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IOHandle Class Reference

Inherited by Socket.

List of all members.

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Detailed Description

A reference-counted I/O handle (descriptor).

An I/O handle is closed when the last remaining reference to it disappears.

Public Methods
	IOHandle ()
	Creates an empty handle.
	IOHandle (int fd)
	Creates a handler from a file descriptor.
int	read (void *buf, unsigned int count)
	Attempts to read bytes into a data buffer.
	operator bool () const
	Returns true if this IOHandle is valid.
int	read_fully (void *buf, unsigned int count)
	Reads bytes into a data buffer, retrying continually until either end-of-stream or an error Condition.
int	write (const void *buf, int count)
	Attempts to write bytes from a data buffer.
int	write_fully (const void *buf, unsigned int count)
	Writes bytes from a data buffer, retrying continually until either end-of-stream or an error Condition.
int	read (databuf buf, unsigned int count)
	Reads up to count bytes into a data buffer, setting the buffer's length to the number of bytes actually read.
int	read_fully (databuf buf, unsigned int count)
	Reads count bytes into a data buffer, retrying continually until either end-of-stream or an error Condition.
int	read (databuf buf)
	Reads up to count bytes into a data buffer, up to the maximum length of the buffer.
int	read_fully (databuf buf)
	Fills up a data buffer, retrying continually until either end-of-stream or an error Condition.
int	write (constbuf in)
	Attempts to write bytes from a data buffer.
int	write_fully (constbuf in)
	Writes bytes from a data buffer, retrying continually until either end-of-stream or an error Condition.
bool	set_blocking (bool block)
	Sets a handle into blocking or non-blocking mode.
Status	stat () const
	Returns the Status of the handle.
int	get_fd () const
	Returns the file descriptor.
string	as_string () const
Static Public Methods
pair< IOHandle, IOHandle >	pipe ()
Protected Methods
void	set_status (const Status &s)

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Constructor & Destructor Documentation

IOHandle::IOHandle (    )

Creates an empty handle.

IOHandle::IOHandle (  int    fd )  [explicit]

Creates a handler from a file descriptor. This should only be invoked once per file descriptor.

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Member Function Documentation

string IOHandle::as_string (    )  const

int IOHandle::get_fd (    )  const

Returns the file descriptor.

IOHandle::operator bool (    )  const

Returns true if this IOHandle is valid.

pair<IOHandle, IOHandle> IOHandle::pipe (    )  [static]

int IOHandle::read (  databuf    buf )

Reads up to count bytes into a data buffer, up to the maximum length of the buffer. Sets the buffer's length to the number of bytes actually read. Returns: if all bytes were successfully read, count; else 0.

int IOHandle::read (  databuf    buf, unsigned int    count )

Reads up to count bytes into a data buffer, setting the buffer's length to the number of bytes actually read. Returns: the number of bytes actually read, or -1 if no bytes are available or an error occurs, or 0 on end-of-stream.

int IOHandle::read (  void *    buf, unsigned int    count )

Attempts to read bytes into a data buffer. This call may block if the handler has not been put into non-blocking mode. Returns: the number of bytes actually read, or -1 if no bytes are available or an error occurs, or 0 on end-of-stream.

int IOHandle::read_fully (  databuf    buf )

Fills up a data buffer, retrying continually until either end-of-stream or an error Condition. Sets buf's length to the number of bytes read, which is always either buf.max_length() or 0. This should never be called on a non-blocking Socket because it may consume large of CPU time waiting for bytes. Returns: if all bytes were successfully read, count; else 0.

int IOHandle::read_fully (  databuf    buf, unsigned int    count )

Reads count bytes into a data buffer, retrying continually until either end-of-stream or an error Condition. Sets buf's length to the number of bytes read, which is always either count or 0. This should never be called on a non-blocking Socket because it may consume large of CPU time waiting for bytes. Returns: if all bytes were successfully read, count; else 0.

int IOHandle::read_fully (  void *    buf, unsigned int    count )

Reads bytes into a data buffer, retrying continually until either end-of-stream or an error Condition. This should never be called on a non-blocking Socket because it may consume large of CPU time waiting for bytes. Returns: if all bytes were successfully read, count; else 0.

bool IOHandle::set_blocking (  bool    block )

Sets a handle into blocking or non-blocking mode. Returns: true if successful.

void IOHandle::set_status (  const Status &    s )  [protected]

Status IOHandle::stat (    )  const

Returns the Status of the handle.

int IOHandle::write (  constbuf    in )

Attempts to write bytes from a data buffer. This call may block if the handler has not been put into non-blocking mode. Returns: the number of bytes actually written, or -1 if no bytes can be written or an error occurs, or 0 on end-of-stream.

int IOHandle::write (  const void *    buf, int    count )

Attempts to write bytes from a data buffer. This call may block if the handler has not been put into non-blocking mode. Returns: the number of bytes actually written, or -1 if no bytes can be written or an error occurs, or 0 on end-of-stream.

int IOHandle::write_fully (  constbuf    in )

Writes bytes from a data buffer, retrying continually until either end-of-stream or an error Condition. This should never be called on a non-blocking Socket because it may consume large of CPU time waiting for bytes. Returns: if all bytes were successfully written, the buffer's length; else 0.

int IOHandle::write_fully (  const void *    buf, unsigned int    count )

Writes bytes from a data buffer, retrying continually until either end-of-stream or an error Condition. This should never be called on a non-blocking Socket because it may consume large of CPU time waiting for bytes. Returns: if all bytes were successfully written, count; else 0.

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The documentation for this class was generated from the following file:

• io

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