org.jruby.util.io

Class ChannelDescriptor

java.lang.Object

org.jruby.util.io.ChannelDescriptor

public class ChannelDescriptor
extends java.lang.Object

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.

Field Summary

Fields

Modifier and Type	Field and Description
private java.io.InputStream	baseInputStream Used to work-around blocking problems with STDIN.
private boolean	canBeSeekable Process streams get Channel.newChannel()ed into FileChannel but are not actually seekable.
private java.nio.channels.Channel	channel The java.nio.channels.Channel this descriptor wraps.
private static boolean	DEBUG Whether to log debugging information
private static java.lang.Class	FILE_CHANNEL_IMPL
private static java.lang.reflect.Field	FILE_CHANNEL_IMPL_FD
private static java.lang.reflect.Field	FILE_DESCRIPTOR_FD
private java.io.FileDescriptor	fileDescriptor The java.io.FileDescriptor object for this descriptor.
private static java.util.Map<java.lang.Integer,ChannelDescriptor>	filenoDescriptorMap
private int	internalFileno The file number (equivalent to the int file descriptor value in POSIX) for this descriptor.
protected static java.util.concurrent.atomic.AtomicInteger	internalFilenoIndex
private boolean	isInAppendMode If the incoming channel is already in append mode (i.e.
private static Logger	LOG
private ModeFlags	originalModes The original org.jruby.util.io.ModeFlags with which the specified channel was opened.
private boolean	readableChannel Whether the current channe is writable or not.
private java.util.concurrent.atomic.AtomicInteger	refCounter The reference count for the provided channel.
private boolean	seekableChannel Whether the current channel is seekable or not.
private static java.lang.Class	SEL_CH_IMPL
private static java.lang.reflect.Method	SEL_CH_IMPL_GET_FD
private boolean	writableChannel Whether the current channel is readable or not.

Constructor Summary

Constructors

Modifier	Constructor and Description
	ChannelDescriptor(java.nio.channels.Channel channel) Construct a new ChannelDescriptor with the given channel, file number, and file descriptor object.
	ChannelDescriptor(java.nio.channels.Channel channel, java.io.FileDescriptor fileDescriptor) Construct a new ChannelDescriptor with the given channel, file number, and file descriptor object.
	ChannelDescriptor(java.nio.channels.Channel channel, int fileno, java.io.FileDescriptor fileDescriptor) Deprecated.
private	ChannelDescriptor(java.nio.channels.Channel channel, int fileno, ModeFlags originalModes, java.io.FileDescriptor fileDescriptor)
private	ChannelDescriptor(java.nio.channels.Channel channel, int fileno, ModeFlags originalModes, java.io.FileDescriptor fileDescriptor, java.util.concurrent.atomic.AtomicInteger refCounter, boolean canBeSeekable, boolean isInAppendMode) Construct a new ChannelDescriptor with the specified channel, file number, mode flags, file descriptor object and reference counter.
	ChannelDescriptor(java.nio.channels.Channel channel, ModeFlags originalModes) Construct a new ChannelDescriptor with the given channel, file number, mode flags, and file descriptor object.
	ChannelDescriptor(java.nio.channels.Channel channel, ModeFlags originalModes, java.io.FileDescriptor fileDescriptor) Construct a new ChannelDescriptor with the given channel, file number, mode flags, and file descriptor object.
	ChannelDescriptor(java.nio.channels.Channel channel, ModeFlags originalModes, java.io.FileDescriptor fileDescriptor, boolean isInAppendMode) Construct a new ChannelDescriptor with the given channel, file number, mode flags, and file descriptor object.
	ChannelDescriptor(java.io.InputStream baseInputStream, ModeFlags originalModes) Special constructor to create the ChannelDescriptor out of the stream, file number, mode flags, and file descriptor object.
	ChannelDescriptor(java.io.InputStream baseInputStream, ModeFlags originalModes, java.io.FileDescriptor fileDescriptor) Special constructor to create the ChannelDescriptor out of the stream, file number, mode flags, and file descriptor object.

