sun.net.httpserver.LeftOverInputStream Maven / Gradle / Ivy
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/*
* @(#)LeftOverInputStream.java 1.6 07/03/14
*
* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package sun.net.httpserver;
import java.io.*;
import com.sun.net.httpserver.*;
import com.sun.net.httpserver.spi.*;
/**
* a (filter) input stream which can tell us if bytes are "left over"
* on the underlying stream which can be read (without blocking)
* on another instance of this class.
*
* The class can also report if all bytes "expected" to be read
* were read, by the time close() was called. In that case,
* bytes may be drained to consume them (by calling drain() ).
*
* isEOF() returns true, when all expected bytes have been read
*/
abstract class LeftOverInputStream extends FilterInputStream {
ExchangeImpl t;
ServerImpl server;
protected boolean closed = false;
protected boolean eof = false;
byte[] one = new byte [1];
public LeftOverInputStream (ExchangeImpl t, InputStream src) {
super (src);
this.t = t;
this.server = t.getServerImpl();
}
/**
* if bytes are left over buffered on *the UNDERLYING* stream
*/
public boolean isDataBuffered () throws IOException {
assert eof;
return super.available() > 0;
}
public void close () throws IOException {
if (closed) {
return;
}
closed = true;
if (!eof) {
eof = drain (ServerConfig.getDrainAmount());
}
}
public boolean isClosed () {
return closed;
}
public boolean isEOF () {
return eof;
}
protected abstract int readImpl (byte[]b, int off, int len) throws IOException;
public synchronized int read () throws IOException {
if (closed) {
throw new IOException ("Stream is closed");
}
int c = readImpl (one, 0, 1);
if (c == -1 || c == 0) {
return c;
} else {
return one[0] & 0xFF;
}
}
public synchronized int read (byte[]b, int off, int len) throws IOException {
if (closed) {
throw new IOException ("Stream is closed");
}
return readImpl (b, off, len);
}
/**
* read and discard up to l bytes or "eof" occurs,
* (whichever is first). Then return true if the stream
* is at eof (ie. all bytes were read) or false if not
* (still bytes to be read)
*/
public boolean drain (long l) throws IOException {
int bufSize = 2048;
byte[] db = new byte [bufSize];
while (l > 0) {
long len = readImpl (db, 0, bufSize);
if (len == -1) {
eof = true;
return true;
} else {
l = l - len;
}
}
return false;
}
}