The Internal API is the foundation of ZenFS, providing a standardized interface for managing file systems and file operations. All backends must instantiate a FileSystem implementation that conforms to this API, ensuring compatibility with the Virtual File System (VFS) and applications using ZenFS.
FileSystemThe FileSystem class is the core of the internal API. It abstracts file storage operations, metadata management, and error handling. FileSystem does a few things:
Storage Abstraction: Defines how files and directories are represented within a backend.
Usage Information (UsageInfo): Tracks available storage, block sizes, and inode counts.
Metadata: Various pieces of metadata, which are used by the VFS. This includes:
attributes is designed to keep track of simple values. This is analogous to options in /etc/fstab.name is for the name of the file system type. For example, tmpfs is the name of InMemory. This is modeled after file_system_type->name in Linuxid is a unique 32-bit unsigned integer for the type of file system. It is currently unused internally but may in the future (one compelling use case is to resolve collisions of name). This is primarily designed for users, for example it could be used for partition tables.label is an optional field that is designed to be used with instances. This is the same as labels in the context of normal partitions and file systems.File Operations: Implements core actions like creating, reading, writing, and deleting files.
Error Handling: Standardizes file system errors through ErrnoError.
FileThe File class provides low-level mechanisms for working with files, ensuring standard behaviors across backends.
Backends in ZenFS do not implement file operations directly. Instead, they instantiate a FileSystem implementation that conforms to the internal API.