Method Summary

Modifier and Type	Method and Description
void	checkNewModes(ModeFlags newModes) Check whether a specified set of mode flags is a superset of this descriptor's original set of mode flags.
void	checkOpen() Check whether the isOpen returns true, raising a BadDescriptorException if it returns false.
void	close() Close this descriptor.
ChannelDescriptor	dup() Mimics the POSIX dup(2) function, returning a new descriptor that references the same open channel.
ChannelDescriptor	dup2(int fileno) Mimics the POSIX dup2(2) function, returning a new descriptor that references the same open channel but with a specified fileno.
void	dup2Into(ChannelDescriptor other) Mimics the POSIX dup2(2) function, returning a new descriptor that references the same open channel but with a specified fileno.
(package private) void	finish(boolean close)
(package private) java.io.InputStream	getBaseInputStream() This is intentionally non-public, since it should not be really used outside of very limited use case (handling of STDIN).
java.nio.channels.Channel	getChannel() The channel associated with this descriptor.
static ChannelDescriptor	getDescriptorByFileno(int aFileno)
static java.io.FileDescriptor	getDescriptorFromChannel(java.nio.channels.Channel channel)
java.io.FileDescriptor	getFileDescriptor() Get the FileDescriptor object associated with this descriptor.
int	getFileno() Get this descriptor's file number.
static java.util.Map<java.lang.Integer,ChannelDescriptor>	getFilenoDescriptorMapReadOnly()
private static ModeFlags	getModesFromChannel(java.nio.channels.Channel channel) Build a set of mode flags using the specified channel's actual capabilities.
static int	getNewFileno()
ModeFlags	getOriginalModes() Get the original mode flags for the descriptor.
int	internalWrite(java.nio.ByteBuffer buffer) Write the bytes in the specified byte list to the associated channel.
boolean	isNull() Whether the channel associated with this descriptor is a NullChannel, for which many operations are simply noops.
boolean	isOpen() Whether the channel associated with this descriptor is open.
boolean	isReadable() Whether the channel associated with this descriptor is readable (i.e.
boolean	isSeekable() Whether the channel associated with this descriptor is seekable (i.e.
boolean	isWritable() Whether the channel associated with this descriptor is writable (i.e.
long	lseek(long offset, int whence) Perform a low-level seek operation on the associated channel if it is instanceof FileChannel, or raise PipeException if it is not a FileChannel.
static ChannelDescriptor	open(java.lang.String cwd, java.lang.String path, ModeFlags flags) Open a new descriptor using the given working directory, file path, mode flags, and file permission.
static ChannelDescriptor	open(java.lang.String cwd, java.lang.String path, ModeFlags flags, java.lang.ClassLoader classLoader) Open a new descriptor using the given working directory, file path, mode flags, and file permission.
static ChannelDescriptor	open(java.lang.String cwd, java.lang.String path, ModeFlags flags, int perm, jnr.posix.POSIX posix) Open a new descriptor using the given working directory, file path, mode flags, and file permission.
static ChannelDescriptor	open(java.lang.String cwd, java.lang.String path, ModeFlags flags, int perm, jnr.posix.POSIX posix, java.lang.ClassLoader classLoader) Open a new descriptor using the given working directory, file path, mode flags, and file permission.
int	read(java.nio.ByteBuffer buffer) Perform a low-level read of the remaining number of bytes into the specified byte buffer.
int	read(int number, org.jruby.util.ByteList byteList) Perform a low-level read of the specified number of bytes into the specified byte list.
private static void	registerDescriptor(ChannelDescriptor descriptor)
ChannelDescriptor	reopen(java.nio.channels.Channel channel, ModeFlags modes)
ChannelDescriptor	reopen(java.io.RandomAccessFile file, ModeFlags modes)
void	setCanBeSeekable(boolean canBeSeekable) Set the channel to be explicitly seekable or not, for streams that appear to be seekable with the instanceof FileChannel check.
static void	unregisterDescriptor(int aFileno)
int	write(java.nio.ByteBuffer buffer) Write the bytes in the specified byte list to the associated channel.
int	write(org.jruby.util.ByteList buf) Write the bytes in the specified byte list to the associated channel.
int	write(org.jruby.util.ByteList buf, int offset, int len) Write the bytes in the specified byte list to the associated channel.
int	write(int c) Write the byte represented by the specified int to the associated channel.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

