Say hello to QScriptProgram :-)

QScriptProgram encapsulates a Qt Script program (AKA a script).
It retains the compiled representation of the script, so that
repeated evaluation of the same script becomes faster.

An overload of QScriptEngine::evaluate() that takes a QScriptProgram
has been added.

Reviewed-by: Olivier Goffart

7 files changed, 510 insertions, 58 deletions

diff --git a/src/script/api/api.pri b/src/script/api/api.pri
index 17ec9b6..aebadd5 100644
--- a/src/script/api/api.pri
+++ b/src/script/api/api.pri
@@ -6,6 +6,7 @@ SOURCES += \
     $$PWD/qscriptengine.cpp \
     $$PWD/qscriptengineagent.cpp \
     $$PWD/qscriptextensionplugin.cpp \
+    $$PWD/qscriptprogram.cpp \
     $$PWD/qscriptstring.cpp \
     $$PWD/qscriptvalue.cpp \
     $$PWD/qscriptvalueiterator.cpp \
@@ -23,6 +24,8 @@ HEADERS += \
     $$PWD/qscriptengineagent_p.h \
     $$PWD/qscriptextensioninterface.h \
     $$PWD/qscriptextensionplugin.h \
+    $$PWD/qscriptprogram.h \
+    $$PWD/qscriptprogram_p.h \
     $$PWD/qscriptstring.h \
     $$PWD/qscriptstring_p.h \
     $$PWD/qscriptvalue.h \
diff --git a/src/script/api/qscriptengine.cpp b/src/script/api/qscriptengine.cpp
index 9288723..2b60a46 100644
--- a/src/script/api/qscriptengine.cpp
+++ b/src/script/api/qscriptengine.cpp
@@ -51,6 +51,8 @@
 #include "qscriptvalue_p.h"
 #include "qscriptvalueiterator.h"
 #include "qscriptclass.h"
+#include "qscriptprogram.h"
+#include "qscriptprogram_p.h"
 #include "qdebug.h"
 
 #include <QtCore/qstringlist.h>
@@ -1155,6 +1157,73 @@ void QScriptEnginePrivate::agentDeleted(QScriptEngineAgent *agent)
     }
 }
 
+JSC::JSValue QScriptEnginePrivate::evaluateHelper(JSC::ExecState *exec, intptr_t sourceId,
+                                                  JSC::EvalExecutable *executable,
+                                                  bool &compile)
+{
+    Q_Q(QScriptEngine);
+    JSC::JSLock lock(false); // ### hmmm
+    QBoolBlocker inEvalBlocker(inEval, true);
+    q->currentContext()->activationObject(); //force the creation of a context for native function;
+
+    JSC::Debugger* debugger = originalGlobalObject()->debugger();
+    if (debugger)
+        debugger->evaluateStart(sourceId);
+
+    q->clearExceptions();
+    JSC::DynamicGlobalObjectScope dynamicGlobalObjectScope(exec, exec->scopeChain()->globalObject());
+
+    if (compile) {
+        JSC::JSObject* error = executable->compile(exec, exec->scopeChain());
+        if (error) {
+            compile = false;
+            exec->setException(error);
+
+            if (debugger) {
+                debugger->exceptionThrow(JSC::DebuggerCallFrame(exec, error), sourceId, false);
+                debugger->evaluateStop(error, sourceId);
+            }
+
+            return error;
+        }
+    }
+
+    JSC::JSValue thisValue = thisForContext(exec);
+    JSC::JSObject* thisObject = (!thisValue || thisValue.isUndefinedOrNull())
+                                ? exec->dynamicGlobalObject() : thisValue.toObject(exec);
+    JSC::JSValue exceptionValue;
+    timeoutChecker()->setShouldAbort(false);
+    if (processEventsInterval > 0)
+        timeoutChecker()->reset();
+
+    JSC::JSValue result = exec->interpreter()->execute(executable, exec, thisObject, exec->scopeChain(), &exceptionValue);
+
+    if (timeoutChecker()->shouldAbort()) {
+        if (abortResult.isError())
+            exec->setException(scriptValueToJSCValue(abortResult));
+
+        if (debugger)
+            debugger->evaluateStop(scriptValueToJSCValue(abortResult), sourceId);
+
+        return scriptValueToJSCValue(abortResult);
+    }
+
+    if (exceptionValue) {
+        exec->setException(exceptionValue);
+
+        if (debugger)
+            debugger->evaluateStop(exceptionValue, sourceId);
+
+        return exceptionValue;
+    }
+
+    if (debugger)
+        debugger->evaluateStop(result, sourceId);
+
+    Q_ASSERT(!exec->hadException());
+    return result;
+}
+
 #ifndef QT_NO_QOBJECT
 
