Mercurial > gemma
view pkg/controllers/diff.go @ 3488:aa264021e2bf zpg-ldc
merged default into zpg-ldc branch.
author | Sascha L. Teichmann <sascha.teichmann@intevation.de> |
---|---|
date | Mon, 27 May 2019 16:38:07 +0200 |
parents | 857bb070b9f1 |
children | 2a079d0a71c1 |
line wrap: on
line source
// 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 controllers import ( "database/sql" "fmt" "log" "net/http" "sync" "time" "golang.org/x/sync/semaphore" "gemma.intevation.de/gemma/pkg/common" "gemma.intevation.de/gemma/pkg/models" "gemma.intevation.de/gemma/pkg/octree" ) const ( contourTolerance = 0.1 contourStep = 0.1 ) const ( diffIDSQL = ` SELECT sd.id FROM caching.sounding_differences sd JOIN waterway.sounding_results srm ON sd.minuend = srm.id JOIN waterway.sounding_results srs ON sd.subtrahend = srs.id WHERE srm.bottleneck_id = srs.bottleneck_id AND srm.bottleneck_id = $1 AND srm.date_info = $2::date AND srs.date_info = $3::date ` insertDiffSQL = ` WITH soundings AS ( SELECT sr.id AS id, sr.date_info AS date_info FROM waterway.sounding_results sr WHERE sr.bottleneck_id = $1 ) INSERT INTO caching.sounding_differences (minuend, subtrahend) SELECT m.id, s.id FROM soundings m, soundings s WHERE m.date_info = $2::date AND s.date_info = $3::date RETURNING id ` insertDiffContourSQL = ` INSERT INTO caching.sounding_differences_contour_lines ( sounding_differences_id, height, lines ) SELECT $5, $4, ST_Transform( ST_Multi( ST_CollectionExtract( ST_SimplifyPreserveTopology( ST_Multi(ST_Collectionextract( ST_MakeValid(ST_GeomFromWKB($1, $2::integer)), 2)), $3 ), 2 ) ), 4326 ) ` ) // Only allow three diffence calculation at once. // TODO: Make this configurable? var diffCalculationSemaphore = semaphore.NewWeighted(int64(3)) func diffCalculation( input interface{}, req *http.Request, conn *sql.Conn, ) (jr JSONResult, err error) { begin := time.Now() start := begin dci := input.(*models.DiffCalculationInput) ctx := req.Context() var id int64 err = conn.QueryRowContext( ctx, diffIDSQL, dci.Bottleneck, dci.Minuend.Time, dci.Subtrahend.Time, ).Scan(&id) switch { case err == sql.ErrNoRows: // We need to calculate it. case err != nil: return default: // We already have this diff jr = JSONResult{ Result: map[string]int64{"id": id}, } return } // DoS counter measure. if err = diffCalculationSemaphore.Acquire(ctx, 1); err != nil { return } defer diffCalculationSemaphore.Release(1) minuendTree, err := octree.FromCache( ctx, conn, dci.Bottleneck, dci.Minuend.Time) log.Printf("info: loading minuend octree took %s\n", time.Since(start)) if err != nil { return } if minuendTree == nil { err = JSONError{ Code: http.StatusNotFound, Message: fmt.Sprintf("Cannot find survey for %s/%s.", dci.Bottleneck, dci.Minuend.Format(common.DateFormat)), } return } start = time.Now() subtrahendTree, err := octree.FromCache( ctx, conn, dci.Bottleneck, dci.Subtrahend.Time) log.Printf("info: loading subtrahend octree took %s\n", time.Since(start)) if err != nil { return } if subtrahendTree == nil { err = JSONError{ Code: http.StatusNotFound, Message: fmt.Sprintf("Cannot find survey for %s/%s.", dci.Bottleneck, dci.Subtrahend.Format(common.DateFormat)), } return } // We need a slow path implementation for this. if minuendTree.EPSG != subtrahendTree.EPSG { err = JSONError{ Code: http.StatusInternalServerError, Message: "Calculating differences between two different " + "EPSG code octrees are not supported, yet.", } return } start = time.Now() points := minuendTree.Diff(subtrahendTree) log.Printf("info: A - B took %v\n", time.Since(start)) // The Triangulation and the loading of the clipping // polygon can be done concurrently. jobs := make(chan func()) wg := new(sync.WaitGroup) for i := 0; i < 2; i++ { wg.Add(1) go func() { defer wg.Done() for job := range jobs { job() } }() } var ( tri *octree.Triangulation triErr error clip *octree.Polygon clipErr error ) jobs <- func() { start := time.Now() tri, triErr = points.Triangulate() log.Printf("info: triangulation took %v\n", time.Since(start)) } jobs <- func() { start := time.Now() clip, clipErr = octree.LoadClippingPolygon( ctx, conn, minuendTree.EPSG, dci.Bottleneck, dci.Minuend.Time, dci.Subtrahend.Time) log.Printf("info: loading clipping polygon took %v\n", time.Since(start)) } close(jobs) wg.Wait() switch { case triErr != nil && clipErr != nil: err = fmt.Errorf("%v %v", triErr, clipErr) return case triErr != nil: err = triErr return case clipErr != nil: err = clipErr return } start = time.Now() tin := tri.Tin() removed := tin.Clip(clip) log.Printf("info: clipping TIN took %v\n", time.Since(start)) start = time.Now() log.Printf("info: Number of triangles to clip: %d\n", len(removed)) builder := octree.NewBuilder(tin) builder.Build(removed) log.Printf("info: building octree took %v\n", time.Since(start)) tree := builder.Tree() log.Printf("info: min/max: %f %f\n", tree.Min.Z, tree.Max.Z) heights := octree.SampleDiffHeights( tree.Min.Z, tree.Max.Z, contourStep) log.Printf("info: num heights: %d\n", len(heights)) start = time.Now() // XXX: Maybe we should start this transaction earlier!? var tx *sql.Tx if tx, err = conn.BeginTx(ctx, nil); err != nil { return } defer tx.Rollback() var stmt *sql.Stmt if stmt, err = tx.PrepareContext(ctx, insertDiffContourSQL); err != nil { return } defer stmt.Close() if err = tx.QueryRowContext( ctx, insertDiffSQL, dci.Bottleneck, dci.Minuend.Time, dci.Subtrahend.Time, ).Scan(&id); err != nil { return } octree.DoContours(tree, heights, func(res *octree.ContourResult) { if err == nil && len(res.Lines) > 0 { _, err = stmt.ExecContext( ctx, res.Lines.AsWKB2D(), minuendTree.EPSG, contourTolerance, res.Height, id, ) } }) log.Printf("info: calculating and storing iso lines took %v\n", time.Since(start)) if err != nil { return } if err = tx.Commit(); err != nil { log.Printf("info: difference calculation failed after %v\n", time.Since(begin)) return } log.Printf("info: difference calculation succeed after %v\n", time.Since(begin)) jr = JSONResult{ Result: map[string]int64{"id": id}, } return }