client/common_lib/kernel_versions.py

   1 #
   2 # kernel_versions.py -- linux kernel version comparisons
   3 #
   4 __author__ = """Copyright Andy Whitcroft 2007"""
   5
   6 import sys,re
   7
   8 #
   9 # Sort key for ordering versions chronologically.  The key ordering
  10 # problem is between that introduced by -rcN.  These come _before_
  11 # their accompanying version.
  12 #
  13 #   2.6.0 -> 2.6.1-rc1 -> 2.6.1
  14 #
  15 # In order to sort them we convert all non-rc releases to a pseudo
  16 # -rc99 release.  We also convert all numbers to two digits.  The
  17 # result is then sortable textually.
  18 #
  19 #   02.06.00-rc99 -> 02.06.01-rc01 -> 02.06.01-rc99
  20 #
  21 encode_sep = re.compile(r'(\D+)')
  22
  23 def version_encode(version):
  24     bits = encode_sep.split(version)
  25     n = 9
  26     if len(bits[0]) == 0:
  27         n += 2
  28     if len(bits) == n or (len(bits) > n and bits[n] != '_rc'):
  29         # Insert missing _rc99 after 2 . 6 . 18 -smp- 220 . 0
  30         bits.insert(n, '_rc')
  31         bits.insert(n+1, '99')
  32     n = 5
  33     if len(bits[0]) == 0:
  34         n += 2
  35     if len(bits) <= n or bits[n] != '-rc':
  36         bits.insert(n, '-rc')
  37         bits.insert(n+1, '99')
  38     for n in range(0, len(bits), 2):
  39         if len(bits[n]) == 1:
  40             bits[n] = '0' + bits[n]
  41
  42     return ''.join(bits)
  43
  44
  45 def version_limit(version, n):
  46     bits = encode_sep.split(version)
  47     return ''.join(bits[0:n])
  48
  49
  50 def version_len(version):
  51     return len(encode_sep.split(version))
  52
  53 #
  54 # Given a list of versions find the nearest version which is deemed
  55 # less than or equal to the target.  Versions are in linux order
  56 # as follows:
  57 #
  58 #   2.6.0 -> 2.6.1 -> 2.6.2-rc1 -> 2.6.2-rc2 -> 2.6.2 -> 2.6.3-rc1
  59 #              |        |\
  60 #              |        | 2.6.2-rc1-mm1 -> 2.6.2-rc1-mm2
  61 #              |        \
  62 #              |         2.6.2-rc1-ac1 -> 2.6.2-rc1-ac2
  63 #              \
  64 #               2.6.1-mm1 -> 2.6.1-mm2
  65 #
  66 # Note that a 2.6.1-mm1 is not a predecessor of 2.6.2-rc1-mm1.
  67 #
  68 def version_choose_config(version, candidates):
  69     # Check if we have an exact match ... if so magic
  70     if version in candidates:
  71         return version
  72
  73     # Sort the search key into the list ordered by 'age'
  74     deco = [ (version_encode(v), i, v) for i, v in
  75                                     enumerate(candidates + [ version ]) ]
  76     deco.sort()
  77     versions = [ v for _, _, v in deco ]
  78
  79     # Everything sorted below us is of interst.
  80     for n in range(len(versions) - 1, -1, -1):
  81         if versions[n] == version:
  82             break
  83     n -= 1
  84
  85     # Try ever shorter 'prefixes' 2.6.20-rc3-mm, 2.6.20-rc, 2.6. etc
  86     # to match against the ordered list newest to oldest.
  87     length = version_len(version) - 1
  88     version = version_limit(version, length)
  89     while length > 1:
  90         for o in range(n, -1, -1):
  91             if version_len(versions[o]) == (length + 1) and \
  92                                 version_limit(versions[o], length) == version:
  93                 return versions[o]
  94         length -= 2
  95         version = version_limit(version, length)
  96
  97     return None
  98
  99
 100 def is_released_kernel(version):
 101     # True if version name suggests a released kernel,
 102     #   not some release candidate or experimental kernel name
 103     #   e.g.  2.6.18-smp-200.0  includes no other text, underscores, etc
 104     version = version.strip('01234567890.-')
 105     return version in ['', 'smp', 'smpx', 'pae']
 106
 107
 108 def is_release_candidate(version):
 109     # True if version names a released kernel or release candidate,
 110     #   not some experimental name containing arbitrary text
 111     #   e.g.  2.6.18-smp-220.0_rc3  but not  2.6.18_patched
 112     version = re.sub(r'[_-]rc\d+', '', version)
 113     return is_released_kernel(version)