Save a performance experiment with PyPy.

Summary: PyPy runs the OSH parser more slowly than CPython.

This wasn't that surprising since it's a string-based workload.  Saving
it anyway.

benchmarks/fake_libc.py

@@ -0,0 +1,14 @@
#!/usr/bin/python
"""
fake_libc.py

For PyPy.
"""

def regex_parse(regex_str):
  return True

# This makes things fall through to the first case statement...
def fnmatch(s, to_match):
  return True

benchmarks/pypy.sh

@@ -0,0 +1,35 @@
#!/bin/bash
#
# Summary: PyPy is slower than CPython for parsing.  (I bet it also uses more
# memory, although I didn't measure that.)
#
# I don't plan on using PyPy, but this is simple enough to save for posterity.
#
# Usage:
#   ./pypy.sh <function name>

set -o nounset
set -o pipefail
set -o errexit

readonly PYPY=~/install/pypy2-v5.9.0-linux64/bin/pypy

parse-abuild() {
  local vm=$1
  time $vm bin/oil.py osh -n ~/git/alpine/abuild/abuild >/dev/null
}

# ~3.5 seconds
parse-with-cpython() {
  parse-abuild python
}

# ~4.8 seconds
# NOTE: We could run it in a loop to see if the JIT warms up, but that would
# only be for curiousity.  Most shell processes are short-lived, so it's the
# wrong thing to optimize for.
parse-with-pypy() {
  parse-abuild $PYPY
}

"$@"

core/cmd_exec.py

@@ -39,7 +39,10 @@
from osh import ast_ as ast
from osh import parse_lib

import libc  # for fnmatch
try:
  import libc  # for fnmatch
except ImportError:
  from benchmarks import fake_libc as libc

EBuiltin = builtin.EBuiltin

core/expr_eval.py

@@ -12,7 +12,10 @@
import os
import stat

import libc  # for fnmatch
try:
  import libc  # for fnmatch
except ImportError:
  from benchmarks import fake_libc as libc

from core.id_kind import BOOL_OPS, OperandType, Id, IdName
from core import util

core/glob_.py

@@ -5,7 +5,10 @@

import re

import libc
try:
  import libc
except ImportError:
  from benchmarks import fake_libc as libc

from core.util import log

osh/bool_parse.py

@@ -42,7 +42,10 @@

from osh.lex import LexMode

import libc  # for regex_parse
try:
  import libc  # for regex_parse
except ImportError:
  from benchmarks import fake_libc as libc

log = util.log