org.jgroups.util.ByteArrayDataInputStream Maven / Gradle / Ivy
package org.jgroups.util;
import java.io.*;
/**
* Implements {@link java.io.DataInput} over a byte[] buffer. This class is not thread safe.
* @author Bela Ban
* @since 3.5
*/
public class ByteArrayDataInputStream implements DataInput {
protected final byte[] buf;
protected int pos; // current position to read next byte from buf
// index of last byte to be read, reading beyond will return -1 or throw EOFException. Limit has to be < buf.length
protected final int limit;
public ByteArrayDataInputStream(byte[] buf) {
this(buf, 0, buf != null? buf.length : 0);
}
public ByteArrayDataInputStream(byte[] buf, int offset, int length) {
this.buf=buf;
this.limit=Math.min(buf.length, offset+length);
this.pos=checkBounds(offset);
}
public ByteArrayDataInputStream position(int pos) {
this.pos=checkBounds(pos); return this;
}
public int position() {return pos;}
public int limit() {return limit;}
public int capacity() {return buf.length;}
/**
* Reads the next byte of data from buf. The value byte is returned as an int in the range
* 0 to 255. If no byte is available because the end of the buffer has been reached,
* the value -1 is returned.
* @return the next byte of data, or -1 if the end of the stream has been reached.
*/
public int read() {
return (pos < limit) ? (buf[pos++] & 0xff) : -1;
}
public int read(byte b[], int off, int len) {
if (b == null)
throw new NullPointerException();
if(off < 0 || len < 0 || len > b.length - off)
throw new IndexOutOfBoundsException();
if(pos >= limit)
return -1;
int avail=limit - pos;
if(len > avail)
len=avail;
if(len <= 0)
return 0;
System.arraycopy(buf, pos, b, off, len);
pos += len;
return len;
}
public void readFully(byte[] b) throws IOException {
readFully(b, 0, b.length);
}
public void readFully(byte[] b, int off, int len) throws IOException {
if (len < 0)
throw new IndexOutOfBoundsException();
int n = 0;
while (n < len) {
int count=read(b, off + n, len - n);
if (count < 0)
throw new EOFException();
n += count;
}
}
public int skipBytes(int n) {
int k = limit - pos;
if (n < k)
k = n < 0 ? 0 : n;
pos += k;
return k;
}
public boolean readBoolean() throws IOException {
int ch=read();
if(ch < 0)
throw new EOFException();
return ch != 0;
}
public byte readByte() throws IOException {
int ch=read();
if (ch < 0)
throw new EOFException();
return (byte)(ch);
}
public int readUnsignedByte() throws IOException {
int ch=read();
if (ch < 0)
throw new EOFException();
return ch;
}
public short readShort() throws IOException {
int ch1=read();
int ch2=read();
if ((ch1 | ch2) < 0)
throw new EOFException();
return (short)((ch1 << 8) + (ch2 << 0));
}
public int readUnsignedShort() throws IOException {
int ch1=read();
int ch2=read();
if ((ch1 | ch2) < 0)
throw new EOFException();
return (ch1 << 8) + (ch2 << 0);
}
public char readChar() throws IOException {
int ch1=read();
int ch2=read();
if ((ch1 | ch2) < 0)
throw new EOFException();
return (char)((ch1 << 8) + (ch2 << 0));
}
public int readInt() throws IOException {
int ch1=read();
int ch2=read();
int ch3=read();
int ch4=read();
if ((ch1 | ch2 | ch3 | ch4) < 0)
throw new EOFException();
return ((ch1 << 24) + (ch2 << 16) + (ch3 << 8) + (ch4 << 0));
}
public long readLong() throws IOException {
return (((long)read() << 56) +
((long)(read() & 0xff) << 48) +
((long)(read() & 0xff) << 40) +
((long)(read() & 0xff) << 32) +
((long)(read() & 0xff) << 24) +
((read() & 0xff) << 16) +
((read() & 0xff) << 8) +
((read() & 0xff) << 0));
}
public float readFloat() throws IOException {
return Float.intBitsToFloat(readInt());
}
public double readDouble() throws IOException {
return Double.longBitsToDouble(readLong());
}
public String readLine() throws IOException {
StringBuilder sb=new StringBuilder(35);
int ch;
while(true) {
ch=read();
if(ch == -1)
return sb.length() == 0? null : sb.toString();
if(ch == '\r')
;
else {
if(ch == '\n')
break;
sb.append((char)ch);
}
}
return sb.toString();
}
public String readUTF() throws IOException {
int utflen=readUnsignedShort();
byte[] bytearr=new byte[utflen];
char[] chararr=new char[utflen];
if(((short)utflen) == -1)
return null;
int c, char2, char3;
int count = 0;
int chararr_count=0;
readFully(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 String toString() {
return "pos=" + pos + " lim=" + limit + " cap=" + buf.length;
}
protected int checkBounds(int pos) {
if(pos < 0 || pos >= limit)
throw new IndexOutOfBoundsException("pos=" + pos + ", limit=" + limit);
return pos;
}
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy