## 2.7.1
* Documentation and tests only; the library behaves as in 2.7.0.
* The documentation of `prefixSameAsStart` was wrong on one point and silent
on another. It said that the option does nothing after `iterFirst` or
`iterLast`: it does, the iterator stays within the prefix of the key that
it finds there. And it did not say that every key, sought or stored, has
to be at least as long as the `prefixLength`: RocksDB takes the prefix of
a key without checking its length, and reads past the end of a shorter
one. Both are now in the Haddock and in the README, and the first has
tests.
## 2.7.0
* Bounded iterators. `withIterConfig` creates an iterator that RocksDB itself
stops, as an `IterConfig` says: at a `lowerBound` or an `upperBound`, or at
the end of the prefix that it was sent to, with `prefixSameAsStart`. Until
now a scan of a range could only stop by reading the first key past it,
and when the keys past it had been deleted, RocksDB stepped over the marker
of every one to find that key. A scan of an empty range followed by 20,000
deleted keys took 2,600 microseconds; with an upper bound it takes 2.5.
`prefixUpperBound` gives the bound that ends a prefix, and
`createIteratorConfig` manages such an iterator by hand.
* `totalOrderSeek`, also in `IterConfig`, walks every key in order in a
database that has a `prefixLength`, where a plain iterator only promises
the keys of one prefix.
* The `DB` record has a new field, `snapshot`, with the snapshot that its
read options read from. Code that builds a `DB` by hand has to set it;
code that gets one from `withDB`, `withDBCF` or `withSnapshot` needs no
change. This is why the version is 2.7.0 and not 2.6.5.
## 2.6.4
* Iterators read rows about three times faster. `iterValid`, `iterKey` and
`iterValue` now reach RocksDB through unsafe foreign calls. The three only
read what the iterator already holds, and reading one row with `iterEntry`
and `iterNext` makes five of them; as safe calls each cost about 0.4
microseconds. Walking 700,000 rows took 2.8 microseconds a row before and
0.8 after. The calls that move an iterator, which can read from disk, are
safe calls as before.
## 2.6.3
* Documentation only; the library behaves as in 2.6.2.
* References in the Haddock that named both a type and its constructor, such
as `DB` and `Config`, now say that they mean the type, and two that named
nothing in scope are fixed: the documentation builds without warnings about
ambiguous or unresolved identifiers.
* The documentation of `withIter` said to set a snapshot in the read options,
which the API has no way to do. It now says how: create the iterator from
the `DB` that `withSnapshot` provides.
* Remove an unused import.
* The test suite grows from 17 tests to 51. It now covers deletes, batches,
`withSnapshot`, iteration backwards, empty keys and values, binary data,
and the errors of opening a database, none of which had a test. Six of the
tests are QuickCheck properties that compare the database with a `Map`
after random writes. The suite also compiles without warnings.
* A badge in the README shows the state of CI on `master`.
## 2.6.2
* Build the Bloom filters that `bloomFilter` asks for. The bits per key were
passed to `rocksdb_filterpolicy_create_bloom_full` as an integer, which is
what RocksDB took until 6.23; since 6.24 the function takes a `double`. An
integer and a `double` travel in different registers, so RocksDB read
something else as the bits per key and built no filters: table files had
`filter block size=0`, and a lookup of an absent key read a data block in
every file that could hold it. Nothing failed, and no test noticed. In a
measurement with 2,600,000 keys, such a lookup took about 5.5 microseconds
without the filters and 1.5 with them.
The function is now imported with the `capi` calling convention, through a
stub compiled against `rocksdb/c.h`, so the C compiler passes the argument
as the installed RocksDB declares it, before or after 6.24. The headers
were already needed to install RocksDB for development; they are now
needed to build this package too.
Databases opened with `bloomFilter` start building filters when they are
opened with this version: for the table files written from then on, at
about 1.25 bytes per key. Files written before have none until compaction
rewrites them.
* Pass the error pointer that `rocksdb_approximate_sizes` takes since RocksDB
6.16. `approximateSize` called it with one argument too few, leaving RocksDB
to read a pointer that was never passed, and to write an error message
through it if the call failed. It now throws an `IOError` on failure.
* Both were found by comparing every foreign import with the `rocksdb/c.h` of
RocksDB 11.1: the other 70 match.
* Tests that table files have filters when asked for and not otherwise, and
of `approximateSize`, which had none.
## 2.6.1
* Documentation, lots of it, with detailed explanations.
## 2.6.0
* Add `multiGet` and `multiGetCF`, which read the values of many keys in
one call to RocksDB's `MultiGet`.
* Add `blockCacheSize` to `Config`: the bytes of a least-recently-used block
cache shared by the database and all its column families. Without it
RocksDB gives each column family its own default cache, of 32 MiB in
RocksDB 8.
* Add `cacheIndexAndFilterBlocks` to `Config`, to keep the index and filter
blocks of a column family in the block cache, at high priority, with
those of level 0 pinned, instead of in memory outside the cache for every
open file.
* Stop leaking the block-based table options of every database and column
family opened with a Bloom filter.
## 2.5.0
* Add the `EstimateTableReadersMem`, `CurSizeAllMemTables` and
`BlockCacheUsage` properties, and `PropertyName` for any other property by
its name.
* Add `getPropertyCF` to read a property of a column family.
* Add `maxTotalWalSize` (`max_total_wal_size`) to `Config`, to bound the
write-ahead log.
* Add `createMissingColumnFamilies` (`create_missing_column_families`) to
`Config`, to add column families to an existing database.
* Destroy the handle of the default column family when `withDBCF` opens an
existing database. It was leaked, and RocksDB built with assertions
aborted when the database was closed.
## 2.4.0
* Add `writeBufferSize` (`write_buffer_size`) and `dbWriteBufferSize`
(`db_write_buffer_size`) to `Config`, to bound memtable memory.
## 2.3.1
* Do not call next/prev on invalid iterators (fixes assertion failure).
## 2.3.0
* Remove UnliftIO and remain in IO monad.
## 2.2.0
* Move Iterator module to plain IO.
* Properly manage read options in createSnapshot.
* Add nix flake for development.
* API allows manual database lifecycle management.
## 2.1.7
* Simplify author name.
## 2.1.6
* Refactor memory use further.
* Improve tests.
## 2.1.5
* Fix errors not releasing memory.
## 2.1.4
* Add ResourceT support for snapshots and iterators.
## 2.1.3
* Correct bug where database was ignoring prefix length config.
## 2.1.2
* Correct bug when opening database with column families.
## 2.1.1
* Expose ColumnFamily type.
## 2.1.0
* Add support for column families.
## 2.0.0
* Fork into a different project
* Rewrite most of the code to make it faster and easier to use
* Remove many features that I don't need or want to maintain
## 1.0.1
* Add support for UTF-8 characters in a database's path
## 1.0.0
* First version by Serokell
## 0.3x.0
* ResourceT is no longer compulsory
## 0.2.0
* requires LevelDB v1.7
* support for filter policy (LevelDB v1.5), either custom or using the built-in
bloom filter implementation
* write batch values no longer require a `memcpy` to be early-finalizer-safe
(introduced in 0.1.1)
## 0.1.0
* memory (foreign pointers) is managed through
[ResourceT](http://hackage.haskell.org/package/resourcet). Note that this
requires to lift monadic actions inside the `MonadResource` monad, see the
examples.
* links against shared library (LevelDB v1.3 or higher)
* LevelDB 1.3 API fully supported (including custom comparators, excluding
custom environments)
## 0.0.x
* experimental releases