NativeLayer Class Reference

Public Member Functions
	NativeLayer (OGRLayer *new_layer)
bool	is_valid () const
void	write_feature_cache_to_ram_layer ()
void	save_override ()
void	save_modified_layer (std::string path)
ExtentData	get_extent ()
std::shared_ptr< Feature >	create_feature ()
void	add_field (std::string name)
void	remove_field (std::string name)
std::list< std::shared_ptr< Feature > >	get_features ()
std::list< std::shared_ptr< Feature > >	get_features_near_position (double pos_x, double pos_y, double radius, int max_amount)
std::list< std::shared_ptr< Feature > >	get_features_in_square (double top_left_x, double top_left_y, double size_meters, int max_amount)
std::list< std::shared_ptr< Feature > >	get_feature_for_ogrfeature (OGRFeature *feature)
std::list< std::shared_ptr< Feature > >	get_feature_by_id (int id)
	Returns the feature corresponding to the given ID.
std::list< std::shared_ptr< Feature > >	get_features_by_attribute_filter (std::string filter)
	Filter the features of the layer by a given SQL-like query, e.g. "attributename < 1000".
void	clear_feature_cache ()
bool	is_feature_deleted (OGRFeature *feature)

Public Attributes
OGRLayer *	layer
OGRLayer *	ram_layer
std::map< GUIntBig, std::list< std::shared_ptr< Feature > > >	feature_cache
int	disk_feature_count
int	ram_feature_count

Member Function Documentation

clear_feature_cache()

void NativeLayer::clear_feature_cache

(

)

Removes all entries from the feature cache. Make sure this is not called when features exist which need to remain synchronized (signals across different origins)

create_feature()

std::shared_ptr< Feature > NativeLayer::create_feature

(

)

Create a new feature on the in-RAM layer corresponding to the actual disk layer. No changes are made on the original layer, so that layer can be opened as read-only. The exact type of the returned feature corresponds to the layer's geometry type.

get_feature_for_ogrfeature()

std::list< std::shared_ptr< Feature > > NativeLayer::get_feature_for_ogrfeature

(

OGRFeature *

feature

)

Returns the feature corresponding to the given OGRFeature: Either the cached one, or if there is none, a new one (then placed within the cache). Takes ownership of the passed OGRFeature, deleting it if it is not required thanks to a cache hit, and passing it on to the new Feature otherwise.

get_features()

std::list< std::shared_ptr< Feature > > NativeLayer::get_features

(

)

Return all features, regardless of what the geometry is (or if there even is geometry). Note that this means that no geometry will be available in those features - this should only be used for attributes.

get_features_in_square()

std::list< std::shared_ptr< Feature > > NativeLayer::get_features_in_square	(	double	top_left_x,
		double	top_left_y,
		double	size_meters,
		int	max_amount
	)

Return all features, regardless of what the geometry is, which somehow overlap with the rectangle created by the given top-left position and size. Parts of the geometry outside the rectangle are not cut, so features may extend outside of the circle. To prevent hangups from unexpectedly many features, a maximum amount can be given so that the remaining features are skipped.

get_features_near_position()

std::list< std::shared_ptr< Feature > > NativeLayer::get_features_near_position	(	double	pos_x,
		double	pos_y,
		double	radius,
		int	max_amount
	)

Return all features, regardless of what the geometry is, which somehow overlap with the circle created by the given position and radius. Parts of the geometry outside the circle are not cut, so features may extend outside of the circle. To prevent hangups from unexpectedly many features, a maximum amount can be given so that the remaining features are skipped.

Member Data Documentation

feature_cache

std::map<GUIntBig, std::list<std::shared_ptr<Feature> > > NativeLayer::feature_cache

Keeps track of all features which are in use due to having been returned, in order to ensure that we don't return two different Feature instances pointing to the same data. That way, updates to features don't need to be written anywhere: they exist within the Features of the feature cache.

A list of Feature pointers is used for the case of multi-features (e.g. MULTILINESTRING), where one OGRFeature corresponds to multiple of our Features. Usually though, each list has only one element.

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

• /github/workspace/src/vector-extractor/NativeLayer.h
• /github/workspace/src/vector-extractor/NativeLayer.cpp