/*
***** BEGIN LICENSE BLOCK *****
* Version: CPL 1.0/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Common Public
* License Version 1.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.eclipse.org/legal/cpl-v10.html
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* Copyright (C) 2008 Charles O Nutter <headius@headius.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
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* use your version of this file under the terms of the CPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the CPL, the GPL or the LGPL.
***** END LICENSE BLOCK *****/
package org.jruby.util.io;
import static java.util.logging.Logger.getLogger;
import static org.jruby.util.io.ModeFlags.RDONLY;
import static org.jruby.util.io.ModeFlags.RDWR;
import static org.jruby.util.io.ModeFlags.WRONLY;
import java.io.File;
import java.io.FileDescriptor;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.RandomAccessFile;
import java.net.URL;
import java.nio.ByteBuffer;
import java.nio.channels.Channel;
import java.nio.channels.Channels;
import java.nio.channels.FileChannel;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.WritableByteChannel;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.jar.JarFile;
import java.util.zip.ZipEntry;
import org.jruby.RubyFile;
import org.jruby.ext.posix.POSIX;
import org.jruby.util.ByteList;
import org.jruby.util.JRubyFile;
/**
* ChannelDescriptor provides an abstraction similar to the concept of a
* "file descriptor" on any POSIX system. In our case, it's a numbered object
* (fileno) enclosing a Channel (@see java.nio.channels.Channel), FileDescriptor
* (@see java.io.FileDescriptor), and flags under which the original open occured
* (@see org.jruby.util.io.ModeFlags). Several operations you would normally
* expect to use with a POSIX file descriptor are implemented here and used by
* higher-level classes to implement higher-level IO behavior.
*
* Note that the channel specified when constructing a ChannelDescriptor will
* be reference-counted; that is, until all known references to it through this
* class have gone away, it will be left open. This is to support operations
* like "dup" which must produce two independent ChannelDescriptor instances
* that can be closed separately without affecting the other.
*
* At present there's no way to simulate the behavior on some platforms where
* POSIX dup also allows independent positioning information.
*/
public class ChannelDescriptor {
/** Whether to log debugging information */
private static final boolean DEBUG = false;
/** The java.nio.channels.Channel this descriptor wraps. */
private Channel channel;
/**
* The file number (equivalent to the int file descriptor value in POSIX)
* for this descriptor. This is generated new for most ChannelDescriptor
* instances, except when they need to masquerade as another fileno.
*/
private int internalFileno;
/** The java.io.FileDescriptor object for this descriptor. */
private FileDescriptor fileDescriptor;
/**
* The original org.jruby.util.io.ModeFlags with which the specified
* channel was opened.
*/
private ModeFlags originalModes;
/**
* The reference count for the provided channel.
* Only counts references through ChannelDescriptor instances.
*/
private AtomicInteger refCounter;
/**
* Used to work-around blocking problems with STDIN. In most cases <code>null</code>.
* See {@link #ChannelDescriptor(InputStream, int, ModeFlags, FileDescriptor)}
* for more details. You probably should not use it.
*/
private InputStream baseInputStream;
/**
* Process streams get Channel.newChannel()ed into FileChannel but are not actually
* seekable. So instead of just the isSeekable check doing instanceof FileChannel,
* we must also add this boolean to check, which we set to false when it's known
* that the incoming channel is from a process.
*
* FIXME: This is gross, and it's NIO's fault for not providing a nice way to
* tell if a channel is "really" seekable.
*/
private boolean canBeSeekable = true;
/**
* Construct a new ChannelDescriptor with the specified channel, file number,
* mode flags, file descriptor object and reference counter. This constructor
* is only used when constructing a new copy of an existing ChannelDescriptor
* with an existing reference count, to allow the two instances to safely
* share and appropriately close a given channel.
*
* @param channel The channel for the new descriptor, which will be shared with another
* @param fileno The new file number for the new descriptor
* @param originalModes The mode flags to use as the "origina" set for this descriptor
* @param fileDescriptor The java.io.FileDescriptor object to associate with this ChannelDescriptor
* @param refCounter The reference counter from another ChannelDescriptor being duped.
