channelbuffer.java

来自「mysql的jdbc驱动」· Java 代码 · 共 661 行 · 第 1/2 页

		case 252:
			return readInt();

		case 253:
			return readLongInt();

		case 254:
			return readLong();

		default:
			return sw;
		}
	}

	final long readLong() {
		long l = ((long)this.directBuffer.get() & 0xff)
				| (((long)this.directBuffer.get() & 0xff) << 8)
				| (((long)this.directBuffer.get() & 0xff) << 16)
				| (((long)this.directBuffer.get() & 0xff) << 24);

		// this.directBuffer.position(this.position);

		return l;
	}

	final int readLongInt() {

		int i = (this.directBuffer.get() & 0xff)
				| ((this.directBuffer.get() & 0xff) << 8)
				| ((this.directBuffer.get() & 0xff) << 16);

		// this.directBuffer.position(this.position);

		return i;
	}

	// 2000-06-05 Fixed
	final long readLongLong() {

		long l = (this.directBuffer.get() & 0xff)
				| ((long) (this.directBuffer.get() & 0xff) << 8)
				| ((long) (this.directBuffer.get() & 0xff) << 16)
				| ((long) (this.directBuffer.get() & 0xff) << 24)
				| ((long) (this.directBuffer.get() & 0xff) << 32)
				| ((long) (this.directBuffer.get() & 0xff) << 40)
				| ((long) (this.directBuffer.get() & 0xff) << 48)
				| ((long) (this.directBuffer.get() & 0xff) << 56);

		// this.directBuffer.position(this.position);

		return l;
	}

	final int readnBytes() {
		int sw = this.directBuffer.get() & 0xff;
		// this.directBuffer.position(this.position);

		switch (sw) {
		case 1:
			return this.directBuffer.get() & 0xff;

		case 2:
			return this.readInt();

		case 3:
			return this.readLongInt();

		case 4:
			return (int) this.readLong();

		default:
			return 255;
		}
	}

	//
	// Read a null-terminated string
	//
	// To avoid alloc'ing a new byte array, we
	// do this by hand, rather than calling getNullTerminatedBytes()
	//
	final String readString() {

		int len = 0;
		int maxLen = getBufLength();
		int oldPosition = getPosition();

		while ((getPosition() < maxLen) && (this.directBuffer.get() != 0)) {
			len++;
		}

		setPosition(oldPosition);

		String s = new String(bufferToArray(), getPosition(), len);

		this.directBuffer.position(getPosition() + len + 1); // update cursor

		return s;
	}

	final String readString(String encoding) throws SQLException {

		int len = 0;

		int maxLen = getBufLength();

		while ((getPosition() < maxLen) && (this.directBuffer.get() != 0)) {
			len++;
		}

		try {
			return new String(bufferToArray(), getPosition(), len, encoding);
		} catch (UnsupportedEncodingException uEE) {
			throw new SQLException(
					Messages.getString("ChannelBuffer.0") //$NON-NLS-1$
							+ encoding + Messages.getString("ChannelBuffer.1"), SQLError.SQL_STATE_ILLEGAL_ARGUMENT); //$NON-NLS-1$
		} finally {
			this.directBuffer.position(getPosition() + len + 1); // update
																	// cursor
		}
	}

	void setBufLength(int bufLengthToSet) {
		this.bufLength = bufLengthToSet;
		this.directBuffer.limit(this.bufLength);
		this.dirty = true;
	}

	/**
	 * Sets the array of bytes to use as a buffer to read from.
	 * 
	 * @param byteBuffer
	 *            the array of bytes to use as a buffer
	 */
	public void setByteBuffer(byte[] byteBuffer) {
		this.directBuffer = ByteBuffer.wrap(byteBuffer);
	}

	/**
	 * Set the current position to write to/ read from
	 * 
	 * @param position
	 *            the position (0-based index)
	 */
	public void setPosition(int position) {
		// this.position = position;
		this.directBuffer.position(position);
	}

	final void writeByte(byte b) throws SQLException {
		ensureCapacity(1);

		this.directBuffer.put(b);
		this.dirty = true;
	}

	// Write a byte array
	final void writeBytesNoNull(byte[] bytes) throws SQLException {
		int len = bytes.length;
		ensureCapacity(len);

		this.directBuffer.put(bytes, 0, len);
		this.dirty = true;
	}

	// Write a byte array with the given offset and length
	final void writeBytesNoNull(byte[] bytes, int offset, int length)
			throws SQLException {
		ensureCapacity(length);

