 32-63 range indicate a font with
     * support for a CJK range. We aren't looking at some other bits
     * in the 64-69 range such as half width forms as its unlikely a font
     * would include those and none of these.
     */
    supportsCJK = ((range2 & 0x29bf0000) != 0);

    /* This should be generalised, but for now just need to know if
     * Hiragana or Katakana ranges are supported by the font.
     * In the 4 longs representing unicode ranges supported
     * bits 49 & 50 indicate hiragana and katakana
     * This is bits 17 & 18 in the 2nd ulong. If either is supported
     * we presume this is a JA font.
     */
    supportsJA = ((range2 & 0x60000) != 0);
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
protected void fillBytes(final Plane[] planes, final byte[][] yuvBytes) {
  // Because of the variable row stride it's not possible to know in
  // advance the actual necessary dimensions of the yuv planes.
  for (int i = 0; i < planes.length; ++i) {
    final ByteBuffer buffer = planes[i].getBuffer();
    if (yuvBytes[i] == null) {
      LOGGER.d("Initializing buffer %d at size %d", i, buffer.capacity());
      yuvBytes[i] = new byte[buffer.capacity()];
    }
    buffer.get(yuvBytes[i]);
  }
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
@Test(expected = IllegalArgumentException.class)
public void testWriteEndTxnMarkerNonTransactionalBatch() {
    ByteBuffer buffer = ByteBuffer.allocate(128);
    buffer.position(bufferOffset);

    long pid = 9809;
    short epoch = 15;
    int sequence = RecordBatch.NO_SEQUENCE;

    MemoryRecordsBuilder builder = new MemoryRecordsBuilder(buffer, RecordBatch.CURRENT_MAGIC_VALUE, compressionType, TimestampType.CREATE_TIME,
            0L, 0L, pid, epoch, sequence, false, true, RecordBatch.NO_PARTITION_LEADER_EPOCH, buffer.capacity());
    builder.appendEndTxnMarker(RecordBatch.NO_TIMESTAMP, new EndTransactionMarker(ControlRecordType.ABORT, 0));
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
private ByteBuffer ensure(ByteBuffer buffer, int size) {
  if (buffer == null) {
    buffer = allocator.allocate(size);
  } else if (buffer.capacity() >= size) {
    buffer.clear();
  } else {
    allocator.release(buffer);
    release(buffer);
    buffer = allocator.allocate(size);
  }
  return buffer;
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
/**
 * @param doNotCopy if true then byte arrays/buffers/sources will not be copied to this hdos but
 *        instead referenced.
 */
public HeapDataOutputStream(ByteBuffer initialBuffer, Version version, boolean doNotCopy) {
  if (initialBuffer.position() != 0) {
    initialBuffer = initialBuffer.slice();
  }
  int allocSize = initialBuffer.capacity();
  if (allocSize < 32) {
    this.MIN_CHUNK_SIZE = 32;
  } else {
    this.MIN_CHUNK_SIZE = allocSize;
  }
  this.buffer = initialBuffer;
  this.version = version;
  this.doNotCopy = doNotCopy;
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
@Test(expected = IllegalArgumentException.class)
public void testWriteControlBatchNotAllowedMagicV1() {
    ByteBuffer buffer = ByteBuffer.allocate(128);
    buffer.position(bufferOffset);

    long pid = 9809;
    short epoch = 15;
    int sequence = 2342;

    new MemoryRecordsBuilder(buffer, RecordBatch.MAGIC_VALUE_V1, compressionType, TimestampType.CREATE_TIME,
            0L, 0L, pid, epoch, sequence, false, true, RecordBatch.NO_PARTITION_LEADER_EPOCH, buffer.capacity());
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
/**
 * libsecp256k1 PrivKey Tweak-Mul - Tweak privkey by multiplying to it
 *
 * @param tweak some bytes to tweak with
 * @param seckey 32-byte seckey
 */
public static byte[] privKeyTweakMul(byte[] privkey, byte[] tweak) throws AssertFailException {
    Preconditions.checkArgument(privkey.length == 32);

