Virtual File-System: Embedded

Public access to the factory for embedded guest virtual file-systems. "Embedded" VFS operating modes use in-memory file system implementations. Embedded I/O can use tarballs, zip archives, or other sources for file system data.

Usage

Virtual file-systems can be created using the factory methods provided by this object, for example empty, writable, and forBundle. One or more bundles can be provided; they will be decoded in the order supplied, and consulted via the VFS internals with order preserved.

Archives or sources of different types and origins can be combined in a single VFS instance. For example, in-memory data can be combined with on-disk data, or with data from a remote source.

Elide VFS

Elide uses embedded virtual filesystems for built-in features like support for the Node API. VFS features may be active to support these features even when Host I/O is enabled for a given run. In these cases, the VFS is used in an "overlay" fashion, where the VFS is consulted first, and then the host file system is consulted if the VFS does not contain the requested file (on read).

Writable VFS instances absorb writes and changes to the VFS, but do not modify the underlying source data. This allows applications to use in-memory VFS for temporary files and other data, without modifying the original source data.

Persistent data should always be written to disk using Host I/O. For disk-based persistence, VFS should be mounted read-only, with Host I/O granted at runtime.