lmdb, branch HEAD

release: v0.1.0

2026-05-24T20:50:15Z

commit fcc8fd9b88e6cc81d8a282143cbf09804b6e48c6 parent c8d31da1834ea29bc4e00a6cdfc748fc3ebd01b1 Author: Jared Tobin Date: Sun, 24 May 2026 18:20:15 -0230 release: v0.1.0

docs: flesh out README sample, add Performance section

2026-05-24T20:40:38Z

commit c8d31da1834ea29bc4e00a6cdfc748fc3ebd01b1 parent 08059713a94e7dffca071f84a936ee7124a77c27 Author: Jared Tobin Date: Sun, 24 May 2026 18:10:38 -0230 docs: flesh out README sample, add Performance section The previous GHCi sample only covered put/get. Expand it to: - highlight envMapSize as the first thing users should think about (the 10 MiB default is the most common footgun) - demonstrate a cursor range scan via cursorSeek + cursorNext

silence CApiFFI pointer-type warnings on clang 15+

2026-05-24T19:52:40Z

commit 08059713a94e7dffca071f84a936ee7124a77c27 parent abfe775537fe006c4bac13092c007844d209ab92 Author: Jared Tobin Date: Sun, 24 May 2026 17:22:40 -0230 silence CApiFFI pointer-type warnings on clang 15+ For each `foreign import capi` declaration over an opaque struct (`Ptr (Ptr MDB_env)` etc.), GHC emits a tiny wrapper: HsInt32 ghczuwrapper...(void** a1) { return mdb_env_create(a1); } clang 15+ flags the `void**` -> `MDB_env**` conversion under -Wincompatible-pointer-types, and GHC prints those warnings wrapped in its own diagnostic format ("error: warning: ..."). The build still succeeds, but the output is noisy and reads as if it's failing. Add `-optc-Wno-incompatible-pointer-types` so the warning is suppressed for the wrapper compilation. Doesn't touch our own C (already silenced via `cc-options: -w`) or our Haskell.

vendor LMDB 0.9.33 under cbits/

2026-05-24T19:49:17Z

commit abfe775537fe006c4bac13092c007844d209ab92 parent d2eb60d378143cf6612eeda250acce2c6471f69a Author: Jared Tobin Date: Sun, 24 May 2026 17:19:17 -0230 vendor LMDB 0.9.33 under cbits/ Drop the system-liblmdb dependency in favour of vendoring the upstream LMDB C sources. Five files from the LMDB_0.9.33 tag of LMDB/lmdb on GitHub: lmdb.h, mdb.c, midl.c, midl.h, and LICENSE (the OpenLDAP Public License 2.8, MIT-compatible). Motivation: this lets `cabal install ppad-lmdb` succeed on any host with a C toolchain, without needing distro packages, nix, pkg-config, or matching liblmdb header versions. LMDB is tiny (~10k LOC, two .c files, C89, depends only on POSIX/Win32), so the cost of vendoring is low. Changes: - cbits/: lmdb.h, mdb.c, midl.c, midl.h, LICENSE. - ppad-lmdb.cabal: drop `pkgconfig-depends: lmdb`; add `c-sources` + `include-dirs: cbits` + `cc-options: -w` (LMDB compiles with some old-style warnings that aren't our problem); add `extra-libraries: pthread` everywhere except Windows; list the vendored files under `extra-source-files` so `sdist` ships them. Synopsis/description updated. - flake.nix: drop `pkgs.lmdb` and `pkgs.pkg-config` from buildInputs; banner now reports the vendored revision instead of the nixpkgs version. - README + Database.LMDB haddock: replace the pkg-config text with the vendoring note (the haddock was already implicitly claiming this). Verification: clean rebuild succeeds; all 8 tests pass; bench numbers within noise of the pre-vendoring run (put 1k 572 us vs 590 us, get 1k 307 us vs 313 us, scan 10k 1.21 ms vs 1.22 ms). The GHC CApiFFI `void** -> MDB_env**` warnings are unchanged from before -- they come from GHC's generated wrappers, not the vendored code.

