xtdb-core/xtdb.api.tx/TxIndexer

TxIndexer

Per-tx entry point for external sources. The source provides tx metadata + a writer that populates the OpenTx and returns a TxResult indicating success or failure (with optional userMetadata — the source can decide metadata after writing, not before).

executeTx and submitTx own the full lifecycle: smoothing, opening the OpenTx, running the writer, adding the xt/txs row, publishing the resulting tx, and closing the OpenTx. They differ only in whether the caller waits for the result.

Types

TxResult

sealed interface TxResult

The outcome a writer returns: commit or abort, plus optional userMetadata recorded on the xt/txs table.

Functions

executeTx

abstract suspend fun executeTx(externalSourceToken: ExternalSourceToken?, systemTime: Instant? = null, writer: suspend (OpenTx) -> TxIndexer.TxResult): TransactionResult

Indexes one external-source transaction: opens an OpenTx, runs writer to populate it, then commits or aborts per the returned TxResult. Returns only once the tx is durably replicated.

submitTx

abstract suspend fun submitTx(externalSourceToken: ExternalSourceToken?, systemTime: Instant? = null, writer: suspend (OpenTx) -> TxIndexer.TxResult): Deferred<TransactionResult>

Like executeTx, but hands the transaction off and returns a durability handle without waiting on it — for a high-volume source that keeps submitting while the indexer works through the backlog, acknowledging progress out of band once transactions become durable (e.g. the Postgres source advancing its replication-slot LSN).