from __future__ import absolute_import
import hashlib
import logging
import sys
from pip.basecommand import Command
from pip.status_codes import ERROR
from pip.utils import read_chunks
from pip.utils.hashes import FAVORITE_HASH, STRONG_HASHES
logger = logging.getLogger(__name__)
class HashCommand(Command):
"""
Compute a hash of a local package archive.
These can be used with --hash in a requirements file to do repeatable
installs.
"""
name = 'hash'
usage = '%prog [options] <file> ...'
summary = 'Compute hashes of package archives.'
def __init__(self, *args, **kw):
super(HashCommand, self).__init__(*args, **kw)
self.cmd_opts.add_option(
'-a', '--algorithm',
dest='algorithm',
choices=STRONG_HASHES,
action='store',
default=FAVORITE_HASH,
help='The hash algorithm to use: one of %s' %
', '.join(STRONG_HASHES))
self.parser.insert_option_group(0, self.cmd_opts)
def run(self, options, args):
if not args:
self.parser.print_usage(sys.stderr)
return ERROR
algorithm = options.algorithm
for path in args:
logger.info('%s:\n--hash=%s:%s',
path, algorithm, _hash_of_file(path, algorithm))
def _hash_of_file(path, algorithm):
"""Return the hash digest of a file."""
with open(path, 'rb') as archive:
hash = hashlib.new(algorithm)
for chunk in read_chunks(archive):
hash.update(chunk)
return hash.hexdigest()
