Base class for all readers. More...

#include <reader.hpp>

Inheritance diagram for reader_base:

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Collaboration diagram for reader_base:

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Public Member Functions
	reader_base (reader_base const &)=delete

reader_base &	operator= (reader_base const &)=delete

void	close ()

virtual bool	seekable () const

bool	seek (uint64_t offset, uint64_t size=nosize)
	If seek fails, the reader is in an undefined state and must be closed.

bool	rewind ()
	Only seekable readers can be rewound.

std::wstring const &	name () const

virtual uint64_t	size () const
	Size of the reader. If the size is indetermined, nosize is returned.

virtual datetime	mtime () const
	Last modification time, might be indetermined.

std::pair< aio_result, buffer_lease >	get_buffer (aio_waiter &h)
	Gets the next buffer with data from the reader. More...

std::pair< aio_result, buffer_lease >	get_buffer (event_handler &h)

bool	error () const

Public Member Functions inherited from aio_waitable
void	remove_waiter (aio_waiter &h)

void	remove_waiter (event_handler &h)

Protected Member Functions
	reader_base (std::wstring &&name, aio_buffer_pool &pool, size_t max_buffers) noexcept
	Constructs a reader. More...

	reader_base (std::wstring_view name, aio_buffer_pool &pool, size_t max_buffers) noexcept

virtual std::pair< aio_result, buffer_lease >	do_get_buffer (scoped_lock &l)=0

virtual bool	do_seek (scoped_lock &)

virtual void	do_close (scoped_lock &)

Protected Member Functions inherited from aio_waiter
virtual void	on_buffer_availability (aio_waitable const *w)=0

Protected Member Functions inherited from aio_waitable
void	remove_waiters ()
	Call in destructor of most-derived class.

void	add_waiter (aio_waiter &h)

void	add_waiter (event_handler &h)

void	signal_availibility ()

void	remove_waiter (aio_waiter &h)

void	remove_waiter (event_handler &h)

Protected Attributes
mutex	mtx_

aio_buffer_pool &	buffer_pool_

logger_interface &	logger_

std::wstring const	name_

size_t const	max_buffers_ {}

std::list< buffer_lease >	buffers_

uint64_t	size_ {nosize}

uint64_t	max_size_ {nosize}

uint64_t	start_offset_ {nosize}

uint64_t	remaining_ {nosize}

bool	get_buffer_called_ {}

bool	error_ {}

bool	eof_ {}

Additional Inherited Members
Public Types inherited from aio_base
using	size_type = uint64_t

Static Public Attributes inherited from aio_base
static constexpr auto	nosize = static_cast<size_type>(-1)

Detailed Description

Base class for all readers.

All readers have a name describing them for logging purposes.

The initial state of a freshly opened reader is readable, get_buffer() can be called.

See the aio demo program for example usage.

Constructor & Destructor Documentation

◆ reader_base()

reader_base	(	std::wstring &&	name,
		aio_buffer_pool &	pool,
		size_t	max_buffers
	)

inlineprotectednoexcept

Constructs a reader.

The passed aio_buffer_pool must live longer than the reader.

max_buffers controls the amount of buffers the reader is prepared to use at any given time.

See also: reader_factory::min_buffer_usage() and; reader_factory::multiple_buffer_usage()

Member Function Documentation

◆ do_seek()

virtual bool do_seek ( scoped_lock & )

inlineprotectedvirtual

When this gets called, buffers_ has already been cleared and the waiters have been removed. start_offset_, size_ and remaining_ have already been set.

◆ get_buffer()

std::pair<aio_result, buffer_lease> get_buffer ( aio_waiter & h )

Gets the next buffer with data from the reader.

If it returns aio_result::ok, a buffer may be returned as well for the caller to consume. If no buffer is returned on aio_result::ok, the reader has reached eof.

If aio_result::error is returned, the reader has failed and can only be closed.

After getting aio_result::wait, do not call get_buffer again until after the passed waiter got on_buffer_availability() invoked.

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

reader.hpp

Public Member Functions

Protected Member Functions