 JSC::JSValue QScriptEnginePrivate::newQObject(
@@ -2115,75 +2184,41 @@ QScriptSyntaxCheckResult QScriptEnginePrivate::checkSyntax(const QString &progra
 QScriptValue QScriptEngine::evaluate(const QString &program, const QString &fileName, int lineNumber)
 {
     Q_D(QScriptEngine);
-
-    JSC::JSLock lock(false); // ### hmmm
-    QBoolBlocker inEval(d->inEval, true);
-    currentContext()->activationObject(); //force the creation of a context for native function;
-
-    JSC::Debugger* debugger = d->originalGlobalObject()->debugger();
-
-    JSC::UString jscProgram = program;
-    JSC::UString jscFileName = fileName;
-    JSC::ExecState* exec = d->currentFrame;
     WTF::PassRefPtr<QScript::UStringSourceProviderWithFeedback> provider
-            = QScript::UStringSourceProviderWithFeedback::create(jscProgram, jscFileName, lineNumber, d);
+            = QScript::UStringSourceProviderWithFeedback::create(program, fileName, lineNumber, d);
     intptr_t sourceId = provider->asID();
     JSC::SourceCode source(provider, lineNumber); //after construction of SourceCode provider variable will be null.
 
-    if (debugger)
-        debugger->evaluateStart(sourceId);
-
-    clearExceptions();
-    JSC::DynamicGlobalObjectScope dynamicGlobalObjectScope(exec, exec->scopeChain()->globalObject());
-
+    JSC::ExecState* exec = d->currentFrame;
     JSC::EvalExecutable executable(exec, source);
-    JSC::JSObject* error = executable.compile(exec, exec->scopeChain());
-    if (error) {
-        exec->setException(error);
-
-        if (debugger) {
-            debugger->exceptionThrow(JSC::DebuggerCallFrame(exec, error), sourceId, false);
-            debugger->evaluateStop(error, sourceId);
-        }
-
-        return d->scriptValueFromJSCValue(error);
-    }
-
-    JSC::JSValue thisValue = d->thisForContext(exec);
-    JSC::JSObject* thisObject = (!thisValue || thisValue.isUndefinedOrNull()) ? exec->dynamicGlobalObject() : thisValue.toObject(exec);
-    JSC::JSValue exceptionValue;
-    d->timeoutChecker()->setShouldAbort(false);
-    if (d->processEventsInterval > 0)
-        d->timeoutChecker()->reset();
-    JSC::JSValue result = exec->interpreter()->execute(&executable, exec, thisObject, exec->scopeChain(), &exceptionValue);
-
-    if (d->timeoutChecker()->shouldAbort()) {
-        if (d->abortResult.isError())
-            exec->setException(d->scriptValueToJSCValue(d->abortResult));
-
-        if (debugger)
-            debugger->evaluateStop(d->scriptValueToJSCValue(d->abortResult), sourceId);
-
-        return d->abortResult;
-    }
-
-    if (exceptionValue) {
-        exec->setException(exceptionValue);
-
-        if (debugger)
-            debugger->evaluateStop(exceptionValue, sourceId);
+    bool compile = true;
+    return d->scriptValueFromJSCValue(d->evaluateHelper(exec, sourceId, &executable, compile));
+}
 
-        return d->scriptValueFromJSCValue(exceptionValue);
-    }
+/*!
+  \internal
+  \since 4.6
 
-    if (debugger)
-        debugger->evaluateStop(result, sourceId);
+  Evaluates the given \a program and returns the result of the
+  evaluation.
+*/
+QScriptValue QScriptEngine::evaluate(const QScriptProgram &program)
+{
+    Q_D(QScriptEngine);
+    QScriptProgramPrivate *program_d = QScriptProgramPrivate::get(program);
+    if (!program_d)
+        return QScriptValue();
 
-    Q_ASSERT(!exec->hadException());
+    JSC::ExecState* exec = d->currentFrame;
+    JSC::EvalExecutable *executable = program_d->executable(exec, d);
+    bool compile = !program_d->isCompiled;
+    JSC::JSValue result = d->evaluateHelper(exec, program_d->sourceId,
+                                            executable, compile);
+    if (compile)
+        program_d->isCompiled = true;
     return d->scriptValueFromJSCValue(result);
 }
 
-
 /*!
   Returns the current context.
 
diff --git a/src/script/api/qscriptengine.h b/src/script/api/qscriptengine.h
index 701f9c6..3f438da 100644
--- a/src/script/api/qscriptengine.h
+++ b/src/script/api/qscriptengine.h
@@ -67,6 +67,7 @@ class QDateTime;
 class QScriptClass;
 class QScriptEngineAgent;
 class QScriptEnginePrivate;
+class QScriptProgram;
 
 #ifndef QT_NO_QOBJECT
 
@@ -166,6 +167,8 @@ public:
 
     QScriptValue evaluate(const QString &program, const QString &fileName = QString(), int lineNumber = 1);
 
