Be smarter about storing property maps.

The current code just dumps such maps into the file via the ">>"
operator, so no strings are shared. This patch fixes that.
Example results for building Qt Creator:
Size of build graph on disk: ~65 MB -> ~34 MB.
Size of build graph in memory: ~250MB -> ~150 MB.

Change-Id: Ic89d0f6c37ba1cd7b3aa8a35517bb6a6a37061c2
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>

6 files changed, 90 insertions, 11 deletions

diff --git a/src/lib/corelib/buildgraph/command.cpp b/src/lib/corelib/buildgraph/command.cpp
index fa7e4cbee..4019bb38e 100644
--- a/src/lib/corelib/buildgraph/command.cpp
+++ b/src/lib/corelib/buildgraph/command.cpp
@@ -283,14 +283,14 @@ void JavaScriptCommand::load(PersistentPool &pool)
 {
     AbstractCommand::load(pool);
     m_sourceCode = pool.idLoadString();
-    pool.stream() >> m_properties;
+    m_properties = pool.loadVariantMap();
 }
 
 void JavaScriptCommand::store(PersistentPool &pool) const
 {
     AbstractCommand::store(pool);
     pool.storeString(m_sourceCode);
-    pool.stream() << m_properties;
+    pool.store(m_properties);
 }
 
 QList<AbstractCommandPtr> loadCommandList(PersistentPool &pool)
diff --git a/src/lib/corelib/language/language.cpp b/src/lib/corelib/language/language.cpp
index 20ef70b52..5c5fac445 100644
--- a/src/lib/corelib/language/language.cpp
+++ b/src/lib/corelib/language/language.cpp
@@ -468,7 +468,7 @@ void ResolvedProduct::load(PersistentPool &pool)
         >> sourceDirectory
         >> destinationDirectory
         >> location;
-    pool.stream() >> productProperties;
+    productProperties = pool.loadVariantMap();
     moduleProperties = pool.idLoadS<PropertyMapInternal>();
     pool.loadContainerS(rules);
     pool.loadContainerS(dependencies);
@@ -493,7 +493,7 @@ void ResolvedProduct::store(PersistentPool &pool) const
         << destinationDirectory
         << location;
 
-    pool.stream() << productProperties;
+    pool.store(productProperties);
     pool.store(moduleProperties);
     pool.storeContainer(rules);
     pool.storeContainer(dependencies);
@@ -837,7 +837,7 @@ void ResolvedProject::load(PersistentPool &pool)
         subProjects.append(p);
     }
 
-    pool.stream() >> m_projectProperties;
+    m_projectProperties = pool.loadVariantMap();
 }
 
 void ResolvedProject::store(PersistentPool &pool) const
@@ -852,7 +852,7 @@ void ResolvedProject::store(PersistentPool &pool) const
     pool.stream() << subProjects.count();
     foreach (const ResolvedProjectConstPtr &project, subProjects)
         pool.store(project);
-    pool.stream() << m_projectProperties;
+    pool.store(m_projectProperties);
 }
 
 
diff --git a/src/lib/corelib/language/propertymapinternal.cpp b/src/lib/corelib/language/propertymapinternal.cpp
index 89515e74e..31da2dcd3 100644
--- a/src/lib/corelib/language/propertymapinternal.cpp
+++ b/src/lib/corelib/language/propertymapinternal.cpp
@@ -93,12 +93,12 @@ QString PropertyMapInternal::toJSLiteral() const
 
 void PropertyMapInternal::load(PersistentPool &pool)
 {
-    pool.stream() >> m_value;
+    m_value = pool.loadVariantMap();
 }
 
 void PropertyMapInternal::store(PersistentPool &pool) const
 {
-    pool.stream() << m_value;
+    pool.store(m_value);
 }
 
