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Code Issues

Improvement #7038 - Improve performance of STARTING WITH of fixed-byte charsets with insensitive collations.

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This commit is contained in:
Adriano dos Santos Fernandes 2021-11-04 16:26:22 -03:00
parent 6140244780
commit 551ed996ae
1 changed files with 27 additions and 4 deletions
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31
src/jrd/Collation.cpp
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@ -444,15 +444,17 @@ template <typename CharType, typename StrConverter>
class StartsMatcher : public PatternMatcher
{
public:
StartsMatcher(MemoryPool& pool, TextType* ttype, const CharType* str, SLONG str_len)
StartsMatcher(MemoryPool& pool, TextType* ttype, const CharType* str, SLONG str_len, SLONG aPatternByteLength)
: PatternMatcher(pool, ttype),
evaluator(pool, str, str_len)
evaluator(pool, str, str_len),
patternByteLength(ttype->getCharSet()->isMultiByte() ? -1 : aPatternByteLength)
{
}
void reset()
{
evaluator.reset();
processedByteLength = 0;
}
bool result()
@ -462,8 +464,17 @@ public:
bool process(const UCHAR* str, SLONG length)
{
if (patternByteLength != -1)
{
if (processedByteLength + length > patternByteLength)
length = patternByteLength - processedByteLength;
}
processedByteLength += length;
StrConverter cvt(pool, textType, str, length);
fb_assert(length % sizeof(CharType) == 0);
return evaluator.processNextChunk(
reinterpret_cast<const CharType*>(str), length / sizeof(CharType));
}
@ -471,27 +482,39 @@ public:
static StartsMatcher* create(MemoryPool& pool, TextType* ttype,
const UCHAR* str, SLONG length)
{
const auto patternByteLength = length;
StrConverter cvt(pool, ttype, str, length);
fb_assert(length % sizeof(CharType) == 0);
return FB_NEW_POOL(pool) StartsMatcher(pool, ttype,
reinterpret_cast<const CharType*>(str), length / sizeof(CharType));
reinterpret_cast<const CharType*>(str), length / sizeof(CharType), patternByteLength);
}
static bool evaluate(MemoryPool& pool, TextType* ttype, const UCHAR* s, SLONG sl,
const UCHAR* p, SLONG pl)
{
if (!ttype->getCharSet()->isMultiByte() && sl > pl)
sl = pl;
StrConverter cvt1(pool, ttype, p, pl);
StrConverter cvt2(pool, ttype, s, sl);
fb_assert(pl % sizeof(CharType) == 0);
StrConverter cvt2(pool, ttype, s, sl);
fb_assert(sl % sizeof(CharType) == 0);
Firebird::StartsEvaluator<CharType> evaluator(pool,
reinterpret_cast<const CharType*>(p), pl / sizeof(CharType));
evaluator.processNextChunk(reinterpret_cast<const CharType*>(s), sl / sizeof(CharType));
return evaluator.getResult();
}
private:
Firebird::StartsEvaluator<CharType> evaluator;
const SLONG patternByteLength; // -1 used for MBCS and not optimize things
SLONG processedByteLength = 0;
};
template <typename CharType, typename StrConverter = CanonicalConverter<UpcaseConverter<> > >