*/
private ChannelDescriptor(Channel channel, int fileno, ModeFlags originalModes, FileDescriptor fileDescriptor, AtomicInteger refCounter, boolean canBeSeekable) {
this.refCounter = refCounter;
this.channel = channel;
this.internalFileno = fileno;
this.originalModes = originalModes;
this.fileDescriptor = fileDescriptor;
this.canBeSeekable = canBeSeekable;
registerDescriptor(this);
}
private ChannelDescriptor(Channel channel, int fileno, ModeFlags originalModes, FileDescriptor fileDescriptor) {
this(channel, fileno, originalModes, fileDescriptor, new AtomicInteger(1), true);
}
/**
* Construct a new ChannelDescriptor with the given channel, file number, mode flags,
* and file descriptor object. The channel will be kept open until all ChannelDescriptor
* references to it have been closed.
*
* @param channel The channel for the new descriptor
* @param fileno The file number for the new descriptor
* @param originalModes The mode flags for the new descriptor
* @param fileDescriptor The java.io.FileDescriptor object for the new descriptor
*/
public ChannelDescriptor(Channel channel, ModeFlags originalModes, FileDescriptor fileDescriptor) {
this(channel, getNewFileno(), originalModes, fileDescriptor, new AtomicInteger(1), true);
}
/**
* Construct a new ChannelDescriptor with the given channel, file number, mode flags,
* and file descriptor object. The channel will be kept open until all ChannelDescriptor
* references to it have been closed.
*
* @param channel The channel for the new descriptor
* @param originalModes The mode flags for the new descriptor
* @param fileDescriptor The java.io.FileDescriptor object for the new descriptor
*/
public ChannelDescriptor(Channel channel, ModeFlags originalModes) {
this(channel, getNewFileno(), originalModes, new FileDescriptor(), new AtomicInteger(1), true);
}
/**
* Special constructor to create the ChannelDescriptor out of the stream, file number,
* mode flags, and file descriptor object. The channel will be created from the
* provided stream. The channel will be kept open until all ChannelDescriptor
* references to it have been closed. <b>Note:</b> in most cases, you should not
* use this constructor, it's reserved mostly for STDIN.
*
* @param baseInputStream The stream to create the channel for the new descriptor
* @param fileno The file number for the new descriptor
* @param originalModes The mode flags for the new descriptor
* @param fileDescriptor The java.io.FileDescriptor object for the new descriptor
*/
public ChannelDescriptor(InputStream baseInputStream, ModeFlags originalModes, FileDescriptor fileDescriptor) {
// The reason why we need the stream is to be able to invoke available() on it.
// STDIN in Java is non-interruptible, non-selectable, and attempt to read
// on such stream might lead to thread being blocked without *any* way to unblock it.
// That's where available() comes it, so at least we could check whether
// anything is available to be read without blocking.
this(Channels.newChannel(baseInputStream), getNewFileno(), originalModes, fileDescriptor, new AtomicInteger(1), true);
this.baseInputStream = baseInputStream;
}
/**
* Special constructor to create the ChannelDescriptor out of the stream, file number,
* mode flags, and file descriptor object. The channel will be created from the
* provided stream. The channel will be kept open until all ChannelDescriptor
* references to it have been closed. <b>Note:</b> in most cases, you should not
* use this constructor, it's reserved mostly for STDIN.
*
* @param baseInputStream The stream to create the channel for the new descriptor
* @param originalModes The mode flags for the new descriptor
* @param fileDescriptor The java.io.FileDescriptor object for the new descriptor
*/
public ChannelDescriptor(InputStream baseInputStream, ModeFlags originalModes) {
// The reason why we need the stream is to be able to invoke available() on it.
// STDIN in Java is non-interruptible, non-selectable, and attempt to read
// on such stream might lead to thread being blocked without *any* way to unblock it.
