Files
fastwc/benchmarks/std.sh
T
huntedbytheirs c4d4f0b713 first: setup
setting up repo.
2026-08-29 13:48:15 -04:00

258 lines
9.0 KiB
Bash
Executable File

#!/usr/bin/env bash
#
# std.sh — shared "standard library" for the fastwc benchmark scripts.
#
# Provides the helpers every benchmark script needs:
# checkfastwc() verify a release build of fastwc exists
# checkwc() locate the coreutils or busybox wc implementation
# createrandstr() print one random 10-character alphanumeric string
# createtxt() create (or reuse) a text file with N such lines
# run_benchmark_suite() run every word/line case for the selected wc
#
# Source this file from a benchmark script, then:
# checkfastwc
# checkwc coreutils # or: checkwc busybox
# BENCH_NAME="coreutils"
# run_benchmark_suite
#
# The suite fails fast: the moment fastwc is slower than (or disagrees
# with) the selected wc implementation, it writes a human readable report
# to FAILED-benchmark.txt and returns non-zero.
set -u
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
FASTWC="$SCRIPT_DIR/../bin/release/fastwc"
DATA_DIR="$SCRIPT_DIR/.data"
GENFILE="$SCRIPT_DIR/tools/genfile" # optional C helper, built by test-all.sh
BENCH_NAME="${BENCH_NAME:-wc}" # set by the caller: coreutils | busybox
BENCH_REPS="${BENCH_REPS:-3}" # interleaved runs per case; minimum is kept
RESULT_ROWS="" # accumulated results table
WC_CMD=() # filled by checkwc(), e.g. (wc) or (busybox wc)
TEXT_FILE="" # filled by createtxt()
if [[ -z "$BENCH_REPS" || "$BENCH_REPS" -lt 1 ]]; then
BENCH_REPS=1
fi
# checkfastwc — make sure ../bin/release/fastwc exists and is executable.
# Mimics autotools configure: prints "checking for ... yes/no" and bails
# out with a helpful message when the release build is missing.
checkfastwc() {
printf 'checking for release build fastwc... '
if [[ -x "$FASTWC" ]]; then
printf 'yes\n'
return 0
fi
printf 'no\n'
printf 'configure: error: no release build of fastwc found at %s\n' "$FASTWC" >&2
printf 'configure: error: run "make release" first to generate one\n' >&2
exit 1
}
# checkwc <coreutils|busybox> — locate the requested wc implementation and
# store its invocation in $WC_CMD. Mimics autotools configure output and
# exits on failure.
checkwc() {
local impl="$1"
case "$impl" in
coreutils)
printf 'checking for coreutils wc... '
if command -v wc >/dev/null 2>&1 \
&& wc --version 2>/dev/null | head -n1 | grep -qi 'GNU coreutils'; then
printf 'yes\n'
WC_CMD=(wc)
else
printf 'no\n'
printf 'configure: error: GNU Coreutils wc not found in PATH\n' >&2
exit 1
fi
;;
busybox)
printf 'checking for busybox wc... '
if command -v busybox >/dev/null 2>&1 \
&& busybox --list 2>/dev/null | grep -qx 'wc'; then
printf 'yes\n'
WC_CMD=(busybox wc)
else
printf 'no\n'
printf 'configure: error: busybox (with the wc applet) not found in PATH\n' >&2
exit 1
fi
;;
*)
printf 'checkwc: error: unknown implementation "%s" (expected coreutils or busybox)\n' "$impl" >&2
exit 1
;;
esac
}
# createrandstr — print one 10-character random alphanumeric combination.
createrandstr() {
local chars='abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'
local out='' i
for ((i = 0; i < 10; i++)); do
out+="${chars:$((RANDOM % ${#chars})):1}"
done
printf '%s\n' "$out"
}
# createtxt <lines> — make sure a text file with <lines> rows of random
# 10-character alphanumeric strings exists. A copy generated by a previous
# run is reused (checked by exact byte size: 10 chars + '\n' per line), so
# repeated benchmark runs are cheap. Prints the path and sets $TEXT_FILE.
createtxt() {
local lines="$1"
local expect=$((lines * 11))
local have=0
TEXT_FILE="$DATA_DIR/words-$lines.txt"
if [[ -f "$TEXT_FILE" ]]; then
have=$(stat -c '%s' "$TEXT_FILE" 2>/dev/null || printf '0')
fi
if [[ "$have" -ne "$expect" ]]; then
mkdir -p "$DATA_DIR"
if [[ -x "$GENFILE" ]]; then
"$GENFILE" "$lines" > "$TEXT_FILE" || {
printf 'createtxt: error: failed to generate %s\n' "$TEXT_FILE" >&2
return 1
}
else
printf 'createtxt: warning: %s not built, using slow shell fallback\n' "$GENFILE" >&2
printf 'createtxt: warning: run ./test-all.sh to build the helper tools\n' >&2
: > "$TEXT_FILE"
for ((i = 0; i < lines; i++)); do
createrandstr >> "$TEXT_FILE"
done
fi
fi
printf '%s\n' "$TEXT_FILE"