+    QScriptValue evaluate(const QScriptProgram &program);
+
     bool isEvaluating() const;
     void abortEvaluation(const QScriptValue &result = QScriptValue());
 
diff --git a/src/script/api/qscriptengine_p.h b/src/script/api/qscriptengine_p.h
index ec7c144..d12b0f4 100644
--- a/src/script/api/qscriptengine_p.h
+++ b/src/script/api/qscriptengine_p.h
@@ -70,6 +70,7 @@
 
 namespace JSC
 {
+    class EvalExecutable;
     class ExecState;
     typedef ExecState CallFrame;
     class JSCell;
@@ -211,6 +212,10 @@ public:
                                        const QByteArray &targetType,
                                        void **result);
 
+    JSC::JSValue evaluateHelper(JSC::ExecState *exec, intptr_t sourceId,
+                                JSC::EvalExecutable *executable,
+                                bool &compile);
+
     QScript::QObjectData *qobjectData(QObject *object);
     void disposeQObject(QObject *object);
     void emitSignalHandlerException();
diff --git a/src/script/api/qscriptprogram.cpp b/src/script/api/qscriptprogram.cpp
new file mode 100644
index 0000000..c30f381
--- /dev/null
+++ b/src/script/api/qscriptprogram.cpp
@@ -0,0 +1,225 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtScript module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "config.h"
+#include "qscriptprogram.h"
+#include "qscriptprogram_p.h"
+#include "qscriptengine.h"
+#include "qscriptengine_p.h"
+
+#include "Executable.h"
+
+QT_BEGIN_NAMESPACE
+
+/*!
+  \internal
+
+  \since 4.6
+  \class QScriptProgram
+
+  \brief The QScriptProgram class encapsulates a Qt Script program.
+
+  \ingroup script
+
+  QScriptProgram retains the compiled representation of the script if
+  possible. Thus, QScriptProgram can be used to evaluate the same
+  script multiple times more efficiently.
+
+  \code
+  QScriptEngine engine;
+  QScriptProgram program("1 + 2");
+  QScriptValue result = engine.evaluate(program);
+  \endcode
+*/
+
+QScriptProgramPrivate::QScriptProgramPrivate(const QString &src,
+                                             const QString &fn,
+                                             int ln)
+    : sourceCode(src), fileName(fn), firstLineNumber(ln),
+      engine(0), _executable(0), sourceId(-1), isCompiled(false)
+{
+    ref = 0;
+}
+
+QScriptProgramPrivate::~QScriptProgramPrivate()
+{
+    delete _executable;
+}
+
+QScriptProgramPrivate *QScriptProgramPrivate::get(const QScriptProgram &q)
+{
+    return const_cast<QScriptProgramPrivate*>(q.d_func());
+}
+
+JSC::EvalExecutable *QScriptProgramPrivate::executable(JSC::ExecState *exec,
+                                                       QScriptEnginePrivate *eng)
+{
+    if (_executable) {
+        if (eng == engine)
+            return _executable;
+        delete _executable;
+    }
+    WTF::PassRefPtr<QScript::UStringSourceProviderWithFeedback> provider
+        = QScript::UStringSourceProviderWithFeedback::create(sourceCode, fileName, firstLineNumber, eng);
+    sourceId = provider->asID();
+    JSC::SourceCode source(provider, firstLineNumber); //after construction of SourceCode provider variable will be null.
+    _executable = new JSC::EvalExecutable(exec, source);
+    engine = eng;
+    isCompiled = false;
+    return _executable;
+}
+
+/*!
+  Constructs a null QScriptProgram.
+*/
+QScriptProgram::QScriptProgram()
+    : d_ptr(0)
+{
+}
+
+/*!
+  Constructs a new QScriptProgram with the given \a sourceCode, \a
+  fileName and \a firstLineNumber.
+*/
+QScriptProgram::QScriptProgram(const QString &sourceCode,
+                               const QString fileName,
+                               int firstLineNumber)
+    : d_ptr(new QScriptProgramPrivate(sourceCode, fileName, firstLineNumber))
+{
+}
+
+/*!
+  Constructs a new QScriptProgram that is a copy of \a other.
+*/
+QScriptProgram::QScriptProgram(const QScriptProgram &other)
+    : d_ptr(other.d_ptr)
+{
+}
+
+/*!
+  Destroys this QScriptProgram.
+*/
+QScriptProgram::~QScriptProgram()
+{
+    Q_D(QScriptProgram);
+    //    if (d->engine && (d->ref == 1))
+    //      d->engine->unregisterScriptProgram(d);
+}
+
+/*!
+  Assigns the \a other value to this QScriptProgram.
+*/
+QScriptProgram &QScriptProgram::operator=(const QScriptProgram &other)
