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Record and review dataset pipeline snapshots

Source: R/ops.R
ops_snapshot.Rd

Captures a lightweight summary of a data.frame at a given pipeline stage and stores it in the session cache. Subsequent calls automatically compute deltas against the previous snapshot, making it easy to track how data changes through derive_*, assoc_*, and other processing steps.

Usage

ops_snapshot(
  data = NULL,
  label = NULL,
  reset = FALSE,
  verbose = TRUE,
  check_na = TRUE
)

Arguments

data

A data.frame or data.table to snapshot. Pass NULL (or omit) to print the full snapshot history without recording a new entry.

label

(character) A short name for this pipeline stage, e.g. "raw", "after_derive_missing". Defaults to "snapshot_N" where N is the sequential index.

reset

(logical) If TRUE, clears the entire snapshot history and returns invisibly. Default FALSE.

verbose

(logical) Print the CLI report. Default TRUE.

check_na

(logical) Whether to count columns with any NA or blank string values and include the delta in the report. Set to FALSE to skip the NA scan (useful for large datasets or when NA tracking is not needed). Default TRUE.

Value

When data is supplied, returns the new snapshot row invisibly (a one-row data.table). When called with no data, returns the full history data.table invisibly.

Examples

dt <- ops_toy(n = 100)
#> ✔ ops_toy: 100 participants | 75 columns | scenario = "cohort" | seed = 42
ops_snapshot(dt, label = "raw")
#> ── snapshot: raw ───────────────────────────────────────────────────────────────
#> rows 100
#> cols 75
#> NA cols 51
#> size 0.09 MB
#> ────────────────────────────────────────────────────────────────────────────────

dt <- derive_missing(dt)
#> ✔ derive_missing: replaced 47 values across 3 columns (action = "na").
ops_snapshot(dt, label = "after_derive_missing")
#> ── snapshot: after_derive_missing ──────────────────────────────────────────────
#> rows 100 (= 0)
#> cols 75 (= 0)
#> NA cols 53 (+2)
#> size 0.09 MB (= 0)
#> ────────────────────────────────────────────────────────────────────────────────

# View full history
ops_snapshot()
#> ── ops_snapshot history ────────────────────────────────────────────────────────
#>      idx                label timestamp  nrow  ncol n_na_cols size_mb
#>    <int>               <char>    <char> <int> <int>     <int>   <num>
#> 1:     1                  raw  09:19:22   100    75        51    0.09
#> 2:     2 after_derive_missing  09:19:22   100    75        53    0.09
#> ────────────────────────────────────────────────────────────────────────────────

# Reset history
ops_snapshot(reset = TRUE)
#> ✔ Snapshot history cleared.