A generic state machine that connects two virtual conections. More...

#include <I_OneWayTunnel.h>

Collaboration diagram for OneWayTunnel:

Public Member Functions
	OneWayTunnel ()
virtual	~OneWayTunnel ()
void	init (VConnection vcSource, VConnection vcTarget, Continuation aCont=NULL, int size_estimate=0, ProxyMutex aMutex=NULL, int64_t nbytes=TUNNEL_TILL_DONE, bool asingle_buffer=true, bool aclose_source=true, bool aclose_target=true, Transform_fn manipulate_fn=NULL, int water_mark=0)
	This init function sets up the read (calls do_io_read) and the write (calls do_io_write).
void	init (VConnection vcSource, VConnection vcTarget, Continuation aCont, VIO SourceVio, IOBufferReader *reader, bool aclose_source=true, bool aclose_target=true)
	This init function sets up only the write side.
void	init (Continuation aCont, VIO SourceVio, VIO *TargetVio, bool aclose_source=true, bool aclose_target=true)
	Use this init function if both the read and the write sides have already been setup.
	OneWayTunnel (Continuation *aCont, Transform_fn manipulate_fn=NULL, bool aclose_source=false, bool aclose_target=false)
int	startEvent (int event, void *data)
virtual void	transform (MIOBufferAccessor &in_buf, MIOBufferAccessor &out_buf)
void	close_source_vio (int result)
	Result is -1 for any error.
virtual void	close_target_vio (int result, VIO *vio=ONE_WAY_TUNNEL_CLOSE_ALL)
void	connection_closed (int result)
virtual void	reenable_all ()
bool	last_connection ()
Static Public Member Functions
static OneWayTunnel *	OneWayTunnel_alloc ()
	Allocates a OneWayTunnel object.
static void	OneWayTunnel_free (OneWayTunnel *)
	Deallocates a OneWayTunnel object.
static void	SetupTwoWayTunnel (OneWayTunnel east, OneWayTunnel west)
Data Fields
VIO *	vioSource
VIO *	vioTarget
Continuation *	cont
Transform_fn	manipulate_fn
int	n_connections
int	lerrno
bool	single_buffer
bool	close_source
bool	close_target
bool	tunnel_till_done
OneWayTunnel *	tunnel_peer
	Non-NULL when this is one side of a two way tunnel.
bool	free_vcs

Detailed Description

A generic state machine that connects two virtual conections.

A OneWayTunnel is a module that connects two virtual connections, a source vc and a target vc, and copies the data between source and target. Once the tunnel is started using the init() call, it handles all the events from the source and target and optionally calls a continuation back when its done. On success it calls back the continuation with VC_EVENT_EOS, and with VC_EVENT_ERROR on failure.

If manipulate_fn is not NULL, then the tunnel acts as a filter, processing all data arriving from the source vc by the manipulate_fn function, before sending to the target vc. By default, the manipulate_fn is set to NULL, yielding the identity function. manipulate_fn takes a IOBuffer containing the data to be written into the target virtual connection which it may manipulate in any manner it sees fit.

Definition at line 65 of file I_OneWayTunnel.h.

Constructor & Destructor Documentation

OneWayTunnel::OneWayTunnel ( )

Definition at line 65 of file OneWayTunnel.cc.

OneWayTunnel::~OneWayTunnel ( ) [virtual]

Definition at line 96 of file OneWayTunnel.cc.

OneWayTunnel::OneWayTunnel	(	Continuation *	aCont,
		Transform_fn	manipulate_fn = `NULL`,
		bool	aclose_source = `false`,
		bool	aclose_target = `false`
	)

Definition at line 100 of file OneWayTunnel.cc.

References ink_assert.

Member Function Documentation

void OneWayTunnel::close_source_vio ( int result )

Result is -1 for any error.

Definition at line 325 of file OneWayTunnel.cc.

References VIO::buffer, MIOBufferAccessor::clear(), close_source, VConnection::do_io_close(), free_MIOBuffer(), free_vcs, last_connection(), lerrno, n_connections, single_buffer, VIO::vc_server, vioSource, and MIOBufferAccessor::writer().

Referenced by startEvent(), and OneWayMultiTunnel::startEvent().

void OneWayTunnel::close_target_vio	(	int	result,
		VIO *	vio = `ONE_WAY_TUNNEL_CLOSE_ALL`
	)			`[virtual]`

Reimplemented in OneWayMultiTunnel.

Definition at line 342 of file OneWayTunnel.cc.

References VIO::buffer, MIOBufferAccessor::clear(), close_target, VConnection::do_io_close(), free_MIOBuffer(), free_vcs, last_connection(), lerrno, n_connections, single_buffer, VIO::vc_server, vioTarget, and MIOBufferAccessor::writer().

Referenced by startEvent().

void OneWayTunnel::connection_closed ( int result )

Definition at line 365 of file OneWayTunnel.cc.

References cont, Continuation::handleEvent(), OneWayTunnel_free(), VC_EVENT_EOS, and VC_EVENT_ERROR.

