org.jgroups.util.PartialOutputStream Maven / Gradle / Ivy
Go to download
This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
The newest version!
package org.jgroups.util;
import java.io.DataOutput;
import java.io.IOException;
/**
* Decorates an output stream ({@link java.io.DataOutput}) and writes only a subset [start..end] (both indices
* inclusive) of the original data to the underlying output stream.
* Example: start=5, length=5: range=[5..9], bytes are written for positions 5,6,7,8,9 (5 bytes)
* @author Bela Ban
* @since 5.0
*/
public class PartialOutputStream extends BaseDataOutputStream {
protected final DataOutput out;
protected final int offset, end;
public PartialOutputStream(DataOutput out, int offset, int length) {
this.out=out;
this.offset=offset;
this.end=offset+length-1;
}
public void write(int b) {
if(pos > end) // greater than range
return;
if(pos < offset) // smaller than range
pos++;
else // in range
_write(b);
}
public void write(byte[] b, int off, int len) {
if(pos > end) // greater than range
return;
if(pos < offset) { // smaller than range
int bytess_to_skip=offset-pos;
if(bytess_to_skip >= len)
pos+=len;
else {
pos+=bytess_to_skip;
write(b, off + bytess_to_skip, len - bytess_to_skip);
}
}
else { // in range
int bytes_to_be_written=Math.min(len, remaining());
_write(b, off, bytes_to_be_written);
}
}
/** Number of bytes left to be written */
public int remaining() {
int start=Math.max(offset, pos);
return Math.max(0, end-start+1);
}
public String toString() {
return String.format("%s, range=[%d..%d] (remaining=%d) (%s)",
super.toString(), offset, end, remaining(), inRange()? "in range" : "outside range");
}
protected void ensureCapacity(int bytes) {
}
protected void _write(int b) {
try {
out.write(b);
}
catch(IOException e) {
throw new RuntimeException(e);
}
finally {
pos++;
}
}
protected void _write(byte[] b, int off, int len) {
try {
out.write(b, off, len);
}
catch(IOException e) {
throw new RuntimeException(e);
}
finally {
pos+=len;
}
}
/** Checks if pos is in range [offset..end] */
protected boolean inRange() {
return pos >= offset && pos <= end;
}
}