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/*
* Copyright (c) 2001-2007 Sun Microsystems, Inc. All rights reserved.
*
* The Sun Project JXTA(TM) Software License
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3. The end-user documentation included with the redistribution, if any, must
* include the following acknowledgment: "This product includes software
* developed by Sun Microsystems, Inc. for JXTA(TM) technology."
* Alternately, this acknowledgment may appear in the software itself, if
* and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA" must
* not be used to endorse or promote products derived from this software
* without prior written permission. For written permission, please contact
* Project JXTA at http://www.jxta.org.
*
* 5. Products derived from this software may not be called "JXTA", nor may
* "JXTA" appear in their name, without prior written permission of Sun.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SUN
* MICROSYSTEMS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
* OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* JXTA is a registered trademark of Sun Microsystems, Inc. in the United
* States and other countries.
*
* Please see the license information page at :
* for instructions on use of
* the license in source files.
*
* ====================================================================
*
* This software consists of voluntary contributions made by many individuals
* on behalf of Project JXTA. For more information on Project JXTA, please see
* http://www.jxta.org.
*
* This license is based on the BSD license adopted by the Apache Foundation.
*/
package net.jxta.endpoint;
import net.jxta.document.MimeMediaType;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.SequenceInputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.zip.CRC32;
import java.util.zip.Checksum;
/**
* A Message Element using {@link java.io.InputStream} as the source for the
* element data. This implementation copies all of the data from the stream at
* the time of creation.
*
* InputStreamMessageElement is not as efficient as other message element types
* and should only be used when an input stream is the only available source for
* the element data.
*/
public class InputStreamMessageElement extends MessageElement {
/**
* The bytes of this element.
*/
protected final List databytes;
/**
* The length of the data.
*/
protected final long length;
/**
* Cached Hash Code
*/
protected transient int cachedHashCode = 0;
/**
* Create a new MessageElement. This constructor copies the data as needed
* and closes the stream upon completion.
*
* @param name Name of the MessageElement. May be the empty string ("") if
* the MessageElement is not named.
* @param type Type of the MessageElement. null is the same as specifying
* the type "Application/Octet-stream".
* @param in the stream containing the body of the MessageElement. The
* stream will be closed by the MessageElement.
* @param sig optional message digest/digital signature element or null if
* no signature is desired.
* @throws IOException If there is a problem reading from the source stream.
*/
public InputStreamMessageElement(String name, MimeMediaType type, InputStream in, MessageElement sig) throws IOException {
this(name, type, in, Long.MAX_VALUE, sig);
}
/**
* Create a new Message Element.
*
* @param name Name of the MessageElement. May be the empty string ("") if
* the MessageElement is not named.
* @param type Type of the MessageElement. null is the same as specifying
* the type "Application/Octet-stream".
* @param in the stream containing the body of the MessageElement.
* The stream will NOT be closed unless EOF is unexpectedly reached.
* @param len The size of the Element will be limited to len bytes
* from the stream. If you are using the stream interface and know
* the size of the stream, specifying it here improves performance
* and space efficiency a lot. The stream must contain at least
* len bytes.
* @param sig optional message digest/digital signature element or null if
* no signature is desired.
* @throws IOException if there is a problem reading from the source stream
*/
public InputStreamMessageElement(String name, MimeMediaType type, InputStream in, long len, MessageElement sig) throws IOException {
super(name, type, sig);
if ((len < 0)) {
throw new IllegalArgumentException("len must be >= 0");
}
// copy the data from the stream
databytes = CopyToDataBytes(in, len);
// calculate the length
long buffersSum = 0;
for (byte[] aBuffer : databytes) {
buffersSum += aBuffer.length;
}
length = buffersSum;
// fail if the length is not as promised.
if ((len != Long.MAX_VALUE) && (len != length)) {
throw new IllegalArgumentException("Stream was shorter than promised length.");
}
}
/**
* {@inheritDoc}
*/
@Override
public boolean equals(Object target) {
if (this == target) {
return true;
}
if (target instanceof MessageElement) {
if (!super.equals(target)) {
return false;
}
if (target instanceof InputStreamMessageElement) {
// have to do a slow stream comparison.
