Mercurial > gemma
view pkg/models/cross.go @ 5520:05db984d3db1
Improve performance of bottleneck area calculation
Avoid buffer calculations by replacing them with simple distance comparisons
and calculate the boundary of the result geometry only once per iteration.
In some edge cases with very large numbers of iterations, this reduced
the runtime of a bottleneck import by a factor of more than twenty.
author | Tom Gottfried <tom@intevation.de> |
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date | Thu, 21 Oct 2021 19:50:39 +0200 |
parents | 4847ac70103a |
children | 1222b777f51f |
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// This is Free Software under GNU Affero General Public License v >= 3.0 // without warranty, see README.md and license for details. // // SPDX-License-Identifier: AGPL-3.0-or-later // License-Filename: LICENSES/AGPL-3.0.txt // // Copyright (C) 2018 by via donau // – Österreichische Wasserstraßen-Gesellschaft mbH // Software engineering by Intevation GmbH // // Author(s): // * Sascha L. Teichmann <sascha.teichmann@intevation.de> package models import ( "bytes" "encoding/binary" "encoding/json" "errors" "fmt" "math" "time" "gemma.intevation.de/gemma/pkg/common" "gemma.intevation.de/gemma/pkg/wkb" ) type ( GeoJSONFeature string GeoJSONLineStringType string GeoJSONDate struct{ time.Time } GeoJSONLineString struct { Type GeoJSONLineStringType `json:"type"` } GeoJSONCoordinate struct { Lat float64 Lon float64 } GeoJSONCoordinateZ struct { Lat float64 Lon float64 Z float64 } CrossSectionInputProperties struct { Bottleneck string `json:"bottleneck"` Date GeoJSONDate `json:"date"` } GeoJSONLineCoordinates []GeoJSONCoordinate GeoJSONLineCoordinatesZ []GeoJSONCoordinateZ GeoJSONMultiLineCoordinatesZ []GeoJSONLineCoordinatesZ CrossSectionInputGeometry struct { Type GeoJSONLineStringType `json:"type"` Coordinates GeoJSONLineCoordinates `json:"coordinates"` } CrossSectionInput struct { Type GeoJSONFeature `json:"type"` Geometry CrossSectionInputGeometry `json:"geometry"` Properties CrossSectionInputProperties `json:"properties"` } CrossSectionOutputGeometry struct { Type string `json:"type"` Coordinates GeoJSONMultiLineCoordinatesZ `json:"coordinates"` } CrossSectionOutput struct { Type string `json:"type"` Geometry CrossSectionOutputGeometry `json:"geometry"` Properties map[string]interface{} `json:"properties"` } ) var ( errNoGeoJSONFeature = errors.New("not a valid GeoJSON feature") errNoGeoJSONLineStringType = errors.New("not a valid GeoJSON linestring type") errTooLessComponents = errors.New("too less components in coordinate") errTooLessCoordinates = errors.New("too less coordinates") ) func (lc *GeoJSONLineCoordinates) UnmarshalJSON(data []byte) error { var coords []GeoJSONCoordinate if err := json.Unmarshal(data, &coords); err != nil { return err } if len(coords) < 2 { return errTooLessCoordinates } *lc = GeoJSONLineCoordinates(coords) return nil } func (d *GeoJSONDate) UnmarshalJSON(data []byte) error { var s string if err := json.Unmarshal(data, &s); err != nil { return err } t, err := time.Parse(common.DateFormat, s) if err != nil { return err } *d = GeoJSONDate{t} return nil } func (c *GeoJSONCoordinate) UnmarshalJSON(data []byte) error { var pos []float64 if err := json.Unmarshal(data, &pos); err != nil { return err } if len(pos) < 2 { return errTooLessComponents } *c = GeoJSONCoordinate{Lat: pos[0], Lon: pos[1]} return nil } func (t *GeoJSONFeature) UnmarshalJSON(data []byte) error { var s string if err := json.Unmarshal(data, &s); err != nil { return err } if s != "Feature" { return errNoGeoJSONFeature } *t = GeoJSONFeature(s) return nil } func (t *GeoJSONLineStringType) UnmarshalJSON(data []byte) error { var s string if err := json.Unmarshal(data, &s); err != nil { return err } if s != "LineString" { return errNoGeoJSONLineStringType } *t = GeoJSONLineStringType(s) return nil } func (lc GeoJSONLineCoordinates) AsWKB() []byte { size := 1 + 4 + 4 + len(lc)*(2*8) buf := bytes.NewBuffer(make([]byte, 0, size)) binary.Write(buf, binary.LittleEndian, wkb.NDR) binary.Write(buf, binary.LittleEndian, wkb.LineString) binary.Write(buf, binary.LittleEndian, uint32(len(lc))) for i := range lc { c := &lc[i] binary.Write(buf, binary.LittleEndian, math.Float64bits(c.Lat)) binary.Write(buf, binary.LittleEndian, math.Float64bits(c.Lon)) } return buf.Bytes() } func (cz GeoJSONCoordinateZ) MarshalJSON() ([]byte, error) { var buf bytes.Buffer fmt.Fprintf(&buf, "[%.8f,%.8f,%.8f]", cz.Lat, cz.Lon, cz.Z) return buf.Bytes(), nil } func (lcz *GeoJSONLineCoordinatesZ) Scan(src interface{}) error { data, ok := src.([]byte) if !ok { return errNoByteSlice } return lcz.FromWKB(data) } func (lcz *GeoJSONLineCoordinatesZ) FromWKB(data []byte) error { r := bytes.NewReader(data) endian, err := r.ReadByte() var order binary.ByteOrder switch { case err != nil: return err case endian == wkb.NDR: order = binary.LittleEndian case endian == wkb.XDR: order = binary.BigEndian default: return fmt.Errorf("unknown byte order %x", endian) } var geomType uint32 err = binary.Read(r, order, &geomType) switch { case err != nil: return err case geomType != wkb.LineStringZ: return fmt.Errorf("unknown geometry type %x", geomType) } var num uint32 if err = binary.Read(r, order, &num); err != nil { return err } coords := make(GeoJSONLineCoordinatesZ, num) for i := range coords { c := &coords[i] for _, addr := range []*float64{&c.Lat, &c.Lon, &c.Z} { if err = binary.Read(r, order, addr); err != nil { return err } } } *lcz = coords return nil } func (cz GeoJSONCoordinateZ) Equals(other GeoJSONCoordinateZ) bool { const ( xyEps = 1e-7 zEps = 1e-5 ) return math.Abs(cz.Lat-other.Lat) < xyEps && math.Abs(cz.Lon-other.Lon) < xyEps && math.Abs(cz.Z-other.Z) < zEps } func deg2rad(d float64) float64 { return d * math.Pi / 180.0 } func (cz GeoJSONCoordinateZ) Distance(other GeoJSONCoordinateZ) float64 { const EarthRadius = 6378137.0 dLat := deg2rad(other.Lat - cz.Lat) dLng := math.Abs(deg2rad(other.Lon - cz.Lon)) if dLng > math.Pi { dLng = 2*math.Pi - dLng } x := dLng * math.Cos(deg2rad((cz.Lat+other.Lat)/2.0)) return math.Sqrt(dLat*dLat+x*x) * EarthRadius } func (mls *GeoJSONMultiLineCoordinatesZ) FromWKB(data []byte) error { r := bytes.NewReader(data) var order binary.ByteOrder endian, err := r.ReadByte() switch { case err != nil: return err case endian == wkb.NDR: order = binary.LittleEndian case endian == wkb.XDR: order = binary.BigEndian default: return fmt.Errorf("unknown byte order %x", endian) } var geomType uint32 err = binary.Read(r, order, &geomType) switch { case err != nil: return err case geomType != wkb.MultiLineStringZ: return fmt.Errorf("unknown geometry type %d", geomType) } var numLines uint32 if err = binary.Read(r, order, &numLines); err != nil { return err } lines := make(GeoJSONMultiLineCoordinatesZ, numLines) for i := range lines { endian, err = r.ReadByte() switch { case err != nil: return err case endian == wkb.NDR: order = binary.LittleEndian case endian == wkb.XDR: order = binary.BigEndian default: return fmt.Errorf("unknown byte order %x", endian) } err = binary.Read(r, order, &geomType) switch { case err != nil: return err case geomType != wkb.LineStringZ: return fmt.Errorf("unknown geometry type %d", geomType) } var numPoints uint32 if err = binary.Read(r, order, &numPoints); err != nil { return err } points := make(GeoJSONLineCoordinatesZ, numPoints) for j := range points { var lat, lon, z uint64 if err = binary.Read(r, order, &lat); err != nil { return err } if err = binary.Read(r, order, &lon); err != nil { return err } if err = binary.Read(r, order, &z); err != nil { return err } c := &points[j] c.Lat = math.Float64frombits(lat) c.Lon = math.Float64frombits(lon) c.Z = math.Float64frombits(z) } lines[i] = points } *mls = lines return nil } func (mls *GeoJSONMultiLineCoordinatesZ) Scan(src interface{}) error { if src == nil { return nil } data, ok := src.([]byte) if !ok { return errNoByteSlice } return mls.FromWKB(data) }