done with getEventByID

include/hepnos/FileDataStore.hpp

@@ -43,6 +43,15 @@ public:
             return FileNamespace();
     }
 
+    event_type getEventByID(std::uint64_t id) {
+        std::stringstream ss;
+        ss << _path << ".ref/" << std::setfill('0') << std::setw(20) << id;
+        std::string link = ss.str();
+        if(!fs::exists(link)) return FileEvent();
+        std::string p = fs::canonical(link).string();
+        return FileEvent(p);
+    }
+
 private:
 
     std::string _path;

include/hepnos/FileEvent.hpp

@@ -13,11 +13,13 @@ namespace hepnos {
 namespace fs = boost::filesystem;
 
 class FileSubRun;
+class FileDataStore;
 
 class FileEvent : public ProductAccessor<FileProductAccessorBackend> {
 
     private:
 
+        friend class FileDataStore;
         friend class FileSubRun;
         friend class FileObjectIterator<FileEvent>;
 
@@ -42,6 +44,24 @@ class FileEvent : public ProductAccessor<FileProductAccessorBackend> {
             createRefAndSetID();
         }
 
+        FileEvent(const std::string& dir)
+        : ProductAccessor<FileProductAccessorBackend>(dir)
+        , _eventNumber(0)
+        , _path(dir) {
+            if(_path.back() != '/') _path += std::string("/");
+            std::size_t i,j;
+            j = _path.size()-1;
+            if(_path[j] == '/') j--;
+            i = j;
+            while(_path[i] != '/') i--;
+            i += 1;
+            while(_path[i] == '0') i++;
+            j += 1;
+            std::string eventDir(&dir[i], j-i);
+            if(eventDir.size() > 0)
+                _eventNumber = std::stoi(eventDir);
+        }
+
         FileEvent()
         : ProductAccessor<FileProductAccessorBackend>("")
         , _eventNumber(std::numeric_limits<std::uint64_t>::max())