# Patchwork - automated patch tracking system

# Copyright (C) 2008 Jeremy Kerr <jk@ozlabs.org>

# Copyright (C) 2015 Intel Corporation

#

# This file is part of the Patchwork package.

#

# Patchwork is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# Patchwork is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with Patchwork; if not, write to the Free Software

# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

from __future__ import absolute_import

import hashlib

import django

from django.db import models

from django.utils import six

if django.VERSION < (1, 8):

HashFieldBase = six.with_metaclass(models.SubfieldBase,

models.CharField) # noqa

else:

HashFieldBase = models.CharField

class HashField(HashFieldBase):

def __init__(self, *args, **kwargs):

self.n_bytes = len(hashlib.sha1().hexdigest())

kwargs['max_length'] = self.n_bytes

super(HashField, self).__init__(*args, **kwargs)

def construct(self, value):

if isinstance(value, six.text_type):

value = value.encode('utf-8')

return hashlib.sha1(value)

def from_db_value(self, value, *args, **kwargs):

return self.to_python(value)

def db_type(self, connection=None):

return 'char(%d)' % self.n_bytes