Fingerprint a dataset

Computes a DataFingerprint: a content hash of x plus the structural facts (dimensions, column names) that make a mismatch between two runs diagnosable. Used to record which data a run actually used, so undocumented drift between experiments is visible.

Usage

data_fingerprint(x, method = "object", algorithm = "sha256", source = NULL)

Arguments

x

tabular data: The dataset. Required for every method, so that dimensions and column names are always recorded, even when hashing file bytes.

method

Character {"file", "object", "table"}: What to hash. "object" hashes the serialized R object (cheap, R-only). "file" hashes the raw bytes of source. "table" hashes the canonical Arrow IPC representation (cross-language; requires the arrow package).

algorithm

Character: Hash algorithm passed to digest::digest. See DATA_HASH_ALGORITHMS.

source

Optional Character: Path x was read from. Required when method is "file".

Value

DataFingerprint object.

Author

EDG

Examples

fp <- data_fingerprint(iris)
fp
#> <DataFingerprint>
#>        hash: 2191b3e4d777… (sha256, object)
#>         dim: 150 x 5
#>      source: NULL
#> portability: single_language
# A logically identical table with a different R representation hashes
# differently under "object", which is why it is "single_language":
data_fingerprint(iris)@hash == data_fingerprint(as.data.frame(iris))@hash
#> [1] TRUE