senf::ReadHelper< Handle > Class Template Reference

Asynchronous reading helper. More...

#include <senf/Scheduler/ReadHelper.hh>

Inheritance diagram for senf::ReadHelper< Handle >:
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List of all members.

Detailed Description

template<class Handle>
class senf::ReadHelper< Handle >

Asynchronous reading helper.

This class provides a simple asynchronous reading facility. This helper will register with the Scheduler and read incoming data. It will collect the data until a specific number of bytes has been read or some Predicate evaluated on the data read thus far signals end of data.

The ReadHelper accepts the same flexible file handle interfaces as the Scheduler.

The callback must take a ReadHelper::ptr argument. Using this ReadHelper instance, the callback can access the data read or retrieve state information.

The ReadHelper separates the data into two parts: data() will return the matched data, tail() will return any surplus data already read. If you don't specify a predicate, tail() will always be empty (there may however some data be left in the socket input buffer after the ReadHelper returns).

The predicate is any class instance with an operator(std::string const &). This operator is called, whenever some data has been read. If the data is not yet complete, the predicate must return std::string::npos. If the ReadHelper should stop reading more data, the predicate must return the number of bytes which are to be considered 'matched'.

Todo:
Move all not Handle dependent members to a ReadHandleBase class

Add an optional std::string const & tail argument to the constructors which takes the tail() of a previous ReadHelper instance.

Definition at line 69 of file ReadHelper.hh.


Classes
struct   InternalPredicate
  Abstract predicate interface. More...

Public Types
typedef boost::intrusive_ptr
< ReadHelper > 		 ptr
  Smart pointer type for this class.
typedef boost::function< void(ptr)>  Callback
  Callback type.

Public Member Functions
Handle  handle () const
  Access the handle object.
std::string::size_type  maxSize () const
  Return maximum number of bytes to be read.
std::string const &  data () const
  return data read
std::string const &  tail () const
  return data read but not matched by the predicate
bool  complete () const
  Check whether the read has completed successfully.
bool  error () const
  Check for error condition.
void  throw_error () const
  If an error occurred, throw it.
void  revoke ()
  Remove the ReadHelper from the scheduler.

Structors and default members
static ptr  dispatch (Handle handle, std::string::size_type maxSize, Callback callback)
  Register new ReadHandler instance.
template<class Predicate >
static ptr  dispatch (Handle handle, std::string::size_type maxSize, Predicate const &predicate, Callback callback)
  Register new ReadHelper instance.

Member Typedef Documentation

template<class Handle>
typedef boost::function<void (ptr)> senf::ReadHelper< Handle >::
Callback

Callback type.

Definition at line 77 of file ReadHelper.hh.

template<class Handle>
typedef boost::intrusive_ptr<ReadHelper> senf::ReadHelper< Handle >::
ptr

Smart pointer type for this class.

Definition at line 76 of file ReadHelper.hh.

Member Function Documentation

template<class Handle >
bool senf::ReadHelper< Handle >::
complete ()

Check whether the read has completed successfully.

Definition at line 80 of file ReadHelper.cti.

template<class Handle >
std::string const & senf::ReadHelper< Handle >::
data ()

return data read

Definition at line 66 of file ReadHelper.cti.

template<class Handle>
template<class Predicate >
senf::ReadHelper< Handle >::ptr senf::ReadHelper< Handle >::
dispatch ( Handle  handle,
std::string::size_type  maxSize,
Predicate const &  predicate,
Callback  callback )

Register new ReadHelper instance.

The registered Callback will be called after the predicate returns a Value other than std::string::npos, maxSize bytes have been read, or EOF or some error condition is encountered.

Postcondition:
The returned ReadHelper instance is registered with the Scheduler to handle read events .
Parameters:
[in]  handle  file descriptor or handle providing the Handle interface defined above.
[in]  maxSize  maximum number of bytes to read
[in]  predicate  predicate to check
[in]  callback  callback
Returns:
smart pointer to new ReadHelper instance

Definition at line 43 of file ReadHelper.cti.

template<class Handle>
senf::ReadHelper< Handle >::ptr senf::ReadHelper< Handle >::
dispatch ( Handle  handle,
std::string::size_type  maxSize,
Callback  callback )

Register new ReadHandler instance.

The registered Callback will be called after maxSize bytes have been read or EOF or some error is encountered.

Postcondition:
The returned ReadHelper instance is registered with the Scheduler to handle read events.
Parameters:
[in]  handle  file descriptor or handle providing the Handle interface defined above.
[in]  maxSize  maximum number of bytes to read
[in]  callback  callback
Returns:
Smart pointer to new ReadHelper instance

Definition at line 34 of file ReadHelper.cti.

template<class Handle >
bool senf::ReadHelper< Handle >::
error ()

Check for error condition.

Definition at line 87 of file ReadHelper.cti.

template<class Handle >
Handle senf::ReadHelper< Handle >::
handle ()

Access the handle object.

Definition at line 52 of file ReadHelper.cti.

template<class Handle >
std::string::size_type senf::ReadHelper< Handle >::
maxSize ()

Return maximum number of bytes to be read.

Definition at line 59 of file ReadHelper.cti.

template<class Handle >
void senf::ReadHelper< Handle >::
revoke ()

Remove the ReadHelper from the scheduler.

Definition at line 48 of file ReadHelper.ct.

template<class Handle >
std::string const & senf::ReadHelper< Handle >::
tail ()

return data read but not matched by the predicate

Definition at line 73 of file ReadHelper.cti.

template<class Handle >
void senf::ReadHelper< Handle >::
throw_error ()

If an error occurred, throw it.

Definition at line 94 of file ReadHelper.cti.

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