blob: 12470695c5ed9006338dc658675f14c4f816eef4 [file] [log] [blame]
#!/usr/bin/env python
# Copyright 2017 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
def compare_int(left, right):
if left == right:
return 0
return -1 if left < right else 1
def compare_char(left, right):
# 'man deb-version' specifies that characters are compared using
# their ASCII values, except alphabetic characters come before
# special characters and ~ comes before everything else.
table = '~$ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz+-.:'
left = table.find(left)
right = table.find(right)
assert left >= 0 and right >= 0
return compare_int(left, right)
def compare_part(left, right):
if isinstance(left, int) and isinstance(right, int):
return compare_int(left, right)
assert isinstance(left, (str, unicode)) and isinstance(right, (str, unicode))
# 'man deb-version' specifies that '~' should be matched before the
# empty string. Add a '$' to the end of the strings to make this
# comparison easier.
left += '$'
right += '$'
i = 0
while i < len(left) and i < len(right):
comp = compare_char(left[i], right[i])
if comp != 0:
return comp
i += 1
return compare_int(len(left), len(right))
def get_parts_from_component(component):
# 'man deb-version' specifies that components should be compared
# part-by-part, where parts are either strings or numbers. Strings
# are compared lexicographically while numbers are compared using
# magnitude. Components must start with a string part and end with
# a number part. The empty string will be prepended and 0 will be
# appended to satisfy this requirement. For example, the component
# '1.2.3' will be expanded to ['', 1, '.', 2, '.', 3], and the empty
# component will be expanded to ['', 0].
part_is_string = True
parts = []
part = ''
for c in component:
char_is_string = not c.isdigit()
if char_is_string != part_is_string:
parts.append(part if part_is_string else int(part))
part = ''
part_is_string = char_is_string
part += c
if part_is_string:
parts.append(part)
part = ''
parts.append(0 if part == '' else int(part))
return parts
def compare_component(left, right):
i = 0
left = get_parts_from_component(left)
right = get_parts_from_component(right)
while i < len(left) and i < len(right):
comp = compare_part(left[i], right[i])
if comp != 0:
return comp
i += 1
return compare_int(len(left), len(right))
class DebVersion:
def __init__(self, version_string):
self.version_string = version_string
self.epoch = 0
self.upstream_version = ''
self.debian_revision = None
colon = version_string.find(':')
if colon >= 0:
self.epoch = int(version_string[:colon])
hyphen = version_string.rfind('-')
if hyphen >= 0:
self.debian_revision = version_string[hyphen + 1:]
upstream_version_start = colon + 1
upstream_version_end = hyphen if hyphen >= 0 else len(version_string)
self.upstream_version = version_string[upstream_version_start:
upstream_version_end]
def __str__(self):
return self.version_string
# Comparison algorithm is specified in 'man deb-version'.
def __cmp__(self, other):
assert(isinstance(other, DebVersion))
# Epoch comparison.
if self.epoch != other.epoch:
return 1 if self.epoch > other.epoch else -1
# Upstream version comparison.
upstream_version_cmp = compare_component(self.upstream_version,
other.upstream_version)
if upstream_version_cmp != 0:
return upstream_version_cmp
# Debian revision comparison.
if self.debian_revision == None and other.debian_revision == None:
return 0
if self.debian_revision == None:
return -1
if other.debian_revision == None:
return 1
return compare_component(self.debian_revision, other.debian_revision)