branchcache: add a "pure topological head" fast path
In a narrow but actually quick common case, all topological heads are all on
the same branch and all open. In this case, computing the branch map is very
simple. We can quickly detect situation where this situation will not change.
So we update the V3 format to be able to express this situation and upgrade the
update code to detect we remains in that mode.
The branch cache is populated with the actual value when the branch map is
accessed, but the update_disk method can do the update without needing to
populate it.
#!/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.
#
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)