seastar::input_stream< CharType > Class Template Reference

Detailed Description

template<typename CharType>
class seastar::input_stream< CharType >

Buffers data from a data_source and provides a stream interface to the user.

Note

All methods must be called sequentially. That is, no method may be invoked before the previous method's returned future is resolved.

#include <seastar/core/iostream.hh>

Public Types
using	consumption_result_type = consumption_result< CharType >
using	unconsumed_remainder = std::optional< tmp_buf >
using	char_type = CharType

Public Member Functions
	input_stream (data_source fd) noexcept
	input_stream (input_stream &&)=default
input_stream &	operator= (input_stream &&)=default
future< temporary_buffer< CharType > >	read_exactly (size_t n)
template<typename Consumer >
future	consume (Consumer &&c)
template<typename Consumer >
future	consume (Consumer &c)
bool	eof () const
future< tmp_buf >	read ()
future< tmp_buf >	read_up_to (size_t n)
future	close ()
future	skip (uint64_t n)
	Ignores n next bytes from the stream.
data_source	detach () &&

Protected Member Functions
void	reset ()
data_source *	fd ()

Member Function Documentation

close()

template<typename CharType >

future seastar::input_stream< CharType >::close ( )

inline

Detaches the input_stream from the underlying data source.

Waits for any background operations (for example, read-ahead) to complete, so that the any resources the stream is using can be safely destroyed. An example is a file resource used by the stream returned by make_file_input_stream().

Returns

a future that becomes ready when this stream no longer needs the data source.

detach()

template<typename CharType >

data_source seastar::input_stream< CharType >::detach

Detaches the underlying data_source from the input_stream.

The intended usage is custom data_source_impl implementations wrapping an existing input_stream, therefore it shouldn't be called on an input_stream that was already used. After calling detach() the input_stream is in an unusable, moved-from state.

Exceptions

std::logic_error

if called on a used stream

Returns

the data_source

read()

template<typename CharType >

future< temporary_buffer< CharType > > seastar::input_stream< CharType >::read

Returns some data from the stream, or an empty buffer on end of stream.

read_exactly()

template<typename CharType >

future< temporary_buffer< CharType > > seastar::input_stream< CharType >::read_exactly

(

size_t

n

)

Reads n bytes from the stream, or fewer if reached the end of stream.

Returns

a future that waits until n bytes are available in the stream and returns them. If the end of stream is reached before n bytes were read, fewer than n bytes will be returned - so despite the method's name, the caller must not assume the returned buffer will always contain exactly n bytes.

Exceptions

if	an I/O error occurs during the read. As explained above, prematurely reaching the end of stream is not an I/O error.

read_up_to()

template<typename CharType >

future< temporary_buffer< CharType > > seastar::input_stream< CharType >::read_up_to

(

size_t

n

)

Returns up to n bytes from the stream, or an empty buffer on end of stream.

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

• seastar/core/iostream.hh
• seastar/core/iostream-impl.hh