ReadablePacket.java

package me.xcoding.opencdc.mysql.protocol;

import java.io.InputStream;

import me.xcoding.opencdc.mysql.protocol.BasicReader;

public abstract class ReadablePacket extends InputStream implements BasicReader {
	/** FIXME Splits the data into packets of size (224–1) bytes */
	protected final byte[] buffer; //new byte[16 << 20];
	
	protected int offset = 0;
	protected int end = 4; // FIXME
	
	public ReadablePacket(int batchSize) {
		this.buffer = new byte[batchSize];
	}
	
	@Override
	public int readVarLenInt(int length) {
		int v = 0;
		for(int i=0; i<length; i++) {
			v |= ((buffer[offset++] & FF) << (i << 3));
		}
		return v;
	}
	
	@Override
	public int readVarLenIntS(int length) {
		if(length == 0) {
			return 0;
		}
		
		int v = 0;
		for(int i=1; i<length; i++) {
			v = (v << 8) | (buffer[offset++] & FF);
		}
		v = (v << 8) | buffer[offset++];
		
		return v;
	}

	@Override
	public int readVarLenIntU(int length) {
		int v = 0;
		for(int i=0; i<length; i++) {
			v = (v << 8) | (buffer[offset++] & FF);
		}
		return v;
	}

	@Override
	public long readVarLenLongS(int length) {
		if(length < 1) 
			return 0;

		long v = 0;
		for(int i=1; i<length; i++) {
			v = (v << 8) | (buffer[offset++] & FF);
		}
		
		v = (v << 8) | buffer[offset++];
		return v;
	}

	@Override
	public long readVarLenLongU(int length) {
		long v = 0;
		for(int i=0; i<length; i++) {
			System.out.print(Integer.toHexString(buffer[offset] & FF) + " ");
			v = (v << 8) | (buffer[offset++] & FF);
		}
		return v;
	}
	
	@Override
	public int readFixedIntT1() {
		return (buffer[offset++] & FF);
	}
	
	@Override
	public int readFixedIntS1() {
		return buffer[offset++];
	}

	@Override
	public int readFixedIntT2() {
		return (buffer[offset++] & FF) | ((buffer[offset++] & FF) << 8);
	}

	@Override
	public int readFixedIntS2() {
		return (buffer[offset++] & FF) | ((buffer[offset++]) << 8);
	}
	
	@Override
	public int readFixedIntT3() {
		return (buffer[offset++] & FF) | ((buffer[offset++] & FF) << 8) 
				| ((buffer[offset++] & FF) << 16);
	}
	
	@Override
	public int readFixedIntS3() {
		return (buffer[offset++] & FF) | ((buffer[offset++] & FF) << 8) 
				| ((buffer[offset++]) << 16);
	}

	@Override
	public int readFixedIntT4() {
		return (buffer[offset++] & FF) | ((buffer[offset++] & FF) << 8)
				| ((buffer[offset++] & FF) << 16) | ((buffer[offset++] & FF) << 24);
	}

	@Override
	public long readFixedIntT6() {
		int v1 = (buffer[offset++] & FF) | ((buffer[offset++] & FF) << 8)
				| ((buffer[offset++] & FF) << 16);
		
		int v2 = (buffer[offset++] & FF) | ((buffer[offset++] & FF) << 8)
				| ((buffer[offset++] & FF) << 16);
		
		return v1 | (v2 << 24);
	}
	
	@Override
	public long readFixedIntS6() {
		int v1 = (buffer[offset++] & FF) | ((buffer[offset++] & FF) << 8)
				| ((buffer[offset++] & FF) << 16);
		
		int v2 = (buffer[offset++] & FF) | ((buffer[offset++] & FF) << 8)
				| ((buffer[offset++]) << 16);
		
		return v1 | (v2 << 24);
	}

	@Override
	public long readFixedIntT8() {
		int v1 = (buffer[offset++] & FF) | ((buffer[offset++] & FF) << 8)
				| ((buffer[offset++] & FF) << 16) | ((buffer[offset++] & FF) << 24);
		int v2 = (buffer[offset++] & FF) | ((buffer[offset++] & FF) << 8)
				| ((buffer[offset++] & FF) << 16) | ((buffer[offset++] & FF) << 24);
		
		return v1 | (v2 << 32);
	}

	@Override
	public long readLenEncInt() {
		int type = buffer[offset++] & FF;
		
		if(type < 0xFB) {
			return type;
		} else if(type < 0xFC) {
			return (buffer[offset++] & FF) | ((buffer[offset++] & FF) << 8); 
		} else if(type < 0xFD) {
			return (buffer[offset++] & FF) | ((buffer[offset++] & FF) << 8)
					| ((buffer[offset++] & FF) << 16);
		} else if(type < 0xFE) {
			return this.readFixedIntT8();
		} else {
			return -1;
		}
	}

	@Override
	public String readStringLenEnc() {
		int len = (int) readLenEncInt();
		
		return readStringVarLen(len);
	}

	@Override
	public String readStringNull() {
		int start = offset;
		while(buffer[++offset] != 0);
		
		int l = offset - start;
		byte[] b = new byte[l];
		System.arraycopy(buffer, start, b, 0, l);
		
		offset++;
		
		return new String(b);
	}

	@Override // FIXME EOF
	public String readStringEOF() {
		int len = end - offset;
		
		byte[] b = new byte[len];
		System.arraycopy(buffer, offset, b, 0, len);
		offset = end;
		
		return new String(b);
	}

	@Override
	public String readStringFixLen(int length) {
		byte[] b = new byte[length];
		System.arraycopy(buffer, offset, b, 0, length);
		
		offset = offset + length;
		return new String(b);
	}

	@Override
	public String readStringVarLen(int length) {
		byte[] b = new byte[length];
		System.arraycopy(buffer, offset, b, 0, length);
		
		offset = offset + length;
		return new String(b);
	}

	@Override
	public byte[] readBytesEOF() {
		int len = end - offset;
		System.out.println("ReadablePacket.readBytesEOF()" + (end - offset));
		byte[] b = new byte[len];
		System.arraycopy(buffer, offset, b, 0, len);
		offset = end;
		
		return b;
	}

	@Override
	public byte[] readBytesNull() {
		int start = offset;
		while(buffer[++offset] != 0);
		
		int l = offset - start;
		byte[] b = new byte[l];
		System.arraycopy(buffer, start, b, 0, l);
		offset++;
		
		return b;
	}

	@Override
	public byte[] readBytesLenEnc() {
		int len = (int) this.readLenEncInt();
		
		byte[] b = new byte[len];
		System.arraycopy(buffer, offset, b, 0, len);
		offset = offset + len;
		
		return b;
	}

	@Override
	public byte[] readBytesVarLen(int length) {
		byte[] b = new byte[length];
		System.arraycopy(buffer, offset, b, 0, length);
		offset = offset + length;
		
		return b;
	}
	
	@Override
	public int skip(int off) {
		return offset += off;
	}

}