wireform-hudi

wireform-hudi implements an Apache Hudi timeline reader for Copy-on-Write tables. Hudi tracks every table mutation as an instant on a timeline under .hoodie/, with commit metadata in JSON or Avro. Use this package when you need to discover active base files, replay replace commits, or time-travel to a specific instant from Haskell.

Key features

• JSON and Avro instant payloads for commit, deltacommit, and cleaner actions
• Replace-commit handling that supersedes prior file slices
• Clean instant handling that removes obsolete files from the snapshot
• File slice tracking with FileSlice and TableState
• Time travel to any committed instant
• Interop-tested against hudi-rs

Basic usage

Open a Hudi table and list the active base file paths:

import qualified Hudi.IO as H
import qualified Hudi.Timeline as HT
import qualified Data.Map.Strict as Map
import qualified Data.Text as T

listActiveBaseFiles :: FilePath -> IO ()
listActiveBaseFiles tableRoot = do
  result <- H.openHudiTable tableRoot
  case result of
    Left err ->
      putStrLn err
    Right table ->
      mapM_ (putStrLn . T.unpack) (H.activeBaseFilePaths table)

Time-travel to a specific instant and inspect the file slices:

import qualified Hudi.Timeline as HT

inspectAtInstant :: FilePath -> Text -> IO ()
inspectAtInstant tableRoot instantTime = do
  result <- H.openHudiTableAt tableRoot instantTime
  case result of
    Left err ->
      putStrLn err
    Right table -> do
      let partitions = H.tsPartitions (H.hutState table)
      putStrLn $
        "instant="
          ++ T.unpack instantTime
          ++ " partitions="
          ++ show (Map.size partitions)

For lower-level timeline inspection, scanTimeline returns every parseable instant file together with its absolute path, sorted by timestamp and state.

Notable modules

Module	Purpose
Hudi.Timeline	Instant parsing, commit metadata, TableState
Hudi.Avro	Avro 1.x+ instant payload decoder
Hudi.IO	openHudiTable, openHudiTableAt, active file helpers

Timeline model

Hudi Copy-on-Write tables accumulate base Parquet files through commit instants. A replacecommit instant drops file slices listed in partitionToReplaceFileIds. A clean instant removes files that are no longer referenced. openHudiTable replays the timeline in order to produce the current TableState.

Interop

The probe suite verifies JSON instants, Avro 1.x+ instants, and replacecommit handling against hudi-rs, including INSERT_OVERWRITE semantics that drop replaced file IDs.