diff options
| -rw-r--r-- | src/corelib/tools/qregularexpression.cpp | 32 | ||||
| -rw-r--r-- | src/corelib/tools/qregularexpression.h | 3 |
2 files changed, 27 insertions, 8 deletions
diff --git a/src/corelib/tools/qregularexpression.cpp b/src/corelib/tools/qregularexpression.cpp index 26988a4420..316681e652 100644 --- a/src/corelib/tools/qregularexpression.cpp +++ b/src/corelib/tools/qregularexpression.cpp @@ -705,6 +705,17 @@ QT_BEGIN_NAMESPACE JIT-compiled) on its first usage, instead of after a certain (undefined) number of usages. See also \l{QRegularExpression::}{optimize()}. This enum value has been introduced in Qt 5.4. + + \value DontAutomaticallyOptimizeOption + Regular expressions are automatically optimized after a + certain number of usages; setting this option prevents such + optimizations, therefore avoiding possible unpredictable spikes in + CPU and memory usage. If both this option and the + \c{OptimizeOnFirstUsageOption} option are set, then this option takes + precedence. Note: this option will still let the regular expression + to be optimized by manually calling + \l{QRegularExpression::}{optimize()}. This enum value has been + introduced in Qt 5.4. */ /*! @@ -1108,7 +1119,10 @@ static bool isJitEnabled() setting the studyData member variable to the result of the study. It gets called by doMatch() every time a match is performed. As of now, the optimizations on the pattern are performed after a certain number of usages - (i.e. the qt_qregularexpression_optimize_after_use_count constant). + (i.e. the qt_qregularexpression_optimize_after_use_count constant) unless + the DontAutomaticallyOptimizeOption option is set on the QRegularExpression + object, or anyhow by calling optimize() (which will pass + ImmediateOptimizeOption). Notice that although the method is protected by a mutex, one thread may invoke this function and return immediately (i.e. not study the pattern, @@ -1248,13 +1262,15 @@ QRegularExpressionMatchPrivate *QRegularExpressionPrivate::doMatch(const QString matchType, matchOptions, capturingCount + 1); - const OptimizePatternOption optimizePatternOption = - (patternOptions & QRegularExpression::OptimizeOnFirstUsageOption) - ? ImmediateOptimizeOption - : LazyOptimizeOption; + if (!(patternOptions & QRegularExpression::DontAutomaticallyOptimizeOption)) { + const OptimizePatternOption optimizePatternOption = + (patternOptions & QRegularExpression::OptimizeOnFirstUsageOption) + ? ImmediateOptimizeOption + : LazyOptimizeOption; - // this is mutex protected - const_cast<QRegularExpressionPrivate *>(this)->optimizePattern(optimizePatternOption); + // this is mutex protected + const_cast<QRegularExpressionPrivate *>(this)->optimizePattern(optimizePatternOption); + } // work with a local copy of the study data, as we are running pcre_exec // potentially more than once, and we don't want to run call it @@ -2370,6 +2386,8 @@ QDebug operator<<(QDebug debug, QRegularExpression::PatternOptions patternOption flags.append("UseUnicodePropertiesOption|"); if (patternOptions & QRegularExpression::OptimizeOnFirstUsageOption) flags.append("OptimizeOnFirstUsageOption|"); + if (patternOptions & QRegularExpression::DontAutomaticallyOptimizeOption) + flags.append("DontAutomaticallyOptimizeOption|"); flags.chop(1); } diff --git a/src/corelib/tools/qregularexpression.h b/src/corelib/tools/qregularexpression.h index 6154ea7c51..bf75d12a05 100644 --- a/src/corelib/tools/qregularexpression.h +++ b/src/corelib/tools/qregularexpression.h @@ -70,7 +70,8 @@ public: InvertedGreedinessOption = 0x0010, DontCaptureOption = 0x0020, UseUnicodePropertiesOption = 0x0040, - OptimizeOnFirstUsageOption = 0x0080 + OptimizeOnFirstUsageOption = 0x0080, + DontAutomaticallyOptimizeOption = 0x0100 }; Q_DECLARE_FLAGS(PatternOptions, PatternOption) |