 } // namespace Internal
diff --git a/src/lib/corelib/tools/persistence.cpp b/src/lib/corelib/tools/persistence.cpp
index 0264353d3..5e89b0ce2 100644
--- a/src/lib/corelib/tools/persistence.cpp
+++ b/src/lib/corelib/tools/persistence.cpp
@@ -40,7 +40,7 @@
 namespace qbs {
 namespace Internal {
 
-static const char QBS_PERSISTENCE_MAGIC[] = "QBSPERSISTENCE-74";
+static const char QBS_PERSISTENCE_MAGIC[] = "QBSPERSISTENCE-75";
 
 PersistentPool::PersistentPool(const Logger &logger) : m_logger(logger)
 {
@@ -148,6 +148,80 @@ void PersistentPool::store(const PersistentObject *object)
     }
 }
 
+void PersistentPool::store(const QVariantMap &map)
+{
+    m_stream << map.count();
+    for (QVariantMap::ConstIterator it = map.constBegin(); it != map.constEnd(); ++it) {
+        storeString(it.key());
+        store(it.value());
+    }
+}
+
+QVariantMap PersistentPool::loadVariantMap()
+{
+    int count;
+    m_stream >> count;
+    QVariantMap map;
+    for (int i = 0; i < count; ++i) {
+        const QString key = idLoadString();
+        const QVariant value = loadVariant();
+        map.insert(key, value);
+    }
+    return map;
+}
+
+void PersistentPool::store(const QVariant &variant)
+{
+    const quint32 type = static_cast<quint32>(variant.type());
+    m_stream << type;
+    switch (type) {
+    case QMetaType::QString:
+        storeString(variant.toString());
+        break;
+    case QMetaType::QStringList:
+        storeStringList(variant.toStringList());
+        break;
+    case QMetaType::QVariantList:
+        storeContainer(variant.toList());
+        break;
+    case QMetaType::QVariantMap:
+        store(variant.toMap());
+        break;
+    default:
+        m_stream << variant;
+    }
+}
+
+QVariant PersistentPool::loadVariant()
+{
+    quint32 type;
+    m_stream >> type;
+    QVariant value;
+    switch (type) {
+    case QMetaType::QString:
+        value = idLoadString();
+        break;
+    case QMetaType::QStringList:
+        value = idLoadStringList();
+        break;
+    case QMetaType::QVariantList: {
+        QVariantList l;
+        int count;
+        m_stream >> count;
+        for (int i = 0; i < count; ++i)
+            l << loadVariant();
+        value = l;
+        break;
+    }
+    case QMetaType::QVariantMap:
+        value = loadVariantMap();
+        break;
+    default:
+        m_stream >> value;
+    }
+    return value;
+}
+
 void PersistentPool::clear()
 {
     m_loaded.clear();
diff --git a/src/lib/corelib/tools/persistence.h b/src/lib/corelib/tools/persistence.h
index 429ff467c..878f22f2a 100644
--- a/src/lib/corelib/tools/persistence.h
+++ b/src/lib/corelib/tools/persistence.h
@@ -70,6 +70,12 @@ public:
     void store(const PersistentObject *object);
     template <typename T> void storeContainer(const T &container);
 
+    void store(const QVariantMap &map);
+    QVariantMap loadVariantMap();
+
+    void store(const QVariant &variant);
+    QVariant loadVariant();
+
     void storeString(const QString &t);
     QString loadString(int id);
     QString idLoadString();
diff --git a/src/lib/corelib/tools/propertyfinder.cpp b/src/lib/corelib/tools/propertyfinder.cpp
index 96c081f01..d5ef0d648 100644
--- a/src/lib/corelib/tools/propertyfinder.cpp
+++ b/src/lib/corelib/tools/propertyfinder.cpp
@@ -82,8 +82,7 @@ void PropertyFinder::findModuleValues(const QVariantMap &properties, bool search
 
 void PropertyFinder::addToList(const QVariant &value)
 {
-    // Note: This means that manually setting a property to "null" will not lead to a "hit".
-    if (!value.isNull() && !m_values.contains(value))
+    if (value.isValid() && !m_values.contains(value))
         m_values << value;
 }