QGIS API Documentation 3.99.0-Master (26c88405ac0)
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QgsArrowSchema Class Reference

Wrapper around an ArrowSchema. More...

#include <qgsarrowiterator.h>

Public Member Functions

 QgsArrowSchema ()
 Construct invalid schema holder.
 QgsArrowSchema (const QgsArrowSchema &other)
 Copy constructor.
 ~QgsArrowSchema ()
unsigned long long cSchemaAddress () const
 Returns the address of the underlying ArrowSchema for import or export across boundaries.
void exportToAddress (unsigned long long otherAddress)
 Export this array to the address of an empty ArrowSchema for export across boundaries.
int geometryColumnIndex () const
 Returns the index of the column in this schema that should be populated with a feature geometry.
bool isValid () const
 Returns true if this wrapper object holds a valid ArrowSchema.
QgsArrowSchemaoperator= (const QgsArrowSchema &other)
 Assignment operator.
struct ArrowSchema * schema ()
 Access the underlying ArrowSchema from C++.
const struct ArrowSchema * schema () const
 Access the underlying ArrowSchema immutably from C++.
void setGeometryColumnIndex (int geometryColumnIndex)
 Set the index of the column in this schema that should be populated with a feature geometry.

Detailed Description

Wrapper around an ArrowSchema.

This object provides a helper to allow schemas to be passed to or returned from QGIS functions in C++ or Python. See the documentation for the Arrow C Data Interface for how to interact with the underlying ArrowSchema. https://arrow.apache.org/docs/format/CDataInterface.html

This object also stores the index of the geometry column that should be/will be populated from the geometry of iterated-over features.

Since
QGIS 4.0

Definition at line 143 of file qgsarrowiterator.h.

Constructor & Destructor Documentation

◆ QgsArrowSchema() [1/2]

QgsArrowSchema::QgsArrowSchema ( )

Construct invalid schema holder.

Definition at line 58 of file qgsarrowiterator.cpp.

◆ QgsArrowSchema() [2/2]

QgsArrowSchema::QgsArrowSchema ( const QgsArrowSchema & other)

Copy constructor.

Definition at line 61 of file qgsarrowiterator.cpp.

◆ ~QgsArrowSchema()

QgsArrowSchema::~QgsArrowSchema ( )

Definition at line 78 of file qgsarrowiterator.cpp.

Member Function Documentation

◆ cSchemaAddress()

unsigned long long QgsArrowSchema::cSchemaAddress ( ) const

Returns the address of the underlying ArrowSchema for import or export across boundaries.

Warning
This is intended for advanced usage and may cause a crash if used incorrectly.

Definition at line 96 of file qgsarrowiterator.cpp.

◆ exportToAddress()

void QgsArrowSchema::exportToAddress ( unsigned long long otherAddress)

Export this array to the address of an empty ArrowSchema for export across boundaries.

Warning
This is intended for advanced usage and may cause a crash if used incorrectly.

Definition at line 101 of file qgsarrowiterator.cpp.

◆ geometryColumnIndex()

int QgsArrowSchema::geometryColumnIndex ( ) const

Returns the index of the column in this schema that should be populated with a feature geometry.

Returns -1 if this value has not been specified.

Definition at line 112 of file qgsarrowiterator.cpp.

◆ isValid()

bool QgsArrowSchema::isValid ( ) const

Returns true if this wrapper object holds a valid ArrowSchema.

Definition at line 107 of file qgsarrowiterator.cpp.

◆ operator=()

QgsArrowSchema & QgsArrowSchema::operator= ( const QgsArrowSchema & other)

Assignment operator.

Definition at line 67 of file qgsarrowiterator.cpp.

◆ schema() [1/2]

struct ArrowSchema * QgsArrowSchema::schema ( )

Access the underlying ArrowSchema from C++.

Definition at line 86 of file qgsarrowiterator.cpp.

◆ schema() [2/2]

const struct ArrowSchema * QgsArrowSchema::schema ( ) const

Access the underlying ArrowSchema immutably from C++.

Definition at line 91 of file qgsarrowiterator.cpp.

◆ setGeometryColumnIndex()

void QgsArrowSchema::setGeometryColumnIndex ( int geometryColumnIndex)

Set the index of the column in this schema that should be populated with a feature geometry.

Definition at line 114 of file qgsarrowiterator.cpp.


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