ChunkWriteStream>>#nextPut: contains a very inefficient loop

[svenvc]

ChunkWriteStream>>#nextPut: contains a very inefficient loop, making lots of copies while it goes forward.

Here is a better implementation, POC style:

(PharoSyntaxTutorial>>#theEnd) sourceCode in: [ :string |
	"double exclamation marks ($!) in string and add an extra one at the end"
	String streamContents: [ :out | | start bangIndex |
		start := 1.
		[ (bangIndex := string indexOf: $! startingAt: start) = 0 ] whileFalse: [ 
			out next: bangIndex - start + 1 putAll: string startingAt: start.
			out nextPut: $!.
			start := bangIndex + 1 ].
		out next: string size - start + 1 putAll: string startingAt: start.
		out nextPut: $! ]
]

This does require the addition of #next:putAll:startingAt: to SourceFile (just a delegation).

Also, the #flush might be 'too early' for larger batches

[svenvc]

WriteStream>>#nextChunkPut: contains the same inefficient loop

[svenvc]

#5034

[Ducasse]

Nobody ever looked at this ugly code since decades.
Thanks!
You get an impact.
I was wondering how we could collect some benchmarks.
what was the improvement?

[svenvc]

I don't think it will be faster, but it will certainly generate less garbage, especially when there are $! in the source code.

But it is a bit hard to measure.