flake: formatting nit

2026-05-24T19:17:15Z

commit d2eb60d378143cf6612eeda250acce2c6471f69a parent d53d51b03e1160de9e3105cdbfd5b482e5025dbd Author: Jared Tobin Date: Sun, 24 May 2026 16:47:15 -0230 flake: formatting nit

perf: inline hot paths and combine MDB_val allocations

2026-05-24T19:05:26Z

commit d53d51b03e1160de9e3105cdbfd5b482e5025dbd parent 0c973be28ac9a83e02ec64cf7811aeee03b3e7aa Author: Jared Tobin Date: Sun, 24 May 2026 16:35:26 -0230 perf: inline hot paths and combine MDB_val allocations The Haskell layer over the FFI was using `with` + `alloca` pairs and shared `cursorAt` with a `Maybe BS.ByteString` dispatch on every cursor step. None of it costs much per call, but cursor scans iterate it tens of thousands of times per second. - INLINE on `check`, `withBSAsVal`, `peekVal`, `get`, `put`, `del`, all `cursor*` wrappers, and the `MDB_val` Storable methods. Lets `-O1` consumers see through the wrappers at each call site. - `withBSAsVal` / `peekVal` poke fields directly via `pokeByteOff` / `peekByteOff` rather than going through `with` and the Storable instance. Same generated code under inlining, but no longer depends on it. - `get`, `put`, `cursorMove`, `cursorSeek` use a single `allocaBytes 32` to hold both the input-key and output-value (or the two input) `MDB_val` structs side-by-side instead of two separate allocations. - `cursorAt` split into `cursorMove` (no input key — used by first/last/next/prev) and an inlined seek body. Removes the per-call `Maybe` dispatch that the hot scan path was paying. Criterion (3s time-limit): put 10k inserts 4.319 ms -> 4.160 ms (-3.7%) get 1k random 332.1 us -> 312.8 us (-5.8%) get 10k random 3.200 ms -> 2.971 ms (-7.2%) cursor scan 10k 1.439 ms -> 1.217 ms (-15.4%) Weigh: 1k put 9,919,040 B -> 9,782,608 B (-1.4%) 1k get 5,063,024 B -> 4,922,792 B (-2.8%) scan 1k entries 423,448 B -> 267,040 B (-37%) Test suite still passes. Also bundles unrelated doc tidy-ups: README badges, dev section pointing at `nix develop`, cabal synopsis/description reflow.

init: minimal LMDB bindings

2026-05-24T18:47:57Z

commit 0c973be28ac9a83e02ec64cf7811aeee03b3e7aa Author: Jared Tobin Date: Sun, 24 May 2026 16:17:57 -0230 init: minimal LMDB bindings A first cut at ppad-lmdb. Wraps the system liblmdb (via pkg-config, provided by pkgs.lmdb in the flake) and exposes a safe, bracketed interface keyed on strict ByteStrings. Surface (Database.LMDB): - Env / open / close / withEnv with an EnvFlags record - Phantom-typed transactions: withReadTxn (Txn RO) and withWriteTxn (Txn RW). Writing through an RO Txn fails to type-check - openDbi, get / put / del - Cursors: withCursor, cursorFirst / Last / Next / Prev, cursorSeek (MDB_SET_RANGE) - LMDBException with the common cases tagged plus a catch-all Database.LMDB.Internal exposes the raw foreign-import-capi declarations and flag constants for power users. Tests (tasty): six unit cases (roundtrip, missing key, del truthiness, write-txn rollback on exception, cursor walk, cursorSeek) plus two QuickCheck properties (put/get roundtrip, cursor enumerates Map.toAscList). Benches: criterion bench/Main.hs covers put/get/cursor at 1k/10k entries; weigh bench/Weight.hs reports per-op allocations. Note: sanitize flag intentionally omitted - we vendor no C, so clang doesn't add the ASan runtime to the link line and the flag would only give a false signal of safety.