OpfsFileSystem class

A FileSystem for the sqlite3 wasm library based on the file system access API.

By design, this file system can only store two files: /database and /database-journal. Thus, when this file system is used, the only sqlite3 database that will be persisted properly is the one at /database.

The limitation of only being able to store two files comes from the fact that we can't synchronously open files in with the file system access API, only reads and writes are synchronous. By having a known amount of files to store, we can simply open both files in OpfsFileSystem.inDirectory or OpfsFileSystem.loadFromStorage, which is asynchronous too. The actual file system work, which needs to be synchronous for sqlite3 to function, does not need any further wrapper.

Please note that OpfsFileSystems are only available in dedicated web workers, not in the JavaScript context for a tab or a shared web worker.

Implemented types

Properties

files → List<String>
Lists all files stored in this file system.
no setteroverride
hashCode → int
The hash code for this object.
no setterinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

clear() → void
Deletes all files stored in this file system.
override
close() → void
createFile(String path, {bool errorIfNotExists = false, bool errorIfAlreadyExists = false}) → void
Creates an empty file at path.
override
createTemporaryFile() → String
Creates a temporary file with a unique name.
override
deleteFile(String path) → void
Deletes a file at path if it exists, throwing a FileSystemException otherwise.
override
exists(String path) → bool
Whether a file at path exists.
override
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
read(String path, Uint8List target, int offset) → int
Reads a chunk of the file at path and offset offset into the target buffer.
override
sizeOfFile(String path) → int
Returns the size of a file at path if it exists.
override
toString() → String
A string representation of this object.
inherited
truncateFile(String path, int length) → void
Sets the size of the file at path to length.
override
write(String path, Uint8List bytes, int offset) → void
Writes a chunk from bytes into the file at path path and offset offset.
override

Operators

operator ==(Object other) → bool
The equality operator.
inherited

Static Methods

inDirectory(Object root) → Future<OpfsFileSystem>
Loads an OpfsFileSystem in the desired root directory, which must be a Dart wrapper around a FileSystemDirectoryHandle.
loadFromStorage(String path) → Future<OpfsFileSystem>
Loads an OpfsFileSystem in the desired path under the root directory for OPFS as given by navigator.storage.getDirectory() in JavaScript.