DatabaseImplementation enum

An implemented mechanism to use SQLite on the web.

Due to the large variety of browsers and the web standards they support, a number of implementations are available. The most important are:

  • opfsShared: Only available on Firefox, but very efficient.
  • opfsWithExternalLocks: Only available on recent Chrome versions, also quite efficient.
  • opfsAtomics: Only available when using COEP and COOP headers, but also reasonably efficient and supported across browsers.
  • indexedDbShared: A less efficient IndexedDB-based implementation used as a fallback on older Chrome versions.

All other options are not recommended, but may be selected if there's no better option (e.g. older Chrome versions on Android may use indexedDbUnsafeWorker).

Inheritance
Available extensions

Values

inMemoryLocal → const DatabaseImplementation

Host an in-memory database in the current tab.

This isn't really useful outside of tests.

const DatabaseImplementation(StorageMode.inMemory, AccessMode.inCurrentContext)
inMemoryShared → const DatabaseImplementation

Host an in-memory database in a shared worker.

This isn't really useful outside of tests.

const DatabaseImplementation(StorageMode.inMemory, AccessMode.throughSharedWorker)
indexedDbUnsafeLocal → const DatabaseImplementation

Open an IndexedDB database with a dedicated worker per tab.

There is no concurrency control between these tabs, so this effectively does not support multiple tabs. It's mostly included for legacy reasons.

const DatabaseImplementation(StorageMode.indexedDb, AccessMode.inCurrentContext)
indexedDbUnsafeWorker → const DatabaseImplementation

Open an IndexedDB database with a dedicated worker per tab.

There is no concurrency control between these tabs, so this effectively does not support multiple tabs. It's mostly included for legacy reasons.

const DatabaseImplementation(StorageMode.indexedDb, AccessMode.throughDedicatedWorker)
indexedDbShared → const DatabaseImplementation

Open an IndexedDB database in a shared worker.

const DatabaseImplementation(StorageMode.indexedDb, AccessMode.throughSharedWorker)
opfsWithExternalLocks → const DatabaseImplementation

Open an synchronous database stored in OPFS.

The database is opened with the non-standard readwrite-unsafe option, and the web locks API is used to ensure two tabs don't access the same database concurrently.

const DatabaseImplementation(StorageMode.opfs, AccessMode.throughDedicatedWorker)
opfsAtomics → const DatabaseImplementation

Open an asynchronous database stored in OPFS. It is "syncified" by using a pair of two dedicated workers implementing an RPC channel over shared memory and atomics.

const DatabaseImplementation(StorageMode.opfs, AccessMode.throughDedicatedWorker)
opfsShared → const DatabaseImplementation

Open a synchronous database stored in OPFS.

This works by letting a shared worker spawn a dedicated worker. This is supposed to work, but only implemented in Firefox.

const DatabaseImplementation(StorageMode.opfs, AccessMode.throughSharedWorker)

Properties

access → AccessMode
final
hashCode → int
The hash code for this object.
no setterinherited
index → int
A numeric identifier for the enumerated value.
no setterinherited
name → String

Available on Enum, provided by the EnumName extension

The name of the enum value.
no setter
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
storage → StorageMode
final

Methods

noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
inherited

Operators

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

Constants

values → const List<DatabaseImplementation>
A constant List of the values in this enum, in order of their declaration.