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Seal a snapshot (v0.1.1)

Source: R/snapshots-seal.R
ledgr_snapshot_seal.Rd

Transitions a snapshot from CREATED to SEALED and stores a deterministic snapshot_hash in a single DuckDB transaction.

Usage

ledgr_snapshot_seal(con, snapshot_id)

Arguments

con

A DBI connection to DuckDB or a ledgr_snapshot.

snapshot_id

Snapshot id (must exist and be status CREATED or SEALED) when con is a connection.

Value

The computed snapshot hash (character(1)) or a list when called with a snapshot object.

Details

Snapshot mutability rule: sealing computes the hash while status is CREATED. Calling ledgr_snapshot_seal() again on an already sealed snapshot is idempotent: it returns the existing snapshot hash and does not mutate snapshot contents. After sealing, snapshot write operations must be rejected by ledgr code paths. When basic metadata such as start_date, end_date, n_bars, or n_instruments is missing, sealing derives it from the imported snapshot tables. Metadata does not contribute to snapshot_hash.

Errors:

  • LEDGR_SNAPSHOT_NOT_FOUND if snapshot_id does not exist.

  • Already sealed snapshots return their existing hash idempotently.

  • LEDGR_SNAPSHOT_NOT_MUTABLE if the snapshot status is not CREATED.

  • LEDGR_SNAPSHOT_EMPTY if there are 0 bars or 0 instruments.

  • LEDGR_SNAPSHOT_REFERENTIAL_INTEGRITY if bars reference missing instruments.

  • LEDGR_SNAPSHOT_OHLC_INVALID if OHLC bars are internally inconsistent.

  • LEDGR_SNAPSHOT_SEAL_FAILED on hashing/transaction failures (snapshot is marked FAILED).

Articles

Durable experiment stores: vignette("experiment-store", package = "ledgr") system.file("doc", "experiment-store.html", package = "ledgr")

Examples

db_path <- tempfile(fileext = ".duckdb")
con <- ledgr_db_init(db_path)
snapshot_id <- ledgr_snapshot_create(
  con,
  snapshot_id = "snapshot_20200101_000000_abcd"
)
bars_csv <- tempfile(fileext = ".csv")
utils::write.csv(data.frame(
  instrument_id = "AAA",
  ts_utc = c("2020-01-01T00:00:00Z", "2020-01-02T00:00:00Z"),
  open = c(100, 101),
  high = c(101, 102),
  low = c(99, 100),
  close = c(100, 101),
  volume = 1000
), bars_csv, row.names = FALSE)
ledgr_snapshot_import_bars_csv(con, snapshot_id, bars_csv)
ledgr_snapshot_seal(con, snapshot_id)
#> [1] "cdce2950fdab774786acf556eb1f8f76ccc2c932afc2e2a2e6e02358f13d2d94"
DBI::dbDisconnect(con, shutdown = TRUE)