// XXX 20020615 [email protected] the performance of this could be much improved.
MessageElement likeMe = (MessageElement) target;
try {
InputStream myStream = getStream();
InputStream itsStream = likeMe.getStream();
int mine;
int its;
do {
mine = myStream.read();
its = itsStream.read();
if (mine != its) {
return false;
} // content didn't match
} while ((-1 != mine) && (-1 != its));
return ((-1 == mine) && (-1 == its)); // end at the same time?
} catch (IOException fatal) {
throw new IllegalStateException("MessageElements could not be compared." + fatal);
}
}
}
return false; // not a new message element
}
/**
* {@inheritDoc}
*/
@Override
public synchronized int hashCode() {
if (0 == cachedHashCode) {
Checksum crc = new CRC32();
for (byte[] aBuffer : databytes) {
crc.update(aBuffer, 0, aBuffer.length);
}
int result = super.hashCode() + (int) crc.getValue() * 6037; // a prime
cachedHashCode = 0 != result ? result : 1;
}
return cachedHashCode;
}
/**
* {@inheritDoc}
*/
@Override
public long getByteLength() {
return length;
}
/**
* {@inheritDoc}
*/
public InputStream getStream() throws IOException {
List buffers = new ArrayList();
for (byte[] aBuffer : databytes) {
buffers.add(new ByteArrayInputStream(aBuffer));
}
return new SequenceInputStream(Collections.enumeration(buffers));
}
/**
* {@inheritDoc}
*/
@Override
public void sendToStream(OutputStream sendTo) throws IOException {
for (byte[] aBuffer : databytes) {
sendTo.write(aBuffer);
}
}
/**
* Copy data from a stream with best possible efficiency. Unfortunately,
* this still results in a lot of copying since we have often have no
* fore-knowledge of the length of the stream.
*
* @param in the stream to copy from
* @param limit the maximum number of bytes to copy from the stream.
* Long.LONG_MAX will read until EOF.
* @return A list of buffers.
* @throws IOException if there is a problem reading from the stream.
*/
protected List CopyToDataBytes(InputStream in, long limit) throws IOException {
final long INITIAL_INTERMEDIATE_BUFFERSIZE = 6;
final long MAXIMUM_INTERMEDIATE_BUFFERSIZE = 18;
List buffs = new ArrayList();
boolean atEOF = false;
long read = 0;
long currentIntermediateBufferSize = INITIAL_INTERMEDIATE_BUFFERSIZE;
// build a list of buffers containing all the element data.
do {
long readRequest = (limit - read);
if (Long.MAX_VALUE == limit) {
readRequest = Math.min(readRequest, (1L << currentIntermediateBufferSize));
}
readRequest = Math.min(readRequest, Integer.MAX_VALUE); // limited by size of arrays which are Integer indexed.
byte[] nextBuffer = new byte[(int) readRequest];
int offsetInThisBuffer = 0;
// fully read the buffer if we can.
do {
int readLength = in.read(nextBuffer, offsetInThisBuffer, nextBuffer.length - offsetInThisBuffer);
if (readLength == -1) {
atEOF = true;
break;
}
offsetInThisBuffer += readLength;
} while (offsetInThisBuffer < nextBuffer.length);
// handle the final buffer.
if (atEOF) {
byte[] anotherBuffer = new byte[offsetInThisBuffer];
System.arraycopy(nextBuffer, 0, anotherBuffer, 0, offsetInThisBuffer);
nextBuffer = anotherBuffer;
}
read += nextBuffer.length;
buffs.add(nextBuffer);
if (currentIntermediateBufferSize < MAXIMUM_INTERMEDIATE_BUFFERSIZE) {
currentIntermediateBufferSize++;
}
} while (!atEOF && (read < limit));
// we are done, close if we are at EOF.
if (atEOF) {
in.close();
in = null;
}
return buffs;
}
}
