org.elasticsearch.common.io.stream.StreamInput Maven / Gradle / Ivy
/*
* Licensed to Elastic Search and Shay Banon under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. Elastic Search licenses this
* file to you 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.elasticsearch.common.io.stream;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.io.UTFDataFormatException;
/**
* @author kimchy (shay.banon)
*/
public abstract class StreamInput extends InputStream {
/**
* working arrays initialized on demand by readUTF
*/
private byte bytearr[] = new byte[80];
protected char chararr[] = new char[80];
/**
* Reads and returns a single byte.
*/
public abstract byte readByte() throws IOException;
/**
* Reads a specified number of bytes into an array at the specified offset.
*
* @param b the array to read bytes into
* @param offset the offset in the array to start storing bytes
* @param len the number of bytes to read
*/
public abstract void readBytes(byte[] b, int offset, int len) throws IOException;
public void readFully(byte[] b) throws IOException {
readBytes(b, 0, b.length);
}
public short readShort() throws IOException {
return (short) (((readByte() & 0xFF) << 8) | (readByte() & 0xFF));
}
/**
* Reads four bytes and returns an int.
*/
public int readInt() throws IOException {
return ((readByte() & 0xFF) << 24) | ((readByte() & 0xFF) << 16)
| ((readByte() & 0xFF) << 8) | (readByte() & 0xFF);
}
/**
* Reads an int stored in variable-length format. Reads between one and
* five bytes. Smaller values take fewer bytes. Negative numbers are not
* supported.
*/
public int readVInt() throws IOException {
byte b = readByte();
int i = b & 0x7F;
if ((b & 0x80) == 0) return i;
b = readByte();
i |= (b & 0x7F) << 7;
if ((b & 0x80) == 0) return i;
b = readByte();
i |= (b & 0x7F) << 14;
if ((b & 0x80) == 0) return i;
b = readByte();
i |= (b & 0x7F) << 21;
if ((b & 0x80) == 0) return i;
b = readByte();
assert (b & 0x80) == 0;
return i | ((b & 0x7F) << 28);
}
/**
* Reads eight bytes and returns a long.
*/
public long readLong() throws IOException {
return (((long) readInt()) << 32) | (readInt() & 0xFFFFFFFFL);
}
/**
* Reads a long stored in variable-length format. Reads between one and
* nine bytes. Smaller values take fewer bytes. Negative numbers are not
* supported.
*/
public long readVLong() throws IOException {
byte b = readByte();
long i = b & 0x7FL;
if ((b & 0x80) == 0) return i;
b = readByte();
i |= (b & 0x7FL) << 7;
if ((b & 0x80) == 0) return i;
b = readByte();
i |= (b & 0x7FL) << 14;
if ((b & 0x80) == 0) return i;
b = readByte();
i |= (b & 0x7FL) << 21;
if ((b & 0x80) == 0) return i;
b = readByte();
i |= (b & 0x7FL) << 28;
if ((b & 0x80) == 0) return i;
b = readByte();
i |= (b & 0x7FL) << 35;
if ((b & 0x80) == 0) return i;
b = readByte();
i |= (b & 0x7FL) << 42;
if ((b & 0x80) == 0) return i;
b = readByte();
i |= (b & 0x7FL) << 49;
if ((b & 0x80) == 0) return i;
b = readByte();
assert (b & 0x80) == 0;
return i | ((b & 0x7FL) << 56);
}
// COPIED from DataInputStream
public String readUTF() throws IOException {
int utflen = readInt();
if (utflen == 0) {
return "";
}
if (bytearr.length < utflen) {
bytearr = new byte[utflen * 2];
chararr = new char[utflen * 2];
}
char[] chararr = this.chararr;
byte[] bytearr = this.bytearr;
int c, char2, char3;
int count = 0;
int chararr_count = 0;
readBytes(bytearr, 0, utflen);
while (count < utflen) {
c = (int) bytearr[count] & 0xff;
if (c > 127) break;
count++;
chararr[chararr_count++] = (char) c;
}
while (count < utflen) {
c = (int) bytearr[count] & 0xff;
switch (c >> 4) {
case 0:
case 1:
case 2:
case 3:
case 4:
case 5:
case 6:
case 7:
/* 0xxxxxxx*/
count++;
chararr[chararr_count++] = (char) c;
break;
case 12:
case 13:
/* 110x xxxx 10xx xxxx*/
count += 2;
if (count > utflen)
throw new UTFDataFormatException(
"malformed input: partial character at end");
char2 = (int) bytearr[count - 1];
if ((char2 & 0xC0) != 0x80)
throw new UTFDataFormatException(
"malformed input around byte " + count);
chararr[chararr_count++] = (char) (((c & 0x1F) << 6) |
(char2 & 0x3F));
break;
case 14:
/* 1110 xxxx 10xx xxxx 10xx xxxx */
count += 3;
if (count > utflen)
throw new UTFDataFormatException(
"malformed input: partial character at end");
char2 = (int) bytearr[count - 2];
char3 = (int) bytearr[count - 1];
if (((char2 & 0xC0) != 0x80) || ((char3 & 0xC0) != 0x80))
throw new UTFDataFormatException(
"malformed input around byte " + (count - 1));
chararr[chararr_count++] = (char) (((c & 0x0F) << 12) |
((char2 & 0x3F) << 6) |
((char3 & 0x3F) << 0));
break;
default:
/* 10xx xxxx, 1111 xxxx */
throw new UTFDataFormatException(
"malformed input around byte " + count);
}
}
// The number of chars produced may be less than utflen
return new String(chararr, 0, chararr_count);
}
public final float readFloat() throws IOException {
return Float.intBitsToFloat(readInt());
}
public final double readDouble() throws IOException {
return Double.longBitsToDouble(readLong());
}
/**
* Reads a boolean.
*/
public final boolean readBoolean() throws IOException {
byte ch = readByte();
if (ch < 0)
throw new EOFException();
return (ch != 0);
}
/**
* Resets the stream.
*/
public abstract void reset() throws IOException;
/**
* Closes the stream to further operations.
*/
public abstract void close() throws IOException;
// // IS
//
// @Override public int read() throws IOException {
// return readByte();
// }
//
// // Here, we assume that we always can read the full byte array
//
// @Override public int read(byte[] b, int off, int len) throws IOException {
// readBytes(b, off, len);
// return len;
// }
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy