build and test for direct_hash

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2026-08-03 11:51:14 +03:00
parent 97353ebddc
commit e8d99cf676
2 changed files with 233 additions and 0 deletions
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#!/usr/bin/env python3
import argparse
import ctypes
import gc
import os
import statistics
import subprocess
import time
from pathlib import Path
HERE = Path(__file__).resolve().parent
BUILD = HERE / "build"
LIBC = ctypes.CDLL(None)
LIBC.free.argtypes = [ctypes.c_void_p]
class SetAPI:
def __init__(self, path: Path):
self.lib = ctypes.CDLL(str(path))
self.lib.set_new.restype = ctypes.c_void_p
self.lib.set_add.argtypes = [ctypes.c_void_p, ctypes.c_char_p]
self.lib.set_fini.argtypes = [ctypes.c_void_p, ctypes.c_int]
self.lib.set_fini.restype = ctypes.c_void_p
self.lib.set_free.argtypes = [ctypes.c_void_p]
self.lib.set_free.restype = ctypes.c_void_p
self.lib.rpmsetcmp.argtypes = [ctypes.c_char_p, ctypes.c_char_p]
self.lib.rpmsetcmp.restype = ctypes.c_int
def new_with_symbols(self, symbols):
value = self.lib.set_new()
if not value:
raise RuntimeError("set_new returned NULL")
for symbol in symbols:
self.lib.set_add(value, symbol)
return value
def release(self, value, result):
if result:
LIBC.free(result)
self.lib.set_free(value)
def encode(self, symbols, bpp):
value = self.new_with_symbols(symbols)
result = self.lib.set_fini(value, bpp)
if not result:
raise RuntimeError("set_fini returned NULL")
encoded = ctypes.string_at(result)
self.release(value, result)
return encoded
def median_fini(api, symbols, bpp, calls, rounds):
samples = []
for _ in range(rounds):
sets = [api.new_with_symbols(symbols) for _ in range(calls)]
results = []
start = time.perf_counter_ns()
for value in sets:
results.append(api.lib.set_fini(value, bpp))
samples.append((time.perf_counter_ns() - start) / calls)
if not all(results):
raise RuntimeError("set_fini returned NULL")
encoded = [ctypes.string_at(result) for result in results]
if len(set(encoded)) != 1:
raise RuntimeError("set_fini is not deterministic")
for value, result in zip(sets, results):
api.release(value, result)
return statistics.median(samples)
def median_build(api, symbols, bpp, calls, rounds):
samples = []
for _ in range(rounds):
sets = []
results = []
start = time.perf_counter_ns()
for _ in range(calls):
value = api.new_with_symbols(symbols)
result = api.lib.set_fini(value, bpp)
sets.append(value)
results.append(result)
samples.append((time.perf_counter_ns() - start) / calls)
if not all(results):
raise RuntimeError("set_fini returned NULL")
for value, result in zip(sets, results):
api.release(value, result)
return statistics.median(samples)
def median_cmp(api, provider, requirement, calls, rounds):
expected = api.lib.rpmsetcmp(provider, requirement)
if expected != 1 or api.lib.rpmsetcmp(provider, provider) != 0:
raise RuntimeError(f"unexpected rpmsetcmp result: {expected}")
for _ in range(100):
api.lib.rpmsetcmp(provider, requirement)
samples = []
for _ in range(rounds):
checksum = 0
start = time.perf_counter_ns()
for _ in range(calls):
checksum += api.lib.rpmsetcmp(provider, requirement)
samples.append((time.perf_counter_ns() - start) / calls)
if checksum != calls:
raise RuntimeError("rpmsetcmp result changed during benchmark")
return statistics.median(samples)
def cold_cmp_once(api, provider, requirement):
read_fd, write_fd = os.pipe()
pid = os.fork()
if pid == 0:
os.close(read_fd)
start = time.perf_counter_ns()
result = api.lib.rpmsetcmp(provider, requirement)
elapsed = time.perf_counter_ns() - start
os.write(write_fd, f"{elapsed} {result}".encode())
os.close(write_fd)
os._exit(0)
os.close(write_fd)
payload = b""
while chunk := os.read(read_fd, 128):
payload += chunk
os.close(read_fd)
_, status = os.waitpid(pid, 0)
if status != 0:
raise RuntimeError(f"cold rpmsetcmp child failed: status={status}")
elapsed, result = map(int, payload.split())
if result != 1:
raise RuntimeError(f"unexpected cold rpmsetcmp result: {result}")
return elapsed
def median_cmp_cold(api, provider, requirement, calls, rounds):
samples = []
for _ in range(rounds):
total = sum(cold_cmp_once(api, provider, requirement) for _ in range(calls))
samples.append(total / calls)
return statistics.median(samples)
def format_time(ns):
return f"{ns / 1000:.2f} us"
def main():
parser = argparse.ArgumentParser(description="Compare set9 and direct-hash set APIs")
parser.add_argument("--symbols", type=int, default=1000)
parser.add_argument("--bpp", type=int, default=32)
parser.add_argument("--rounds", type=int, default=7)
parser.add_argument("--fini-calls", type=int, default=5)
parser.add_argument("--cmp-calls", type=int, default=2000)
parser.add_argument("--cold-calls", type=int, default=20)
parser.add_argument("--skip-build", action="store_true")
args = parser.parse_args()
if args.symbols < 2 or not 10 <= args.bpp <= 32:
parser.error("symbols must be >= 2 and bpp must be in 10..32")
if min(args.rounds, args.fini_calls, args.cmp_calls, args.cold_calls) < 1:
parser.error("rounds and call counts must be positive")
if not args.skip_build:
subprocess.run([str(HERE / "build.sh")], check=True)
symbols = tuple(
f"symbol_{i:08d}_version_ALT_{i % 97}".encode() for i in range(args.symbols)
)
required = symbols[::2]
apis = {
"set9": SetAPI(BUILD / "libset9.so"),
"direct": SetAPI(BUILD / "libdirect-hash.so"),
}
gc.disable()
try:
timings = {}
lengths = {}
for name, api in apis.items():
provider = api.encode(symbols, args.bpp)
requirement = api.encode(required, args.bpp)
wire_format = "D1/base64" if provider.startswith(b"D1") else "golomb/base62"
lengths[name] = (len(provider), wire_format)
timings[name] = (
median_fini(api, symbols, args.bpp, args.fini_calls, args.rounds),
median_build(api, symbols, args.bpp, args.fini_calls, args.rounds),
median_cmp_cold(api, provider, requirement, args.cold_calls, args.rounds),
median_cmp(api, provider, requirement, args.cmp_calls, args.rounds),
)
finally:
gc.enable()
print(f"symbols={args.symbols} required={len(required)} bpp={args.bpp}")
print("implementation set_chars format")
for name in apis:
print(f"{name:<14} {lengths[name][0]:>9} {lengths[name][1]}")
print("\noperation set9 direct direct/set9")
labels = ("set_fini only", "new+add+fini", "rpmsetcmp cold", "rpmsetcmp warm")
for index, label in enumerate(labels):
old = timings["set9"][index]
new = timings["direct"][index]
print(f"{label:<22} {format_time(old):>10} {format_time(new):>10} {new / old:>12.2f}x")
if __name__ == "__main__":
main()