Struct gdal::Dataset

pub struct Dataset { /* private fields */ }

Wrapper around a GDALDataset object.

Represents both a vector dataset containing a collection of layers; and a raster dataset containing a collection of raster-bands.

Implementations

impl Dataset

pub unsafe fn c_dataset(&self) -> GDALDatasetH

Returns the wrapped C pointer

Safety

This method returns a raw C pointer

pub fn open<P: AsRef<Path>>(path: P) -> Result<Dataset>

Open a dataset at the given path with default options.

pub fn open_ex<P: AsRef<Path>>( path: P, options: DatasetOptions<'_> ) -> Result<Dataset>

Open a dataset with extended options. See GDALOpenEx.

pub fn flush_cache(&mut self) -> Result<()>

Flush all write cached data to disk.

See [GDALFlushCache].

Note: on GDAL versions older than 3.7, this function always succeeds.

pub fn close(self) -> Result<()>

Close the dataset.

See [GDALClose].

Note: on GDAL versions older than 3.7.0, this function always succeeds.

pub unsafe fn from_c_dataset(c_dataset: GDALDatasetH) -> Dataset

Creates a new Dataset by wrapping a C pointer

Safety

This method operates on a raw C pointer The dataset must not have been closed (using [GDALClose]) before.

pub fn projection(&self) -> String

Fetch the projection definition string for this dataset.

pub fn set_projection(&mut self, projection: &str) -> Result<()>

Set the projection reference string for this dataset.

pub fn spatial_ref(&self) -> Result<SpatialRef>

Get the spatial reference system for this dataset.

pub fn set_spatial_ref(&mut self, spatial_ref: &SpatialRef) -> Result<()>

Set the spatial reference system for this dataset.

pub fn create_copy<P: AsRef<Path>>( &self, driver: &Driver, filename: P, options: &[RasterCreationOption<'_>] ) -> Result<Dataset>

pub fn driver(&self) -> Driver

Fetch the driver to which this dataset relates.

pub fn rasterband(&self, band_index: isize) -> Result<RasterBand<'_>>

Fetch a band object for a dataset.

Applies to raster datasets, and fetches the rasterband at the given 1-based index.

pub fn root_group(&self) -> Result<Group<'_>>

Opens the root group of a multi-dim GDAL raster

Note

You must have opened the dataset with the GdalOpenFlags::GDAL_OF_MULTIDIM_RASTER flag in order for it to work.

pub fn build_overviews( &mut self, resampling: &str, overviews: &[i32], bands: &[i32] ) -> Result<()>

Builds overviews for the current Dataset. See GDALBuildOverviews.

Arguments

• resampling - resampling method, as accepted by GDAL, e.g. "CUBIC"
• overviews - list of overview decimation factors, e.g. &[2, 4, 8, 16, 32]
• bands - list of bands to build the overviews for, or empty for all bands

pub fn layer_count(&self) -> isize

Get the number of layers in this dataset.

pub fn layer(&self, idx: isize) -> Result<Layer<'_>>

Fetch a layer by index.

Applies to vector datasets, and fetches by the given 0-based index.

pub fn into_layer(self, idx: isize) -> Result<OwnedLayer>

Fetch a layer by index.

Applies to vector datasets, and fetches by the given 0-based index.

pub fn layer_by_name(&self, name: &str) -> Result<Layer<'_>>

Fetch a layer by name.

pub fn into_layer_by_name(self, name: &str) -> Result<OwnedLayer>

Fetch a layer by name.

pub fn layers(&self) -> LayerIterator<'_>

Returns an iterator over the layers of the dataset.

pub fn raster_count(&self) -> isize

Fetch the number of raster bands on this dataset.

pub fn raster_size(&self) -> (usize, usize)

Returns the raster dimensions: (width, height).

pub fn create_layer(&mut self, options: LayerOptions<'_>) -> Result<Layer<'_>>

Creates a new layer. The LayerOptions struct implements Default, so you only need to specify those options that deviate from the default.

