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The high performance and density marshaller
/*
* Copyright 2014 Masazumi Kobayashi
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.mk300.marshal.minimum.io;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
/**
* Data*Streamに対して、可変バイト数で自然数の書込み、読込みを実施する。
* 扱う自然数と対応するバイト数は以下のとおり。
* 0 - 127 -> 1byte
* 128 - 16383 -> 2byte
* 16384 - 2097151 -> 3byte
* 2097152 - 268435455 -> 4byte
* 268435456 - Integer.MAX_VALUE -> 5byte
* @author [email protected]
*
*/
public class NaturalNumberIoHelper {
private static int dv1 = 128; // 7bit 2^7
private static int dv2 = 16384; // 14bit 2^14
private static int dv3 = 2097152; // 21bit 2^21
private static int dv4 = 268435456; // 28bit 2^28
/**
* DataOutputStreamに対して、可変バイト数で自然数の書込みを実施する。
* 扱う自然数と対応するバイト数は以下のとおり。
* 0 - 127 -> 1byte
* 128 - 16383 -> 2byte
* 16384 - 2097151 -> 3byte
* 2097152 - 268435455 -> 4byte
* 268435456 - Integer.MAX_VALUE -> 5byte
* @param dos
* @param naturalNumber
* @throws IOException
*/
public static final void writeNaturalNumber(DataOutputStream dos, int naturalNumber) throws IOException {
if(naturalNumber < 0) {
throw new IOException(naturalNumber + " is not natural number");
}
if( naturalNumber < dv1 ) { // 7bit
int b1 = naturalNumber;
dos.writeByte(b1);
} else if ( naturalNumber < dv2) { // 14bit
int b1 = (naturalNumber / dv1) * -1;
int b2 = (naturalNumber % dv1);
dos.writeByte(b1);
dos.writeByte(b2);
} else if( naturalNumber < dv3) { // 21bit
int b1 = (naturalNumber / dv2) * -1;
int b2 = ((b1*dv2 + naturalNumber) / dv1 + 1) * -1 ;
int b3 = (naturalNumber % dv1);
dos.writeByte(b1);
dos.writeByte(b2);
dos.writeByte(b3);
} else if( naturalNumber < dv4) { // 28bit
int b1 = (naturalNumber / dv3) * -1;
int b2 = ((b1*dv3 + naturalNumber) / dv2 + 1) * -1;
int b3 = ((b1*dv3 + (b2 + 1)*dv2 + naturalNumber) / dv1 + 1) * -1 ;
int b4 = (naturalNumber % dv1);
dos.writeByte(b1);
dos.writeByte(b2);
dos.writeByte(b3);
dos.writeByte(b4);
} else {
int b1 = (naturalNumber / dv4) * -1;
int b2 = ( (b1*dv4 + naturalNumber) / dv3 + 1) * -1;
int b3 = ( (b1*dv4 + (b2+1)*dv3 + naturalNumber) / dv2 + 1) * -1;
int b4 = ( (b1*dv4 + (b2+1)*dv3 + (b3+1)*dv2 + naturalNumber) / dv1 + 1) * -1 ;
int b5 = (naturalNumber % dv1);
dos.writeByte(b1);
dos.writeByte(b2);
dos.writeByte(b3);
dos.writeByte(b4);
dos.writeByte(b5);
}
}
/**
* DataInputStreamに対して、可変バイト数の自然数の読込みを実施する。
* @param dis
* @return
* @throws IOException
*/
public static final int readNaturalNumber(DataInputStream dis) throws IOException {
int naturalNumber = 0;
byte b1 = dis.readByte();
if( b1 >= 0) {
naturalNumber = b1;
} else {
byte b2 = dis.readByte();
if(b2 >= 0) {
naturalNumber = b1 * dv1 * -1 ;
naturalNumber += b2;
} else {
byte b3 = dis.readByte();
if(b3 >= 0) {
naturalNumber += b1 * dv2 * -1;
naturalNumber += (b2+1) * dv1 * -1;
naturalNumber += b3;
} else {
byte b4 = dis.readByte();
if(b4 >=0) {
naturalNumber += b1 * dv3 * -1;
naturalNumber += (b2+1) * dv2 * -1;
naturalNumber += (b3+1) * dv1 * -1;
naturalNumber += b4;
} else {
byte b5 = dis.readByte();
naturalNumber += b1 * dv4 * -1;
naturalNumber += (b2+1) * dv3 * -1;
naturalNumber += (b3+1) * dv2 * -1;
naturalNumber += (b4+1) * dv1 * -1;
naturalNumber += b5;
}
}
}
}
return naturalNumber;
}
public static void main(String[] args) throws Exception {
System.out.println("start ");
for( int i=0 ; i< Integer.MAX_VALUE ; i++) {
try {
testNaturalNumber(i);
} catch (Exception e) {
System.out.println("error " + i);
throw e;
}
}
//
// for( int i=0 ; i< dv1+100 ; i++) {
// try {
// testNaturalNumber(i);
// } catch (Exception e) {
// System.out.println("error " + i);
// throw e;
// }
// }
//
// for( int i=dv2-100 ; i< dv2+100 ; i++) {
// try {
// testNaturalNumber(i);
// } catch (Exception e) {
// System.out.println("error " + i);
// throw e;
// }
// }
//
// for( int i=dv3-100 ; i< dv3+100 ; i++) {
// try {
// testNaturalNumber(i);
// } catch (Exception e) {
// System.out.println("error " + i);
// throw e;
// }
// }
//
// for( int i=dv4-100 ; i< dv4+100 ; i++) {
// try {
// testNaturalNumber(i);
// } catch (Exception e) {
// System.out.println("error " + i);
// throw e;
// }
// }
//
// for( int i=Integer.MAX_VALUE-100 ; i< Integer.MAX_VALUE ; i++) {
// try {
// testNaturalNumber(i);
// } catch (Exception e) {
// System.out.println("error " + i);
// throw e;
// }
// }
System.out.println("Success Finish! ");
}
public static void testNaturalNumber(int number) throws Exception {
BAOutputStream bo = new BAOutputStream();
DataOutputStream dos = new DataOutputStream(bo);
writeNaturalNumber(dos, number);
byte[] bytes = bo.toByteArray();
BAInputStream bi = new BAInputStream(bytes);
DataInputStream di = new DataInputStream(bi);
int ret = readNaturalNumber(di);
if(number % (Integer.MAX_VALUE/200) == 0 || false) {
System.out.println("" + number);
}
if(number != ret) {
throw new RuntimeException("ミスマッチ：" + number);
}
}
}