Files
Nim/tests/benchmarks/strings/hashbench.nim
2026-04-02 07:19:43 +02:00

278 lines
8.1 KiB
Nim

import std/[monotimes, os, random, strutils, tables, times]
const
AlwaysAvail = 7
InlineMax = AlwaysAvail + sizeof(pointer) - 1
Alphabet = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-"
SharedPrefixes = [
"module/submodule/symbol/",
"compiler/semantic/checker/",
"core/runtime/string-table/",
"aaaaaaaaaaaaaa/shared/prefix/",
"zzzzzzzzzzzzzz/shared/prefix/"
]
ScenarioNames = ["short", "inline", "boundary", "long", "prefix", "mixed"]
type
Scenario = enum
scShort
scInline
scBoundary
scLong
scPrefix
scMixed
Config = object
count: int
rounds: int
seed: int64
scenarios: seq[Scenario]
proc defaultConfig(): Config =
Config(
count: 200_000,
rounds: 5,
seed: 20260307'i64,
scenarios: @[scShort, scInline, scBoundary, scLong, scPrefix, scMixed]
)
proc usage() =
echo "String hash-table benchmark for experimenting with the SSO runtime."
echo ""
echo "Usage:"
echo " nim r -d:danger hashbench.nim [--count=N] [--rounds=N] [--seed=N]"
echo " [--scenarios=list]"
echo ""
echo "Scenarios:"
echo " short, inline, boundary, long, prefix, mixed"
echo ""
echo "Current inline limit on this target: ", InlineMax, " bytes"
proc parseScenario(name: string): Scenario =
case name.normalize
of "short":
scShort
of "inline":
scInline
of "boundary":
scBoundary
of "long":
scLong
of "prefix":
scPrefix
of "mixed":
scMixed
else:
quit "unknown scenario: " & name
proc parseConfig(): Config =
result = defaultConfig()
for arg in commandLineParams():
if arg == "--help" or arg == "-h":
usage()
quit 0
elif arg.startsWith("--count="):
result.count = parseInt(arg["--count=".len .. ^1])
elif arg.startsWith("--rounds="):
result.rounds = parseInt(arg["--rounds=".len .. ^1])
elif arg.startsWith("--seed="):
result.seed = parseInt(arg["--seed=".len .. ^1]).int64
elif arg.startsWith("--scenarios="):
result.scenarios.setLen(0)
for item in arg["--scenarios=".len .. ^1].split(','):
if item.len > 0:
result.scenarios.add parseScenario(item)
else:
quit "unknown argument: " & arg
if result.count <= 0:
quit "--count must be > 0"
if result.rounds <= 0:
quit "--rounds must be > 0"
if result.scenarios.len == 0:
quit "at least one scenario is required"
proc scenarioName(s: Scenario): string =
ScenarioNames[s.ord]
proc scenarioList(scenarios: openArray[Scenario]): string =
for i, scenario in scenarios:
if i > 0:
result.add ','
result.add scenarioName(scenario)
proc fixed(x: float; digits: range[0..32]): string =
formatFloat(x, ffDecimal, digits)
proc randomChar(rng: var Rand): char =
Alphabet[rng.rand(Alphabet.high)]
proc makeRandomString(rng: var Rand; len: int; prefix = ""): string =
result = newString(len)
var i = 0
while i < len and i < prefix.len:
result[i] = prefix[i]
inc i
while i < len:
result[i] = randomChar(rng)
inc i
proc pickMixedLength(rng: var Rand): int =
let bucket = rng.rand(0..99)
if bucket < 35:
result = rng.rand(1..AlwaysAvail)
elif bucket < 70:
result = rng.rand(AlwaysAvail + 1 .. InlineMax)
else:
result = rng.rand(InlineMax + 1 .. InlineMax + 48)
proc makeScenarioString(rng: var Rand; kind: Scenario; serial: int): string =
case kind
of scShort:
result = makeRandomString(rng, rng.rand(1..AlwaysAvail))
of scInline:
result = makeRandomString(rng, rng.rand(AlwaysAvail + 1 .. InlineMax))
of scBoundary:
let choices = [
max(1, InlineMax - 2),
max(1, InlineMax - 1),
InlineMax,
InlineMax + 1,
InlineMax + 2
]
result = makeRandomString(rng, choices[rng.rand(choices.high)])
of scLong:
result = makeRandomString(rng, rng.rand(InlineMax + 1 .. InlineMax + 64))
of scPrefix:
let prefix = SharedPrefixes[rng.rand(SharedPrefixes.high)]
let suffixLen = rng.rand(4..24)
result = makeRandomString(rng, prefix.len + suffixLen, prefix)
of scMixed:
result = makeRandomString(rng, pickMixedLength(rng))
if result.len > 0:
result[0] = char(ord('a') + (serial mod 26))
result[^1] = char(ord('0') + (serial mod 10))
proc generateDataset(kind: Scenario; count: int; seed: int64): seq[string] =
var rng = initRand(seed + kind.ord.int64 * 10_000_019'i64)
result = newSeq[string](count)
for i in 0..<count:
result[i] = makeScenarioString(rng, kind, i)
proc averageLen(data: openArray[string]): float =
var total = 0
for s in data:
total += s.len
result = total.float / max(1, data.len).float
proc checksum(data: openArray[string]): uint64 =
for i, s in data:
result = result * 0x9E3779B185EBCA87'u64 + uint64(s.len)
if s.len > 0:
result = result xor (uint64(ord(s[0])) shl (i and 7))
result = result xor (uint64(ord(s[^1])) shl ((i + 3) and 7))
proc makeMissQueries(kind: Scenario; count: int; seed: int64): seq[string] =
result = generateDataset(kind, count, seed + 0x6A09E667'i64)
for i in 0..<result.len:
if result[i].len == 0:
result[i] = "!"