		this.directBuffer.put(bytes, offset, length);

		this.dirty = true;
	}

	final void writeDouble(double d) throws SQLException {
		long l = Double.doubleToLongBits(d);
		writeLongLong(l);
		this.dirty = true;
	}

	final void writeFieldLength(long length) throws SQLException {
		if (length < 251) {
			writeByte((byte) length);
		} else if (length < 65536L) {
			ensureCapacity(3);
			writeByte((byte) 252);
			writeInt((int) length);
		} else if (length < 16777216L) {
			ensureCapacity(4);
			writeByte((byte) 253);
			writeLongInt((int) length);
		} else {
			ensureCapacity(9);
			writeByte((byte) 254);
			writeLongLong(length);
		}

	}

	final void writeFloat(float f) throws SQLException {
		ensureCapacity(4);

		int i = Float.floatToIntBits(f);

		this.directBuffer.put((byte) (i & 0xff));
		this.directBuffer.put((byte) (i >>> 8));
		this.directBuffer.put((byte) (i >>> 16));
		this.directBuffer.put((byte) (i >>> 24));

		this.dirty = true;
	}

	// 2000-06-05 Changed
	final void writeInt(int i) throws SQLException {
		ensureCapacity(2);
		this.directBuffer.put((byte) (i & 0xff));
		this.directBuffer.put((byte) (i >>> 8));

		this.dirty = true;
	}

	// Write a String using the specified character
	// encoding
	final void writeLenBytes(byte[] b) throws SQLException {
		int len = b.length;
		ensureCapacity(len + 9);
		writeFieldLength(len);
		this.directBuffer.put(b, 0, len);

		this.dirty = true;
	}

	// Write a String using the specified character
	// encoding
	final void writeLenString(String s, String encoding, String serverEncoding,
			SingleByteCharsetConverter converter, boolean parserKnowsUnicode)
			throws UnsupportedEncodingException, SQLException {
		byte[] b = null;

		if (converter != null) {
			b = converter.toBytes(s);
		} else {
			b = StringUtils.getBytes(s, encoding, serverEncoding,
					parserKnowsUnicode);
		}

		int len = b.length;
		ensureCapacity(len + 9);
		writeFieldLength(len);
		this.directBuffer.put(b, 0, len);

		this.dirty = true;
	}

	// 2000-06-05 Changed
	final void writeLong(long i) throws SQLException {
		ensureCapacity(4);

		this.directBuffer.put((byte) (i & 0xff));
		this.directBuffer.put((byte) (i >>> 8));
		this.directBuffer.put((byte) (i >>> 16));
		this.directBuffer.put((byte) (i >>> 24));

		this.dirty = true;
	}

	// 2000-06-05 Changed
	final void writeLongInt(int i) throws SQLException {
		ensureCapacity(3);

		this.directBuffer.put((byte) (i & 0xff));
		this.directBuffer.put((byte) (i >>> 8));
		this.directBuffer.put((byte) (i >>> 16));

		this.dirty = true;
	}

	final void writeLongLong(long i) throws SQLException {
		ensureCapacity(8);

		this.directBuffer.put((byte) (i & 0xff));
		this.directBuffer.put((byte) (i >>> 8));
		this.directBuffer.put((byte) (i >>> 16));
		this.directBuffer.put((byte) (i >>> 24));
		this.directBuffer.put((byte) (i >>> 32));
		this.directBuffer.put((byte) (i >>> 40));
		this.directBuffer.put((byte) (i >>> 48));
		this.directBuffer.put((byte) (i >>> 56));

		this.dirty = true;
	}

	// Write null-terminated string
	final void writeString(String s) throws SQLException {
		ensureCapacity((s.length() * 2) + 1);

		writeStringNoNull(s);
		this.directBuffer.put((byte) 0);

		this.dirty = true;
	}

	// Write string, with no termination
	final void writeStringNoNull(String s) throws SQLException {
		int len = s.length();
		ensureCapacity(len * 2);

		this.directBuffer.put(s.getBytes(), 0, len);

		this.dirty = true;
	}

	// Write a String using the specified character
	// encoding
	final void writeStringNoNull(String s, String encoding,
			String serverEncoding, boolean parserKnowsUnicode)
			throws UnsupportedEncodingException, SQLException {
		byte[] b = StringUtils.getBytes(s, encoding, serverEncoding,
				parserKnowsUnicode);

		int len = b.length;
		ensureCapacity(len);

		this.directBuffer.put(b, 0, len);

		this.dirty = true;
	}
}