vg::io::ProtobufIterator< T > Class Template Reference

#include <protobuf_iterator.hpp>

Public Member Functions
	ProtobufIterator (istream &in)
	Constructor. More...
	ProtobufIterator ()=default
	Default constructor for an end iterator. More...
T &	operator* ()
const T &	operator* () const
const ProtobufIterator< T > &	operator++ ()
	In-place pre-increment to advance the iterator. More...
bool	operator== (const ProtobufIterator< T > &other) const
bool	operator!= (const ProtobufIterator< T > &other) const
bool	has_current () const
	Return true if dereferencing the iterator will produce a valid value, and false otherwise. More...
void	advance ()
T	take ()
	Take the current item, which must exist, and advance the iterator to the next one. More...
int64_t	tell_group () const
bool	seek_group (int64_t virtual_offset)

Static Public Member Functions
static pair< ProtobufIterator< T >, ProtobufIterator< T > >	range (istream &in)
	Returns iterators that act like begin() and end() for a stream containing messages. More...
static bool	parse_from_string (T &dest, const string &data)

Private Member Functions
void	fill_value ()

Private Attributes
MessageIterator	message_it
	Wrap a MessageIterator and just do Protobuf parsing on top of that. More...
T	value
	We always maintain a parsed version of the current message. More...

Detailed Description

template<typename T>
class vg::io::ProtobufIterator< T >

Refactored io::for_each function that follows the unidirectional iterator interface. Also supports seeking and telling at the group level in bgzip files. Cannot be copied, but can be moved.

Constructor & Destructor Documentation

ProtobufIterator() [1/2]

template<typename T >

vg::io::ProtobufIterator< T >::ProtobufIterator

(

istream &

in

)

Constructor.

ProtobufIterator() [2/2]

template<typename T >

vg::io::ProtobufIterator< T >::ProtobufIterator ( )

default

Default constructor for an end iterator.

Member Function Documentation

advance()

template<typename T >

auto vg::io::ProtobufIterator< T >::advance

Advance the iterator to the next message, or the end if this was the last message. Basically the same as ++.

fill_value()

template<typename T >

auto vg::io::ProtobufIterator< T >::fill_value

private

Fill in value, if message_it has a value of an appropriate tag. Scans through tag-only groups.

has_current()

template<typename T >

auto vg::io::ProtobufIterator< T >::has_current

Return true if dereferencing the iterator will produce a valid value, and false otherwise.

operator!=()

template<typename T >

auto vg::io::ProtobufIterator< T >::operator!=

(

const ProtobufIterator< T > &

other

)

const

Check if two iterators are not equal. Since you can only have one on a stream, this only has two equality classes: iterators that have hit the end, and iterators that haven't.

operator*() [1/2]

template<typename T >

auto vg::io::ProtobufIterator< T >::operator*

Get the current item. Caller may move it away. Only legal to call if we are not an end iterator.

operator*() [2/2]

template<typename T >

const T& vg::io::ProtobufIterator< T >::operator*

(

)

const

Get the current item when we are const. Only legal to call if we are not an end iterator.

operator++()

template<typename T >

auto vg::io::ProtobufIterator< T >::operator++

In-place pre-increment to advance the iterator.

operator==()

template<typename T >

auto vg::io::ProtobufIterator< T >::operator==

(

const ProtobufIterator< T > &

other

)

const

Check if two iterators are equal. Since you can only have one on a stream, this only has two equality classes: iterators that have hit the end, and iterators that haven't.

parse_from_string()

template<typename T >

auto vg::io::ProtobufIterator< T >::parse_from_string ( T &  dest, const string &  data  )

static

Parse a Protobuf message that may be very large from a string. Use this instead of ParseFromString on the message itself.

Returns the result of the parse attempt (i.e. whether it succeeded).

range()

template<typename T >

auto vg::io::ProtobufIterator< T >::range ( istream &  in )

static

Returns iterators that act like begin() and end() for a stream containing messages.

seek_group()

template<typename T >

auto vg::io::ProtobufIterator< T >::seek_group

(

int64_t

virtual_offset

)

Seek to the given virtual offset and start reading the group that is there. The next value produced will be the first value in that group (or in the next group that actually has values). If already at the start of the group at the given virtual offset, does nothing. Return false if seeking is unsupported or the seek fails.

take()

template<typename T >

auto vg::io::ProtobufIterator< T >::take

Take the current item, which must exist, and advance the iterator to the next one.

tell_group()

template<typename T >

auto vg::io::ProtobufIterator< T >::tell_group

Return the virtual offset of the group being currently read (i.e. the group to which the current message belongs), to seek back to. You can't seek back to the current message, just to the start of the group. Returns -1 instead if the underlying file doesn't support seek/tell. Returns the past-the-end virtual offset of the file if EOF is reached.

Member Data Documentation

message_it

template<typename T >

MessageIterator vg::io::ProtobufIterator< T >::message_it

private

Wrap a MessageIterator and just do Protobuf parsing on top of that.

value

template<typename T >

T vg::io::ProtobufIterator< T >::value

private

We always maintain a parsed version of the current message.

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

• deps/libvgio/include/vg/io/protobuf_iterator.hpp