Mercurial > gemma
view pkg/octree/slice.go @ 2624:9dbaf69c7a66
Improve geoserver config to better calculate bounding boxes
* Disable the use of estimated extents for the postgis storage
configuration for geoserver, which is set via the gemma middleware.
This way we are able to get better bounding boxes for many layers
where the postgis function `ST_EstimatedExtent()` would be far off.
author | Bernhard Reiter <bernhard@intevation.de> |
---|---|
date | Wed, 13 Mar 2019 16:18:39 +0100 |
parents | 7686c7c23506 |
children |
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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, 2019 by via donau // – Österreichische Wasserstraßen-Gesellschaft mbH // Software engineering by Intevation GmbH // // Author(s): // * Sascha L. Teichmann <sascha.teichmann@intevation.de> package octree import ( "runtime" "sync" ) type PointMap map[Point]float64 func (pm PointMap) Triangulate() (*Triangulation, error) { vertices := make([]Vertex, len(pm)) var i int for p, z := range pm { vertices[i] = Vertex{X: p.X, Y: p.Y, Z: z} i++ } return Triangulate(vertices) } func sliceWork( vs []Vertex, dst PointMap, fn func([]Vertex, func([]Vertex) []Vertex), ) { n := runtime.NumCPU() wg := new(sync.WaitGroup) slices := make(chan []Vertex) out := make(chan []Vertex) pool := make(chan []Vertex, n) const pageSize = 2048 turn := func(p []Vertex) []Vertex { if p != nil { out <- p } select { case p = <-pool: default: p = make([]Vertex, 0, pageSize) } return p } for i := 0; i < n; i++ { wg.Add(1) go func() { defer wg.Done() for slice := range slices { fn(slice, turn) } }() } done := make(chan struct{}) go func() { defer close(done) for s := range out { for i := range s { v := &s[i] key := Point{X: v.X, Y: v.Y} if z, found := dst[key]; found { dst[key] = (z + v.Z) * 0.5 } else { dst[key] = v.Z } } select { case pool <- s[:0:pageSize]: default: } } }() size := len(vs)/n + 1 for len(vs) > 0 { var l int if len(vs) < size { l = len(vs) } else { l = size } slices <- vs[:l] vs = vs[l:] } close(slices) wg.Wait() close(out) <-done }