src.org.codehaus.jackson.io.MergedStream Maven / Gradle / Ivy
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World Wind is a collection of components that interactively display 3D geographic information within Java applications or applets.
package org.codehaus.jackson.io;
import java.io.*;
/**
* Simple {@link InputStream} implementation that is used to "unwind" some
* data previously read from an input stream; so that as long as some of
* that data remains, it's returned; but as long as it's read, we'll
* just use data from the underlying original stream.
* This is similar to {@link java.io.PushbackInputStream}, but here there's
* only one implicit pushback, when instance is constructed.
*/
public final class MergedStream
extends InputStream
{
final protected IOContext _context;
final InputStream _in;
byte[] _buffer;
int _ptr;
final int _end;
public MergedStream(IOContext context,
InputStream in, byte[] buf, int start, int end)
{
_context = context;
_in = in;
_buffer = buf;
_ptr = start;
_end = end;
}
public int available()
throws IOException
{
if (_buffer != null) {
return _end - _ptr;
}
return _in.available();
}
public void close()
throws IOException
{
freeMergedBuffer();
_in.close();
}
public void mark(int readlimit)
{
if (_buffer == null) {
_in.mark(readlimit);
}
}
public boolean markSupported()
{
// Only supports marks past the initial rewindable section...
return (_buffer == null) && _in.markSupported();
}
public int read()
throws IOException
{
if (_buffer != null) {
int c = _buffer[_ptr++] & 0xFF;
if (_ptr >= _end) {
freeMergedBuffer();
}
return c;
}
return _in.read();
}
public int read(byte[] b)
throws IOException
{
return read(b, 0, b.length);
}
public int read(byte[] b, int off, int len)
throws IOException
{
if (_buffer != null) {
int avail = _end - _ptr;
if (len > avail) {
len = avail;
}
System.arraycopy(_buffer, _ptr, b, off, len);
_ptr += len;
if (_ptr >= _end) {
freeMergedBuffer();
}
return len;
}
return _in.read(b, off, len);
}
public void reset()
throws IOException
{
if (_buffer == null) {
_in.reset();
}
}
public long skip(long n)
throws IOException
{
long count = 0L;
if (_buffer != null) {
int amount = _end - _ptr;
if (amount > n) { // all in pushed back segment?
_ptr += (int) n;
return n;
}
freeMergedBuffer();
count += amount;
n -= amount;
}
if (n > 0) {
count += _in.skip(n);
}
return count;
}
private void freeMergedBuffer()
{
byte[] buf = _buffer;
if (buf != null) {
_buffer = null;
_context.releaseReadIOBuffer(buf);
}
}
}