Geometry_well_formed_checker Class Reference

WKB scanner event handler that checks if the WKB string is well formed. More...

Inheritance diagram for Geometry_well_formed_checker:

Public Member Functions
	Geometry_well_formed_checker (Geometry::wkbType type, Geometry::wkbByteOrder required_byte_order)
	Create a new even handler. More...
void	on_wkb_start (Geometry::wkbByteOrder bo, Geometry::wkbType geotype, const void *, uint32, bool has_hdr) override
	Notified when scanner sees the start of a geometry WKB. More...
void	on_wkb_end (const void *wkb) override
	Notified when scanner sees the end of a geometry WKB. More...
bool	continue_scan () const override
bool	is_well_formed ()
	Check if the parsed WKB was well-formed, as far as this handler knows. More...
const char *	get_last_position ()
	Get the position after the last parsed byte. More...
Public Member Functions inherited from WKB_scanner_event_handler
virtual	~WKB_scanner_event_handler ()=default

Private Attributes
Prealloced_array< Geometry::wkbType, 8 >	type
Geometry::wkbType	previous_type
	Current stack of types. More...
int	points_in_linestring
	Type of previous start/end. More...
const void *	last_position
	Points in current ls. More...
bool	is_ok
	Last wkb pointer seen. More...
Geometry::wkbByteOrder	required_byte_order
	Whether the WKB is OK so far. More...

Detailed Description

WKB scanner event handler that checks if the WKB string is well formed.

This doesn't check if the geometry is valid (e.g., it's not checking if a polygon is self-intersecting), it only checks some simple rules for WKB well-formedness:

R1. The byte order is as specified (constructor parameter) R2. The wkbType is within the supported range R3. The geometry is of the specified type (constructor parameter), or a subtype R4. Nested geometries contain only geometries that can be contained by that type R5. Linestrings have at least two points R6. Polygon rings have at least four points R7. Polygons have at least one ring R8. Collections, except geometrycollection, contain at least one element.

An additional requirement, that the WKB ends exactly at the end of the string, is checked by Geometry::is_well_formed(). The last parse position is maintained as last_position here to make that test possible.

Constructor & Destructor Documentation

Geometry_well_formed_checker()

Geometry_well_formed_checker::Geometry_well_formed_checker ( Geometry::wkbType  type, Geometry::wkbByteOrder  required_byte_order  )

inline

Create a new even handler.

Parameters

type	Expected geometry type. If set to Geometry::wkb_invalid_type, any geometry is allowed.
required_byte_order	The expected byted order

Member Function Documentation

continue_scan()

bool Geometry_well_formed_checker::continue_scan ( ) const

inlineoverridevirtual

Reimplemented from WKB_scanner_event_handler.

get_last_position()

const char * Geometry_well_formed_checker::get_last_position ( )

inline

Get the position after the last parsed byte.

Returns

Pointer pointing to after the last parsed byte.

is_well_formed()

bool Geometry_well_formed_checker::is_well_formed ( )

inline

Check if the parsed WKB was well-formed, as far as this handler knows.

There may be other conditions that cause the object to not be well-formed.

See also

Geometry::is_well_formed

Returns

True if the WKB was well-formed, false otherwise.

on_wkb_end()

void Geometry_well_formed_checker::on_wkb_end ( const void *  wkb )

inlineoverridevirtual

Notified when scanner sees the end of a geometry WKB.

Parameters

wkb	the position of the first byte after the WKB byte string which the scanner just scanned.

Implements WKB_scanner_event_handler.

on_wkb_start()

void Geometry_well_formed_checker::on_wkb_start ( Geometry::wkbByteOrder  bo, Geometry::wkbType  geotype, const void *  wkb, uint32  len, bool  has_hdr  )

inlineoverridevirtual

Notified when scanner sees the start of a geometry WKB.

Parameters

bo	byte order of the WKB.
geotype	geometry type of the WKB;
wkb	WKB byte string, the first byte after the WKB header if any.
len	NO. of bytes of the WKB byte string starting from wkb. There can be many geometries in the [wkb, wkb+len) buffer.
has_hdr	whether there is a WKB header right before 'wkb' in the byte string.

Implements WKB_scanner_event_handler.

Member Data Documentation

is_ok

bool Geometry_well_formed_checker::is_ok

private

Last wkb pointer seen.

last_position

const void* Geometry_well_formed_checker::last_position

private

Points in current ls.

points_in_linestring

int Geometry_well_formed_checker::points_in_linestring

private

Type of previous start/end.

previous_type

Geometry::wkbType Geometry_well_formed_checker::previous_type

private

Current stack of types.

required_byte_order

Geometry::wkbByteOrder Geometry_well_formed_checker::required_byte_order

private

Whether the WKB is OK so far.

type

Prealloced_array<Geometry::wkbType, 8> Geometry_well_formed_checker::type

private

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

• sql/spatial.cc