From 751190f084f55dde8e940548a5fb4c2cda88ea4c Mon Sep 17 00:00:00 2001
From: Johannes Rudolph <johannes.rudolph@gmail.com>
Date: Mon, 8 Jun 2015 15:04:19 +0200
Subject: [PATCH] =htc compact outgoing ByteStrings in parsers to avoid
 referencing more memory than necessary

This was discussed previously in the context of spray where we came to the
conclusion that it makes sense to deliver compact ByteStrings on API
boundaries to avoid to carry around unused parts of ByteStrings.
---
 .../akka/http/impl/engine/parsing/HttpMessageParser.scala   | 6 +++---
 .../akka/http/impl/engine/parsing/HttpResponseParser.scala  | 2 +-
 .../scala/akka/http/impl/engine/ws/FrameEventParser.scala   | 4 ++--
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/akka-http-core/src/main/scala/akka/http/impl/engine/parsing/HttpMessageParser.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/parsing/HttpMessageParser.scala
index b5bd371965..b2d440a172 100644
--- a/akka-http-core/src/main/scala/akka/http/impl/engine/parsing/HttpMessageParser.scala
+++ b/akka-http-core/src/main/scala/akka/http/impl/engine/parsing/HttpMessageParser.scala
@@ -170,11 +170,11 @@ private[http] abstract class HttpMessageParser[Output >: MessageOutput <: Parser
     val remainingInputBytes = input.length - bodyStart
     if (remainingInputBytes > 0) {
       if (remainingInputBytes < remainingBodyBytes) {
-        emit(EntityPart(input drop bodyStart))
+        emit(EntityPart(input.drop(bodyStart).compact))
         continue(parseFixedLengthBody(remainingBodyBytes - remainingInputBytes, isLastMessage))
       } else {
         val offset = bodyStart + remainingBodyBytes.toInt
-        emit(EntityPart(input.slice(bodyStart, offset)))
+        emit(EntityPart(input.slice(bodyStart, offset).compact))
         emit(MessageEnd)
         setCompletionHandling(CompletionOk)
         if (isLastMessage) terminate()
@@ -211,7 +211,7 @@ private[http] abstract class HttpMessageParser[Output >: MessageOutput <: Parser
       if (chunkSize > 0) {
         val chunkBodyEnd = cursor + chunkSize
         def result(terminatorLen: Int) = {
-          emit(EntityChunk(HttpEntity.Chunk(input.slice(cursor, chunkBodyEnd), extension)))
+          emit(EntityChunk(HttpEntity.Chunk(input.slice(cursor, chunkBodyEnd).compact, extension)))
           Trampoline(_ ⇒ parseChunk(input, chunkBodyEnd + terminatorLen, isLastMessage))
         }
         byteChar(input, chunkBodyEnd) match {
diff --git a/akka-http-core/src/main/scala/akka/http/impl/engine/parsing/HttpResponseParser.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/parsing/HttpResponseParser.scala
index 7922a3e1e8..4751f68123 100644
--- a/akka-http-core/src/main/scala/akka/http/impl/engine/parsing/HttpResponseParser.scala
+++ b/akka-http-core/src/main/scala/akka/http/impl/engine/parsing/HttpResponseParser.scala
@@ -132,7 +132,7 @@ private[http] class HttpResponseParser(_settings: ParserSettings, _headerParser:
   // currently we do not check for `settings.maxContentLength` overflow
   def parseToCloseBody(input: ByteString, bodyStart: Int): StateResult = {
     if (input.length > bodyStart)
-      emit(EntityPart(input drop bodyStart))
+      emit(EntityPart(input.drop(bodyStart).compact))
     continue(parseToCloseBody)
   }
 }
\ No newline at end of file
diff --git a/akka-http-core/src/main/scala/akka/http/impl/engine/ws/FrameEventParser.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/ws/FrameEventParser.scala
index 86ae74d01d..927b2a3a67 100644
--- a/akka-http-core/src/main/scala/akka/http/impl/engine/ws/FrameEventParser.scala
+++ b/akka-http-core/src/main/scala/akka/http/impl/engine/ws/FrameEventParser.scala
@@ -87,7 +87,7 @@ private[http] class FrameEventParser extends ByteStringParserStage[FrameEvent] {
         if (thisFrameData.length == length) ReadFrameHeader
         else readData(length - thisFrameData.length)
 
-      pushAndBecomeWithRemaining(FrameStart(header, thisFrameData), nextState, remaining, ctx)
+      pushAndBecomeWithRemaining(FrameStart(header, thisFrameData.compact), nextState, remaining, ctx)
     }
   }
 
@@ -103,7 +103,7 @@ private[http] class FrameEventParser extends ByteStringParserStage[FrameEvent] {
           val frameData = elem.take(remaining.toInt)
           val remainingData = elem.drop(remaining.toInt)
 
-          pushAndBecomeWithRemaining(FrameData(frameData, lastPart = true), ReadFrameHeader, remainingData, ctx)
+          pushAndBecomeWithRemaining(FrameData(frameData.compact, lastPart = true), ReadFrameHeader, remainingData, ctx)
         }
     }