update

client/core/persistence/JsonFileAtomic.cpp

@@ -0,0 +1,62 @@
+#include "persistence/JsonFileAtomic.h"
+
+#include <QDir>
+#include <QFile>
+#include <QFileInfo>
+
+namespace core::persistence {
+
+bool writeBytesAtomic(const QString& absolutePath, const QByteArray& bytes) {
+    if (absolutePath.isEmpty()) {
+        return false;
+    }
+    const QString parent = QFileInfo(absolutePath).absolutePath();
+    if (!QFileInfo(parent).exists()) {
+        QDir().mkpath(parent);
+    }
+    const QString tmpAbs = absolutePath + QStringLiteral(".tmp");
+    if (QFileInfo::exists(tmpAbs)) {
+        QFile::remove(tmpAbs);
+    }
+    QFile f(tmpAbs);
+    if (!f.open(QIODevice::WriteOnly | QIODevice::Truncate)) {
+        return false;
+    }
+    const bool ok = f.write(bytes) == bytes.size();
+    f.close();
+    if (!ok || f.error() != QFile::NoError) {
+        QFile::remove(tmpAbs);
+        return false;
+    }
+    QFile::remove(absolutePath);
+    if (!QFile::rename(tmpAbs, absolutePath)) {
+        QFile::remove(tmpAbs);
+        return false;
+    }
+    return true;
+}
+
+bool writeJsonAtomic(const QString& absolutePath, const QJsonObject& obj, bool pretty) {
+    const QJsonDocument doc(obj);
+    const QByteArray bytes = doc.toJson(pretty ? QJsonDocument::Indented : QJsonDocument::Compact);
+    return writeBytesAtomic(absolutePath, bytes);
+}
+
+bool readJsonObject(const QString& absolutePath, QJsonObject& out) {
+    out = QJsonObject();
+    QFile f(absolutePath);
+    if (!f.open(QIODevice::ReadOnly)) {
+        return false;
+    }
+    const QByteArray data = f.readAll();
+    QJsonParseError err;
+    const QJsonDocument doc = QJsonDocument::fromJson(data, &err);
+    if (err.error != QJsonParseError::NoError || !doc.isObject()) {
+        return false;
+    }
+    out = doc.object();
+    return true;
+}
+
+}  // namespace core::persistence
+