/*
* 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
* trunk/opends/resource/legal-notices/OpenDS.LICENSE
* or https://OpenDS.dev.java.net/OpenDS.LICENSE.
* 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
* trunk/opends/resource/legal-notices/OpenDS.LICENSE. 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 2008 Sun Microsystems, Inc.
*/
package org.opends.server.protocols.internal;
import java.io.IOException;
import java.io.InputStream;
import java.util.concurrent.ArrayBlockingQueue;
import org.opends.server.protocols.asn1.ASN1;
import org.opends.server.protocols.asn1.ASN1Writer;
import org.opends.server.protocols.ldap.LDAPMessage;
import org.opends.server.types.ByteSequenceReader;
import org.opends.server.types.ByteStringBuilder;
/**
* This class provides an implementation of a
* {@code java.io.InputStream} that can be used to facilitate internal
* communication with the Directory Server. On the backend, this
* input stream will be populated by ASN.1 elements encoded from LDAP
* messages created from internal operation responses.
*/
@org.opends.server.types.PublicAPI(
stability=org.opends.server.types.StabilityLevel.UNCOMMITTED,
mayInstantiate=false,
mayExtend=false,
mayInvoke=true)
public final class InternalLDAPInputStream
extends InputStream
{
// The queue of LDAP messages providing the data to be made
// available to the client.
private final ArrayBlockingQueue<LDAPMessage> messageQueue;
// Indicates whether this stream has been closed.
private boolean closed;
// The byte buffer with partial data to be written to the client.
private final ByteStringBuilder messageBuffer;
// The byte buffer reader.
private final ByteSequenceReader messageReader;
// The byte buffer writer.
private final ASN1Writer writer;
// The internal LDAP socket serviced by this input stream.
private final InternalLDAPSocket socket;
/**
* Creates a new internal LDAP input stream that will service the
* provided internal LDAP socket.
*
* @param socket The internal LDAP socket serviced by this
* internal LDAP input stream.
*/
public InternalLDAPInputStream(InternalLDAPSocket socket)
{
this.socket = socket;
this.messageQueue = new ArrayBlockingQueue<LDAPMessage>(10);
this.messageBuffer = new ByteStringBuilder();
this.messageReader = messageBuffer.asReader();
this.writer = ASN1.getWriter(messageBuffer);
this.closed = false;
}
/**
* Adds the provided LDAP message to the set of messages to be
* returned to the client. Note that this may block if there is
* already a significant backlog of messages to be returned.
*
* @param message The message to add to the set of messages to be
* returned to the client.
*/
@org.opends.server.types.PublicAPI(
stability=org.opends.server.types.StabilityLevel.PRIVATE,
mayInstantiate=false,
mayExtend=false,
mayInvoke=false)
void addLDAPMessage(LDAPMessage message)
{
// If the stream is closed, then simply drop the message.
if (closed)
{
return;
}
try
{
messageQueue.put(message);
return;
}
catch (Exception e)
{
// This shouldn't happen, but if it does then try three more
// times before giving up and dropping the message.
for (int i=0; i < 3; i++)
{
try
{
messageQueue.put(message);
break;
} catch (Exception e2) {}
}
return;
}
}
/**
* Retrieves the number of bytes that can be read (or skipped over)
* from this input stream without blocking.
*
* @return The number of bytes that can be read (or skipped over)
* from this input stream wihtout blocking.
* @throws IOException if an I/O error occurs.
*/
@Override()
public synchronized int available() throws IOException
{
if (messageReader.remaining() < 1)
{
LDAPMessage message = messageQueue.poll();
if ((message == null) || (message instanceof NullLDAPMessage))
{
if (message != null)
{
messageQueue.clear();
closed = true;
}
return 0;
}
else
{
messageBuffer.clear();
messageReader.rewind();
message.write(writer);
}
}
return messageReader.remaining();
}
/**
* Closes this input stream. This will add a special marker
* element to the message queue indicating that the end of the
* stream has been reached. If the queue is full, thenit will be
* cleared before adding the marker element.
*/
@Override()
public void close()
{
socket.close();
}
/**
* Closes this input stream through an internal mechanism that will
* not cause an infinite recursion loop by trying to also close the
* input stream.
*/
@org.opends.server.types.PublicAPI(
stability=org.opends.server.types.StabilityLevel.PRIVATE,
mayInstantiate=false,
mayExtend=false,
mayInvoke=false)
void closeInternal()
{
if (closed)
{
return;
}
closed = true;
NullLDAPMessage nullMessage = new NullLDAPMessage();
while (! messageQueue.offer(nullMessage))
{
messageQueue.clear();
}
}
/**
* Marks the current position in the input stream. This will not
* have any effect, as this input stream inplementation does not
* support marking.
