DVCapture class

The capture log for one database.

Stored through the record operations every engine implements (DVRecordAdapter), never through SQL, so the log lives wherever the application's data does: a SQL table, or a document database's collection.

Constructors

DVCapture({required DVDatabaseAdapter database, required Duration retention, DateTime clock()?, Duration lease = const Duration(seconds: 30), Duration strandedAfter = const Duration(minutes: 5)})

Properties

consumers → Map<String, DVCaptureConsumer>

The consumers registered here, by name.

no setter

database → DVDatabaseAdapter

final

hashCode → int

The hash code for this object.

no setter, inherited

lease → Duration

How long a publisher may hold a range of sequences before another process treats it as dead and moves past it.

final

onPublished ↔ void Function(int published)?

Called after changes are published, with how many. The framework's delivery runtime uses it to send them on without waiting for its next tick; a failure in it never reaches the write that published.

getter/setter pair

retention → Duration

How long a published change is kept. Bounded and declared: a consumer further behind than this is told to backfill (DV-CDC-002).

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

strandedAfter → Duration

How old a staged change must be before publishStranded treats the transaction that staged it as gone.

final

tracked → Map<String, DVRecordTable>

The captured tables this log knows, by name.

no setter

Methods

changes({int after = 0, int? limit}) → Future<List<DVCapturedChange>>

Published record changes after after, oldest first. Schema changes are not included; changes an erasure purged are.

consumer(String name, {required DVCaptureSink sink, String? tenant, Set<String>? models, int batchSize = 500, Duration? lagThreshold}) → DVCaptureConsumer

A consumer: one destination's position in the log.

dispatchBackfill(DVCaptureBackfillJob job, {DVQueues queues = const DVQueues()}) → Future<DVJobEnvelope<DVCaptureBackfillJob>>

dispatchDelivery(String consumer, {DVQueues queues = const DVQueues(), String queue = 'default'}) → Future<DVJobEnvelope<DVCaptureDeliveryJob>>

ensureSchema() → Future<void>

eraseRecord(DVRecordTable table, Object key) → Future<DVCapturedChange>

Removes every value the log holds for one record, and captures what an erasure left of it: a delete when it is gone, or its anonymized values when a retention kept it. Returns that change, published.

head() → Future<int>

The newest published sequence.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

prune() → Future<int>

Removes published changes older than retention, returning how many.

publishStranded() → Future<int>

Publishes changes a crash left staged: written, never given a sequence.

record({required DVRecordTable table, required DVCaptureOp operation, required Object key, required int version, required Map<String, Object?> values, String? tenant, bool erased = false}) → Future<String>

Captures one write. Called by DVRecordTable after the row is written.

recordErasure(DVRecordTable table, Object key, {int? version}) → Future<String>

Purges every value the log holds for one record and captures what a removal left of it, returning the change id: published at once, or staged and published after commit inside DV.transaction.

registerJobs(DVQueues queues) → void

Registers delivery and backfill on the durable job layer, with the codecs a queue shared between processes stores them under. A refused batch throws, so the queue retries it with its backoff.

toString() → String

A string representation of this object.

inherited

track(DVRecordTable table) → void

Makes table known to backfill jobs. DVRecordTable calls it, and so does the framework for every captured model it starts with.

Operators

operator ==(Object other) → bool

The equality operator.

inherited

Static Properties

configured → DVCapture?

The log a model declared @DVModel(capture: true) writes to.

no setter

Static Methods

configure(DVCapture log) → void

Records every captured model in this process to log.

unconfigure() → void

Forgets the configured log. A captured model then records to a log in the configured database, as a process the server did not start does.

Constants

backfillTable → const String

checkpointTable → const String

defaultRetention → const Duration

How long a published change is kept when nothing declared a retention.

logTable → const String

schemaTable → const String

stateTable → const String