/*
|
* CDDL HEADER START
|
*
|
* The contents of this file are subject to the terms of the
|
* Common Development and Distribution License, Version 1.0 only
|
* (the "License"). You may not use this file except in compliance
|
* with the License.
|
*
|
* You can obtain a copy of the license at legal-notices/CDDLv1_0.txt
|
* or http://forgerock.org/license/CDDLv1.0.html.
|
* See the License for the specific language governing permissions
|
* and limitations under the License.
|
*
|
* When distributing Covered Code, include this CDDL HEADER in each
|
* file and include the License file at legal-notices/CDDLv1_0.txt.
|
* If applicable, add the following below this CDDL HEADER, with the
|
* fields enclosed by brackets "[]" replaced with your own identifying
|
* information:
|
* Portions Copyright [yyyy] [name of copyright owner]
|
*
|
* CDDL HEADER END
|
*
|
*
|
* Copyright 2006-2009 Sun Microsystems, Inc.
|
* Portions Copyright 2011-2015 ForgeRock AS.
|
*/
|
package org.opends.server.protocols.ldap;
|
|
import java.io.IOException;
|
import java.io.InputStream;
|
import java.nio.ByteBuffer;
|
import java.nio.channels.IllegalBlockingModeException;
|
import java.nio.channels.ReadableByteChannel;
|
|
import org.forgerock.opendj.io.ASN1;
|
import org.forgerock.opendj.io.ASN1Reader;
|
import org.forgerock.opendj.ldap.ByteSequenceReader;
|
import org.forgerock.opendj.ldap.ByteString;
|
import org.forgerock.opendj.ldap.ByteStringBuilder;
|
import org.forgerock.opendj.ldap.DecodeException;
|
|
/**
|
* This class is for reading ASN.1 elements from a readable byte
|
* channel. It will handle all partial element reads from the channel
|
* and save any unread ASN.1 elements if required. All data read from
|
* the channel will be ready to be read as ASN.1 elements no matter
|
* how many times the channel is read. However, to minimize the the
|
* amount of memory used by this reader, the client should read ASN.1
|
* elements as soon as they are read off the channel.
|
* <p>
|
* {@code ASN1ByteChannelReader}s are created using the factory
|
* methods in {@link ASN1}.
|
* <p>
|
* The client should use this class in the following manner:
|
*<p>
|
* When NIO signals new data is available in the channel, the client
|
* should call {@link #processChannelData()}.
|
*<p>
|
* If bytes are read from the channel, the client should call
|
* {@link #elementAvailable()} to see if a complete element is ready to
|
* be read. However, if no data is actually read, the client should
|
* wait for the next signal and try again.
|
* <p>
|
* As long as a complete element is ready, the client should read the
|
* appropriate ASN.1 element(s). Once no more complete elements are
|
* available, the client should call {@link #processChannelData()}
|
* again to read more data (if available).
|
* <p>
|
* <b>NOTE:</b> Since this reader is non blocking, reading ASN.1
|
* elements before making sure they are ready could result in
|
* {@link IllegalBlockingModeException}s being thrown while reading
|
* ASN.1 elements. Once an exception is thrown, the state of the reader
|
* is no longer stable and can not be used again.
|
*/
|
final class ASN1ByteChannelReader implements ASN1Reader
|
{
|
/** The byte channel to read from. */
|
private final ReadableByteChannel byteChannel;
|
|
/** The wrapped ASN.1 reader. */
|
private final ASN1Reader reader;
|
|
/**
|
* The NIO ByteStringBuilder that stores any immediate data read off the
|
* channel.
|
*/
|
private final ByteBuffer byteBuffer;
|
|
/**
|
* The save buffer used to store any unprocessed data waiting to be read as
|
* ASN.1 elements. (Usually due to reading incomplete elements from the
|
* channel).
|
*/
|
private final ByteStringBuilder saveBuffer;
|
|
/** The save buffer reader. */
|
private final ByteSequenceReader saveBufferReader;
|
|
/**
|
* An adaptor class for reading from a save buffer and the NIO byte buffer
|
* sequentially using the InputStream interface.