LOG

private static final Logger LOG

DEBUG

private static final boolean DEBUG

Whether to log debugging information

See Also:

Constant Field Values

channel

private java.nio.channels.Channel channel

The java.nio.channels.Channel this descriptor wraps.

internalFileno

private int internalFileno

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.

fileDescriptor

private java.io.FileDescriptor fileDescriptor

The java.io.FileDescriptor object for this descriptor.

originalModes

private ModeFlags originalModes

The original org.jruby.util.io.ModeFlags with which the specified channel was opened.

refCounter

private java.util.concurrent.atomic.AtomicInteger refCounter

The reference count for the provided channel. Only counts references through ChannelDescriptor instances.

baseInputStream

private java.io.InputStream baseInputStream

Used to work-around blocking problems with STDIN. In most cases null. See ChannelDescriptor(java.io.InputStream, ModeFlags, java.io.FileDescriptor) for more details. You probably should not use it.

canBeSeekable

private boolean canBeSeekable

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.

isInAppendMode

private boolean isInAppendMode

If the incoming channel is already in append mode (i.e. it will do the requisite seeking), we don't want to do our own additional seeks.

readableChannel

private boolean readableChannel

Whether the current channe is writable or not.

writableChannel

private boolean writableChannel

Whether the current channel is readable or not.

seekableChannel

private boolean seekableChannel

Whether the current channel is seekable or not.

internalFilenoIndex

protected static final java.util.concurrent.atomic.AtomicInteger internalFilenoIndex

filenoDescriptorMap

private static final java.util.Map<java.lang.Integer,ChannelDescriptor> filenoDescriptorMap

SEL_CH_IMPL

private static final java.lang.Class SEL_CH_IMPL

SEL_CH_IMPL_GET_FD

private static final java.lang.reflect.Method SEL_CH_IMPL_GET_FD

FILE_CHANNEL_IMPL

private static final java.lang.Class FILE_CHANNEL_IMPL

FILE_CHANNEL_IMPL_FD

private static final java.lang.reflect.Field FILE_CHANNEL_IMPL_FD

FILE_DESCRIPTOR_FD

private static final java.lang.reflect.Field FILE_DESCRIPTOR_FD

Constructor Detail

ChannelDescriptor

private ChannelDescriptor(java.nio.channels.Channel channel,
                          int fileno,
                          ModeFlags originalModes,
                          java.io.FileDescriptor fileDescriptor,
                          java.util.concurrent.atomic.AtomicInteger refCounter,
                          boolean canBeSeekable,
                          boolean isInAppendMode)

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.

Parameters:

channel - The channel for the new descriptor, which will be shared with another

fileno - The new file number for the new descriptor

originalModes - The mode flags to use as the "origina" set for this descriptor

fileDescriptor - The java.io.FileDescriptor object to associate with this ChannelDescriptor

refCounter - The reference counter from another ChannelDescriptor being duped.

canBeSeekable - If the underlying channel can be considered seekable.

isInAppendMode - If the underlying channel is already in append mode.

ChannelDescriptor

private ChannelDescriptor(java.nio.channels.Channel channel,
                          int fileno,
                          ModeFlags originalModes,
                          java.io.FileDescriptor fileDescriptor)

ChannelDescriptor

public ChannelDescriptor(java.nio.channels.Channel channel,
                         ModeFlags originalModes,
                         java.io.FileDescriptor fileDescriptor)

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.

Parameters:

channel - The channel for the new descriptor

originalModes - The mode flags for the new descriptor

fileDescriptor - The java.io.FileDescriptor object for the new descriptor

ChannelDescriptor

public ChannelDescriptor(java.nio.channels.Channel channel,
                         ModeFlags originalModes,
                         java.io.FileDescriptor fileDescriptor,
                         boolean isInAppendMode)

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.

Parameters:

channel - The channel for the new descriptor

originalModes - The mode flags for the new descriptor

fileDescriptor - The java.io.FileDescriptor object for the new descriptor

ChannelDescriptor

public ChannelDescriptor(java.nio.channels.Channel channel,
                         ModeFlags originalModes)

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.

