nimbus-eth1/nimbus/db/kvt/kvt_init/rocks_db/rdb_init.nim

174 lines
6.0 KiB
Nim

# nimbus-eth1
# Copyright (c) 2023-2024 Status Research & Development GmbH
# Licensed under either of
# * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
# http://www.apache.org/licenses/LICENSE-2.0)
# * MIT license ([LICENSE-MIT](LICENSE-MIT) or
# http://opensource.org/licenses/MIT)
# at your option. This file may not be copied, modified, or distributed
# except according to those terms.
## Rocksdb constructor/destructor for Kvt DB
## =========================================
{.push raises: [].}
import
std/[sequtils, os],
rocksdb,
results,
../../../aristo/aristo_init/persistent,
../../../opts,
../../kvt_desc,
../../kvt_desc/desc_error as kdb,
./rdb_desc
# ------------------------------------------------------------------------------
# Private helpers
# ------------------------------------------------------------------------------
proc getCFInitOptions(opts: DbOptions): ColFamilyOptionsRef =
# TODO the configuration options below have not been tuned but are rather
# based on gut feeling, guesses and by looking at other clients - it
# would make sense to test different settings and combinations once the
# data model itself has settled down as their optimal values will depend
# on the shape of the data - it'll also be different per column family..
let cfOpts = defaultColFamilyOptions()
if opts.writeBufferSize > 0:
cfOpts.setWriteBufferSize(opts.writeBufferSize)
# Without this option, the WAL might never get flushed since a small column
# family (like the admin CF) with only tiny writes might keep it open - this
# negatively affects startup times since the WAL is replayed on every startup.
# https://github.com/facebook/rocksdb/blob/af50823069818fc127438e39fef91d2486d6e76c/include/rocksdb/options.h#L719
# Flushing the oldest
let writeBufferSize =
if opts.writeBufferSize > 0:
opts.writeBufferSize
else:
64 * 1024 * 1024 # TODO read from rocksdb?
cfOpts.setMaxTotalWalSize(2 * writeBufferSize)
# When data is written to rocksdb, it is first put in an in-memory table
# whose index is a skip list. Since the mem table holds the most recent data,
# all reads must go through this skiplist which results in slow lookups for
# already-written data.
# We enable a bloom filter on the mem table to avoid this lookup in the cases
# where the data is actually on disk already (ie wasn't updated recently).
# TODO there's also a hashskiplist that has both a hash index and a skip list
# which maybe could be used - uses more memory, requires a key prefix
# extractor
cfOpts.setMemtableWholeKeyFiltering(true)
cfOpts.setMemtablePrefixBloomSizeRatio(0.1)
# LZ4 seems to cut database size to 2/3 roughly, at the time of writing
# Using it for the bottom-most level means it applies to 90% of data but
# delays compression until data has settled a bit, which seems like a
# reasonable tradeoff.
# TODO evaluate zstd compression with a trained dictionary
# https://github.com/facebook/rocksdb/wiki/Compression
cfOpts.setBottommostCompression(Compression.lz4Compression)
cfOpts
proc getDbInitOptions(opts: DbOptions): DbOptionsRef =
result = defaultDbOptions()
result.setMaxOpenFiles(opts.maxOpenFiles)
result.setMaxBytesForLevelBase(opts.writeBufferSize)
if opts.rowCacheSize > 0:
result.setRowCache(cacheCreateLRU(opts.rowCacheSize))
if opts.blockCacheSize > 0:
let tableOpts = defaultTableOptions()
tableOpts.setBlockCache(cacheCreateLRU(opts.rowCacheSize))
result.setBlockBasedTableFactory(tableOpts)
# ------------------------------------------------------------------------------
# Public constructor
# ------------------------------------------------------------------------------
proc init*(
rdb: var RdbInst;
basePath: string;
opts: DbOptions;
): Result[void,(KvtError,string)] =
## Database backend constructor for stand-alone version
##
const initFailed = "RocksDB/init() failed"
rdb.basePath = basePath
let
dataDir = rdb.dataDir
try:
dataDir.createDir
except OSError, IOError:
return err((kdb.RdbBeCantCreateDataDir, ""))
# Expand argument `opts` to rocksdb options
let (cfOpts, dbOpts) = (opts.getCFInitOptions, opts.getDbInitOptions)
# Column familiy names to allocate when opening the database.
let cfs = KvtCFs.mapIt(($it).initColFamilyDescriptor cfOpts)
# Open database for the extended family :)
let baseDb = openRocksDb(dataDir, dbOpts, columnFamilies=cfs).valueOr:
raiseAssert initFailed & " cannot create base descriptor: " & error
# Initialise column handlers (this stores implicitely `baseDb`)
for col in KvtCFs:
rdb.store[col] = baseDb.withColFamily($col).valueOr:
raiseAssert initFailed & " cannot initialise " &
$col & " descriptor: " & error
ok()
proc init*(
rdb: var RdbInst;
adb: AristoDbRef;
opts: DbOptions;
): Result[void,(KvtError,string)] =
## Initalise column handlers piggy-backing on the `Aristo` backend.
##
let
cfOpts = opts.getCFInitOptions()
iCfs = KvtCFs.toSeq.mapIt(initColFamilyDescriptor($it, cfOpts))
oCfs = adb.reinit(iCfs).valueOr:
return err((RdbBeHostError,$error))
# Collect column family descriptors (this stores implicitely `baseDb`)
for n in KvtCFs:
assert oCfs[n.ord].name != "" # debugging only
rdb.store[n] = oCfs[n.ord]
ok()
proc destroy*(rdb: var RdbInst; eradicate: bool) =
## Destructor (no need to do anything if piggybacked)
if 0 < rdb.basePath.len:
rdb.baseDb.close()
if eradicate:
try:
rdb.dataDir.removeDir
# Remove the base folder if it is empty
block done:
for w in rdb.baseDir.walkDirRec:
# Ignore backup files
if 0 < w.len and w[^1] != '~':
break done
rdb.baseDir.removeDir
except CatchableError:
discard
# ------------------------------------------------------------------------------
# End
# ------------------------------------------------------------------------------