// That's where available() comes it, so at least we could check whether
// anything is available to be read without blocking.
this(Channels.newChannel(baseInputStream), getNewFileno(), originalModes, new FileDescriptor(), new AtomicInteger(1), true);
this.baseInputStream = baseInputStream;
}
/**
* Construct a new ChannelDescriptor with the given channel, file number,
* and file descriptor object. The channel will be kept open until all ChannelDescriptor
* references to it have been closed. The channel's capabilities will be used
* to determine the "original" set of mode flags.
*
* @param channel The channel for the new descriptor
* @param fileno The file number for the new descriptor
* @param fileDescriptor The java.io.FileDescriptor object for the new descriptor
*/
public ChannelDescriptor(Channel channel, FileDescriptor fileDescriptor) throws InvalidValueException {
this(channel, getModesFromChannel(channel), fileDescriptor);
}
@Deprecated
public ChannelDescriptor(Channel channel, int fileno, FileDescriptor fileDescriptor) throws InvalidValueException {
this(channel, getModesFromChannel(channel), fileDescriptor);
}
/**
* Construct a new ChannelDescriptor with the given channel, file number,
* and file descriptor object. The channel will be kept open until all ChannelDescriptor
* references to it have been closed. The channel's capabilities will be used
* to determine the "original" set of mode flags. This version generates a
* new fileno.
*
* @param channel The channel for the new descriptor
* @param fileDescriptor The java.io.FileDescriptor object for the new descriptor
*/
public ChannelDescriptor(Channel channel) throws InvalidValueException {
this(channel, getModesFromChannel(channel), new FileDescriptor());
}
/**
* Get this descriptor's file number.
*
* @return the fileno for this descriptor
*/
public int getFileno() {
return internalFileno;
}
/**
* Get the FileDescriptor object associated with this descriptor. This is
* not guaranteed to be a "valid" descriptor in the terms of the Java
* implementation, but is provided for completeness and for cases where it
* is possible to get a valid FileDescriptor for a given channel.
*
* @return the java.io.FileDescriptor object associated with this descriptor
*/
public FileDescriptor getFileDescriptor() {
return fileDescriptor;
}
/**
* The channel associated with this descriptor. The channel will be reference
* counted through ChannelDescriptor and kept open until all ChannelDescriptor
* objects have been closed. References that leave ChannelDescriptor through
* this method will not be counted.
*
* @return the java.nio.channels.Channel associated with this descriptor
*/
public Channel getChannel() {
return channel;
}
/**
* This is intentionally non-public, since it should not be really
* used outside of very limited use case (handling of STDIN).
* See {@link #ChannelDescriptor(InputStream, int, ModeFlags, FileDescriptor)}
* for more info.
*/
/*package-protected*/ InputStream getBaseInputStream() {
return baseInputStream;
}
/**
* Whether the channel associated with this descriptor is seekable (i.e.
* whether it is instanceof FileChannel).
*
* @return true if the associated channel is seekable, false otherwise
*/
public boolean isSeekable() {
return canBeSeekable && channel instanceof FileChannel;
}
/**
* Set the channel to be explicitly seekable or not, for streams that appear
* to be seekable with the instanceof FileChannel check.
*
* @param seekable Whether the channel is seekable or not.
*/
public void setCanBeSeekable(boolean canBeSeekable) {
this.canBeSeekable = canBeSeekable;
}
/**
* Whether the channel associated with this descriptor is a NullChannel,
* for which many operations are simply noops.
*/
public boolean isNull() {
return channel instanceof NullChannel;
}
/**
* Whether the channel associated with this descriptor is writable (i.e.
* whether it is instanceof WritableByteChannel).
*
* @return true if the associated channel is writable, false otherwise
*/
public boolean isWritable() {
return channel instanceof WritableByteChannel;
}
/**
* Whether the channel associated with this descriptor is open.
*
* @return true if the associated channel is open, false otherwise
*/
public boolean isOpen() {
return channel.isOpen();
}
/**
* Check whether the isOpen returns true, raising a BadDescriptorException if
* it returns false.
