coverage

Documentation

Overview

package coverage provides methods for deriving map tile coverage for Who's On First records.

Index

• func CoverageWithFeature(ctx context.Context, opts *CoverageOptions, body []byte) (map[uint]maptile.Set, error)
• func CoverageWithFeatureAndCallback(ctx context.Context, opts *CoverageOptions, body []byte, ...) error
• func CoverageWithFeatureAndChannels(ctx context.Context, opts *CoverageOptions, body []byte, rsp_ch chan *Coverage, ...)
• type Coverage
• type CoverageCallbackFunc
• type CoverageOptions
  • func DefaultCoverageOptions() (*CoverageOptions, error)

Functions

func CoverageWithFeature

func CoverageWithFeature(ctx context.Context, opts *CoverageOptions, body []byte) (map[uint]maptile.Set, error)

CoverageWithFeature returns a map of tiles for a Who's On Feature record. The map is keyed by zoom level and the value of each is a list of tiles that cover the feature.

func CoverageWithFeatureAndCallback

func CoverageWithFeatureAndCallback(ctx context.Context, opts *CoverageOptions, body []byte, cb CoverageCallbackFunc) error

CoverageWithFeatureAndCallback will dispatch coverage information for each zoom level defined in 'opts' to a callback function defined in 'cb'.

func CoverageWithFeatureAndChannels

func CoverageWithFeatureAndChannels(ctx context.Context, opts *CoverageOptions, body []byte, rsp_ch chan *Coverage, err_ch chan error, done_ch chan bool)

CoverageWithFeatureAndChannels returns coverage information for each zoom level defined in 'opts' as it is determined using channels.

Types

type Coverage

type Coverage struct {
	// The Who's On First ID of the record being processed.
	Id int64
	// The zoom level being processed.
	Zoom uint
	// The set of tiles that cover feature 'Id' at zoom level 'Zoom'.
	Tiles maptile.Set
}

Coverage is a struct containing information returned by the CoverageWithFeatureAndChannels.

type CoverageCallbackFunc

type CoverageCallbackFunc func(context.Context, *Coverage) error

CoverageCallbackFunc is a user-defined callback function invoked by CoverageWithFeatureAndCallback method.

type CoverageOptions

type CoverageOptions struct {
	// A valid go-spatial/geom/slippy.Grid used to generate coverage information.
	Grid slippy.Grid
	// A list of zoom levels to determine coverage for.
	ZoomLevels []uint
}

CoverageOptions defines common options for the CoverageWithFeature and CoverageWithFeatureAndChannels methods

func DefaultCoverageOptions

func DefaultCoverageOptions() (*CoverageOptions, error)

DefaultCoverageOptions returns a CoverageOptions instance with a 4326 grid and zoom levels ranging from 1 to 20.