Merge caches with same key in Evaluator

Reduce hash lookups and memory footprint.

========== Performance data for Resolving ==========
    Old instruction count: 2465977485
    New instruction count: 2457362647
    Relative change: -1 %
    Old peak memory usage: 21248960 Bytes
    New peak memory usage: 21237680 Bytes
    Relative change: -1 %
========== Performance data for Rule Execution ==========
    Old instruction count: 4898426038
    New instruction count: 4857983226
    Relative change: -1 %
    Old peak memory usage: 27604240 Bytes
    New peak memory usage: 27593424 Bytes
    Relative change: -1 %
========== Performance data for Null Build ==========
    Old instruction count: 4509789474
    New instruction count: 4490616946
    Relative change: -1 %
    Old peak memory usage: 30680456 Bytes
    New peak memory usage: 30670784 Bytes
    Relative change: -1 %

Change-Id: Ie613447cf9da4bc3d2bfdab42c9a9b5ace643540
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

4 files changed, 40 insertions, 43 deletions

diff --git a/src/lib/corelib/language/evaluator.cpp b/src/lib/corelib/language/evaluator.cpp
index be581c3b1..07cd4852a 100644
--- a/src/lib/corelib/language/evaluator.cpp
+++ b/src/lib/corelib/language/evaluator.cpp
@@ -205,31 +205,26 @@ bool Evaluator::evaluateProperty(QScriptValue *result, const Item *item, const Q
     return true;
 }
 
-QScriptValue Evaluator::fileScope(const FileContextConstPtr &file)
-{
-    QScriptValue &result = m_fileScopeMap[file];
-    if (result.isObject()) {
-        // already initialized
-        return result;
+Evaluator::FileContextScopes Evaluator::fileContextScopes(const FileContextConstPtr &file)
+{
+    FileContextScopes &result = m_fileContextScopesMap[file];
+    if (!result.fileScope.isObject()) {
+        if (file->idScope())
+            result.fileScope = scriptValue(file->idScope());
+        else
+            result.fileScope = m_scriptEngine->newObject();
+        result.fileScope.setProperty(QLatin1String("filePath"), file->filePath());
+        result.fileScope.setProperty(QLatin1String("path"), file->dirPath());
+    }
+    if (!result.importScope.isObject()) {
+        try {
+            result.importScope = m_scriptEngine->newObject();
+            m_scriptEngine->import(file, result.importScope);
+            JsExtensions::setupExtensions(file->jsExtensions(), result.importScope);
+        } catch (const ErrorInfo &e) {
+            result.importScope = m_scriptEngine->currentContext()->throwError(e.toString());
+        }
     }
-
-    if (file->idScope())
-        result = scriptValue(file->idScope());
-    else
-        result = m_scriptEngine->newObject();
-    result.setProperty(QLatin1String("filePath"), file->filePath());
-    result.setProperty(QLatin1String("path"), file->dirPath());
-    return result;
-}
-
-QScriptValue Evaluator::importScope(const FileContextConstPtr &file)
-{
-    QScriptValue &result = m_importScopeMap[file];
-    if (result.isObject())
-        return result;
-    result = m_scriptEngine->newObject();
-    m_scriptEngine->import(file, result);
-    JsExtensions::setupExtensions(file->jsExtensions(), result);
     return result;
 }
 
diff --git a/src/lib/corelib/language/evaluator.h b/src/lib/corelib/language/evaluator.h
index 759cc5d4e..b602326ca 100644
--- a/src/lib/corelib/language/evaluator.h
+++ b/src/lib/corelib/language/evaluator.h
@@ -75,8 +75,14 @@ public:
     QStringList stringListValue(const Item *item, const QString &name, bool *propertyWasSet = 0);
 
     QScriptValue scriptValue(const Item *item);
-    QScriptValue fileScope(const FileContextConstPtr &file);
-    QScriptValue importScope(const FileContextConstPtr &file);
+
+    struct FileContextScopes
+    {
+        QScriptValue fileScope;
+        QScriptValue importScope;
+    };
+
+    FileContextScopes fileContextScopes(const FileContextConstPtr &file);
 
     void setCachingEnabled(bool enabled);
 