*
* @throws org.jruby.util.io.BadDescriptorException if isOpen returns false
*/
public void checkOpen() throws BadDescriptorException {
if (!isOpen()) {
throw new BadDescriptorException();
}
}
/**
* Get the original mode flags for the descriptor.
*
* @return the original mode flags for the descriptor
*/
public ModeFlags getOriginalModes() {
return originalModes;
}
/**
* Check whether a specified set of mode flags is a superset of this
* descriptor's original set of mode flags.
*
* @param newModes The modes to confirm as superset
* @throws org.jruby.util.io.InvalidValueException if the modes are not a superset
*/
public void checkNewModes(ModeFlags newModes) throws InvalidValueException {
if (!newModes.isSubsetOf(originalModes)) {
throw new InvalidValueException();
}
}
/**
* Mimics the POSIX dup(2) function, returning a new descriptor that references
* the same open channel.
*
* @return A duplicate ChannelDescriptor based on this one
*/
public ChannelDescriptor dup() {
synchronized (refCounter) {
refCounter.incrementAndGet();
int newFileno = getNewFileno();
if (DEBUG) getLogger("ChannelDescriptor").info("Reopen fileno " + newFileno + ", refs now: " + refCounter.get());
return new ChannelDescriptor(channel, newFileno, originalModes, fileDescriptor, refCounter, canBeSeekable);
}
}
/**
* Mimics the POSIX dup2(2) function, returning a new descriptor that references
* the same open channel but with a specified fileno.
*
* @param fileno The fileno to use for the new descriptor
* @return A duplicate ChannelDescriptor based on this one
*/
public ChannelDescriptor dup2(int fileno) {
synchronized (refCounter) {
refCounter.incrementAndGet();
if (DEBUG) getLogger("ChannelDescriptor").info("Reopen fileno " + fileno + ", refs now: " + refCounter.get());
return new ChannelDescriptor(channel, fileno, originalModes, fileDescriptor, refCounter, canBeSeekable);
}
}
/**
* Mimics the POSIX dup2(2) function, returning a new descriptor that references
* the same open channel but with a specified fileno. This differs from the fileno
* version by making the target descriptor into a new reference to the current
* descriptor's channel, closing what it originally pointed to and preserving
* its original fileno.
*
* @param fileno The fileno to use for the new descriptor
* @return A duplicate ChannelDescriptor based on this one
*/
public void dup2Into(ChannelDescriptor other) throws BadDescriptorException, IOException {
synchronized (refCounter) {
refCounter.incrementAndGet();
if (DEBUG) getLogger("ChannelDescriptor").info("Reopen fileno " + internalFileno + ", refs now: " + refCounter.get());
other.close();
other.channel = channel;
other.originalModes = originalModes;
other.fileDescriptor = fileDescriptor;
other.refCounter = refCounter;
other.canBeSeekable = canBeSeekable;
}
}
public ChannelDescriptor reopen(Channel channel, ModeFlags modes) {
return new ChannelDescriptor(channel, internalFileno, modes, fileDescriptor);
}
public ChannelDescriptor reopen(RandomAccessFile file, ModeFlags modes) throws IOException {
return new ChannelDescriptor(file.getChannel(), internalFileno, modes, file.getFD());
}
/**
* Perform a low-level seek operation on the associated channel if it is
* instanceof FileChannel, or raise PipeException if it is not a FileChannel.
* Calls checkOpen to confirm the target channel is open. This is equivalent
* to the lseek(2) POSIX function, and like that function it bypasses any
* buffer flushing or invalidation as in ChannelStream.fseek.
*
* @param offset the offset value to use
* @param whence whence to seek
* @throws java.io.IOException If there is an exception while seeking
* @throws org.jruby.util.io.InvalidValueException If the value specified for
* offset or whence is invalid
* @throws org.jruby.util.io.PipeException If the target channel is not seekable
* @throws org.jruby.util.io.BadDescriptorException If the target channel is
* already closed.