Examples

Create a new layer with an empty name, no spatial reference, and unknown geometry type:

let blank_layer = dataset.create_layer(Default::default()).unwrap();

Create a new named line string layer using WGS84:

let roads = dataset.create_layer(LayerOptions {
    name: "roads",
    srs: Some(&SpatialRef::from_epsg(4326).unwrap()),
    ty: gdal_sys::OGRwkbGeometryType::wkbLineString,
    ..Default::default()
}).unwrap();

pub fn set_geo_transform(&mut self, transformation: &GeoTransform) -> Result<()>

Set the Dataset’s affine transformation; also called a geo-transformation.

This is like a linear transformation preserves points, straight lines and planes. Also, sets of parallel lines remain parallel after an affine transformation.

Arguments

• transformation - coefficients of the transformation, which are:
  • x-coordinate of the top-left corner pixel (x-offset)
  • width of a pixel (x-resolution)
  • row rotation (typically zero)
  • y-coordinate of the top-left corner pixel
  • column rotation (typically zero)
  • height of a pixel (y-resolution, typically negative)

pub fn geo_transform(&self) -> Result<GeoTransform>

Get the coefficients of the Dataset’s affine transformation.

Returns

• x-coordinate of the top-left corner pixel (x-offset)
• width of a pixel (x-resolution)
• row rotation (typically zero)
• y-coordinate of the top-left corner pixel
• column rotation (typically zero)
• height of a pixel (y-resolution, typically negative)

pub fn start_transaction(&mut self) -> Result<Transaction<'_>>

For datasources which support transactions, this creates a transaction.

Because the transaction implements DerefMut, it can be used in place of the original Dataset to make modifications. All changes done after the start of the transaction are applied to the datasource when commit is called. They may be canceled by calling rollback instead, or by dropping the Transaction without calling commit.

Depending on the driver, using a transaction can give a huge performance improvement when creating a lot of geometry at once. This is because the driver doesn’t need to commit every feature to disk individually.

If starting the transaction fails, this function will return OGRErr::OGRERR_FAILURE. For datasources that do not support transactions, this function will always return OGRErr::OGRERR_UNSUPPORTED_OPERATION.

Limitations:

• Datasources which do not support efficient transactions natively may use less efficient emulation of transactions instead; as of GDAL 3.1, this only applies to the closed-source FileGDB driver, which (unlike OpenFileGDB) is not available in a GDAL build by default.

• At the time of writing, transactions only apply on vector layers.

• Nested transactions are not supported.

• If an error occurs after a successful start_transaction, the whole transaction may or may not be implicitly canceled, depending on the driver. For example, the PG driver will cancel it, but the SQLite and GPKG drivers will not.

Example:

fn create_point_grid(dataset: &mut Dataset) -> gdal::errors::Result<()> {
    use gdal::vector::Geometry;

    // Start the transaction.
    let mut txn = dataset.start_transaction()?;

    let mut layer = txn.create_layer(LayerOptions {
        name: "grid",
        ty: gdal_sys::OGRwkbGeometryType::wkbPoint,
        ..Default::default()
    })?;
    for y in 0..100 {
        for x in 0..100 {
            let wkt = format!("POINT ({} {})", x, y);
            layer.create_feature(Geometry::from_wkt(&wkt)?)?;
        }
    }

    // We got through without errors. Commit the transaction and return.
    txn.commit()?;
    Ok(())
}

pub fn execute_sql<S: AsRef<str>>( &self, query: S, spatial_filter: Option<&Geometry>, dialect: Dialect ) -> Result<Option<ResultSet<'_>>>

Execute a SQL query against the Dataset. It is equivalent to calling GDALDatasetExecuteSQL. Returns a sql::ResultSet, which can be treated just as any other Layer.