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

    byte[][] retByteArray;
    r.lock();
    try {
        retByteArray = secp256k1_privkey_tweak_mul(byteBuff, Secp256k1Context.getContext());
    } finally {
        r.unlock();
    }

    byte[] privArr = retByteArray[0];

    int privLen = (byte) new BigInteger(new byte[] { retByteArray[1][0] }).intValue() & 0xFF;
    int retVal = new BigInteger(new byte[] { retByteArray[1][1] }).intValue();

    assertEquals(privArr.length, privLen, "Got bad pubkey length.");

    assertEquals(retVal, 1, "Failed return value check.");

    return privArr;
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
/**
 * libsecp256k1 PrivKey Tweak-Mul - Tweak privkey by multiplying to it
 *
 * @param tweak some bytes to tweak with
 * @param privkey 32-byte seckey
 */
public static byte[] privKeyTweakMul(byte[] privkey, byte[] tweak) throws AssertFailException {
    Preconditions.checkArgument(privkey.length == 32);

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

    byte[][] retByteArray;
    r.lock();
    try {
        retByteArray = secp256k1_privkey_tweak_mul(byteBuff, Secp256k1Context.getContext());
    } finally {
        r.unlock();
    }

    byte[] privArr = retByteArray[0];

    int privLen = (byte) new BigInteger(new byte[] { retByteArray[1][0] }).intValue() & 0xFF;
    int retVal = new BigInteger(new byte[] { retByteArray[1][1] }).intValue();

    assertEquals(privArr.length, privLen, "Got bad pubkey length.");

    assertEquals(retVal, 1, "Failed return value check.");

    return privArr;
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
/**
 * Returns a copy of the the bytes of this dex.
 */
public byte[] getBytes() {
    ByteBuffer data = this.data.duplicate(); // positioned ByteBuffers aren't thread safe
    byte[] result = new byte[data.capacity()];
    data.position(0);
    data.get(result);
    return result;
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
public final void decode(SocketAddress address, byte[] array, int offset, int length) {
    ByteBuffer buffer = mAddressByteBufferMap.get(address);
    if (buffer == null) {
        buffer = ByteBuffer.allocate(CACHE_BUFFER_LENGTH);
        mAddressByteBufferMap.put(address, buffer);
        buffer.flip();
        LoggerFactory.getLogger().info("创建 " + address.toString() + " 数据缓冲区ByteBuffer");
    }
    LoggerFactory.getLogger().info(String.format("%s 上次未解码 position=%d limit=%d", address.toString(), buffer.position(), buffer.limit()));
    if (buffer.limit() + length > buffer.capacity()) {
        LoggerFactory.getLogger().warn(address.toString() + " -> decode缓存区已满，读取的数据被丢弃!!!!!");
        return;
    }
    buffer.compact();
    buffer.put(array, offset, length);
    buffer.flip();
    buffer.mark();
    LoggerFactory.getLogger().info(String.format("%s 合并未解码 position=%d limit=%d", address.toString(), buffer.position(), buffer.limit()));
    LoggerFactory.getLogger().info(address.toString() + " 开始解码数据");
    while (buffer.hasRemaining() && (decode(address, buffer) != null)) {
        LoggerFactory.getLogger().info(address.toString() + " 成功解码一条数据");
        buffer.compact();
        buffer.flip();
        buffer.mark();
    }
    LoggerFactory.getLogger().info(address.toString() + " 退出解码");
    buffer.reset();
    LoggerFactory.getLogger().info(String.format("%s 未解码数据 position=%d limit=%d", address.toString(), buffer.position(), buffer.limit()));
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
static CMap createCMap(ByteBuffer buffer, int offset, char[] xlat) {
    /* First do a sanity check that this cmap subtable is contained
     * within the cmap table.
     */
    int subtableFormat = buffer.getChar(offset);
    long subtableLength;
    if (subtableFormat < 8) {
        subtableLength = buffer.getChar(offset+2);
    } else {
        subtableLength = buffer.getInt(offset+4) & INTMASK;
    }
    if (offset+subtableLength > buffer.capacity()) {
        if (FontUtilities.isLogging()) {
            FontUtilities.getLogger().warning("Cmap subtable overflows buffer.");
        }
    }
    switch (subtableFormat) {
    case 0:  return new CMapFormat0(buffer, offset);
    case 2:  return new CMapFormat2(buffer, offset, xlat);
    case 4:  return new CMapFormat4(buffer, offset, xlat);
    case 6:  return new CMapFormat6(buffer, offset, xlat);
    case 8:  return new CMapFormat8(buffer, offset, xlat);
    case 10: return new CMapFormat10(buffer, offset, xlat);
    case 12: return new CMapFormat12(buffer, offset, xlat);
    default: throw new RuntimeException("Cmap format unimplemented: " +
                                        (int)buffer.getChar(offset));
    }
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
@Test
public void buildUsingLogAppendTime() {
    ByteBuffer buffer = ByteBuffer.allocate(1024);
    buffer.position(bufferOffset);