Parameters:

channel - The channel for the new descriptor

originalModes - The mode flags for the new descriptor

ChannelDescriptor

public ChannelDescriptor(java.io.InputStream baseInputStream,
                         ModeFlags originalModes,
                         java.io.FileDescriptor fileDescriptor)

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. Note: in most cases, you should not use this constructor, it's reserved mostly for STDIN.

Parameters:

baseInputStream - The stream to create the channel for the new descriptor

originalModes - The mode flags for the new descriptor

fileDescriptor - The java.io.FileDescriptor object for the new descriptor

ChannelDescriptor

public ChannelDescriptor(java.io.InputStream baseInputStream,
                         ModeFlags originalModes)

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. Note: in most cases, you should not use this constructor, it's reserved mostly for STDIN.

Parameters:

baseInputStream - The stream to create the channel for the new descriptor

originalModes - The mode flags for the new descriptor

ChannelDescriptor

public ChannelDescriptor(java.nio.channels.Channel channel,
                         java.io.FileDescriptor fileDescriptor)
                  throws InvalidValueException

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.

Parameters:

channel - The channel for the new descriptor

fileDescriptor - The java.io.FileDescriptor object for the new descriptor

Throws:

InvalidValueException

ChannelDescriptor

@Deprecated
public ChannelDescriptor(java.nio.channels.Channel channel,
                                     int fileno,
                                     java.io.FileDescriptor fileDescriptor)
                              throws InvalidValueException

Deprecated.

Throws:

InvalidValueException

ChannelDescriptor

public ChannelDescriptor(java.nio.channels.Channel channel)
                  throws InvalidValueException

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.

Parameters:

channel - The channel for the new descriptor

Throws:

InvalidValueException

Method Detail

getFileno

public int getFileno()

Get this descriptor's file number.

Returns:

the fileno for this descriptor

getFileDescriptor

public java.io.FileDescriptor getFileDescriptor()

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.

Returns:

the java.io.FileDescriptor object associated with this descriptor

getChannel

public java.nio.channels.Channel getChannel()

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.

Returns:

the java.nio.channels.Channel associated with this descriptor

getBaseInputStream

java.io.InputStream getBaseInputStream()

This is intentionally non-public, since it should not be really used outside of very limited use case (handling of STDIN). See ChannelDescriptor(java.io.InputStream, ModeFlags, java.io.FileDescriptor) for more info.

isSeekable

public boolean isSeekable()

Whether the channel associated with this descriptor is seekable (i.e. whether it is instanceof FileChannel).

Returns:

true if the associated channel is seekable, false otherwise

setCanBeSeekable

public void setCanBeSeekable(boolean canBeSeekable)

Set the channel to be explicitly seekable or not, for streams that appear to be seekable with the instanceof FileChannel check.

Parameters:

canBeSeekable - Whether the channel is seekable or not.

isNull

public boolean isNull()

Whether the channel associated with this descriptor is a NullChannel, for which many operations are simply noops.

isWritable

public boolean isWritable()

Whether the channel associated with this descriptor is writable (i.e. whether it is instanceof WritableByteChannel).

Returns:

true if the associated channel is writable, false otherwise

isReadable

public boolean isReadable()

Whether the channel associated with this descriptor is readable (i.e. whether it is instanceof ReadableByteChannel).

Returns:

true if the associated channel is readable, false otherwise

isOpen

public boolean isOpen()

Whether the channel associated with this descriptor is open.

Returns:

true if the associated channel is open, false otherwise

checkOpen

public void checkOpen()
               throws BadDescriptorException

Check whether the isOpen returns true, raising a BadDescriptorException if it returns false.

Throws:

BadDescriptorException - if isOpen returns false

getOriginalModes

public ModeFlags getOriginalModes()

Get the original mode flags for the descriptor.

Returns:

the original mode flags for the descriptor

checkNewModes

public void checkNewModes(ModeFlags newModes)
                   throws InvalidValueException

Check whether a specified set of mode flags is a superset of this descriptor's original set of mode flags.

Parameters:

newModes - The modes to confirm as superset

Throws:

InvalidValueException - if the modes are not a superset

dup

public ChannelDescriptor dup()

Mimics the POSIX dup(2) function, returning a new descriptor that references the same open channel.

