1 files changed, 61 insertions, 0 deletions
diff --git a/lib/lock_holder.h b/lib/lock_holder.h
new file mode 100644
index 00000000..a7cf3436
--- /dev/null
+++ b/lib/lock_holder.h
@@ -0,0 +1,61 @@
+#ifndef LOCK_HOLDER_H_INCLUDED
+#define LOCK_HOLDER_H_INCLUDED
+
+#include <map>
+#include <zen/zstring.h>
+#include "dir_lock.h"
+#include "status_handler.h"
+#include "dir_exist_async.h"
+
+namespace zen
+{
+const Zstring LOCK_FILE_ENDING = Zstr(".ffs_lock"); //intermediate locks created by DirLock use this extension, too!
+
+//convenience class for creating and holding locks for a number of directories
+class LockHolder
+{
+public:
+    LockHolder(bool allowUserInteraction) : allowUserInteraction_(allowUserInteraction) {}
+
+    void addDir(const Zstring& dirnameFmt, ProcessCallback& procCallback) //resolved dirname ending with path separator
+    {
+        if (dirnameFmt.empty())
+            return;
+
+        if (!dirExistsUpdating(dirnameFmt, allowUserInteraction_, procCallback))
+            return;
+
+        if (lockHolder.find(dirnameFmt) != lockHolder.end()) return;
+        assert(endsWith(dirnameFmt, FILE_NAME_SEPARATOR)); //this is really the contract, formatting does other things as well, e.g. macro substitution
+
+        class WaitOnLockHandler : public DirLockCallback
+        {
+        public:
+            WaitOnLockHandler(ProcessCallback& pc) : pc_(pc) {}
+            virtual void requestUiRefresh() { pc_.requestUiRefresh(); }  //allowed to throw exceptions
+            virtual void reportInfo(const std::wstring& text) { pc_.reportStatus(text); }
+        private:
+            ProcessCallback& pc_;
+        } callback(procCallback);
+
+        try
+        {
+            lockHolder.insert(std::make_pair(dirnameFmt, DirLock(dirnameFmt + Zstr("sync") + LOCK_FILE_ENDING, &callback)));
+        }
+        catch (const FileError& e)
+        {
+            bool dummy = false; //this warning shall not be shown but logged only
+            procCallback.reportWarning(e.msg(), dummy); //may throw!
+        }
+    }
+
+private:
+    typedef std::map<Zstring, DirLock, LessFilename> DirnameLockMap;
+    DirnameLockMap lockHolder;
+    const bool allowUserInteraction_;
+};
+
+}
+
+
+#endif // LOCK_HOLDER_H_INCLUDED