* @return the new offset into the FileChannel.
*/
public long lseek(long offset, int whence) throws IOException, InvalidValueException, PipeException, BadDescriptorException {
if (channel instanceof FileChannel) {
checkOpen();
FileChannel fileChannel = (FileChannel)channel;
try {
long pos;
switch (whence) {
case Stream.SEEK_SET:
pos = offset;
fileChannel.position(pos);
break;
case Stream.SEEK_CUR:
pos = fileChannel.position() + offset;
fileChannel.position(pos);
break;
case Stream.SEEK_END:
pos = fileChannel.size() + offset;
fileChannel.position(pos);
break;
default:
throw new InvalidValueException();
}
return pos;
} catch (IllegalArgumentException e) {
throw new InvalidValueException();
}
} else {
throw new PipeException();
}
}
/**
* Perform a low-level read of the specified number of bytes into the specified
* byte list. The incoming bytes will be appended to the byte list. This is
* equivalent to the read(2) POSIX function, and like that function it
* ignores read and write buffers defined elsewhere.
*
* @param number the number of bytes to read
* @param byteList the byte list on which to append the incoming bytes
* @return the number of bytes actually read
* @throws java.io.IOException if there is an exception during IO
* @throws org.jruby.util.io.BadDescriptorException if the associated
* channel is already closed.
* @see java.util.ByteList
*/
public int read(int number, ByteList byteList) throws IOException, BadDescriptorException {
checkOpen();
byteList.ensure(byteList.length() + number);
int bytesRead = read(ByteBuffer.wrap(byteList.getUnsafeBytes(),
byteList.begin() + byteList.length(), number));
if (bytesRead > 0) {
byteList.length(byteList.length() + bytesRead);
}
return bytesRead;
}
/**
* Perform a low-level read of the remaining number of bytes into the specified
* byte buffer. The incoming bytes will be used to fill the remaining space in
* the target byte buffer. This is equivalent to the read(2) POSIX function,
* and like that function it ignores read and write buffers defined elsewhere.
*
* @param buffer the java.nio.ByteBuffer in which to put the incoming bytes
* @return the number of bytes actually read
* @throws java.io.IOException if there is an exception during IO
* @throws org.jruby.util.io.BadDescriptorException if the associated
* channel is already closed
* @see java.nio.ByteBuffer
*/
public int read(ByteBuffer buffer) throws IOException, BadDescriptorException {
checkOpen();
// TODO: It would be nice to throw a better error for this
if (!(channel instanceof ReadableByteChannel)) {
throw new BadDescriptorException();
}
ReadableByteChannel readChannel = (ReadableByteChannel) channel;
int bytesRead = 0;
bytesRead = readChannel.read(buffer);
return bytesRead;
}
/**
* Write the bytes in the specified byte list to the associated channel.
*
* @param buf the byte list containing the bytes to be written
* @return the number of bytes actually written
* @throws java.io.IOException if there is an exception during IO
* @throws org.jruby.util.io.BadDescriptorException if the associated
* channel is already closed
*/
public int internalWrite(ByteBuffer buffer) throws IOException, BadDescriptorException {
checkOpen();
// TODO: It would be nice to throw a better error for this
if (!(channel instanceof WritableByteChannel)) {
throw new BadDescriptorException();
}
WritableByteChannel writeChannel = (WritableByteChannel)channel;
if (isSeekable() && originalModes.isAppendable()) {
FileChannel fileChannel = (FileChannel)channel;
fileChannel.position(fileChannel.size());
}
return writeChannel.write(buffer);
}
/**
* Write the bytes in the specified byte list to the associated channel.
*
* @param buf the byte list containing the bytes to be written
* @return the number of bytes actually written
* @throws java.io.IOException if there is an exception during IO
* @throws org.jruby.util.io.BadDescriptorException if the associated
* channel is already closed
*/
public int write(ByteBuffer buffer) throws IOException, BadDescriptorException {
checkOpen();
return internalWrite(buffer);
}
/**
* Write the bytes in the specified byte list to the associated channel.
