From 832f25fc2ac19c58476f55ebdc7001945104f023 Mon Sep 17 00:00:00 2001
From: bjorn <bjorn@bringert.net>
Date: Wed, 26 Nov 2008 16:19:54 +0000
Subject: [PATCH] Don't use string sharing in LexGF.

Profiling showed that when loading a large .gfo file, shareString was responsible for
15-18% of the CPU time, and a lot of the allocation. Since we already use ByteStrings for
reading the source files, shareString mostly has the effect of creating lots
of small ByteStrings instead of one large one. Since the plain size of the .gfo is seldom
a problem (unlike when it was read as a String), it is ok to keep the whole file
as one ByteString in RAM, and have all tokens point into that.
Profiling after the change showed 15-20% reduction in CPU time and in total allocation.
---
 src/GF/Source/LexGF.hs | 4 ++--
 src/GF/Source/LexGF.x  | 4 ++--
 src/GF/Source/Makefile | 2 +-
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/GF/Source/LexGF.hs b/src/GF/Source/LexGF.hs
index 316da3afd..c45e03f78 100644
--- a/src/GF/Source/LexGF.hs
+++ b/src/GF/Source/LexGF.hs
@@ -4,7 +4,7 @@
 {-# OPTIONS -fno-warn-incomplete-patterns #-}
 module GF.Source.LexGF where
 
-import GF.Source.SharedString
+
 import qualified Data.ByteString.Char8 as BS
 
 #if __GLASGOW_HASKELL__ >= 603
@@ -44,7 +44,7 @@ alex_accept = listArray (0::Int,34) [[],[],[(AlexAccSkip)],[(AlexAccSkip)],[],[(
 tok f p s = f p s
 
 share :: BS.ByteString -> BS.ByteString
-share = shareString
+share = id
 
 data Tok =
    TS !BS.ByteString !Int    -- reserved words and symbols
diff --git a/src/GF/Source/LexGF.x b/src/GF/Source/LexGF.x
index 46419df74..3579d0cd8 100644
--- a/src/GF/Source/LexGF.x
+++ b/src/GF/Source/LexGF.x
@@ -4,7 +4,7 @@
 {-# OPTIONS -fno-warn-incomplete-patterns #-}
 module GF.Source.LexGF where
 
-import GF.Source.SharedString
+
 import qualified Data.ByteString.Char8 as BS
 }
 
@@ -39,7 +39,7 @@ $d+ \. $d+ (e (\-)? $d+)? { tok (\p s -> PT p (TD $ share s)) }
 tok f p s = f p s
 
 share :: BS.ByteString -> BS.ByteString
-share = shareString
+share = id
 
 data Tok =
    TS !BS.ByteString !Int    -- reserved words and symbols
diff --git a/src/GF/Source/Makefile b/src/GF/Source/Makefile
index a07f78ba5..082efa5ef 100644
--- a/src/GF/Source/Makefile
+++ b/src/GF/Source/Makefile
@@ -1,5 +1,5 @@
 all:
-	cd ../.. && bnfc -p GF.Source -bytestrings -sharestrings GF/Source/GF.cf
+	cd ../.. && bnfc -p GF.Source -bytestrings GF/Source/GF.cf
 	rm ErrM.hs
 	perl -i -pe 's/%name pModHeader ModHeader/%partial pModHeader ModHeader/' ParGF.y
 	perl -i -pe 's/GF.Source.ErrM/GF.Data.ErrM/' *.hs *.x *.y