Class AttachmentQueue

Namespace

PowerSync.Common.Attachments

Assembly

PowerSync.Common.dll

Manages the lifecycle and synchronization of attachments between local and remote storage. Provides automatic synchronization, upload/download queuing, attachment monitoring, verification and repair of local files, and cleanup of archived attachments.

public sealed class AttachmentQueue : IAsyncDisposable

Inheritance

object

AttachmentQueue

Implements

IAsyncDisposable

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Constructors

AttachmentQueue(AttachmentQueueOptions)

Methods

ClearQueueAsync()

Clears the attachment queue and deletes all attachment files from local storage.

DeleteFileAsync(string, Func<ITransaction, Attachment, Task>?)

Marks an existing attachment for deletion. The remote and local files are removed asynchronously on the next sync pass.

DisposeAsync()

Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources asynchronously.

ExpireCacheAsync()

Removes archived attachments that exceed ArchivedCacheLimit, along with their local files. Archived rows up to the limit are kept as a cache so that briefly re-referenced attachments can be restored without a re-download.

SaveFileAsync(Stream, string, string?, string?, string?, Func<ITransaction, Attachment, Task>?)

Saves a file to local storage and queues it for upload to remote storage. The file bytes are written to local storage immediately; the upload happens asynchronously on the next sync pass.

StartSyncAsync()

Starts the attachment synchronization process.

StopSyncAsync()

Stops the attachment synchronization process. Cancels the sync pipeline, stops the periodic timer, and tears down all attachment watchers. Waits for any in-flight upload/download/delete to finish. Syncing can be resumed by calling StartSyncAsync() again.

SyncStorageAsync()

Synchronizes all active attachments between local and remote storage. Uploads pending files, downloads newly referenced ones, applies pending deletes, and prunes archived rows.

TriggerSync()

Requests a sync pass to run as soon as possible. Useful from error handlers ("retry now") or UI ("sync now"). Coalesces with any in-flight or pending sync; safe to call rapidly.

VerifyAttachmentsAsync()

Verifies the integrity of all attachment records and repairs inconsistencies. Checks each attachment record against the local filesystem and:

• Updates LocalUri if the file exists at a different path.
• Archives non-Synced attachments whose local files are missing.
• Requeues synced attachments for download if their local files are missing.