*
* @param buf the byte list containing the bytes to be written
* @return the number of bytes actually written
* @throws java.io.IOException if there is an exception during IO
* @throws org.jruby.util.io.BadDescriptorException if the associated
* channel is already closed
*/
public int write(ByteList buf) throws IOException, BadDescriptorException {
checkOpen();
return internalWrite(ByteBuffer.wrap(buf.getUnsafeBytes(), buf.begin(), buf.length()));
}
/**
* Write the bytes in the specified byte list to the associated channel.
*
* @param buf the byte list containing the bytes to be written
* @param offset the offset to start at. this is relative to the begin variable in the but
* @param len the amount of bytes to write. this should not be longer than the buffer
* @return the number of bytes actually written
* @throws java.io.IOException if there is an exception during IO
* @throws org.jruby.util.io.BadDescriptorException if the associated
* channel is already closed
*/
public int write(ByteList buf, int offset, int len) throws IOException, BadDescriptorException {
checkOpen();
return internalWrite(ByteBuffer.wrap(buf.getUnsafeBytes(), buf.begin()+offset, len));
}
/**
* Write the byte represented by the specified int to the associated channel.
*
* @param c The byte to write
* @return 1 if the byte was written, 0 if not and -1 if there was an error
* (@see java.nio.channels.WritableByteChannel.write(java.nio.ByteBuffer))
* @throws java.io.IOException If there was an exception during IO
* @throws org.jruby.util.io.BadDescriptorException if the associated
* channel is already closed
*/
public int write(int c) throws IOException, BadDescriptorException {
checkOpen();
ByteBuffer buf = ByteBuffer.allocate(1);
buf.put((byte)c);
buf.flip();
return internalWrite(buf);
}
/**
* Open a new descriptor using the given working directory, file path,
* mode flags, and file permission. This is equivalent to the open(2)
* POSIX function. See org.jruby.util.io.ChannelDescriptor.open(String, String, ModeFlags, int, POSIX)
* for the version that also sets file permissions.
*
* @param cwd the "current working directory" to use when opening the file
* @param path the file path to open
* @param flags the mode flags to use for opening the file
* @return a new ChannelDescriptor based on the specified parameters
* @throws java.io.FileNotFoundException if the target file could not be found
* and the create flag was not specified
* @throws org.jruby.util.io.DirectoryAsFileException if the target file is
* a directory being opened as a file
* @throws org.jruby.util.io.FileExistsException if the target file should
* be created anew, but already exists
* @throws java.io.IOException if there is an exception during IO
*/
public static ChannelDescriptor open(String cwd, String path, ModeFlags flags) throws FileNotFoundException, DirectoryAsFileException, FileExistsException, IOException {
return open(cwd, path, flags, 0, null, null);
}
/**
* Open a new descriptor using the given working directory, file path,
* mode flags, and file permission. This is equivalent to the open(2)
* POSIX function. See org.jruby.util.io.ChannelDescriptor.open(String, String, ModeFlags, int, POSIX)
* for the version that also sets file permissions.
*
* @param cwd the "current working directory" to use when opening the file
* @param path the file path to open
* @param flags the mode flags to use for opening the file
* @param classLoader a ClassLoader to use for classpath: resources
* @return a new ChannelDescriptor based on the specified parameters
* @throws java.io.FileNotFoundException if the target file could not be found
* and the create flag was not specified
* @throws org.jruby.util.io.DirectoryAsFileException if the target file is
* a directory being opened as a file
* @throws org.jruby.util.io.FileExistsException if the target file should
* be created anew, but already exists
* @throws java.io.IOException if there is an exception during IO
*/
public static ChannelDescriptor open(String cwd, String path, ModeFlags flags, ClassLoader classLoader) throws FileNotFoundException, DirectoryAsFileException, FileExistsException, IOException {
return open(cwd, path, flags, 0, null, classLoader);
}
/**
* Open a new descriptor using the given working directory, file path,
* mode flags, and file permission. This is equivalent to the open(2)
* POSIX function.
