Mercurial > gemma
view pkg/middleware/json.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 | 4394daeea96a |
children | 6270951dda28 |
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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) 2019 by via donau // – Österreichische Wasserstraßen-Gesellschaft mbH // Software engineering by Intevation GmbH // // Author(s): // * Sascha L. Teichmann <sascha.teichmann@intevation.de> package middleware import ( "context" "encoding/json" "io" "net/http" ) type jsonInputKeyType int const jsonInputKey jsonInputKeyType = 0 // DefaultLimit limits the incoming JSON payload to 2K to // prevent flooding the server. const DefaultLimit = 2048 // GetJSONInput returns the deserialized JSON data from // the incoming request if any. func GetJSONInput(req *http.Request) interface{} { return req.Context().Value(jsonInputKey) } // JSONMiddleware is a middleware to deserialize the incomming // request body to a object to be created by a given input function // and stores the result into the context. // GetJSONInput can be used to receive the deserialized data. // limit limits the size of the incoming body to prevent // flooding the server. func JSONMiddleware(next http.Handler, input func(*http.Request) interface{}, limit int64) http.Handler { return http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) { dst := input(req) defer req.Body.Close() var r io.Reader switch { case limit == 0: r = io.LimitReader(req.Body, DefaultLimit) case limit > 0: r = io.LimitReader(req.Body, limit) default: r = req.Body } if err := json.NewDecoder(r).Decode(dst); err != nil { http.Error(rw, "error: "+err.Error(), http.StatusBadRequest) return } parent := req.Context() ctx := context.WithValue(parent, jsonInputKey, input) req = req.WithContext(ctx) next.ServeHTTP(rw, req) }) }