|
*
|
* Since the NIO byte buffer is re-used when reading off the channel, any
|
* unused data will be appended to the save buffer before reading off the
|
* channel again. This reader will always read the save buffer first before
|
* the actual NIO byte buffer to ensure bytes are read in the same order
|
* as they are received.
|
*
|
* The read methods of this stream will throw an IllegalBlockingModeException
|
* if invoked when there are no data to read from the save buffer or the
|
* channel buffer.
|
*
|
* The stream will not support the mark or reset methods.
|
*/
|
private final class CombinedBufferInputStream extends InputStream
|
{
|
/** {@inheritDoc} */
|
@Override
|
public int available()
|
{
|
// The number of available bytes is the sum of the save buffer
|
// and the last read data in the NIO ByteStringBuilder.
|
return saveBufferReader.remaining() + byteBuffer.remaining();
|
}
|
|
/**
|
* Reads the next byte of data from the save buffer or channel buffer.
|
* The value byte is returned as an int in the range 0 to 255.
|
* If no byte is available in the save buffer or channel buffer,
|
* IllegalBlockingModeException will be thrown.
|
*
|
* @return the next byte of data.
|
* @throws IllegalBlockingModeException if there are more bytes available.
|
*/
|
@Override
|
public int read()
|
{
|
if(saveBufferReader.remaining() > 0)
|
{
|
// Try saved buffer first
|
return 0xFF & saveBufferReader.get();
|
}
|
if(byteBuffer.remaining() > 0)
|
{
|
// Must still be on the channel buffer
|
return 0xFF & byteBuffer.get();
|
}
|
|
throw new IllegalBlockingModeException();
|
}
|
|
/**
|
* Reads up to len bytes of data from the save buffer or channel buffer
|
* into an array of bytes. An attempt is made to read as many as len bytes,
|
* but a smaller number may be read. The number of bytes actually read is
|
* returned as an integer.
|
*
|
* If b is null, a NullPointerException is thrown.
|
*
|
* If the length of b is zero, then no bytes are read and 0 is returned;
|
* otherwise, there is an attempt to read at least one byte. If no byte is
|
* available in the save buffer or channel buffer,
|
* IllegalBlockingModeException will be thrown; otherwise, at least one
|
* byte is read and stored into b.
|
*
|
* The first byte read is stored into element b[0], the next one into
|
* b[o1], and so on. The number of bytes read is, at most, equal to the
|
* length of b. Let k be the number of bytes actually read; these bytes
|
* will be stored in elements b[0] through b[k-1], leaving elements b[k]
|
* through b[b.length-1] unaffected.
|
*
|
* @return the total number of bytes read into the buffer.
|
* @throws IllegalBlockingModeException if there are more bytes available.
|
*/
|
@Override
|
public int read(byte[] b)
|
{
|
return read(b, 0, b.length);
|
}
|
|
/**
|
* Reads up to len bytes of data from the save buffer or channel buffer
|
* into an array of bytes. An attempt is made to read as many as len bytes,
|
* but a smaller number may be read. The number of bytes actually read is
|
* returned as an integer.
|
*
|
* If b is null, a NullPointerException is thrown.
|
*
|
* If off is negative, or len is negative, or off+len is greater than the
|
* length of the array b, then an IndexOutOfBoundsException is thrown.
|
*
|
* If len is zero, then no bytes are read and 0 is returned; otherwise,
|
* there is an attempt to read at least one byte. If no byte is available
|
* in the save buffer or channel buffer, IllegalBlockingModeException will
|
* be thrown; otherwise, at least one byte is read and stored into b.
|
*
|
* The first byte read is stored into element b[off], the next one into
|
* b[off+1], and so on. The number of bytes read is, at most, equal to len.
|
* Let k be the number of bytes actually read; these bytes will be stored
|
* in elements b[off] through b[off+k-1], leaving elements b[off+k]
|
* through b[off+len-1] unaffected.
|
*
|
* In every case, elements b[0] through b[off] and elements b[off+len]
|
* through b[b.length-1] are unaffected.
|
*
|
* @return the total number of bytes read into the buffer.
