Oscar Nierstrasz reported a regex-intensive script that is 10 times
slower in Smalltalk than in Ruby.
This was particularly low hanging fruit: Regex objects are actually no
different from strings, simply they are cached because they are created
read-only. So, we can extend the caching to any read-only string
(including a String literal). This removes the need to send asRegex to
literals -- only when using a variable as the regular expression that
should be necessary.
Before:
st> Time millisecondsToRun: [ 100000 timesRepeat: [ 'a.c' ~ 'abc' ] ]
2200
st> Time millisecondsToRun: [ 100000 timesRepeat: [ 'abc' ~ 'a.c' ] ]
2523
st> Time millisecondsToRun: [ 100000 timesRepeat: [ 'abc' ~ ##('a.c'
asRegex) ] ]
1666
After:
st> Time millisecondsToRun: [ 100000 timesRepeat: [ 'a.c' ~ 'abc' ] ]
1590
st> Time millisecondsToRun: [ 100000 timesRepeat: [ 'abc' ~ 'a.c' ] ]
1732
st> Time millisecondsToRun: [ 100000 timesRepeat: [ 'abc' ~ ##('a.c'
asRegex) ] ]
1609
(Oscar, another change to do in your script is to move temporaries
outside whileXxxx: because that prevents inlining the block).
Paolo
--- orig/libgst/re.c
+++ mod/libgst/re.c
@@ -154,13 +154,7 @@ lookupRegex (OOP patternOOP, struct pre_
int i;
RegexCaching result;
- if (!regexClassOOP)
- {
- regexClassOOP = _gst_class_name_to_oop ("Regex");
- resultsClassOOP = _gst_class_name_to_oop ("Kernel.MatchingRegexResults");
- }
-
- if (OOP_CLASS (patternOOP) != regexClassOOP)
+ if (!IS_OOP_READONLY (patternOOP))
{
*pRegex = allocateNewRegex ();
return REGEX_NOT_CACHED;
@@ -218,7 +212,7 @@ _gst_re_make_cacheable (OOP patternOOP)
resultsClassOOP = _gst_class_name_to_oop ("Kernel.MatchingRegexResults");
}
- if (OOP_CLASS (patternOOP) == regexClassOOP)
+ if (!IS_OOP_READONLY (patternOOP))
return patternOOP;
/* Search in the cache */
@@ -285,6 +279,12 @@ make_re_results (OOP srcOOP, struct pre_
if (!regs->beg || regs->beg[0] == -1)
return _gst_nil_oop;
+ if (!regexClassOOP)
+ {
+ regexClassOOP = _gst_class_name_to_oop ("Regex");
+ resultsClassOOP = _gst_class_name_to_oop ("Kernel.MatchingRegexResults");
+ }
+
resultsOOP = _gst_object_alloc (resultsClassOOP, 0);
results = (gst_registers) OOP_TO_OBJ (resultsOOP);
results->subjectOOP = srcOOP;
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