Torque3D/Engine/source/core/virtualMountSystem.h

//-----------------------------------------------------------------------------
// Copyright (c) 2012 GarageGames, LLC
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//-----------------------------------------------------------------------------
#ifndef _CORE_VMS_H_
#define _CORE_VMS_H_

#include "core/volume.h"
#include "core/util/tDictionary.h"

namespace Torque
{
namespace FS
{

   /// The VirtualMountSystem extend the mount system by allowing you to mount and access multiple filesystems
   /// on a single root.  This allows you to mount multiple volume files on a single root without needing to 
   /// change source paths that reference those volumes to use new roots.  For instance, you could mount
   /// "missions1.zip" and "missions2.zip", on the same root "", and you could access files from either one.
   ///
   /// If you need to mount a writeable filesystem on a VMS, you should mount it as the first filesystem on a root.  
   /// File writes are handled as follows:
   /// 1) If you try to open a file for write, and it exists on one of the virtual mounts, 
   /// that is the mount that will be used for writing.  But if the filesystem is read-only then the writes 
   /// will fail (and you will get appropriate error codes from your FileStream or whatever).  
   /// 2) If you try to open a file for write that doesn't exist, the VMS falls back to the default MountSystem 
   /// behavior, which is to use the first filesystem mounted on the root.  If this filesystem happens to be 
   /// writable, then you will be able to write to the file.
   /// 3) Nothing special is done for the WriteAppend case; that is, it follows the same logic as if you were 
   /// just trying to Write the file.
   ///
   /// Because of rule 1) above, you should take care that any files you need to write (such as prefs.tscript), are not
   /// included in read-only zip archive files.
   class VirtualMountSystem : public MountSystem
   {
      typedef MountSystem Parent;
   public:
      VirtualMountSystem() : mUseParentFind(false) {}

      virtual ~VirtualMountSystem() { }
      bool mount(String root, FileSystemRef fs) override;
      bool mount(String root, const Path &path) override;
      FileSystemRef unmount(String root) override;
      bool unmount(FileSystemRef fs) override;
      S32 findByPattern( const Path &inBasePath, const String &inFilePattern, bool inRecursive, Vector<String> &outList, bool includeDirs=false, bool multiMatch = true ) override;
      bool createPath(const Path& path) override;

   protected:
      void _log(const String& msg) override;
      FileSystemRef _removeMountFromList(String root) override;
      FileSystemRef _getFileSystemFromList(const Path& path) const override ;
      
      // Vector of file system refs
      typedef Vector<FileSystemRef> RootToFSVec;
      // map of path to list of file systems containing path
      typedef Map<String, Vector<FileSystemRef> > PathFSMap;
      // map of root to PathFSMap for that root
      //typedef Map<String, PathFSMap*> RootToPathFSMap;

      //RootToPathFSMap mMountMap;
      PathFSMap mRootMap;

      bool mUseParentFind; // this is needed because findByParent calls itself recursively and in some cases we don't want it to re-enter our version
   };

}
}

#endif