Returns:

A duplicate ChannelDescriptor based on this one

dup2

public ChannelDescriptor dup2(int fileno)

Mimics the POSIX dup2(2) function, returning a new descriptor that references the same open channel but with a specified fileno.

Parameters:

fileno - The fileno to use for the new descriptor

Returns:

A duplicate ChannelDescriptor based on this one

dup2Into

public void dup2Into(ChannelDescriptor other)
              throws BadDescriptorException,
                     java.io.IOException

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.

Parameters:

other - the descriptor to dup this one into

Throws:

BadDescriptorException

java.io.IOException

reopen

public ChannelDescriptor reopen(java.nio.channels.Channel channel,
                                ModeFlags modes)

reopen

public ChannelDescriptor reopen(java.io.RandomAccessFile file,
                                ModeFlags modes)
                         throws java.io.IOException

Throws:

java.io.IOException

lseek

public long lseek(long offset,
                  int whence)
           throws java.io.IOException,
                  InvalidValueException,
                  PipeException,
                  BadDescriptorException

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.

Parameters:

offset - the offset value to use

whence - whence to seek

Returns:

the new offset into the FileChannel.

Throws:

java.io.IOException - If there is an exception while seeking

InvalidValueException - If the value specified for offset or whence is invalid

PipeException - If the target channel is not seekable

BadDescriptorException - If the target channel is already closed.

read

public int read(int number,
                org.jruby.util.ByteList byteList)
         throws java.io.IOException,
                BadDescriptorException

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.

Parameters:

number - the number of bytes to read

byteList - the byte list on which to append the incoming bytes

Returns:

the number of bytes actually read

Throws:

java.io.IOException - if there is an exception during IO

BadDescriptorException - if the associated channel is already closed.

See Also:

ByteList

read

public int read(java.nio.ByteBuffer buffer)
         throws java.io.IOException,
                BadDescriptorException

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.

Parameters:

buffer - the java.nio.ByteBuffer in which to put the incoming bytes

Returns:

the number of bytes actually read

Throws:

java.io.IOException - if there is an exception during IO

BadDescriptorException - if the associated channel is already closed

See Also:

ByteBuffer

internalWrite

public int internalWrite(java.nio.ByteBuffer buffer)
                  throws java.io.IOException,
                         BadDescriptorException

Write the bytes in the specified byte list to the associated channel.

Parameters:

buffer - the byte list containing the bytes to be written

Returns:

the number of bytes actually written

Throws:

java.io.IOException - if there is an exception during IO

BadDescriptorException - if the associated channel is already closed

write

public int write(java.nio.ByteBuffer buffer)
          throws java.io.IOException,
                 BadDescriptorException

Write the bytes in the specified byte list to the associated channel.

Parameters:

buffer - the byte list containing the bytes to be written

Returns:

the number of bytes actually written

Throws:

java.io.IOException - if there is an exception during IO

BadDescriptorException - if the associated channel is already closed

write

public int write(org.jruby.util.ByteList buf)
          throws java.io.IOException,
                 BadDescriptorException

Write the bytes in the specified byte list to the associated channel.

Parameters:

buf - the byte list containing the bytes to be written

Returns:

the number of bytes actually written

Throws:

java.io.IOException - if there is an exception during IO

BadDescriptorException - if the associated channel is already closed

write

public int write(org.jruby.util.ByteList buf,
                 int offset,
                 int len)
          throws java.io.IOException,
                 BadDescriptorException

Write the bytes in the specified byte list to the associated channel.

Parameters:

buf - the byte list containing the bytes to be written

offset - the offset to start at. this is relative to the begin variable in the but

len - the amount of bytes to write. this should not be longer than the buffer

Returns:

the number of bytes actually written

Throws:

java.io.IOException - if there is an exception during IO

BadDescriptorException - if the associated channel is already closed

write

public int write(int c)
          throws java.io.IOException,
                 BadDescriptorException

Write the byte represented by the specified int to the associated channel.

Parameters:

c - The byte to write

Returns:

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

BadDescriptorException - if the associated channel is already closed

open

public static ChannelDescriptor open(java.lang.String cwd,
                                     java.lang.String path,
                                     ModeFlags flags)
                              throws java.io.FileNotFoundException,
                                     DirectoryAsFileException,
                                     FileExistsException,
                                     java.io.IOException

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.