*
* @param cwd the "current working directory" to use when opening the file
* @param path the file path to open
* @param flags the mode flags to use for opening the file
* @param perm the file permissions to use when creating a new file (currently
* unobserved)
* @param posix a POSIX api implementation, used for setting permissions; if null, permissions are ignored
* @return a new ChannelDescriptor based on the specified parameters
* @throws java.io.FileNotFoundException if the target file could not be found
* and the create flag was not specified
* @throws org.jruby.util.io.DirectoryAsFileException if the target file is
* a directory being opened as a file
* @throws org.jruby.util.io.FileExistsException if the target file should
* be created anew, but already exists
* @throws java.io.IOException if there is an exception during IO
*/
public static ChannelDescriptor open(String cwd, String path, ModeFlags flags, int perm, POSIX posix) throws FileNotFoundException, DirectoryAsFileException, FileExistsException, IOException {
return open(cwd, path, flags, perm, posix, null);
}
/**
* Open a new descriptor using the given working directory, file path,
* mode flags, and file permission. This is equivalent to the open(2)
* POSIX function.
*
* @param cwd the "current working directory" to use when opening the file
* @param path the file path to open
* @param flags the mode flags to use for opening the file
* @param perm the file permissions to use when creating a new file (currently
* unobserved)
* @param posix a POSIX api implementation, used for setting permissions; if null, permissions are ignored
* @param classLoader a ClassLoader to use for classpath: resources
* @return a new ChannelDescriptor based on the specified parameters
* @throws java.io.FileNotFoundException if the target file could not be found
* and the create flag was not specified
* @throws org.jruby.util.io.DirectoryAsFileException if the target file is
* a directory being opened as a file
* @throws org.jruby.util.io.FileExistsException if the target file should
* be created anew, but already exists
* @throws java.io.IOException if there is an exception during IO
*/
public static ChannelDescriptor open(String cwd, String path, ModeFlags flags, int perm, POSIX posix, ClassLoader classLoader) throws FileNotFoundException, DirectoryAsFileException, FileExistsException, IOException {
boolean fileCreated = false;
if (path.equals("/dev/null") || path.equalsIgnoreCase("nul:") || path.equalsIgnoreCase("nul")) {
Channel nullChannel = new NullChannel();
// FIXME: don't use RubyIO for this
return new ChannelDescriptor(nullChannel, flags);
} else if (path.startsWith("file:")) {
int bangIndex = path.indexOf("!");
if (bangIndex > 0) {
String filePath = path.substring(5, bangIndex);
String internalPath = path.substring(bangIndex + 2);
if (!new File(filePath).exists()) {
throw new FileNotFoundException(path);
}
JarFile jf = new JarFile(filePath);
ZipEntry entry = RubyFile.getFileEntry(jf, internalPath);
if (entry == null) {
throw new FileNotFoundException(path);
}
InputStream is = jf.getInputStream(entry);
// FIXME: don't use RubyIO for this
return new ChannelDescriptor(Channels.newChannel(is), flags);
} else {
// raw file URL, just open directly
URL url = new URL(path);
InputStream is = url.openStream();
// FIXME: don't use RubyIO for this
return new ChannelDescriptor(Channels.newChannel(is), flags);
}
} else if (path.startsWith("classpath:/") && classLoader != null) {
path = path.substring("classpath:/".length());
InputStream is = classLoader.getResourceAsStream(path);
// FIXME: don't use RubyIO for this
return new ChannelDescriptor(Channels.newChannel(is), flags);
} else {
JRubyFile theFile = JRubyFile.create(cwd,path);
if (theFile.isDirectory() && flags.isWritable()) {
throw new DirectoryAsFileException();
}
if (flags.isCreate()) {
if (theFile.exists() && flags.isExclusive()) {
throw new FileExistsException(path);
}
try {
fileCreated = theFile.createNewFile();
} catch (IOException ioe) {
// See JRUBY-4380.