|
* @throws IllegalBlockingModeException if there are more bytes available.
|
*/
|
@Override
|
public int read(byte[] b, int off, int len)
|
{
|
if (off < 0 || len < 0 || off + len > b.length)
|
{
|
throw new IndexOutOfBoundsException();
|
}
|
|
if(len == 0)
|
{
|
return 0;
|
}
|
|
int bytesCopied=0;
|
int getLen;
|
if(saveBufferReader.remaining() > 0)
|
{
|
// Copy out of the last saved buffer first
|
getLen = Math.min(saveBufferReader.remaining(), len);
|
saveBufferReader.get(b, off, getLen);
|
bytesCopied += getLen;
|
}
|
if(bytesCopied < len && byteBuffer.remaining() > 0)
|
{
|
// Copy out of the channel buffer if we haven't got
|
// everything we needed.
|
getLen = Math.min(byteBuffer.remaining(), len - bytesCopied);
|
byteBuffer.get(b, off + bytesCopied, getLen);
|
bytesCopied += getLen;
|
}
|
if(bytesCopied < len)
|
{
|
throw new IllegalBlockingModeException();
|
}
|
|
return bytesCopied;
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public long skip(long length)
|
{
|
int bytesSkipped=0;
|
int len;
|
if(saveBufferReader.remaining() > 0)
|
{
|
// Skip in the last saved buffer first
|
len = Math.min(saveBufferReader.remaining(), (int)length);
|
saveBufferReader.position(saveBufferReader.position() + len);
|
bytesSkipped += len;
|
}
|
if(bytesSkipped < length && byteBuffer.remaining() > 0)
|
{
|
//Skip in the channel buffer if we haven't skipped enough.
|
len = Math.min(byteBuffer.remaining(), (int)length - bytesSkipped);
|
byteBuffer.position(byteBuffer.position() + len);
|
bytesSkipped += len;
|
}
|
if(bytesSkipped < length)
|
{
|
throw new IllegalBlockingModeException();
|
}
|
|
return bytesSkipped;
|
}
|
}
|
|
/**
|
* Creates a new ASN.1 byte channel reader whose source is the
|
* provided readable byte channel, having a user defined buffer
|
* size, and user defined maximum BER element size.
|
*
|
* @param channel
|
* The readable byte channel to use.
|
* @param bufferSize
|
* The buffer size to use when reading from the channel.
|
* @param maxElementSize
|
* The max ASN.1 element size this reader will read.
|
*/
|
ASN1ByteChannelReader(ReadableByteChannel channel, int bufferSize,
|
int maxElementSize)
|
{
|
this.byteChannel = channel;
|
this.byteBuffer = ByteBuffer.allocate(bufferSize);
|
this.byteBuffer.flip();
|
this.saveBuffer = new ByteStringBuilder();
|
this.saveBufferReader = saveBuffer.asReader();
|
|
CombinedBufferInputStream bufferStream = new CombinedBufferInputStream();
|
this.reader = ASN1.getReader(bufferStream, maxElementSize);
|
}
|
|
/**
|
* Process any new data on the channel so they can be read as ASN.1
|
* elements. This method should only be called when there are no
|
* more complete elements in the reader. Calling this method when
|
* there are complete elements still in the reader will result in
|
* unnecessary memory allocations to store any unread data. This
|
* method will perform the following operations:
|
* <ul>
|
* <li>Clear the save buffer if everything was read.
|
* <li>Append any unread data from the NIO byte buffer to the save
|
* buffer.
|
* <li>Clear the NIO byte buffer and read from the channel.
|
* </ul>
|
*
|
* @return The number of bytes read from the channel or -1 if
|
* channel is closed.
|
* @throws IOException
|
* If an exception occurs while reading from the channel.
