io.gatling.http.fetch.CssParser.scala Maven / Gradle / Ivy
/*
* Copyright 2011-2021 GatlingCorp (https://gatling.io)
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.gatling.http.fetch
import scala.annotation.{ switch, tailrec }
import scala.util.matching.Regex
import io.gatling.http.client.uri.Uri
import io.gatling.http.util.HttpHelper
import com.typesafe.scalalogging.StrictLogging
private[fetch] object CssParser extends StrictLogging {
private val InlineStyleImageUrls = """url\((.*)\)""".r
private val StyleImportsUrls = """@import url\((.*)\)""".r
def extractInlineStyleImageUrls(string: CharSequence): Iterator[String] =
extractUrls(string, InlineStyleImageUrls)
def extractStyleImportsUrls(string: CharSequence): Iterator[String] =
extractUrls(string, StyleImportsUrls)
private def extractUrls(string: CharSequence, regex: Regex): Iterator[String] =
regex.findAllIn(string).matchData.flatMap { m =>
val raw = m.group(1)
extractUrl(raw, 0, raw.length).toList
}
private val SingleQuoteEscapeChar = Some('\'')
private val DoubleQuoteEscapeChar = Some('"')
private val AtImportChars = "@import".toCharArray
private val UrlStartChars = "url(".toCharArray
def extractUrl(string: String, start: Int, end: Int): Option[String] =
if (string.isEmpty) {
None
} else {
var protectChar: Option[Char] = None
var broken = false
@tailrec
def trimLeft(cur: Int): Int =
if (cur == end)
cur
else
(string.charAt(cur): @switch) match {
case ' ' | '\r' | '\n' => trimLeft(cur + 1)
case '\'' =>
protectChar match {
case None =>
protectChar = SingleQuoteEscapeChar
trimLeft(cur + 1)
case _ =>
broken = true
cur
}
case '"' =>
protectChar match {
case None =>
protectChar = DoubleQuoteEscapeChar
trimLeft(cur + 1)
case _ =>
broken = true
cur
}
case _ => cur
}
@tailrec
def trimRight(cur: Int, leftLimit: Int): Int =
if (cur == leftLimit)
cur
else
(string.charAt(cur - 1): @switch) match {
case ' ' | '\r' | '\n' => trimRight(cur - 1, leftLimit)
case '\'' =>
protectChar match {
case `SingleQuoteEscapeChar` =>
trimRight(cur - 1, leftLimit)
case _ =>
broken = true
cur
}
case '"' =>
protectChar match {
case `DoubleQuoteEscapeChar` =>
trimRight(cur - 1, leftLimit)
case _ =>
broken = true
cur
}
case _ => cur
}
val trimmedStart = trimLeft(start)
val trimmedEnd = trimRight(end, trimmedStart)
if (!broken && trimmedStart != trimmedEnd) {
if (string.charAt(trimmedStart) == '#')
// anchors are not real urls
None
else
Some(string.substring(trimmedStart, trimmedEnd))
} else {
logger.debug(s"css url $string broken")
None
}
}
def extractResources(cssURI: Uri, cssContent: String): List[ConcurrentResource] = {
val resources = collection.mutable.ArrayBuffer.empty[ConcurrentResource]
var withinComment = false
var withinImport = false
var withinUrl = false
var urlStart = 0
def charsMatch(i: Int, chars: Array[Char]): Boolean = {
@tailrec
def charsMatchRec(j: Int): Boolean = {
if (j == chars.length)
true
else if (cssContent.charAt(i + j) != chars(j))
false
else
charsMatchRec(j + 1)
}
i < cssContent.length - chars.length && charsMatchRec(1)
}
var i = 0
while (i < cssContent.length) {
(cssContent.charAt(i): @switch) match {
case '/' =>
if (
i < cssContent.length - 1 &&
cssContent.charAt(i + 1) == '*'
) {
withinComment = true
i += 1
} else if (
i > 0 &&
cssContent.charAt(i - 1) == '*'
) {
withinComment = false
}
case '@' if !withinComment && charsMatch(i, AtImportChars) =>
withinImport = true
i = i + "@import".length
case 'u' if !withinComment && withinImport && charsMatch(i, UrlStartChars) =>
i = i + UrlStartChars.length
urlStart = i
withinUrl = true
case ')' if !withinComment && withinUrl =>
for {
url <- extractUrl(cssContent, urlStart, i)
absoluteUri <- HttpHelper.resolveFromUriSilently(cssURI, url)
} {
resources += CssResource(absoluteUri)
withinUrl = false
withinImport = false
}
case _ =>
}
i += 1
}
resources.toList
}
}