Referenced by startEvent(), and OneWayMultiTunnel::startEvent().

void OneWayTunnel::init	(	VConnection *	vcSource,
		VConnection *	vcTarget,
		Continuation *	aCont,
		VIO *	SourceVio,
		IOBufferReader *	reader,
		bool	aclose_source = `true`,
		bool	aclose_target = `true`
	)

This init function sets up only the write side.

It assumes that the read VConnection has already been setup.

Parameters:

	vcSource	source VConnection. Prior to calling this init function, a do_io_read should have been called on this VConnection. The tunnel uses the same MIOBuffer and frees that buffer when the transfer is done (either successful or unsuccessful).
	vcTarget	target VConnection. A do_io_write should not have been called on the vcTarget. The tunnel calls do_io_write on this VC.
	aCont	The Continuation to call back when the tunnel finishes. If not specified, the tunnel deallocates itself without calling back anybody.
	SourceVio	VIO of the vcSource.
	reader	IOBufferReader that reads from the vcSource. This reader is provided to vcTarget.
	aclose_source	if true, the tunnel closes vcSource at the end. If aCont is not specified, this should be set to true.
	aclose_target	if true, the tunnel closes vcTarget at the end. If aCont is not specified, this should be set to true.

Definition at line 164 of file OneWayTunnel.cc.

References close_source, close_target, cont, VConnection::do_io_write(), ink_assert, manipulate_fn, Continuation::mutex, MUTEX_LOCK, n_connections, new_ProxyMutex(), VIO::set_continuation(), SET_HANDLER, single_buffer, startEvent(), this_ethread(), TUNNEL_TILL_DONE, tunnel_till_done, vioSource, and vioTarget.

void OneWayTunnel::init	(	VConnection *	vcSource,
		VConnection *	vcTarget,
		Continuation *	aCont = `NULL`,
		int	size_estimate = `0`,
		ProxyMutex *	aMutex = `NULL`,
		int64_t	nbytes = `TUNNEL_TILL_DONE`,
		bool	asingle_buffer = `true`,
		bool	aclose_source = `true`,
		bool	aclose_target = `true`,
		Transform_fn	manipulate_fn = `NULL`,
		int	water_mark = `0`
	)

This init function sets up the read (calls do_io_read) and the write (calls do_io_write).

Parameters:

	vcSource	source VConnection. A do_io_read should not have been called on the vcSource. The tunnel calls do_io_read on this VC.
	vcTarget	target VConnection. A do_io_write should not have been called on the vcTarget. The tunnel calls do_io_write on this VC.
	aCont	continuation to call back when the tunnel finishes. If not specified, the tunnel deallocates itself without calling back anybody. Otherwise, its the callee's responsibility to deallocate the tunnel with OneWayTunnel_free.
	size_estimate	size of the MIOBuffer to create for reading/writing to/from the VC's.
	aMutex	lock that this tunnel will run under. If aCont is specified, the Continuation's lock is used instead of aMutex.
	nbytes	number of bytes to transfer.
	asingle_buffer	whether the same buffer should be used to read from vcSource and write to vcTarget. This should be set to true in most cases, unless the data needs be transformed.
	aclose_source	if true, the tunnel closes vcSource at the end. If aCont is not specified, this should be set to true.
	aclose_target	if true, the tunnel closes vcTarget at the end. If aCont is not specified, this should be set to true.
	manipulate_fn	if specified, the tunnel calls this function with the input and the output buffer, whenever it gets new data in the input buffer. This function can transform the data in the input buffer
	water_mark	watermark for the MIOBuffer used for reading.

Definition at line 115 of file OneWayTunnel.cc.

References MIOBuffer::alloc_reader(), buffer_size_to_index(), close_source, close_target, cont, Debug, default_large_iobuffer_size, VConnection::do_io_read(), VConnection::do_io_write(), ink_assert, lerrno, manipulate_fn, Continuation::mutex, MUTEX_LOCK, n_connections, new_MIOBuffer, new_ProxyMutex(), SET_HANDLER, single_buffer, startEvent(), this_ethread(), tunnel_till_done, vioSource, vioTarget, and MIOBuffer::water_mark.

Referenced by SocksProxy::mainEvent(), CacheContinuation::replyOpEvent(), and CacheContinuation::setupReadBufTunnel().

void OneWayTunnel::init	(	Continuation *	aCont,
		VIO *	SourceVio,
		VIO *	TargetVio,
		bool	aclose_source = `true`,
		bool	aclose_target = `true`
	)

Use this init function if both the read and the write sides have already been setup.

The tunnel assumes that the read VC and the write VC are using the same buffer and frees that buffer when the transfer is done (either successful or unsuccessful)

Parameters:

	aCont	The Continuation to call back when the tunnel finishes. If not specified, the tunnel deallocates itself without calling back anybody.
	SourceVio	read VIO of the Source VC.
	TargetVio	write VIO of the Target VC.
	aclose_source	if true, the tunnel closes vcSource at the end. If aCont is not specified, this should be set to true.
	aclose_target	if true, the tunnel closes vcTarget at the end. If aCont is not specified, this should be set to true.