Make IDB settings work sync with JSPI

IndexedDB version of QSettings will now use solely the sync versions
of data access functions. Those will suspend with JSPI.
This makes IDB settings conform to the QSettings contract - and also
allows us to enable tests in tst_qsettings for the IDB version of
QSettings.
Also, do not treat the IndexedDB format as one defining read/write
functions in QSettings - those are the same as for ini format, as
IndexedDB settings backend uses a backing ini file.

Change-Id: Iee3471cc79c0cea87378923cf9baac58e56d1272
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>

3 files changed, 95 insertions, 105 deletions

diff --git a/src/corelib/io/qsettings.cpp b/src/corelib/io/qsettings.cpp
index 20dc590483..be0f2536dc 100644
--- a/src/corelib/io/qsettings.cpp
+++ b/src/corelib/io/qsettings.cpp
@@ -878,7 +878,13 @@ QStringList QSettingsPrivate::splitArgs(const QString &s, qsizetype idx)
 
 void QConfFileSettingsPrivate::initFormat()
 {
+#if defined(Q_OS_WASM)
+    extension = (format == QSettings::NativeFormat || format == QSettings::WebIndexedDBFormat)
+            ? ".conf"_L1
+            : ".ini"_L1;
+#else
     extension = (format == QSettings::NativeFormat) ? ".conf"_L1 : ".ini"_L1;
+#endif
     readFunc = nullptr;
     writeFunc = nullptr;
 #if defined(Q_OS_DARWIN)
@@ -887,7 +893,11 @@ void QConfFileSettingsPrivate::initFormat()
     caseSensitivity = IniCaseSensitivity;
 #endif
 
+#if defined Q_OS_WASM
+    if (format > QSettings::IniFormat && format != QSettings::WebIndexedDBFormat) {
+#else
     if (format > QSettings::IniFormat) {
+#endif
         const auto locker = qt_scoped_lock(settingsGlobalMutex);
         const CustomFormatVector *customFormatVector = customFormatVectorFunc();
 
@@ -905,7 +915,11 @@ void QConfFileSettingsPrivate::initFormat()
 void QConfFileSettingsPrivate::initAccess()
 {
     if (!confFiles.isEmpty()) {
+#if defined Q_OS_WASM
+        if (format > QSettings::IniFormat && format != QSettings::WebIndexedDBFormat) {
+#else
         if (format > QSettings::IniFormat) {
+#endif
             if (!readFunc)
                 setStatus(QSettings::AccessError);
         }
@@ -1307,7 +1321,11 @@ QString QConfFileSettingsPrivate::fileName() const
 
 bool QConfFileSettingsPrivate::isWritable() const
 {
+#if defined(Q_OS_WASM)
+    if (format > QSettings::IniFormat && format != QSettings::WebIndexedDBFormat && !writeFunc)
+#else
     if (format > QSettings::IniFormat && !writeFunc)
+#endif
         return false;
 
     if (confFiles.isEmpty())
@@ -1386,6 +1404,13 @@ void QConfFileSettingsPrivate::syncConfFile(QConfFile *confFile)
         */
         if (file.isReadable() && file.size() != 0) {
             bool ok = false;
+
+#ifdef Q_OS_WASM
+            if (format == QSettings::WebIndexedDBFormat) {
+                QByteArray data = file.readAll();
+                ok = readIniFile(data, &confFile->unparsedIniSections);
+            } else
+#endif
 #ifdef Q_OS_DARWIN
             if (format == QSettings::NativeFormat) {
                 QByteArray data = file.readAll();
@@ -1442,6 +1467,11 @@ void QConfFileSettingsPrivate::syncConfFile(QConfFile *confFile)
             return;
         }
 
+#ifdef Q_OS_WASM
+        if (format == QSettings::WebIndexedDBFormat) {
+            ok = writeIniFile(sf, mergedKeys);
+        } else
+#endif
 #ifdef Q_OS_DARWIN
         if (format == QSettings::NativeFormat) {
             ok = writePlistFile(sf, mergedKeys);
diff --git a/src/corelib/io/qsettings_wasm.cpp b/src/corelib/io/qsettings_wasm.cpp
index 8329124804..9b206e26d5 100644
--- a/src/corelib/io/qsettings_wasm.cpp
+++ b/src/corelib/io/qsettings_wasm.cpp
@@ -10,6 +10,7 @@
 #include <QFile>
 #endif // QT_NO_QOBJECT
 #include <QDebug>
+#include <QtCore/private/qstdweb_p.h>
 
 #include <QFileInfo>
 #include <QDir>
@@ -216,7 +217,6 @@ public:
     QWasmIDBSettingsPrivate(QSettings::Scope scope, const QString &organization,
                             const QString &application);
     ~QWasmIDBSettingsPrivate();
-    static QWasmIDBSettingsPrivate *get(void *userData);
 
     std::optional<QVariant> get(const QString &key) const override;
     QStringList children(const QString &prefix, ChildSpec spec) const override;
@@ -224,91 +224,59 @@ public:
     void sync() override;
     void flush() override;
     bool isWritable() const override;
+    void initAccess() override;
 
