3.20

1 files changed, 67 insertions, 4 deletions

diff --git a/shared/check_exist.h b/shared/check_exist.h
index 6ec5534c..14a8a3f8 100644
--- a/shared/check_exist.h
+++ b/shared/check_exist.h
@@ -3,23 +3,86 @@
 // * GNU General Public License: http://www.gnu.org/licenses/gpl.html       *
 // * Copyright (C) 2008-2011 ZenJu (zhnmju123 AT gmx.de)                    *
 // **************************************************************************
-//
+
 #ifndef CHECKEXIST_H_INCLUDED
 #define CHECKEXIST_H_INCLUDED
 
 #include "zstring.h"
+#include "boost_thread_wrap.h" //include <boost/thread.hpp>
+#include "file_handling.h"
+
 
 namespace util
 {
+//check for file or folder existence asynchronously
+boost::unique_future<bool> somethingExistsAsync(const Zstring& somename);
+boost::unique_future<bool>      fileExistsAsync(const Zstring& filename);
+boost::unique_future<bool>       dirExistsAsync(const Zstring&  dirname);
+
+//some syntactic sugar:
 enum ResultExist
 {
     EXISTING_TRUE,
     EXISTING_FALSE,
-    EXISTING_TIMEOUT
+    EXISTING_NOT_READY
 };
 
-ResultExist fileExists(const Zstring& filename, size_t timeout); //timeout in ms
-ResultExist dirExists( const Zstring& dirname,  size_t timeout); //timeout in ms
+ResultExist somethingExists(const Zstring& somename, size_t timeout);
+ResultExist      fileExists(const Zstring& filename, size_t timeout);
+ResultExist       dirExists(const Zstring&  dirname, size_t timeout);
+
+
+
+
+
+
+
+
+
+
+
+
+//################## implementation ##########################
+template <bool (*fun)(const Zstring&)>
+boost::unique_future<bool> objExistsAsync(const Zstring& objname)
+{
+    //thread safety: make it a pure value type for use in the thread!
+    const Zstring objnameVal = objname; //atomic ref-count => binary value-type semantics!
+    boost::packaged_task<bool> pt([=] { return (*fun)(objnameVal); });
+    auto fut = pt.get_future();
+    boost::thread(std::move(pt));
+    return std::move(fut);
+}
+
+
+inline
+boost::unique_future<bool> somethingExistsAsync(const Zstring& somename) { return objExistsAsync<&zen::somethingExists>(somename); }
+
+inline
+boost::unique_future<bool> fileExistsAsync(const Zstring& filename) { return objExistsAsync<&zen::fileExists>(filename); }
+
+inline
+boost::unique_future<bool>  dirExistsAsync(const Zstring& dirname) { return objExistsAsync<&zen::dirExists>(dirname); }
+
+
+template <bool (*fun)(const Zstring&)> inline
+ResultExist objExists(const Zstring& objname, size_t timeout)
+{
+    auto ft = objExistsAsync<fun>(objname);
+    if (!ft.timed_wait(boost::posix_time::milliseconds(timeout)))
+        return EXISTING_NOT_READY;
+    return ft.get() ? EXISTING_TRUE : EXISTING_FALSE;
+}
+
+
+inline
+ResultExist somethingExists(const Zstring& somename, size_t timeout) { return objExists<&zen::somethingExists>(somename, timeout); }
+
+inline
+ResultExist fileExists(const Zstring& filename, size_t timeout) { return objExists<&zen::fileExists>(filename, timeout); }
+
+inline
+ResultExist dirExists(const Zstring& dirname, size_t timeout) { return objExists<&zen::dirExists>(dirname, timeout); }
 }
 
 #endif // CHECKEXIST_H_INCLUDED