penpot/backend/src/app/svgparse.clj
2021-02-10 12:07:35 +01:00

137 lines
3.9 KiB
Clojure

;; This Source Code Form is subject to the terms of the Mozilla Public
;; License, v. 2.0. If a copy of the MPL was not distributed with this
;; file, You can obtain one at http://mozilla.org/MPL/2.0/.
;;
;; This Source Code Form is "Incompatible With Secondary Licenses", as
;; defined by the Mozilla Public License, v. 2.0.
;;
;; Copyright (c) 2020 UXBOX Labs SL
(ns app.svgparse
(:require
[app.common.exceptions :as ex]
[app.metrics :as mtx]
[app.util.graal :as graal]
[app.util.pool :as pool]
[clojure.java.io :as io]
[clojure.spec.alpha :as s]
[clojure.xml :as xml]
[integrant.core :as ig])
(:import
java.util.function.Consumer
org.apache.commons.io.IOUtils))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; SVG Clean
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(declare clean-svg)
(declare prepare-context-pool)
(defmethod ig/pre-init-spec ::svgc [_]
(s/keys :req-un [::mtx/metrics]))
(defmethod ig/init-key ::svgc
[_ {:keys [metrics] :as cfg}]
(let [pool (prepare-context-pool cfg)
cfg (assoc cfg :pool pool)
handler #(clean-svg cfg %)
handler (->> {:registry (:registry metrics)
:type :summary
:name "svgc_timing"
:help "svg optimization function timing"}
(mtx/instrument handler))]
(with-meta handler {::pool pool})))
(defmethod ig/halt-key! ::svgc
[_ f]
(let [{:keys [::pool]} (meta f)]
(pool/clear! pool)
(pool/close! pool)))
(defn- prepare-context-pool
[cfg]
(pool/create
{:min-idle (:min-idle cfg 0)
:max-idle (:max-idle cfg 3)
:max-total (:max-total cfg 3)
:create
(fn []
(let [ctx (graal/context "js")]
(->> (graal/source "js" (io/resource "svgclean.js"))
(graal/eval! ctx))
ctx))
:destroy
(fn [ctx]
(graal/close! ctx))}))
(defn- clean-svg
[{:keys [pool]} data]
(with-open [ctx (pool/acquire pool)]
(let [res (promise)
optimize (-> (graal/get-bindings @ctx "js")
(graal/get-member "svgc")
(graal/get-member "optimize"))
resultp (graal/invoke optimize data)]
(graal/invoke-member resultp "then"
(reify Consumer
(accept [_ val]
(deliver res val))))
(graal/invoke-member resultp "catch"
(reify Consumer
(accept [_ err]
(deliver res err))))
(let [result (deref res)]
(if (instance? Throwable result)
(throw result)
result)))))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Handler
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(declare handler)
(declare process-request)
(s/def ::svgc fn?)
(defmethod ig/pre-init-spec ::handler [_]
(s/keys :req-un [::mtx/metrics ::svgc]))
(defmethod ig/init-key ::handler
[_ {:keys [metrics] :as cfg}]
(let [handler #(handler cfg %)]
(->> {:registry (:registry metrics)
:type :summary
:name "http_handler_svgparse_timing"
:help "svg parse timings"}
(mtx/instrument handler))))
(defn- handler
[cfg {:keys [headers body] :as request}]
(when (not= "image/svg+xml" (get headers "content-type"))
(ex/raise :type :validation
:code :unsupported-mime-type
:mime (get headers "content-type")))
{:status 200
:body (process-request cfg body)})
(defn parse
[data]
(try
(with-open [istream (IOUtils/toInputStream data "UTF-8")]
(xml/parse istream))
(catch org.xml.sax.SAXParseException _e
(ex/raise :type :validation
:code :invalid-svg-file))))
(defn process-request
[{:keys [svgc] :as cfg} body]
(let [data (slurp body)
data (svgc data)]
(parse data)))