// MRI behavior: raise Errno::ENOENT in case
// when the directory for the file doesn't exist.
// Java in such cases just throws IOException.
File parent = theFile.getParentFile();
if (parent != null && parent != theFile && !parent.exists()) {
throw new FileNotFoundException(path);
} else if (!theFile.canWrite()) {
throw new PermissionDeniedException(path);
} else {
// for all other IO errors, just re-throw the original exception
throw ioe;
}
}
} else {
if (!theFile.exists()) {
throw new FileNotFoundException(path);
}
}
// We always open this rw since we can only open it r or rw.
RandomAccessFile file = new RandomAccessFile(theFile, flags.toJavaModeString());
// call chmod after we created the RandomAccesFile
// because otherwise, the file could be read-only
if (fileCreated) {
// attempt to set the permissions, if we have been passed a POSIX instance,
// and only if the file was created in this call.
if (posix != null && perm != -1) {
posix.chmod(theFile.getPath(), perm);
}
}
if (flags.isTruncate()) file.setLength(0L);
// TODO: append should set the FD to end, no? But there is no seek(int) in libc!
//if (modes.isAppendable()) seek(0, Stream.SEEK_END);
return new ChannelDescriptor(file.getChannel(), flags, file.getFD());
}
}
/**
* Close this descriptor. If in closing the last ChannelDescriptor reference
* to the associate channel is closed, the channel itself will be closed.
*
* @throws org.jruby.util.io.BadDescriptorException if the associated
* channel is already closed
* @throws java.io.IOException if there is an exception during IO
*/
public void close() throws BadDescriptorException, IOException {
// tidy up
finish(true);
}
void finish(boolean close) throws BadDescriptorException, IOException {
synchronized (refCounter) {
// if refcount is at or below zero, we're no longer valid
if (refCounter.get() <= 0) {
throw new BadDescriptorException();
}
// if channel is already closed, we're no longer valid
if (!channel.isOpen()) {
throw new BadDescriptorException();
}
// otherwise decrement and possibly close as normal
int count = refCounter.decrementAndGet();
if (DEBUG) getLogger("ChannelDescriptor").info("Descriptor for fileno " + internalFileno + " refs: " + count);
if (count <= 0) {
// if we're the last referrer, close the channel
try {
if (close) channel.close();
} finally {
unregisterDescriptor(internalFileno);
}
}
}
}
/**
* Build a set of mode flags using the specified channel's actual capabilities.
*
* @param channel the channel to examine for capabilities
* @return the mode flags
* @throws org.jruby.util.io.InvalidValueException
*/
private static ModeFlags getModesFromChannel(Channel channel) throws InvalidValueException {
ModeFlags modes;
if (channel instanceof ReadableByteChannel) {
if (channel instanceof WritableByteChannel) {
modes = new ModeFlags(RDWR);
} else {
modes = new ModeFlags(RDONLY);
}
} else if (channel instanceof WritableByteChannel) {
modes = new ModeFlags(WRONLY);
} else {
// FIXME: I don't like this
modes = new ModeFlags(RDWR);
}
return modes;
}
// FIXME shouldn't use static; would interfere with other runtimes in the same JVM
protected static final AtomicInteger internalFilenoIndex = new AtomicInteger(2);
public static int getNewFileno() {
return internalFilenoIndex.incrementAndGet();
}
private static void registerDescriptor(ChannelDescriptor descriptor) {
filenoDescriptorMap.put(descriptor.getFileno(), descriptor);
}
private static void unregisterDescriptor(int aFileno) {
filenoDescriptorMap.remove(aFileno);
}
public static ChannelDescriptor getDescriptorByFileno(int aFileno) {
return filenoDescriptorMap.get(aFileno);
}
private static final Map<Integer, ChannelDescriptor> filenoDescriptorMap = new ConcurrentHashMap<Integer, ChannelDescriptor>();
}