+{
+  //    if (d_func() && d_func()->engine && (d_func()->ref == 1))
+      //        d_func()->engine->unregisterScriptProgram(d_func());
+  //    }
+    d_ptr = other.d_ptr;
+    return *this;
+}
+
+/*!
+  Returns true if this QScriptProgram is null; otherwise
+  returns false.
+*/
+bool QScriptProgram::isNull() const
+{
+    Q_D(const QScriptProgram);
+    return (d == 0);
+}
+
+/*!
+  Returns the source code of this program.
+*/
+QString QScriptProgram::sourceCode() const
+{
+    Q_D(const QScriptProgram);
+    if (!d)
+        return QString();
+    return d->sourceCode;
+}
+
+/*!
+  Returns the filename associated with this program.
+*/
+QString QScriptProgram::fileName() const
+{
+    Q_D(const QScriptProgram);
+    if (!d)
+        return QString();
+    return d->fileName;
+}
+
+/*!
+  Returns the line number associated with this program.
+*/
+int QScriptProgram::firstLineNumber() const
+{
+    Q_D(const QScriptProgram);
+    if (!d)
+        return -1;
+    return d->firstLineNumber;
+}
+
+/*!
+  Returns true if this QScriptProgram is equal to \a other;
+  otherwise returns false.
+*/
+bool QScriptProgram::operator==(const QScriptProgram &other) const
+{
+    Q_D(const QScriptProgram);
+    if (d == other.d_func())
+        return true;
+    return (sourceCode() == other.sourceCode())
+        && (fileName() == other.fileName())
+        && (firstLineNumber() == other.firstLineNumber());
+}
+
+/*!
+  Returns true if this QScriptProgram is not equal to \a other;
+  otherwise returns false.
+*/
+bool QScriptProgram::operator!=(const QScriptProgram &other) const
+{
+    return !operator==(other);
+}
+
+QT_END_NAMESPACE
diff --git a/src/script/api/qscriptprogram.h b/src/script/api/qscriptprogram.h
new file mode 100644
index 0000000..de891cd
--- /dev/null
+++ b/src/script/api/qscriptprogram.h
@@ -0,0 +1,86 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtScript module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QSCRIPTPROGRAM_H
+#define QSCRIPTPROGRAM_H
+
+#include <QtCore/qsharedpointer.h>
+
+#include <QtCore/qstring.h>
+
+QT_BEGIN_HEADER
+
+QT_BEGIN_NAMESPACE
+
+QT_MODULE(Script)
+
+class QScriptProgramPrivate;
+class Q_SCRIPT_EXPORT QScriptProgram
+{
+public:
+    QScriptProgram();
+    QScriptProgram(const QString &sourceCode,
+                   const QString fileName = QString(),
+                   int firstLineNumber = 1);
+    QScriptProgram(const QScriptProgram &other);
+    ~QScriptProgram();
+
+    QScriptProgram &operator=(const QScriptProgram &other);
+
+    bool isNull() const;
+
+    QString sourceCode() const;
+    QString fileName() const;
+    int firstLineNumber() const;
+
+    bool operator==(const QScriptProgram &other) const;
+    bool operator!=(const QScriptProgram &other) const;
+
+private:
+    QExplicitlySharedDataPointer<QScriptProgramPrivate> d_ptr;
+    Q_DECLARE_PRIVATE(QScriptProgram)
+};
+
+QT_END_NAMESPACE
+
+QT_END_HEADER
+
+#endif // QSCRIPTPROGRAM_H
diff --git a/src/script/api/qscriptprogram_p.h b/src/script/api/qscriptprogram_p.h
new file mode 100644
index 0000000..5175079
--- /dev/null
+++ b/src/script/api/qscriptprogram_p.h
@@ -0,0 +1,95 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtScript module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QSCRIPTPROGRAM_P_H
+#define QSCRIPTPROGRAM_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtCore/qobjectdefs.h>
+
+namespace JSC
+{
+    class EvalExecutable;
+    class ExecState;
+}
+
+QT_BEGIN_NAMESPACE
+
+class QScriptEnginePrivate;
+
+class QScriptProgramPrivate
+{
+public:
+    QScriptProgramPrivate(const QString &sourceCode,
+                          const QString &fileName,
+                          int firstLineNumber);
+    ~QScriptProgramPrivate();
+
+    static QScriptProgramPrivate *get(const QScriptProgram &q);
+
+    JSC::EvalExecutable *executable(JSC::ExecState *exec,
+                                    QScriptEnginePrivate *engine);
+
+    QBasicAtomicInt ref;
+
+    QString sourceCode;
+    QString fileName;
+    int firstLineNumber;
+
+    QScriptEnginePrivate *engine;
+    JSC::EvalExecutable *_executable;
+    intptr_t sourceId;
+    bool isCompiled;
+};
+
+QT_END_NAMESPACE
+
+#endif