}
# time_ms <cmd...> — run a command once and print elapsed wall time in ms.
time_ms() {
local s e
s=$(date +%s%N)
"$@" >/dev/null 2>&1
e=$(date +%s%N)
printf '%s\n' "$(( (e - s) / 1000000 ))"
}
# capture_count <cmd...> — print the first whitespace-separated field of a
# command's output, i.e. the count reported by `wc -w/-l` or `fastwc -w/-l`.
capture_count() {
"$@" 2>/dev/null | awk 'NR == 1 { print $1 }'
}
# write_failed_report <label> <reason> <wc_ms> <fast_ms> — write the
# human readable failure report to FAILED-benchmark.txt.
write_failed_report() {
local label="$1" reason="$2" wc_ms="$3" fast_ms="$4"
local report="$SCRIPT_DIR/FAILED-benchmark.txt"
{
printf 'fastwc benchmark FAILED\n'
printf '=======================\n'
printf 'implementation : %s wc\n' "$BENCH_NAME"
printf 'failed test : %s\n' "$label"
printf 'failure : %s\n' "$reason"
printf '\nresults\n'
printf '%s\n' '-------'
printf '%-28s %10s %10s %8s %s\n' 'test' 'wc' 'fastwc' 'ratio' 'status'
printf '%s' "$RESULT_ROWS"
printf '\nfastwc must never be slower than %s wc — benchmark aborted.\n' "$BENCH_NAME"
} > "$report"
printf '\nbenchmark FAILED (%s): %s\n' "$BENCH_NAME" "$reason" >&2
printf 'full results written to %s\n' "$report" >&2
}
# run_case <words|lines> <n-lines> <-w|-l> — create (or reuse) the text file,
# then race the selected wc against fastwc. Fails the benchmark the moment
# fastwc is slower or reports a different count.
run_case() {
local mode="$1" lines="$2" flag="$3"
local noun='lines'; [[ "$lines" -eq 1 ]] && noun='line'
local label="${mode} (${lines} ${noun})"
local file wc_count fast_count wc_ms fast_ms ratio verdict reason row
local i d
file=$(createtxt "$lines") || return 1
# correctness: fastwc must report the same count as the reference wc
wc_count=$(capture_count "${WC_CMD[@]}" "$flag" "$file")
fast_count=$(capture_count "$FASTWC" "$flag" "$file")
# speed: interleaved timing so both commands see identical cache warmth;
# keep the minimum of $BENCH_REPS runs each to reduce noise
wc_ms=''
fast_ms=''
for ((i = 0; i < BENCH_REPS; i++)); do
d=$(time_ms "${WC_CMD[@]}" "$flag" "$file")
[[ -z "$wc_ms" || "$d" -lt "$wc_ms" ]] && wc_ms="$d"
d=$(time_ms "$FASTWC" "$flag" "$file")
[[ -z "$fast_ms" || "$d" -lt "$fast_ms" ]] && fast_ms="$d"
done
if [[ -n "$wc_ms" && "$wc_ms" -gt 0 ]]; then
ratio=$(awk -v f="$fast_ms" -v w="$wc_ms" 'BEGIN { printf "%.2fx", f / w }')
else
ratio='-'
fi
verdict='PASS'
reason=''
if [[ "$fast_count" != "$wc_count" ]]; then
verdict='FAIL'
reason="output mismatch (fastwc: ${fast_count}, ${BENCH_NAME} wc: ${wc_count})"
elif (( fast_ms > wc_ms )); then
verdict='FAIL'
reason="fastwc was slower (fastwc: ${fast_ms}ms vs ${BENCH_NAME} wc: ${wc_ms}ms)"
fi
row=$(printf '%-28s %10s %10s %8s %s\n' \
"$label" "wc: ${wc_ms}ms" "fastwc: ${fast_ms}ms" "$ratio" "$verdict")
RESULT_ROWS+="${row}"$'\n'
printf '%s\n' "$row"
if [[ "$verdict" == 'FAIL' ]]; then
write_failed_report "$label" "$reason" "$wc_ms" "$fast_ms"
return 1
fi
return 0
}
# run_benchmark_suite — run every word and line case for the wc selected by
# checkwc(). Returns non-zero the first time fastwc loses.
run_benchmark_suite() {
local rc=0 size
printf 'benchmarking %s wc vs fastwc (%s interleaved runs each, minimum kept)\n' \
"$BENCH_NAME" "$BENCH_REPS"
printf '%-28s %10s %10s %8s %s\n' 'test' 'wc' 'fastwc' 'ratio' 'status'
printf '%s\n' '--- words ---'
for size in 1 10 100 1000 10000 100000; do
run_case words "$size" -w || { rc=1; break; }
done
if [[ $rc -eq 0 ]]; then
printf '%s\n' '--- lines ---'
for size in 10000 100000 1000000 10000000; do
run_case lines "$size" -l || { rc=1; break; }
done
fi
if [[ $rc -eq 0 ]]; then
printf '\nall %s benchmarks passed — fastwc was never slower than %s wc\n' \
"$BENCH_NAME" "$BENCH_NAME"
fi
return $rc
}