ReplayController Class
Replay controller object It controls where we start (snapshot, local file, no snapshots) As well as dispatch of ops
Signature
export declare abstract class ReplayController extends ReadDocumentStorageServiceBase
Extends: ReadDocumentStorageServiceBase
Methods
| Method | Return Type | Description |
|---|---|---|
| fetchTo(currentOp) | number | undefined | Returns last op number to fetch from current op Note: this API is called while replay() is in progress - next batch of ops is downloaded in parallel |
| getStartingOpSequence() | Promise<number> | Returns sequence number to start processing ops Should be zero if not using snapshot, and snapshot seq# otherwise |
| initStorage(documentService) | Promise<boolean> | Initialize reply controller |
| isDoneFetch(currentOp, lastTimeStamp) | boolean | Returns true if no more ops should be processed (or downloaded for future processing). It's called at end of each batch with latest op timestamp. Also it's called when there are no more ops available (lastTimeStamp === undefined). If false is returned and there are no more ops, request for more ops is made every 2 seconds. Note: this API is called while replay() is in progress - next batch of ops is downloaded in parallel |
| replay(emitter, fetchedOps) | Promise<void> | Replay batch of ops NOTE: new batch of ops is fetched (fetchTo() & isDoneFetch() APIs are called) while this call is in flights |
Method Details
fetchTo
Returns last op number to fetch from current op Note: this API is called while replay() is in progress - next batch of ops is downloaded in parallel
Signature
abstract fetchTo(currentOp: number): number | undefined;
Parameters
| Parameter | Type | Description |
|---|---|---|
| currentOp | number | current op |
Returns
Return type: number | undefined
getStartingOpSequence
Returns sequence number to start processing ops Should be zero if not using snapshot, and snapshot seq# otherwise
Signature
abstract getStartingOpSequence(): Promise<number>;
Returns
Return type: Promise<number>
initStorage
Initialize reply controller
Signature
abstract initStorage(documentService: IDocumentService): Promise<boolean>;
Parameters
| Parameter | Type | Description |
|---|---|---|
| documentService | IDocumentService | the real document service |
Returns
- Boolean, indicating if controller should be used. If false is returned, caller should fallback to original storage.
Return type: Promise<boolean>
isDoneFetch
Returns true if no more ops should be processed (or downloaded for future processing). It's called at end of each batch with latest op timestamp. Also it's called when there are no more ops available (lastTimeStamp === undefined). If false is returned and there are no more ops, request for more ops is made every 2 seconds. Note: this API is called while replay() is in progress - next batch of ops is downloaded in parallel
Signature
abstract isDoneFetch(currentOp: number, lastTimeStamp?: number): boolean;
Parameters
| Parameter | Modifiers | Type | Description |
|---|---|---|---|
| currentOp | number | current op | |
| lastTimeStamp | optional | number | timestamp of last op (if more ops are available). Undefined otherwise. |
Returns
Return type: boolean
replay
Replay batch of ops NOTE: new batch of ops is fetched (fetchTo() & isDoneFetch() APIs are called) while this call is in flights
Signature
abstract replay(emitter: (op: api.ISequencedDocumentMessage[]) => void, fetchedOps: api.ISequencedDocumentMessage[]): Promise<void>;
Parameters
| Parameter | Type | Description |
|---|---|---|
| emitter | (op: api.ISequencedDocumentMessage[]) => void | callback to emit ops |
| fetchedOps | api.ISequencedDocumentMessage[] | ops to process |
Returns
Return type: Promise<void>