    long logAppendTime = System.currentTimeMillis();
    MemoryRecordsBuilder builder = new MemoryRecordsBuilder(buffer, RecordBatch.MAGIC_VALUE_V1, compressionType,
            TimestampType.LOG_APPEND_TIME, 0L, logAppendTime, RecordBatch.NO_PRODUCER_ID, RecordBatch.NO_PRODUCER_EPOCH,
            RecordBatch.NO_SEQUENCE, false, false, RecordBatch.NO_PARTITION_LEADER_EPOCH, buffer.capacity());
    builder.append(0L, "a".getBytes(), "1".getBytes());
    builder.append(0L, "b".getBytes(), "2".getBytes());
    builder.append(0L, "c".getBytes(), "3".getBytes());
    MemoryRecords records = builder.build();

    MemoryRecordsBuilder.RecordsInfo info = builder.info();
    assertEquals(logAppendTime, info.maxTimestamp);

    if (compressionType != CompressionType.NONE)
        assertEquals(2L, info.shallowOffsetOfMaxTimestamp);
    else
        assertEquals(0L, info.shallowOffsetOfMaxTimestamp);

    for (RecordBatch batch : records.batches()) {
        assertEquals(TimestampType.LOG_APPEND_TIME, batch.timestampType());
        for (Record record : batch)
            assertEquals(logAppendTime, record.timestamp());
    }
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
/**
 * libsecp256k1 create ECDH secret - constant time ECDH calculation
 *
 * @param seckey byte array of secret key used in exponentiaion
 * @param pubkey byte array of public key used in exponentiaion
 */
public static byte[] createECDHSecret(byte[] seckey, byte[] pubkey) throws AssertFailException {
    Preconditions.checkArgument(seckey.length <= 32 && pubkey.length <= 65);

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

    byte[][] retByteArray;
    r.lock();
    try {
        retByteArray = secp256k1_ecdh(byteBuff, Secp256k1Context.getContext(), pubkey.length);
    } finally {
        r.unlock();
    }

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

    assertEquals(resArr.length, 32, "Got bad result length.");
    assertEquals(retVal, 1, "Failed return value check.");

    return resArr;
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
/**
 * Return a buffer into the pool. After being returned,
 * the buffer may be recycled, so the user must not
 * continue to use it in any way.
 * @param buf the buffer to return
 */
public void returnBuffer(ByteBuffer buf) {
  buf.clear(); // reset mark, limit, etc
  int size = buf.capacity();
  Queue<WeakReference<ByteBuffer>> list = buffersBySize.get(size);
  if (list == null) {
    list = new ConcurrentLinkedQueue<WeakReference<ByteBuffer>>();
    Queue<WeakReference<ByteBuffer>> prev = buffersBySize.putIfAbsent(size, list);
    // someone else put a queue in the map before we did
    if (prev != null) {
      list = prev;
    }
  }
  list.add(new WeakReference<ByteBuffer>(buf));
}