+str #17310: Basic framing support

akka-docs-dev/rst/scala/code/docs/stream/cookbook/RecipeParseLines.scala

@@ -20,9 +20,10 @@ class RecipeParseLines extends RecipeSpec {
         ByteString("\nHello Akka!\r\nHello Streams!"),
         ByteString("\r\n\r\n")))
 
-      import RecipeParseLines._
-
-      val linesStream = rawData.transform(() => parseLines("\r\n", 100))
+      //#parse-lines
+      import akka.stream.io.Framing
+      val linesStream = rawData.via(Framing.lines("\r\n", maximumLineBytes = 100))
+      //#parse-lines
 
       Await.result(linesStream.grouped(10).runWith(Sink.head), 3.seconds) should be(List(
         "Hello World\r!",
@@ -34,58 +35,3 @@ class RecipeParseLines extends RecipeSpec {
   }
 
 }
-
-object RecipeParseLines {
-
-  import akka.stream.stage._
-
-  //#parse-lines
-  def parseLines(separator: String, maximumLineBytes: Int) =
-    new StatefulStage[ByteString, String] {
-      private val separatorBytes = ByteString(separator)
-      private val firstSeparatorByte = separatorBytes.head
-      private var buffer = ByteString.empty
-      private var nextPossibleMatch = 0
-
-      def initial = new State {
-        override def onPush(chunk: ByteString, ctx: Context[String]): SyncDirective = {
-          buffer ++= chunk
-          if (buffer.size > maximumLineBytes)
-            ctx.fail(new IllegalStateException(s"Read ${buffer.size} bytes " +
-              s"which is more than $maximumLineBytes without seeing a line terminator"))
-          else emit(doParse(Vector.empty).iterator, ctx)
-        }
-
-        @tailrec
-        private def doParse(parsedLinesSoFar: Vector[String]): Vector[String] = {
-          val possibleMatchPos = buffer.indexOf(firstSeparatorByte, from = nextPossibleMatch)
-          if (possibleMatchPos == -1) {
-            // No matching character, we need to accumulate more bytes into the buffer
-            nextPossibleMatch = buffer.size
-            parsedLinesSoFar
-          } else if (possibleMatchPos + separatorBytes.size > buffer.size) {
-            // We have found a possible match (we found the first character of the terminator
-            // sequence) but we don't have yet enough bytes. We remember the position to
-            // retry from next time.
-            nextPossibleMatch = possibleMatchPos
-            parsedLinesSoFar
-          } else {
-            if (buffer.slice(possibleMatchPos, possibleMatchPos + separatorBytes.size)
-              == separatorBytes) {
-              // Found a match
-              val parsedLine = buffer.slice(0, possibleMatchPos).utf8String
-              buffer = buffer.drop(possibleMatchPos + separatorBytes.size)
-              nextPossibleMatch -= possibleMatchPos + separatorBytes.size
-              doParse(parsedLinesSoFar :+ parsedLine)
-            } else {
-              nextPossibleMatch += 1
-              doParse(parsedLinesSoFar)
-            }
-          }
-
-        }
-      }
-    }
-  //#parse-lines
-
-}