fix: Wrong clean cache folder

之前设计的缓存目录名重复,在多实例下, 其它实例退出
会导致缓存目录被误删除. 调整缓存目录设计,改到/tmp
目录且每个实例唯一.

Log: 修复误删除缓存目录的问题
Bug: https://pms.uniontech.com/bug-view-247289.html
Influence: SetWallpaper

libimageviewer/unionimage/imageutils.cpp

@@ -25,6 +25,7 @@
 #include <QReadWriteLock>
 #include <QUrl>
 #include <QApplication>
+#include <QTemporaryDir>
 
 namespace Libutils {
 
@@ -824,32 +825,67 @@ bool isCanRemove(const QString &path)
     return bRet;
 }
 
+// 缓存文件路径及互斥锁
+static QMutex s_CachePathMutex;
+static QString s_CachePath;
+
 /**
- * @brief 取得图像缓存文件夹路径
+   @brief 取得图像缓存文件夹路径，未成功初始化将自动创建
+   @threadsafe
  */
 QString getCacheImagePath()
 {
-    return QDir::homePath() + "/.cache/deepin/deepin-image-viewer/cache_image";
+    QMutexLocker _locker(&s_CachePathMutex);
+    if (s_CachePath.isEmpty()) {
+        _locker.unlock();
+        initCacheImageFolder();
+        _locker.relock();
+    }
+
+    return s_CachePath;
 }
 
 /**
- * @brief 初始化图像缓存文件夹并返回是否初始化成功
+   @brief 初始化图像临时缓存文件夹（/tmp/image-viewer-cache_XXXXXX）并返回是否初始化成功，仅在加载图片时调用
+    看图为多实例进程，不同实例创建缓存位置不同
+   @threadsafe
  */
 bool initCacheImageFolder()
 {
-    QDir homeDir(QDir::homePath());
-    return homeDir.mkpath(".cache/deepin/deepin-image-viewer/cache_image");
+    QMutexLocker _locker(&s_CachePathMutex);
+    if (!s_CachePath.isEmpty()) {
+        return true;
+    }
+
+    QTemporaryDir dir(QDir::tempPath() + QDir::separator() + "image-viewer-cache_XXXXXX");
+    dir.setAutoRemove(false);
+    if (dir.isValid()) {
+        s_CachePath = dir.path();
+        return true;
+    }
+
+    qWarning() << QString("Create cache image folder failed, %1:%2").arg(dir.path()).arg(dir.errorString());
+    return false;
 }
 
 /**
- * @brief 清空图像缓存文件夹并返回是否清理成功，
- *  在程序启动或打开文件时调用
+   @brief 清空图像缓存文件夹并返回是否清理成功，在程序退出时调用。
+   @threadsafe
  */
 bool clearCacheImageFolder()
 {
-    QDir cacheDir(getCacheImagePath());
+    QMutexLocker _locker(&s_CachePathMutex);
+    if (s_CachePath.isEmpty()) {
+        return false;
+    }
+
+    QDir cacheDir(s_CachePath);
     if (cacheDir.exists()) {
-        return cacheDir.removeRecursively();
+        bool ret = cacheDir.removeRecursively();
+        if (ret) {
+            s_CachePath.clear();
+        }
+        return ret;
     }
     return false;
 }

libimageviewer/viewpanel/viewpanel.cpp

@@ -179,7 +179,6 @@ LibViewPanel::~LibViewPanel()
 void LibViewPanel::loadImage(const QString &path, QStringList paths)
 {
     // 初始化图像缓存目录
-    Libutils::image::clearCacheImageFolder();
     Libutils::image::initCacheImageFolder();
 
     QFileInfo info(path);
@@ -883,34 +882,33 @@ static void setWallpaperWithDBus(const QString &path)
 
 void LibViewPanel::setWallpaper(const QImage &img)
 {
-    QThread *th1 = QThread::create([ = ]() {
-        if (!img.isNull()) {
+    if (!img.isNull()) {
+        QString tempPathTemplate = Libutils::image::getCacheImagePath() + QDir::separator() + "XXXXXX_Wallpaper.png";
+        QThread *th1 = QThread::create([ = ]() {
             // 设置锁屏壁纸不能使用相同名称，且临时文件不能立即删除(调用DBus接口拷贝需要时间)，保留至缓存目录，程序退出自动清理
             QTemporaryFile tmpImage;
             tmpImage.setAutoRemove(false);
-            tmpImage.setFileTemplate(Libutils::image::getCacheImagePath() + QDir::separator() + "XXXXXX_Wallpaper.png");
+            tmpImage.setFileTemplate(tempPathTemplate);
             if (!tmpImage.open() || !img.save(tmpImage.fileName(), "PNG")) {
                 qWarning() << QString("Copy image set wallpaper failed! path: %1").arg(tmpImage.fileName());
                 return;
             }
             qInfo() << QString("Copy image set wallpaper, path: %1").arg(tmpImage.fileName());
 
             setWallpaperWithDBus(tmpImage.fileName());
-        }
-    });
-    connect(th1, &QThread::finished, th1, &QObject::deleteLater);
-    th1->start();
+        });
+        connect(th1, &QThread::finished, th1, &QObject::deleteLater);
+        th1->start();
+    }
 }
 
 void LibViewPanel::setWallpaper(const QString &imgPath)
 {
-    QThread *th1 = QThread::create([ = ]() {
-        if (!imgPath.isNull()) {
-            setWallpaperWithDBus(imgPath);
-        }
-    });
-    connect(th1, &QThread::finished, th1, &QObject::deleteLater);
-    th1->start();
+    if (!imgPath.isEmpty()) {
+        QThread *th1 = QThread::create([ = ]() { setWallpaperWithDBus(imgPath); });
+        connect(th1, &QThread::finished, th1, &QObject::deleteLater);
+        th1->start();
+    }
 }
 
 bool LibViewPanel::startdragImage(const QStringList &paths, const QString &firstPath)