|
*/
|
public int processChannelData() throws IOException
|
{
|
// Clear the save buffer if we have read all of it
|
if (saveBufferReader.remaining() == 0)
|
{
|
saveBuffer.clear();
|
saveBufferReader.rewind();
|
}
|
|
// Append any unused data in the channel buffer to the save buffer
|
if (byteBuffer.remaining() > 0)
|
{
|
saveBuffer.appendBytes(byteBuffer, byteBuffer.remaining());
|
}
|
|
byteBuffer.clear();
|
try
|
{
|
return byteChannel.read(byteBuffer);
|
}
|
finally
|
{
|
// Make sure that the buffer is flipped even if the read fails in order to
|
// ensure that subsequent calls which query the remaining data return
|
// valid results.
|
byteBuffer.flip();
|
}
|
}
|
|
/**
|
* Determines if a complete ASN.1 element is ready to be read from
|
* channel.
|
*
|
* @return <code>true</code> if another complete element is available or
|
* <code>false</code> otherwise.
|
* @throws IOException If an error occurs while trying to decode
|
* an ASN1 element.
|
*/
|
@Override
|
public boolean elementAvailable() throws IOException
|
{
|
return reader.elementAvailable();
|
}
|
|
/**
|
* Determines if the channel contains at least one ASN.1 element to be read.
|
*
|
* @return <code>true</code> if another element is available or
|
* <code>false</code> otherwise.
|
* @throws IOException If an error occurs while trying to decode
|
* an ASN1 element.
|
*/
|
@Override
|
public boolean hasNextElement() throws IOException {
|
return reader.hasNextElement();
|
}
|
|
/**
|
* Returns {@code true} if this ASN.1 reader contains unread data.
|
*
|
* @return {@code true} if this ASN.1 reader contains unread data.
|
*/
|
public boolean hasRemainingData()
|
{
|
return saveBufferReader.remaining() != 0 || byteBuffer.remaining() != 0;
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public int peekLength() throws IOException {
|
return reader.peekLength();
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public byte peekType() throws IOException {
|
return reader.peekType();
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public boolean readBoolean() throws IOException {
|
return reader.readBoolean();
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public boolean readBoolean(byte type) throws IOException {
|
return reader.readBoolean(type);
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public void readEndExplicitTag() throws IOException {
|
reader.readEndExplicitTag();
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public void readEndSequence() throws IOException {
|
reader.readEndSequence();
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public void readEndSet() throws IOException {
|
reader.readEndSet();
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public int readEnumerated() throws IOException {
|
return reader.readEnumerated();
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public int readEnumerated(byte type) throws IOException {
|
return reader.readEnumerated(type);
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public long readInteger() throws IOException {
|
return reader.readInteger();
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public long readInteger(byte type) throws IOException {
|
return reader.readInteger(type);
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public void readNull() throws IOException {
|
reader.readNull();
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public void readNull(byte type) throws IOException {
|
reader.readNull(type);
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public ByteString readOctetString() throws IOException {
|
return reader.readOctetString();
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public ByteString readOctetString(byte type) throws IOException {
|
return readOctetString(type);
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public ByteStringBuilder readOctetString(ByteStringBuilder buffer) throws IOException {
|
return reader.readOctetString(buffer);
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public ByteStringBuilder readOctetString(byte type, ByteStringBuilder builder) throws IOException {
|
return readOctetString(type, builder);
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public String readOctetStringAsString() throws IOException {
|
return reader.readOctetStringAsString();
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public String readOctetStringAsString(byte type) throws IOException {
|
return readOctetStringAsString(type);
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public void readStartExplicitTag() throws IOException {
|
reader.readStartExplicitTag();
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public void readStartExplicitTag(byte type) throws IOException {
|
reader.readStartExplicitTag(type);
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public void readStartSequence() throws IOException {
|
reader.readStartSequence();
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public void readStartSequence(byte type) throws IOException {
|
reader.readStartSequence(type);
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public void readStartSet() throws IOException {
|
reader.readStartSet();
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public void readStartSet(byte type) throws IOException {
|
reader.readStartSet(type);
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public void close() throws IOException {
|
reader.close();
|
byteChannel.close();
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public ASN1Reader skipElement() throws IOException {
|
reader.skipElement();
|
return this;
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public ASN1Reader skipElement(byte type) throws DecodeException, IOException
|
{
|
reader.skipElement(type);
|
return this;
|
}
|
}
|