-    void syncToLocal(const char *data, int size);
-    void loadLocal(const QByteArray &filename);
+    void loadLocal();
     void setReady();
-    void initAccess() override;
 
 private:
+    bool writeSettingsToTemporaryFile(void *dataPtr, int size);
+
     QString databaseName;
     QString id;
-    static QList<QWasmIDBSettingsPrivate *> liveSettings;
 };
 
-QList<QWasmIDBSettingsPrivate *> QWasmIDBSettingsPrivate::liveSettings;
 static bool isReadReady = false;
 
-static void QWasmIDBSettingsPrivate_onLoad(void *userData, void *dataPtr, int size)
-{
-    QWasmIDBSettingsPrivate *settings = QWasmIDBSettingsPrivate::get(userData);
-    if (!settings)
-        return;
-
-    QFile file(settings->fileName());
-    QFileInfo fileInfo(settings->fileName());
-    QDir dir(fileInfo.path());
-    if (!dir.exists())
-        dir.mkpath(fileInfo.path());
-
-    if (file.open(QFile::WriteOnly)) {
-        file.write(reinterpret_cast<char *>(dataPtr), size);
-        file.close();
-        settings->setReady();
-    }
-}
-
-static void QWasmIDBSettingsPrivate_onError(void *userData)
-{
-    if (QWasmIDBSettingsPrivate *settings = QWasmIDBSettingsPrivate::get(userData))
-        settings->setStatus(QSettings::AccessError);
-}
-
-static void QWasmIDBSettingsPrivate_onStore(void *userData)
-{
-    if (QWasmIDBSettingsPrivate *settings = QWasmIDBSettingsPrivate::get(userData))
-        settings->setStatus(QSettings::NoError);
-}
-
-static void QWasmIDBSettingsPrivate_onCheck(void *userData, int exists)
-{
-    if (QWasmIDBSettingsPrivate *settings = QWasmIDBSettingsPrivate::get(userData)) {
-        if (exists)
-            settings->loadLocal(settings->fileName().toLocal8Bit());
-        else
-            settings->setReady();
-    }
-}
+constexpr char DbName[] = "/home/web_user";
 
 QWasmIDBSettingsPrivate::QWasmIDBSettingsPrivate(QSettings::Scope scope,
                                                  const QString &organization,
                                                  const QString &application)
-    : QConfFileSettingsPrivate(QSettings::NativeFormat, scope, organization, application)
+    : QConfFileSettingsPrivate(QSettings::WebIndexedDBFormat, scope, organization, application)
 {
-    liveSettings.push_back(this);
+    Q_ASSERT_X(qstdweb::haveJspi(), Q_FUNC_INFO, "QWasmIDBSettingsPrivate needs JSPI to work");
+
+    if (organization.isEmpty()) {
+        setStatus(QSettings::AccessError);
+        return;
+    }
 
     setStatus(QSettings::AccessError); // access error until sandbox gets loaded
     databaseName = organization;
     id = application;
 
-    emscripten_idb_async_exists("/home/web_user",
-                                fileName().toLocal8Bit(),
-                                reinterpret_cast<void*>(this),
-                                QWasmIDBSettingsPrivate_onCheck,
-                                QWasmIDBSettingsPrivate_onError);
-}
+    int exists = 0;
+    int error = 0;
+    emscripten_idb_exists(DbName, fileName().toLocal8Bit(), &exists, &error);
+    if (error) {
+        setStatus(QSettings::AccessError);
+        return;
+    }
+    if (exists) {
+        void *contents;
+        int size;
+        emscripten_idb_load(DbName, fileName().toLocal8Bit(), &contents, &size, &error);
+        if (error || !writeSettingsToTemporaryFile(contents, size)) {
+            setStatus(QSettings::AccessError);
+            return;
+        }
+    }
 
-QWasmIDBSettingsPrivate::~QWasmIDBSettingsPrivate()
-{
-    liveSettings.removeAll(this);
+    setReady();
 }
 
-QWasmIDBSettingsPrivate *QWasmIDBSettingsPrivate::get(void *userData)
-{
-    if (QWasmIDBSettingsPrivate::liveSettings.contains(userData))
-        return reinterpret_cast<QWasmIDBSettingsPrivate *>(userData);
-    return nullptr;
-}
+QWasmIDBSettingsPrivate::~QWasmIDBSettingsPrivate() = default;
 
 void QWasmIDBSettingsPrivate::initAccess()
 {
@@ -324,6 +292,20 @@ std::optional<QVariant> QWasmIDBSettingsPrivate::get(const QString &key) const
     return std::nullopt;
 }
 
