[system/kio-snapshot] /: contextmenu: optimize checking for existence of snapshots (because we don't need the full list)

Git commit 43acca30129880eccf0fb31f4330efabe7b1b594 by Bharadwaj Raju.
Committed on 09/08/2026 at 13:59.
Pushed by bharadwaj-raju into branch 'master'.

contextmenu: optimize checking for existence of snapshots (because we don't need the full list)

M  +37   -0    common/btrfssnapshots.cpp
M  +1    -0    common/btrfssnapshots.h
M  +2    -2    contextmenu/snapshotfileitemaction.cpp

https://invent.kde.org/system/kio-snapshot/-/commit/43acca30129880eccf0fb31f4330efabe7b1b594

diff --git a/common/btrfssnapshots.cpp b/common/btrfssnapshots.cpp
index 2918098..78aa97b 100644
--- a/common/btrfssnapshots.cpp
+++ b/common/btrfssnapshots.cpp
@@ -84,6 +84,43 @@ std::optional<QString> BtrfsSnapshots::getPathForSubvolume(qulonglong subvolume,
     return std::nullopt;
 }
 
+bool BtrfsSnapshots::hasSnapshots(const QString &path, const QString &fsRoot)
+{
+    QDir subvolumeRoot;
+    QFileInfo fileInfo(path);
+    if (fileInfo.isDir()) {
+        subvolumeRoot = QDir(path);
+    } else {
+        subvolumeRoot = QDir(QFileInfo(path).absoluteDir());
+    }
+    struct btrfs_util_subvolume_info subvolume_root_info;
+    enum btrfs_util_error btrfs_err;
+    while (!subvolumeRoot.isRoot() && (btrfs_err = btrfs_util_subvolume_get_info(CSTR(subvolumeRoot.absolutePath()), 0, &subvolume_root_info)) != 0) {
+        subvolumeRoot.cdUp();
+    }
+
+    if (btrfs_err != 0) {
+        return false;
+    }
+
+    struct btrfs_util_subvolume_iterator *iter;
+    btrfs_err = btrfs_util_subvolume_iter_create(CSTR(fsRoot), 0, 0, &iter);
+    if (btrfs_err != 0) {
+        return false;
+    }
+
+    struct btrfs_util_subvolume_info iter_info;
+    char *iter_path;
+    while ((btrfs_err = btrfs_util_subvolume_iter_next_info(iter, &iter_path, &iter_info)) == 0) {
+        if (QByteArrayView::fromArray(iter_info.parent_uuid) == QByteArrayView::fromArray(subvolume_root_info.uuid)) {
+            free(iter_path);
+            return true;
+        }
+        free(iter_path);
+    }
+    return false;
+}
+
 QList<BtrfsSnapshots::FileSnapshot> BtrfsSnapshots::getSnapshotsForFile(const QString &path, const QString &fsRoot)
 {
     QList<FileSnapshot> fileSnapshots;
diff --git a/common/btrfssnapshots.h b/common/btrfssnapshots.h
index 7ea4500..d322948 100644
--- a/common/btrfssnapshots.h
+++ b/common/btrfssnapshots.h
@@ -36,6 +36,7 @@ public:
 std::optional<qulonglong> getSubvolumeForPath(const QString &path, const QString &fsRoot = "/"_L1);
 std::optional<QString> getPathForSubvolume(qulonglong subvolume, const QString &fsRoot = "/"_L1);
 QList<SubvolumeSnapshot> getSnapshotsForSubvolume(const QString &path, const QString &fsRoot = "/"_L1);
+bool hasSnapshots(const QString &path, const QString &fsRoot);
 QList<FileSnapshot> getSnapshotsForFile(const QString &path, const QString &fsRoot = "/"_L1);
 QMap<qulonglong, QString> getNonSnapshotSubvolumes(const QString &fsRoot = "/"_L1);
 }
diff --git a/contextmenu/snapshotfileitemaction.cpp b/contextmenu/snapshotfileitemaction.cpp
index 0665c96..47a1d8f 100644
--- a/contextmenu/snapshotfileitemaction.cpp
+++ b/contextmenu/snapshotfileitemaction.cpp
@@ -66,7 +66,7 @@ QList<QAction *> SnapshotFileItemAction::actions(const KFileItemListProperties &
         }
         QString fsUuid = fsVolume->uuid();
 
-        if (!BtrfsSnapshots::getSnapshotsForSubvolume(itemUrl.toLocalFile(), fsRootPath).empty()) {
+        if (BtrfsSnapshots::hasSnapshots(itemUrl.toLocalFile(), fsRootPath)) {
             auto subvolumeIdOpt = BtrfsSnapshots::getSubvolumeForPath(itemUrl.toLocalFile(), fsRootPath);
             if (!subvolumeIdOpt.has_value()) {
                 qCCritical(SNAPSHOT_FILEITEMACTION()) << "found snapshots for dir" << itemUrl.toLocalFile() << "but it did not have a subvolume id";
@@ -94,7 +94,7 @@ QList<QAction *> SnapshotFileItemAction::actions(const KFileItemListProperties &
             return actions;
         }
         QString fsRootPath = fsRoot->filePath();
-        if (!BtrfsSnapshots::getSnapshotsForFile(itemUrl.toLocalFile(), fsRootPath).empty()) {
+        if (BtrfsSnapshots::hasSnapshots(itemUrl.toLocalFile(), fsRootPath)) {
             QAction *action = new QAction(QIcon::fromTheme("view-history"_L1), i18nc("@action:inmenu", "View snapshots…"), parentWidget);
             connect(action, &QAction::triggered, this, [this, item]() {
                 KIO::OpenUrlJob *job = new KIO::OpenUrlJob(QUrl("filesnapshots://%1"_L1.arg(item.localPath())), "inode/directory"_L1, this);