Mercurial > gemma
view pkg/controllers/surveys.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 | fc01cdaf056d |
children | 3b842e951317 |
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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 Wilde <sascha.wilde@intevation.de> // * Sascha L. Teichmann <sascha.teichmann@intevation.de> // * Bernhard Reiter <bernhard.reiter@intevation.de> package controllers import ( "database/sql" "net/http" "github.com/gorilla/mux" "gemma.intevation.de/gemma/pkg/models" mw "gemma.intevation.de/gemma/pkg/middleware" ) const ( listSurveysSQL = ` SELECT DISTINCT s.bottleneck_id, s.date_info::text, s.depth_reference, COALESCE(g.objname, 'ERROR: MISSING GAUGE') AS gauge_objname, r.value AS waterlevel_value, COALESCE(s.surtyp, 'ERROR: MISSING SURVEY TYPE') AS surtype FROM waterway.bottlenecks AS b JOIN waterway.sounding_results AS s ON b.bottleneck_id = s.bottleneck_id LEFT JOIN waterway.gauges AS g ON b.gauge_location = g.location AND s.date_info::timestamptz <@ g.validity LEFT JOIN waterway.gauges_reference_water_levels AS r ON s.depth_reference = r.depth_reference AND g.location = r.location AND g.validity = r.validity WHERE b.objnam = $1` ) func listSurveys(req *http.Request) (jr mw.JSONResult, err error) { bottleneckName := mux.Vars(req)["bottleneck"] var rows *sql.Rows rows, err = mw.JSONConn(req).QueryContext(req.Context(), listSurveysSQL, bottleneckName) if err != nil { return } defer rows.Close() surveys := []*models.Survey{} // as we do not use the values here, we could simply the code here // to work without an explicit mdels/surverys.go // (like done in controllers/search.go) for rows.Next() { var survey models.Survey var surType string var level sql.NullInt64 if err = rows.Scan( &survey.BottleneckID, &survey.DateInfo, &survey.DepthReference, &survey.ReferenceGauge, &level, &surType, ); err != nil { return } switch { case level.Valid: survey.WaterLevelValue = &level.Int64 case survey.DepthReference == "ZPG": survey.WaterLevelValue = new(int64) } survey.SurveyType = models.SurveyType(surType) surveys = append(surveys, &survey) } if err = rows.Err(); err != nil { return } jr = mw.JSONResult{ Result: struct { Surveys []*models.Survey `json:"surveys"` }{surveys}, } return }