+bool QWasmIDBSettingsPrivate::writeSettingsToTemporaryFile(void *dataPtr, int size)
+{
+    QFile file(fileName());
+    QFileInfo fileInfo(fileName());
+    QDir dir(fileInfo.path());
+    if (!dir.exists())
+        dir.mkpath(fileInfo.path());
+
+    if (!file.open(QFile::WriteOnly))
+        return false;
+
+    return size == file.write(reinterpret_cast<char *>(dataPtr), size);
+}
+
 QStringList QWasmIDBSettingsPrivate::children(const QString &prefix, ChildSpec spec) const
 {
     return QConfFileSettingsPrivate::children(prefix, spec);
@@ -332,11 +314,10 @@ QStringList QWasmIDBSettingsPrivate::children(const QString &prefix, ChildSpec s
 void QWasmIDBSettingsPrivate::clear()
 {
     QConfFileSettingsPrivate::clear();
-    emscripten_idb_async_delete("/home/web_user",
-                                fileName().toLocal8Bit(),
-                                reinterpret_cast<void*>(this),
-                                QWasmIDBSettingsPrivate_onStore,
-                                QWasmIDBSettingsPrivate_onError);
+
+    int error = 0;
+    emscripten_idb_delete(DbName, fileName().toLocal8Bit(), &error);
+    setStatus(!!error ? QSettings::AccessError : QSettings::NoError);
 }
 
 void QWasmIDBSettingsPrivate::sync()
@@ -347,13 +328,11 @@ void QWasmIDBSettingsPrivate::sync()
     if (file.open(QFile::ReadOnly)) {
         QByteArray dataPointer = file.readAll();
 
-        emscripten_idb_async_store("/home/web_user",
-                                  fileName().toLocal8Bit(),
-                                   reinterpret_cast<void *>(dataPointer.data()),
-                                   dataPointer.length(),
-                                   reinterpret_cast<void*>(this),
-                                   QWasmIDBSettingsPrivate_onStore,
-                                   QWasmIDBSettingsPrivate_onError);
+        int error = 0;
+        emscripten_idb_store(DbName, fileName().toLocal8Bit(),
+                             reinterpret_cast<void *>(dataPointer.data()), dataPointer.length(),
+                             &error);
+        setStatus(!!error ? QSettings::AccessError : QSettings::NoError);
     }
 }
 
@@ -367,34 +346,6 @@ bool QWasmIDBSettingsPrivate::isWritable() const
     return isReadReady && QConfFileSettingsPrivate::isWritable();
 }
 
-void QWasmIDBSettingsPrivate::syncToLocal(const char *data, int size)
-{
-    QFile file(fileName());
-
-    if (file.open(QFile::WriteOnly)) {
-        file.write(data, size + 1);
-        QByteArray data = file.readAll();
-
-        emscripten_idb_async_store("/home/web_user",
-                                   fileName().toLocal8Bit(),
-                                   reinterpret_cast<void *>(data.data()),
-                                   data.length(),
-                                   reinterpret_cast<void*>(this),
-                                   QWasmIDBSettingsPrivate_onStore,
-                                   QWasmIDBSettingsPrivate_onError);
-        setReady();
-    }
-}
-
-void QWasmIDBSettingsPrivate::loadLocal(const QByteArray &filename)
-{
-    emscripten_idb_async_load("/home/web_user",
-                              filename.data(),
-                              reinterpret_cast<void*>(this),
-                              QWasmIDBSettingsPrivate_onLoad,
-                              QWasmIDBSettingsPrivate_onError);
-}
-
 void QWasmIDBSettingsPrivate::setReady()
 {
     isReadReady = true;
@@ -422,6 +373,11 @@ QSettingsPrivate *QSettingsPrivate::create(QSettings::Format format, QSettings::
             format = QSettings::IniFormat;
         }
     }
+    if (format == QSettings::WebIndexedDBFormat && !qstdweb::haveJspi()) {
+        qWarning() << "QSettings::WebIndexedDBFormat requires JSPI, falling back to IniFormat with "
+                      "temporary file";
+        format = QSettings::IniFormat;
+    }
 
     // Create settings backend according to selected format
     switch (format) {
diff --git a/tests/auto/corelib/io/qsettings/tst_qsettings.cpp b/tests/auto/corelib/io/qsettings/tst_qsettings.cpp
index 337428d01a..0661ac17ca 100644
--- a/tests/auto/corelib/io/qsettings/tst_qsettings.cpp
+++ b/tests/auto/corelib/io/qsettings/tst_qsettings.cpp
@@ -42,9 +42,9 @@
 #endif
 
 #if defined(Q_OS_WASM)
-#  include <QtCore/private/qstdweb_p.h>
+#include <QtCore/private/qstdweb_p.h>
 
-#  include "emscripten/val.h"
+#include "emscripten/val.h"
 #endif
 
 Q_DECLARE_METATYPE(QSettings::Format)
@@ -89,6 +89,10 @@ static void populateWithFormats()
     QTest::addColumn<QSettings::Format>("format");
 
     QTest::newRow("native") << QSettings::NativeFormat;
+#if defined(Q_OS_WASM)
+    if (qstdweb::haveJspi())
+        QTest::newRow("idb") << QSettings::WebIndexedDBFormat;
+#endif // defined(Q_OS_WASM)
     QTest::newRow("ini") << QSettings::IniFormat;
     QTest::newRow("custom1") << QSettings::CustomFormat1;
     QTest::newRow("custom2") << QSettings::CustomFormat2;