Parameters:

cwd - the "current working directory" to use when opening the file

path - the file path to open

flags - the mode flags to use for opening the file

Returns:

a new ChannelDescriptor based on the specified parameters

Throws:

java.io.FileNotFoundException

DirectoryAsFileException

FileExistsException

java.io.IOException

open

public static ChannelDescriptor open(java.lang.String cwd,
                                     java.lang.String path,
                                     ModeFlags flags,
                                     java.lang.ClassLoader classLoader)
                              throws java.io.FileNotFoundException,
                                     DirectoryAsFileException,
                                     FileExistsException,
                                     java.io.IOException

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.

Parameters:

cwd - the "current working directory" to use when opening the file

path - the file path to open

flags - the mode flags to use for opening the file

classLoader - a ClassLoader to use for classpath: resources

Returns:

a new ChannelDescriptor based on the specified parameters

Throws:

java.io.FileNotFoundException

DirectoryAsFileException

FileExistsException

java.io.IOException

open

public static ChannelDescriptor open(java.lang.String cwd,
                                     java.lang.String path,
                                     ModeFlags flags,
                                     int perm,
                                     jnr.posix.POSIX posix)
                              throws java.io.FileNotFoundException,
                                     DirectoryAsFileException,
                                     FileExistsException,
                                     java.io.IOException

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.

Parameters:

cwd - the "current working directory" to use when opening the file

path - the file path to open

flags - the mode flags to use for opening the file

perm - the file permissions to use when creating a new file (currently unobserved)

posix - a POSIX api implementation, used for setting permissions; if null, permissions are ignored

Returns:

a new ChannelDescriptor based on the specified parameters

Throws:

java.io.FileNotFoundException

DirectoryAsFileException

FileExistsException

java.io.IOException

open

public static ChannelDescriptor open(java.lang.String cwd,
                                     java.lang.String path,
                                     ModeFlags flags,
                                     int perm,
                                     jnr.posix.POSIX posix,
                                     java.lang.ClassLoader classLoader)
                              throws java.io.FileNotFoundException,
                                     DirectoryAsFileException,
                                     FileExistsException,
                                     java.io.IOException

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.

Parameters:

cwd - the "current working directory" to use when opening the file

path - the file path to open

flags - the mode flags to use for opening the file

perm - the file permissions to use when creating a new file (currently unobserved)

posix - a POSIX api implementation, used for setting permissions; if null, permissions are ignored

classLoader - a ClassLoader to use for classpath: resources

Returns:

a new ChannelDescriptor based on the specified parameters

Throws:

java.io.FileNotFoundException

DirectoryAsFileException

FileExistsException

java.io.IOException

close

public void close()
           throws BadDescriptorException,
                  java.io.IOException

Close this descriptor. If in closing the last ChannelDescriptor reference to the associate channel is closed, the channel itself will be closed.

Throws:

BadDescriptorException - if the associated channel is already closed

java.io.IOException - if there is an exception during IO

finish

void finish(boolean close)
     throws BadDescriptorException,
            java.io.IOException

Throws:

BadDescriptorException

java.io.IOException

getModesFromChannel

private static ModeFlags getModesFromChannel(java.nio.channels.Channel channel)
                                      throws InvalidValueException

Build a set of mode flags using the specified channel's actual capabilities.

Parameters:

channel - the channel to examine for capabilities

Returns:

the mode flags

Throws:

InvalidValueException

getNewFileno

public static int getNewFileno()

registerDescriptor

private static void registerDescriptor(ChannelDescriptor descriptor)

unregisterDescriptor

public static void unregisterDescriptor(int aFileno)

getDescriptorByFileno

public static ChannelDescriptor getDescriptorByFileno(int aFileno)

getFilenoDescriptorMapReadOnly

public static java.util.Map<java.lang.Integer,ChannelDescriptor> getFilenoDescriptorMapReadOnly()

getDescriptorFromChannel

public static java.io.FileDescriptor getDescriptorFromChannel(java.nio.channels.Channel channel)