io.gatling.http.action.sse.fsm.SseStreamDecoder.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.action.sse.fsm
import java.nio.CharBuffer
import io.gatling.netty.util.Utf8ByteBufCharsetDecoder
import io.netty.buffer.ByteBuf
object SseStreamDecoder {
private val BOM = '\uFEFF'
private val LF = 0x0a
private val CR = 0x0d
private val EventHeader = "event:".toCharArray
private val DataHeader = "data:".toCharArray
private val IdHeader = "id:".toCharArray
private val RetryHeader = "retry:".toCharArray
}
class SseStreamDecoder extends Utf8ByteBufCharsetDecoder {
import SseStreamDecoder._
private[this] var pendingName: Option[String] = None
private[this] var pendingData: Option[String] = None
private[this] var pendingId: Option[String] = None
private[this] var pendingRetry: Option[Int] = None
private[this] var pendingEvents = collection.mutable.ArrayBuffer.empty[ServerSentEvent]
private[this] var firstEvent = true
private[this] var previousBufferLastCharWasCr = false
private[this] var position = 0
private var charArray: Array[Char] = _
override protected def allocateCharBuffer(l: Int): CharBuffer = {
charArray = new Array[Char](l)
CharBuffer.wrap(charArray)
}
private def parseLine(lineStart: Int, lineEnd: Int): Unit = {
val lineLength = lineEnd - lineStart
def onFieldHeaderMatch(fieldHeader: Array[Char]): Option[String] = {
val fieldHeaderLength = fieldHeader.length
if (lineLength < fieldHeaderLength) {
None
} else if (
(0 until fieldHeaderLength).forall { i =>
charArray(lineStart + i) == fieldHeader(i)
}
) {
val nextPos = lineStart + fieldHeaderLength
val valueStart =
if (charArray(nextPos) == ' ') {
// white space after colon, trim it
nextPos + 1
} else {
nextPos
}
Some(new String(charArray, valueStart, lineEnd - valueStart))
} else {
None
}
}
if (lineLength == 0) {
// empty line, flushing event
if (pendingName.isDefined || pendingData.isDefined || pendingId.isDefined || pendingRetry.isDefined) {
// non empty event (eg just a comment)
pendingEvents += ServerSentEvent(
name = pendingName,
data = pendingData,
id = pendingId,
retry = pendingRetry
)
pendingName = None
pendingData = None
pendingId = None
pendingRetry = None
}
} else if (charArray(lineStart) == ':') {
// comment, skipping
} else {
// parse real line
onFieldHeaderMatch(EventHeader) match {
case None =>
onFieldHeaderMatch(DataHeader) match {
case None =>
onFieldHeaderMatch(IdHeader) match {
case None =>
onFieldHeaderMatch(RetryHeader) match {
case None =>
case res => pendingRetry = res.map(_.toInt)
}
case res => pendingId = res
}
case res => pendingData = res
}
case res => pendingName = res
}
}
}
private def parseChars(): Unit = {
if (firstEvent) {
if (charArray(position) == BOM) {
position += 1
}
firstEvent = false
} else if (previousBufferLastCharWasCr && charArray(position) == LF) {
// last buffer ended with a terminated line
// but we were actually in the middle of a CRLF pair
position += 1
}
// scanning actual content
var i = position
val sbLength = charBuffer.position()
while (i < sbLength) {
charArray(i) match {
case CR =>
parseLine(position, i)
if (i < sbLength - 1 && charArray(i + 1) == LF) {
// skip next LF
i += 2
} else {
i += 1
}
position = i
case LF =>
parseLine(position, i)
i += 1
position = i
case _ =>
i += 1
}
}
}
private def translateCharBuffer(): Unit = {
val sbLength = charBuffer.position()
previousBufferLastCharWasCr = charArray(sbLength - 1) == CR
if (position >= sbLength) {
// all read, clear
charBuffer.position(0)
} else if (position > 0) {
// partially read, translate
System.arraycopy(charArray, position, charArray, 0, sbLength - position)
charBuffer.position(sbLength - position)
}
position = 0
}
private def flushEvents(): Seq[ServerSentEvent] = {
val events = pendingEvents.toVector
pendingEvents.clear()
events
}
def decodeStream(buf: ByteBuf): Seq[ServerSentEvent] = {
if (buf.isReadable) {
ensureCapacity(buf.readableBytes)
if (buf.nioBufferCount == 1) {
decodePartial(buf.internalNioBuffer(buf.readerIndex, buf.readableBytes), false)
} else {
buf.nioBuffers.foreach(decodePartial(_, false))
}
parseChars()
translateCharBuffer()
flushEvents()
} else {
Nil
}
}
}