Queries such as ALTER TABLE, CREATE INDEX, etc. have no sql::ResultSet, and return None, which is distinct from an empty sql::ResultSet.

Arguments

• query: The SQL query
• spatial_filter: Limit results of the query to features that intersect the given Geometry
• dialect: The dialect of SQL to use. See https://gdal.org/user/ogr_sql_sqlite_dialect.html

Example

use gdal::vector::sql;
use gdal::vector::LayerAccess;

let ds = Dataset::open(Path::new("fixtures/roads.geojson")).unwrap();
let query = "SELECT kind, is_bridge, highway FROM roads WHERE highway = 'pedestrian'";
let mut result_set = ds.execute_sql(query, None, sql::Dialect::DEFAULT).unwrap().unwrap();

assert_eq!(10, result_set.feature_count());

for feature in result_set.features() {
    let highway = feature
        .field("highway")
        .unwrap()
        .unwrap()
        .into_string()
        .unwrap();

    assert_eq!("pedestrian", highway);
}

impl Dataset

pub fn gcp_spatial_ref(&self) -> Option<SpatialRef>

Get output spatial reference system for GCPs.

Notes

• This is separate and distinct from Dataset::spatial_ref, and only applies to the representation of ground control points, when embedded.

See: GDALGetGCPSpatialRef

pub fn gcp_projection(&self) -> Option<String>

Get the projection definition string for the GCPs in this dataset.

Notes

• This is separate and distinct from Dataset::projection, and only applies to embedded GCPs.

See: GDALGetGCPProjection

pub fn gcps(&self) -> &[GcpRef<'_>]

Fetch GCPs.

See: GDALDataset::GetGCPs

pub fn set_gcps(&self, gcps: Vec<Gcp>, spatial_ref: &SpatialRef) -> Result<()>

Assign GCPs.

This method assigns the passed set of GCPs to this dataset, as well as setting their coordinate system.

See: GDALDataset::SetGCPs(int, const GDAL_GCP *, const OGRSpatialReference *)

Panics

Panics if gcps has more than libc::c_int::MAX elements.

Trait Implementations

impl Debug for Dataset

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Drop for Dataset

fn drop(&mut self)

Executes the destructor for this type.

impl From<Dataset> for MultiDimTranslateDestination

fn from(dataset: Dataset) -> Self

Converts to this type from the input type.

impl From<OwnedLayer> for Dataset

fn from(owned_layer: OwnedLayer) -> Self

Converts to this type from the input type.

impl Metadata for Dataset

fn description(&self) -> Result<String>

For most crate::Datasets, method returns this is the originating filename. For crate::raster::RasterBands it is a description (if supported) or "".

fn metadata_domains(&self) -> Vec<String>

Metadata in GDAL is partitioned into namespaces, knows as “domains” in the GDAL Data Model. GDAL types with metadata (a.k.a. “Major Objects”) have a default or “root” domain identified by the empty string (""). Specific “Major Object” types may have other conventionally recognized domains. For example, in raster Datasets you may come across the domains SUBDATASETS, IMAGE_STRUCTURE, RPC, IMAGERY, xml:, etc.

fn metadata_domain(&self, domain: &str) -> Option<Vec<String>>

Get all the metadata values within the given domain. Returns None if domain is not defined. Entries in the returned Vec<String> are formatted as “Name=value” pairs

fn metadata_item(&self, key: &str, domain: &str) -> Option<String>

Get a single metadata entry, as indicated by key and domain.

fn set_metadata_item( &mut self, key: &str, value: &str, domain: &str ) -> Result<()>

Set a metadata item in given domain at given key.

fn set_description(&mut self, description: &str) -> Result<()>

For Datasets this sets the dataset name; normally application code should not set the “description” for GDALDatasets. For RasterBands it is actually a description (if supported) or "".

fn metadata(&self) -> MetadataIter<'_>where Self: Sized,

Get an iterator over metadata entries, across all domains.

impl Send for Dataset