tests/printenv.py

revlog: have an explicit "pack_header" method

Having to pass the version header when retrieving the binary version of every
single entry is a bit silly. So we extract that special logic in its own method.
This also prepare the move to newer revlog format, not storing the header within
an actual entry…

Differential Revision: https://phab.mercurial-scm.org/D10510

#!/usr/bin/env python3
#
# simple script to be used in hooks
#
# put something like this in the repo .hg/hgrc:
#
#     [hooks]
#     changegroup = python "$TESTDIR/printenv.py" <hookname> [exit] [output]
#
#   - <hookname> is a mandatory argument (e.g. "changegroup")
#   - [exit] is the exit code of the hook (default: 0)
#   - [output] is the name of the output file (default: use sys.stdout)
#              the file will be opened in append mode.
#
from __future__ import absolute_import
import argparse
import os
import sys

try:
    import msvcrt

    msvcrt.setmode(sys.stdin.fileno(), os.O_BINARY)
    msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
    msvcrt.setmode(sys.stderr.fileno(), os.O_BINARY)
except ImportError:
    pass

parser = argparse.ArgumentParser()
parser.add_argument("name", help="the hook name, used for display")
parser.add_argument(
    "exitcode",
    nargs="?",
    default=0,
    type=int,
    help="the exit code for the hook",
)
parser.add_argument(
    "out", nargs="?", default=None, help="where to write the output"
)
parser.add_argument(
    "--line",
    action="store_true",
    help="print environment variables one per line instead of on a single line",
)
args = parser.parse_args()

if args.out is None:
    out = sys.stdout
    out = getattr(out, "buffer", out)
else:
    out = open(args.out, "ab")

# variables with empty values may not exist on all platforms, filter
# them now for portability sake.
env = [(k, v) for k, v in os.environ.items() if k.startswith("HG_") and v]
env.sort()

out.write(b"%s hook: " % args.name.encode('ascii'))
if os.name == 'nt':
    filter = lambda x: x.replace('\\', '/')
else:
    filter = lambda x: x

vars = [
    b"%s=%s" % (k.encode('ascii'), filter(v).encode('ascii')) for k, v in env
]

# Print variables on out
if not args.line:
    out.write(b" ".join(vars))
else:
    for var in vars:
        out.write(var)
        out.write(b"\n")

out.write(b"\n")
out.close()

sys.exit(args.exitcode)