/*
* Copyright (c) 1998-2011 Caucho Technology -- all rights reserved
*
* This file is part of Resin(R) Open Source
*
* Each copy or derived work must preserve the copyright notice and this
* notice unmodified.
*
* Resin Open Source is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* Resin Open Source is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
* of NON-INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with Resin Open Source; if not, write to the
*
* Free Software Foundation, Inc.
* 59 Temple Place, Suite 330
* Boston, MA 02111-1307 USA
*
* @author Scott Ferguson
*/
package com.caucho.vfs;
import java.io.IOException;
import java.util.logging.*;
import com.caucho.server.util.CauchoSystem;
import com.caucho.util.JniTroubleshoot;
/**
* Stream using with JNI.
*/
public class JniFileStream extends StreamImpl
implements LockableStream
{
private static final Logger log
= Logger.getLogger(JniFileStream.class.getName());
private static final JniTroubleshoot _jniTroubleshoot;
private int _fd;
private long _pos;
private boolean _canRead;
private boolean _canWrite;
/**
* Create a new JniStream based on the java.io.* stream.
*/
public JniFileStream(int fd, boolean canRead, boolean canWrite)
{
_jniTroubleshoot.checkIsValid();
init(fd, canRead, canWrite);
}
void init(int fd, boolean canRead, boolean canWrite)
{
_fd = fd;
_pos = 0;
_canRead = canRead;
_canWrite = canWrite;
}
public static boolean isEnabled()
{
return _jniTroubleshoot.isEnabled();
}
public static JniFileStream openRead(byte []name, int length)
{
int fd = nativeOpenRead(name, length);
if (fd >= 0)
return new JniFileStream(fd, true, false);
else
return null;
}
public static JniFileStream openWrite(byte []name,
int length,
boolean isAppend)
{
int fd = nativeOpenWrite(name, length, isAppend);
if (fd >= 0)
return new JniFileStream(fd, false, true);
else
return null;
}
public boolean canRead()
{
return _canRead && _fd >= 0;
}
public boolean hasSkip()
{
return _fd >= 0;
}
public long skip(long length)
throws IOException
{
long pos = nativeSkip(_fd, length);
if (pos < 0)
return -1;
else {
_pos = pos;
return length;
}
}
/**
* Reads data from the file.
*/
public int read(byte []buf, int offset, int length)
throws IOException
{
if (buf == null)
throw new NullPointerException();
else if (offset < 0 || buf.length < offset + length)
throw new ArrayIndexOutOfBoundsException();
int result = nativeRead(_fd, buf, offset, length);
if (result > 0)
_pos += result;
return result;
}
// XXX: needs update
public int getAvailable() throws IOException
{
if (_fd < 0) {
return -1;
}
else if (getPath() instanceof FilesystemPath) {
long length = getPath().getLength();
return (int) (length - _pos);
}
else
return nativeAvailable(_fd);
}
/**
* Returns true if this is a writeable stream.
*/
public boolean canWrite()
{
return _canWrite && _fd >= 0;
}
/**
* Writes data to the file.
*/
public void write(byte []buf, int offset, int length, boolean isEnd)
throws IOException
{
if (buf == null)
throw new NullPointerException();
else if (offset < 0 || buf.length < offset + length)
throw new ArrayIndexOutOfBoundsException();
nativeWrite(_fd, buf, offset, length);
}
public void seekStart(long offset)
throws IOException
{
nativeSeekStart(_fd, offset);
}
public void seekEnd(long offset)
throws IOException
{
nativeSeekEnd(_fd, offset);
}
public void flush()
throws IOException
{
}
public void flushToDisk()
throws IOException
{
nativeFlushToDisk(_fd);
}
public void close()
throws IOException
{
int fd;
synchronized (this) {
fd = _fd;
_fd = -1;
}
nativeClose(fd);
}
protected void finalize()
throws IOException
{
close();
}
/**
* Native interface to read bytes from the input.
*/
native int nativeRead(int fd, byte []buf, int offset, int length)
throws IOException;
/**
* Native interface to read bytes from the input.
*/
native int nativeAvailable(int fd)
throws IOException;
/**
* Native to open a file for reading
*/
private static native int nativeOpenRead(byte []name, int length);
/**
* Native to open a file for writing
*/
private static native int nativeOpenWrite(byte []name, int length,
boolean isAppend);
/*
private static native void nativeChown(byte []path, int length,
String user, String group);
*/
/**
* Native interface to write bytes to the file
*/
native int nativeWrite(int fd, byte []buf, int offset, int length)
throws IOException;
/**
* Native interface to skip bytes from the input.
*/
native long nativeSkip(int fd, long skip)
throws IOException;
/**
* Native interface to force data to the disk
*/
native int nativeFlushToDisk(int fd)
throws IOException;
/**
* Native interface to read bytes from the input.
*/
static native int nativeClose(int fd)
throws IOException;
/**
* Native interface to seek from the beginning
*/
native int nativeSeekStart(int fd, long offset)
throws IOException;
/**
* Native interface to seek from the beginning
*/
native int nativeSeekEnd(int fd, long offset)
throws IOException;
/**
* Implement LockableStream as a no-op, but maintain
* compatibility with FileWriteStream and FileReadStream
* wrt returning false to indicate error case.
*/
public boolean lock(boolean shared, boolean block)
{
if (shared && !_canRead) {
// Invalid request for a shared "read" lock on a write only stream.
return false;
}
if (!shared && !_canWrite) {
// Invalid request for an exclusive "write" lock on a read only stream.
return false;
}
return true;
}
public boolean unlock()
{
return true;
}
/**
* Returns the debug name for the stream.
*/
public String toString()
{
return "JniFileStream[" + getPath().getNativePath() + "]";
}
static {
JniTroubleshoot jniTroubleshoot = null;
try {
System.loadLibrary("resin_os");
jniTroubleshoot = new JniTroubleshoot(JniFileStream.class, "resin_os");
} catch (Throwable e) {
jniTroubleshoot = new JniTroubleshoot(JniFileStream.class, "resin_os", e);
}
_jniTroubleshoot = jniTroubleshoot;
}
}