*
* @param readLimit The maximum limit of bytes that can be read
* before the mark position becomes invalid.
*/
@Override()
public void mark(int readLimit)
{
// No implementation is required.
}
/**
* Indicates whether this input stream inplementation supports the
* use of the {@code mark} and {@code reset} methods. This
* implementation does not support that functionality.
*
* @return {@code false} because this implementation does not
* support the use of the {@code mark} and {@code reset}
* methods.
*/
@Override()
public boolean markSupported()
{
return false;
}
/**
* Reads the next byte of data from the input stream, blocking if
* necessary until there is data available.
*
* @return The next byte of data read from the input stream, or -1
* if the end of the input stream has been reached.
*
* @throws IOException If a problem occurs while trying to read
* data from the stream.
*/
@Override()
public synchronized int read()
throws IOException
{
if (messageReader.remaining() < 1)
{
LDAPMessage message;
try
{
message = messageQueue.take();
}
catch(InterruptedException ie)
{
// Probably because a shutdown was started. EOF
message = new NullLDAPMessage();
}
if ((message == null) || (message instanceof NullLDAPMessage))
{
if (message instanceof NullLDAPMessage)
{
messageQueue.clear();
closed = true;
return -1;
}
return 0;
}
else
{
messageBuffer.clear();
messageReader.rewind();
message.write(writer);
}
}
return (0xFF & messageReader.get());
}
/**
* Reads some number of bytes from the input stream, blocking if
* necessary until there is data available, and adds them to the
* provided array starting at position 0.
*
* @param b The array to which the data is to be written.
*
* @return The number of bytes actually written into the
* provided array, or -1 if the end of the stream has been
* reached.
*
* @throws IOException If a problem occurs while trying to read
* data from the stream.
*/
@Override()
public int read(byte[] b)
throws IOException
{
return read(b, 0, b.length);
}
/**
* Reads some number of bytes from the input stream, blocking if
* necessary until there is data available, and adds them to the
* provided array starting at the specified position.
*
* @param b The array to which the data is to be written.
* @param off The offset in the array at which to start writing
* data.
* @param len The maximum number of bytes that may be added to the
* array.
*
* @return The number of bytes actually written into the
* provided array, or -1 if the end of the stream has been
* reached.
*
* @throws IOException If a problem occurs while trying to read
* data from the stream.
*/
@Override()
public synchronized int read(byte[] b, int off, int len)
throws IOException
{
if (messageReader.remaining() < 1)
{
LDAPMessage message;
try
{
message = messageQueue.take();
}
catch(InterruptedException ie)
{
// Probably because a shutdown was started. EOF
message = new NullLDAPMessage();
}
if ((message == null) || (message instanceof NullLDAPMessage))
{
if (message instanceof NullLDAPMessage)
{
messageQueue.clear();
closed = true;
return -1;
}
return 0;
}
else
{
messageBuffer.clear();
messageReader.rewind();
message.write(writer);
}
}
int actualLen = Math.min(len, messageReader.remaining());
messageReader.get(b, off, actualLen);
return actualLen;
}
/**
* Repositions this stream to the position at the time that the
* {@code mark} method was called on this stream. This will not
* have any effect, as this input stream inplementation does not
* support marking.
*/
@Override()
public void reset()
{
// No implementation is required.
}
/**
* Skips over and discards up to the specified number of bytes of
* data from this input stream. This implementation will always
* skip the requested number of bytes unless the end of the stream
* is reached.
*
* @param n The maximum number of bytes to skip.
*
* @return The number of bytes actually skipped.
*
* @throws IOException If a problem occurs while trying to read
* data from the input stream.
*/
@Override()
public synchronized long skip(long n)
throws IOException
{
byte[] b;
if (n > 8192)
{
b = new byte[8192];
}
else
{
b = new byte[(int) n];
}
long totalBytesRead = 0L;
while (totalBytesRead < n)
{
int maxLen = (int) Math.min((n - totalBytesRead), b.length);
int bytesRead = read(b, 0, maxLen);
if (bytesRead < 0)
{
if (totalBytesRead > 0)
{
return totalBytesRead;
}
else
{
return bytesRead;
}
}
else
{
totalBytesRead += bytesRead;
}
}
return totalBytesRead;
}
/**
* Retrieves a string representation of this internal LDAP socket.
*
* @return A string representation of this internal LDAP socket.
*/
@Override()
public String toString()
{
return "InternalLDAPInputStream";
}
}