else:
result[i][^1] = char(ord('Q') + (i mod 7))
proc bench(kind: Scenario; cfg: Config) =
let keys = generateDataset(kind, cfg.count, cfg.seed)
let hitQueries = keys
let missQueries = makeMissQueries(kind, cfg.count, cfg.seed)
let avgLen = averageLen(keys)
let keyCheck = checksum(keys) xor checksum(missQueries)
var warm = initTable[string, int](cfg.count * 2)
for i, key in keys:
warm[key] = i
var warmHits = 0
for key in hitQueries:
warmHits += warm[key]
var warmMisses = 0
for key in missQueries:
if warm.hasKey(key):
inc warmMisses
doAssert warmHits >= 0
doAssert warmMisses == 0
var insertTotalNs = 0.0
var hitTotalNs = 0.0
var missTotalNs = 0.0
var insertBestNs = Inf
var hitBestNs = Inf
var missBestNs = Inf
var insertWorstNs = 0.0
var hitWorstNs = 0.0
var missWorstNs = 0.0
var combined = keyCheck + uint64(cfg.count)
for round in 0..<cfg.rounds:
var table = initTable[string, int](cfg.count * 2)
let insertStarted = getMonoTime()
for i, key in keys:
table[key] = i
let insertNs = float((getMonoTime() - insertStarted).inNanoseconds)
var hitSum = 0
let hitStarted = getMonoTime()
for key in hitQueries:
hitSum += table[key]
let hitNs = float((getMonoTime() - hitStarted).inNanoseconds)
var missSum = 0
let missStarted = getMonoTime()
for key in missQueries:
if table.hasKey(key):
inc missSum
let missNs = float((getMonoTime() - missStarted).inNanoseconds)
doAssert hitSum >= 0
doAssert missSum == 0
insertTotalNs += insertNs
hitTotalNs += hitNs
missTotalNs += missNs
insertBestNs = min(insertBestNs, insertNs)
hitBestNs = min(hitBestNs, hitNs)
missBestNs = min(missBestNs, missNs)
insertWorstNs = max(insertWorstNs, insertNs)
hitWorstNs = max(hitWorstNs, hitNs)
missWorstNs = max(missWorstNs, missNs)
combined = combined * 0x9E3779B185EBCA87'u64 +
uint64(cast[uint](hitSum xor missSum xor round))
let insertAvgNs = insertTotalNs / cfg.rounds.float
let hitAvgNs = hitTotalNs / cfg.rounds.float
let missAvgNs = missTotalNs / cfg.rounds.float
echo align(scenarioName(kind), 8), " n=", align($cfg.count, 8),
" avgLen=", align(fixed(avgLen, 1), 6),
" ins=", align(fixed(insertAvgNs / 1e6, 3), 9), " ms",
" hit=", align(fixed(hitAvgNs / 1e6, 3), 9), " ms",
" miss=", align(fixed(missAvgNs / 1e6, 3), 9), " ms",
" ns/op=", align(fixed((insertAvgNs + hitAvgNs + missAvgNs) / (3.0 * cfg.count.float), 1), 8),
" check=0x", toHex(combined, 16)
discard insertBestNs
discard hitBestNs
discard missBestNs
discard insertWorstNs
discard hitWorstNs
discard missWorstNs
proc main() =
let cfg = parseConfig()
echo "inline limit=", InlineMax, " bytes count=", cfg.count,
" rounds=", cfg.rounds, " seed=", cfg.seed
echo "scenarios=", scenarioList(cfg.scenarios)
for scenario in cfg.scenarios:
bench(scenario, cfg)
when not defined(useMalloc): echo "MAXMEM=", formatSize getMaxMem()
when isMainModule:
main()