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Special case handling of one char split on an ASCII string.

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Review URL: http://codereview.chromium.org/7285030

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8506 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
sandholm@chromium.org 2011-07-01 09:29:38 +00:00
parent 41aa022aa8
commit 7a817f620e
1 changed files with 25 additions and 8 deletions
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33
src/runtime.cc
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@ -5754,19 +5754,36 @@ void FindStringIndices(Isolate* isolate,
ASSERT(limit > 0);
// Collect indices of pattern in subject, and the end-of-string index.
// Stop after finding at most limit values.
StringSearch<PatternChar, SubjectChar> search(isolate, pattern);
int pattern_length = pattern.length();
int index = 0;
while (limit > 0) {
index = search.Search(subject, index);
if (index < 0) return;
indices->Add(index);
index += pattern_length;
limit--;
if (sizeof(SubjectChar) == kCharSize &&
sizeof(PatternChar) == kCharSize &&
pattern_length == 1) {
// ASCII subject with one char ASCII pattern allows direct use of memchr.
char pattern_first_char = pattern[0];
const char* subject_start = reinterpret_cast<const char*>(subject.start());
const char* subject_end = subject_start + subject.length();
const char* pos = subject_start;
while (limit > 0) {
pos = reinterpret_cast<const char*>(
memchr(pos, pattern_first_char, subject_end - pos));
if (pos == NULL) return;
indices->Add(pos - subject_start);
pos++;
limit--;
}
} else {
StringSearch<PatternChar, SubjectChar> search(isolate, pattern);
while (limit > 0) {
index = search.Search(subject, index);
if (index < 0) return;
indices->Add(index);
index += pattern_length;
limit--;
}
}
}
RUNTIME_FUNCTION(MaybeObject*, Runtime_StringSplit) {
ASSERT(args.length() == 3);
HandleScope handle_scope(isolate);