0.17.0

Jeremy Shaw, 2026-10-29

• createCheckpointAndClose no longer writes a checkpoint when this process has already made one durable and no events have been logged since, making shutdown fast right after createCheckpoint (e.g. via the remote CreateCheckpoint command) (#181). A checkpoint is still written when the state is freshly created, when events follow the last checkpoint, and when closing a state whose only checkpoint is the one loaded at open (so SafeCopy migrations are still saved).

Breaking changes and changed behaviour

• LocalState has a new field, localLastCheckpoint. Code that builds a LocalState with positional arguments will no longer compile. Code that builds one with record syntax will still compile (with only a -Wmissing-fields warning), but leaves the field undefined: the next createCheckpoint will then kill the log writer thread, and later updates, checkpoints and closes will hang. Initialise the field with newIORef Nothing.
• createCheckpointAndClose no longer always appends a checkpoint. After createCheckpoint followed by createArchive, the newest checkpoints-*.log file is left empty and the latest checkpoint is in the file before it. acid-state itself restores correctly, but backup, replication or monitoring scripts that copy or check only the newest checkpoint file must be updated to look at earlier files too.
• Tools that use the checkpoint log’s size, modification time or entry count to confirm a clean shutdown may no longer see a change at close.

0.16.1.4

Andreas Abel, 2025-08-27

• Drop support for GHC 7
• Tested with GHC 8.2 - 9.14.1-alpha1

0.16.1.3

Andreas Abel, 2023-08-03

• Support template-haskell-2.21 (#162)
• Tested with GHC 7.8 - 9.8.1-alpha1

0.16.1.2

Andreas Abel, 2023-04-06

• Support unix-2.8
• Tested with GHC 7.8 - 9.6.1

0.16.1.1

Andreas Abel, 2022-06-01

• Adapt to changes in hedgehog-1.1 related to barbies
• Support mtl-2.3
• Tested with GHC 7.8 - 9.2.3

0.16.1

David Fox, 2022-02-18

• Support GHC-9.0.2, template-haskell 2.18

0.16.0.1

Jeremy Shaw, 2020-05-19

0.16.0

Jeremy Shaw, 2019-11-14

• support network-3.x and ghc-8.8.1
• Fix tests (#131)
• Haddock documentation fixes
• Update build dependency constraints

0.15.2

• adds acid-state-repair recovery tool (#126)
• parameterize the underlying serialization library (#96)
• support safecopy-0.10, which supports GHC.Generics (#128)

0.15.0

• change text of error messages to include module names (#116)
• depend on filelock library to avoid locking bug (#91)
• permit events that are polymorphic in the base monad, with a MonadReader/MonadState constraint (#94)
• fix a minor memory leak (#104)
• add a test suite and extend examples (#98)
• improve benchmarks (#113)
• expose internal modules (subject to change in the future)

0.14.3

• support building on GHC 8.2
• update links from seize.it to github.com

0.14.2

• createCheckpoint now cuts a new events file (#74)

0.14.1

• fix bug in archiveLog that resulted in logs being moved prematurely (#22)
• tweaks for GHC 8.0.x, template-haskell 2.11.x
• fix compilation of benchmarks

0.14.0

• fixes for cereal 0.5 while maintaining cereal 0.4 compatibility. IMPORTANT: cereal 0.5 / safecopy 0.9 change the serialization format of Float/Double. Migration should be performed automatically on old data. However, you should be aware that once you upgrade to safecopy 0.9 / cereal 0.5, your data will be migrated and not readable by older versions of your application which are compiled against safecopy 0.8 / cereal 0.4.

• additional fixes for TH and kinded type variables (#56)