Crate sos_vfs

Virtual file system.

The API is designed to match the tokio::fs module which in turn is based on std::fs so the API should be familiar.

The default operating system VFS re-exports the tokio::fs module providing access to the operating system’s file system.

Using the memory VFS allows us to compile and target the wasm32-unknown-unknown platform with minimal changes to the code.

The memory file system is enabled by default for wasm32-unknown-unknown or if the mem-fs feature is enabled.

Memory VFS Caveats

Relative paths are resolved from the root of the file system.

Avoid using the PathBuf functions exists(), metadata(), is_dir(), is_file() etc as they will be incorrect when using a virtual file system. Instead use the vfs::metadata() and vfs::try_exists() asynchronous functions.

The SystemTime type is not available on wasm32-unknown-unknwown so Metadata does not support created(), accessed() and modified() for that target.

Memory VFS Unsupported

This functionality is not supported yet but we hope to implement in the future.

The readonly flag on permissions is not supported yet.

Created, accessed and modified times are not set yet for non-webassembly targets that support SystemTime.

Symbolic links are not supported yet which means the hard_link(), symlink(), symlink_metadata(), symlink_file() and symlink_dir() functions are not available.

Structs

• DirBuilder
  A builder for creating directories in various manners.
• DirEntry
  Entries returned by the ReadDir stream.
• File
  A reference to an open file on the filesystem.
• OpenOptions
  Options and flags which can be used to configure how a file is opened.
• ReadDir
  Reads the entries in a directory.

Functions

• canonicalize
  Returns the canonical, absolute form of a path with all intermediate components normalized and symbolic links resolved.
• copy
  Copies the contents of one file to another. This function will also copy the permission bits of the original file to the destination file. This function will overwrite the contents of to.
• create_dir
  Creates a new, empty directory at the provided path.
• create_dir_all
  Recursively creates a directory and all of its parent components if they are missing.
• hard_link
  Creates a new hard link on the filesystem.
• metadata
  Given a path, queries the file system to get information about a file, directory, etc.
• read
  Reads the entire contents of a file into a bytes vector.
• read_dir
  Returns a stream over the entries within a directory.
• read_link
  Reads a symbolic link, returning the file that the link points to.
• read_to_string
  Creates a future which will open a file for reading and read the entire contents into a string and return said string.
• remove_dir
  Removes an existing, empty directory.
• remove_dir_all
  Removes a directory at this path, after removing all its contents. Use carefully!
• remove_file
  Removes a file from the filesystem.
• rename
  Renames a file or directory to a new name, replacing the original file if to already exists.
• set_permissions
  Changes the permissions found on a file or a directory.
• symlink
  Creates a new symbolic link on the filesystem.
• symlink_metadata
  Queries the file system metadata for a path.
• try_exists
  Returns Ok(true) if the path points at an existing entity.
• write
  Creates a future that will open a file for writing and write the entire contents of contents to it.