org.jruby.util.io

Class ModeFlags

java.lang.Object

org.jruby.util.io.ModeFlags

All Implemented Interfaces:

Cloneable

public class ModeFlags
extends Object
implements Cloneable

This file represents the POSIX-like mode flags an open channel (as in a ChannelDescriptor) can have. It provides the basic flags for read/write as well as flags for create, truncate, and others. In addition, it provides methods for querying specific flag settings and converting to two other formats: a Java mode string and an OpenFile mode int. Note: In MRI these are called oflags.

See Also:

ChannelDescriptor, Stream, OpenFile

Field Summary

Fields

Modifier and Type	Field and Description
static int	ACCMODE accmode flag, used to mask the read/write mode
static int	APPEND append flag, to seek to the end of the file
static int	BINARY binary flag, to ensure no encoding changes are made while writing
static int	CREAT create flag, to specify non-existing file should be created
static int	EXCL exclusive access flag, to require locking the target file
static int	NONBLOCK nonblock flag, to perform all operations non-blocking.
static int	RDONLY read-only flag (default value if no other flags set)
static int	RDWR read/write flag
static int	TEXT textmode flag, MRI has no equivalent but we use ModeFlags currently to also capture what are oflags.
static int	TRUNC truncate flag, to truncate the target file to zero length
static int	WRONLY write-only flag

Constructor Summary

Constructors

Constructor and Description
ModeFlags() Construct a new ModeFlags object with the default read-only flag.
ModeFlags(long flags) Construct a new ModeFlags object with the specified flags
ModeFlags(String flagString)

Method Summary

Methods

Modifier and Type	Method and Description
static ModeFlags	createModeFlags(int oflags)
int	getFcntlFileFlags() Convert the flags in this object to a set of flags appropriate for the fcntl.
int	getFlags() Return a value that, when passed to our constructor, would create a copy of this instance.
static ModeFlags	getModesFromChannel(Channel channel) Deprecated.
static int	getOFlagsFromString(Ruby runtime, String modesString)
static int	getOFlagsFromString(String modesString)
int	getOpenFileFlags() Convert the flags in this object to a set of flags appropriate for the OpenFile structure and logic therein.
static int	getOpenFileFlagsFor(int flags) With the provided open flags parameter what fmode values should be set (fmode for us is represented by OpenFile).
boolean	isAppendable() Whether the flags specify to append to existing files.
boolean	isBinary() Whether the flags specify "binary" mode for reads and writes.
boolean	isCreate() Whether the flags specify to create nonexisting files.
boolean	isExclusive() Whether the flags specify exclusive access.
boolean	isReadable() Whether the flags specify "readable", either read/write or read-only.
boolean	isReadOnly() Whether the flags specify"read only".
boolean	isSubsetOf(ModeFlags superset) Check whether the target set of flags is a superset of this one; used to ensure that a file is not re-opened with more privileges than it already had.
boolean	isText() Whether the flags specify "text" mode for reads and writes.
boolean	isTruncate() Whether the flags specify to truncate the target file.
boolean	isWritable() Whether the flags specify "writable", either read/write or write-only
static int	oflagsFrom(jnr.posix.POSIX posix, Channel channel) Build a set of mode flags using the specified channel's actual capabilities.
String	toJavaModeString() Produce a Java IO mode string from the flags in this object.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

RDONLY

public static final int RDONLY

read-only flag (default value if no other flags set)

WRONLY

public static final int WRONLY

write-only flag

RDWR

public static final int RDWR

read/write flag

CREAT

public static final int CREAT

create flag, to specify non-existing file should be created

EXCL

public static final int EXCL

exclusive access flag, to require locking the target file

TRUNC

public static final int TRUNC

truncate flag, to truncate the target file to zero length

APPEND

public static final int APPEND

append flag, to seek to the end of the file

NONBLOCK

public static final int NONBLOCK

nonblock flag, to perform all operations non-blocking. Unused currently

BINARY

public static final int BINARY

binary flag, to ensure no encoding changes are made while writing

TEXT

public static final int TEXT

textmode flag, MRI has no equivalent but we use ModeFlags currently to also capture what are oflags.

See Also:

Constant Field Values

ACCMODE

public static final int ACCMODE

accmode flag, used to mask the read/write mode

Constructor Detail

ModeFlags

public ModeFlags()

Construct a new ModeFlags object with the default read-only flag.

ModeFlags

public ModeFlags(long flags)
          throws InvalidValueException

Construct a new ModeFlags object with the specified flags

Parameters:

flags - The flags to use for this object

Throws:

InvalidValueException - If the modes are invalid

ModeFlags

public ModeFlags(String flagString)
          throws InvalidValueException

Throws:

InvalidValueException

Method Detail

getOFlagsFromString

public static int getOFlagsFromString(String modesString)
                               throws InvalidValueException

Throws:

InvalidValueException

getOFlagsFromString

public static int getOFlagsFromString(Ruby runtime,
                      String modesString)

oflagsFrom

public static int oflagsFrom(jnr.posix.POSIX posix,
             Channel channel)

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

getModesFromChannel

@Deprecated
public static ModeFlags getModesFromChannel(Channel channel)

Deprecated.

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

toJavaModeString

public String toJavaModeString()

Produce a Java IO mode string from the flags in this object.

Returns:

A Java string suitable for opening files with RandomAccessFile

isReadOnly

public final boolean isReadOnly()

Whether the flags specify"read only".

Returns:

true if read-only, false otherwise

isReadable

public boolean isReadable()

Whether the flags specify "readable", either read/write or read-only.

Returns:

true if readable, false otherwise

isBinary

public boolean isBinary()

Whether the flags specify "binary" mode for reads and writes.

Returns:

true if binary mode, false otherwise

isText

public boolean isText()

Whether the flags specify "text" mode for reads and writes.

Returns:

true if text mode, false otherwise

isCreate

public boolean isCreate()

Whether the flags specify to create nonexisting files.

Returns:

true if nonexisting files should be created, false otherwise

isWritable

public boolean isWritable()

Whether the flags specify "writable", either read/write or write-only

Returns:

true if writable, false otherwise

isExclusive

public boolean isExclusive()

Whether the flags specify exclusive access.

Returns:

true if exclusive, false otherwise

isAppendable

public boolean isAppendable()

Whether the flags specify to append to existing files.

Returns:

true if append, false otherwise

isTruncate

public boolean isTruncate()

Whether the flags specify to truncate the target file.

Returns:

true if truncate, false otherwise

isSubsetOf

public boolean isSubsetOf(ModeFlags superset)

Check whether the target set of flags is a superset of this one; used to ensure that a file is not re-opened with more privileges than it already had.

Parameters:

superset - The ModeFlags object which should be a superset of this one

Returns:

true if the object is a superset, false otherwise

toString

public String toString()

Overrides:

toString in class Object

getFlags

public int getFlags()

Return a value that, when passed to our constructor, would create a copy of this instance.

Returns:

an int of the private flags variable.

getOpenFileFlagsFor

public static int getOpenFileFlagsFor(int flags)

With the provided open flags parameter what fmode values should be set (fmode for us is represented by OpenFile).

getOpenFileFlags

public int getOpenFileFlags()

Convert the flags in this object to a set of flags appropriate for the OpenFile structure and logic therein.

Returns:

an int of flags appropriate for OpenFile

getFcntlFileFlags

public int getFcntlFileFlags()

Convert the flags in this object to a set of flags appropriate for the fcntl.

Returns:

an int of flags appropriate for fcntl

createModeFlags

public static ModeFlags createModeFlags(int oflags)