@@ -93,8 +99,7 @@ private:
     ScriptEngine *m_scriptEngine;
     EvaluatorScriptClass *m_scriptClass;
     mutable QHash<const Item *, QScriptValue> m_scriptValueMap;
-    mutable QHash<FileContextConstPtr, QScriptValue> m_fileScopeMap;
-    mutable QHash<FileContextConstPtr, QScriptValue> m_importScopeMap;
+    mutable QHash<FileContextConstPtr, FileContextScopes> m_fileContextScopesMap;
 };
 
 class EvalCacheEnabler
diff --git a/src/lib/corelib/language/evaluatorscriptclass.cpp b/src/lib/corelib/language/evaluatorscriptclass.cpp
index c68a195bc..50aa23707 100644
--- a/src/lib/corelib/language/evaluatorscriptclass.cpp
+++ b/src/lib/corelib/language/evaluatorscriptclass.cpp
@@ -101,15 +101,6 @@ public:
     }
 
 private:
-    QScriptValue importScope(Evaluator *evaluator, const FileContextConstPtr &file)
-    {
-        try {
-            return evaluator->importScope(file);
-        } catch (const ErrorInfo &e) {
-            return evaluator->engine()->currentContext()->throwError(e.toString());
-        }
-    }
-
     void setupConvenienceProperty(const QString &conveniencePropertyName, QScriptValue *extraScope,
                                   const QScriptValue &scriptValue)
     {
@@ -162,6 +153,8 @@ private:
         for (int i = 0; i < value->alternatives().count(); ++i) {
             const JSSourceValue::Alternative *alternative = 0;
             alternative = &value->alternatives().at(i);
+            const Evaluator::FileContextScopes fileCtxScopes
+                    = data->evaluator->fileContextScopes(value->file());
             if (!conditionScopeItem) {
                 // We have to differentiate between module instances and normal items here.
                 //
@@ -194,14 +187,14 @@ private:
                         ? data->item->scope() : data->item;
                 conditionScope = data->evaluator->scriptValue(conditionScopeItem);
                 QBS_ASSERT(conditionScope.isObject(), return);
-                conditionFileScope = data->evaluator->fileScope(value->file());
+                conditionFileScope = fileCtxScopes.fileScope;
             }
             scriptContext->pushScope(conditionFileScope);
             pushItemScopes(conditionScopeItem);
             if (alternative->value->definingItem())
                 pushItemScopes(alternative->value->definingItem());
             scriptContext->pushScope(conditionScope);
-            const QScriptValue theImportScope = importScope(data->evaluator, value->file());
+            const QScriptValue &theImportScope = fileCtxScopes.importScope;
             if (theImportScope.isError()) {
                 scriptContext->popScope();
                 scriptContext->popScope();
@@ -275,7 +268,9 @@ private:
             setupConvenienceProperty(QLatin1String("original"), &extraScope, originalValue);
         }
 
-        pushScope(data->evaluator->fileScope(value->file()));
+        const Evaluator::FileContextScopes fileCtxScopes
+                = data->evaluator->fileContextScopes(value->file());
+        pushScope(fileCtxScopes.fileScope);
         pushItemScopes(data->item);
         if (itemOfProperty && itemOfProperty->type() != ItemType::ModuleInstance) {
             // Own properties of module instances must not have the instance itself in the scope.
@@ -284,7 +279,7 @@ private:
         if (value->definingItem())
             pushItemScopes(value->definingItem());
         pushScope(extraScope);
-        const QScriptValue theImportScope = importScope(data->evaluator, value->file());
+        const QScriptValue &theImportScope = fileCtxScopes.importScope;
         if (theImportScope.isError()) {
             *result = theImportScope;
         } else {
diff --git a/src/lib/corelib/language/moduleloader.cpp b/src/lib/corelib/language/moduleloader.cpp
index b51c337e2..7701a0432 100644
--- a/src/lib/corelib/language/moduleloader.cpp
+++ b/src/lib/corelib/language/moduleloader.cpp
@@ -2253,8 +2253,10 @@ void ModuleLoader::resolveProbe(ProductContext *productContext, Item *parent, It
     ScriptEngine * const engine = m_evaluator->engine();
     QScriptValue scope = engine->newObject();
     engine->currentContext()->pushScope(m_evaluator->scriptValue(parent));
-    engine->currentContext()->pushScope(m_evaluator->fileScope(configureScript->file()));
-    engine->currentContext()->pushScope(m_evaluator->importScope(configureScript->file()));
+    const Evaluator::FileContextScopes fileCtxScopes
+            = m_evaluator->fileContextScopes(configureScript->file());
+    engine->currentContext()->pushScope(fileCtxScopes.fileScope);
+    engine->currentContext()->pushScope(fileCtxScopes.importScope);
     engine->currentContext()->pushScope(scope);
     for (const ProbeProperty &b : qAsConst(probeBindings))
         scope.setProperty(b.first, b.second);