formats.py

   1 import os
   2 from support import pipe_through_command
   3
   4 operations = []
   5 class Operation:
   6         add_extension = 0
   7
   8         def __init__(self, extension):
   9                 operations.append(self)
  10                 self.extension = extension
  11
  12         def can_handle(self, data):
  13                 return isinstance(data, FileData)
  14
  15         def save_to_stream(self, data, stream):
  16                 pipe_through_command(self.command, data.source, stream)
  17
  18 class Compress(Operation):
  19         "Compress a stream into another stream."
  20         add_extension = 1
  21
  22         def __init__(self, extension, command, type):
  23                 Operation.__init__(self, extension)
  24                 self.command = command
  25                 self.type = type
  26
  27         def __str__(self):
  28                 return 'Compress as .%s' % self.extension
  29
  30 class Decompress(Operation):
  31         "Decompress a stream into another stream."
  32         type = 'text/plain'
  33
  34         def __init__(self, extension, command):
  35                 Operation.__init__(self, extension)
  36                 self.command = command
  37
  38         def __str__(self):
  39                 return 'Decompress .%s' % self.extension
  40
  41 class Extract(Operation):
  42         "Extract an archive to a directory."
  43         type = 'inode/directory'
  44
  45         def __init__(self, extension, command):
  46                 Operation.__init__(self, extension)
  47                 self.command = command
  48
  49         def __str__(self):
  50                 return 'Extract from a .%s' % self.extension
  51
  52         def save_to_stream(self, data, stream):
  53                 raise Exception('This operation creates a directory, so you have '
  54                                 'to drag to a filer window on the local machine')
  55
  56         def save_to_file(self, data, path):
  57                 if os.path.exists(path):
  58                         if not os.path.isdir(path):
  59                                 raise Exception("'%s' already exists and is not a directory!" %
  60                                                 path)
  61                         if not rox.confirm('Directory already exists; extract into it?',
  62                                            g.STOCK_YES):
  63                                 raise Exception('Extraction aborted... try somewhere else')
  64                 if not os.path.exists(path):
  65                         os.mkdir(path)
  66                 os.chdir(path)
  67                 pipe_through_command(self.command, data.source, None)
  68
  69 class ExtractPath(Extract):
  70         "Extract an archive (which must be a file) to a directory."
  71         def save_to_file(self, data, path):
  72                 raise Exception('Not implemented yet')
  73
  74 class Archive(Operation):
  75         "Create an archive from a directory."
  76         add_extension = 1
  77
  78         def __init__(self, extension, command, type):
  79                 Operation.__init__(self, extension)
  80                 self.command = command
  81                 self.type = type
  82
  83         def __str__(self):
  84                 return 'Create .%s archive' % self.extension
  85
  86         def can_handle(self, data):
  87                 return isinstance(data, DirData)
  88
  89 tgz = Extract('tgz',    "gunzip -c - | tar xf -")
  90 tbz = Extract('tar.bz2', "bunzip2 -c - | tar xf -")
  91 zip = Extract('zip',    "unzip -")
  92 jar = Extract('jar',    "unzip -")
  93 rar = Extract('rar',    "rar x -")
  94 tar = Extract('tar',    "tar xf -")
  95 rpm = Extract('rpm',    "rpm2cpio - | cpio -id --quiet")
  96 cpio = Extract('cpio',  "cpio -id --quiet")
  97 deb = ExtractPath('deb', "ar x '%s'")
  98
  99 make_tgz = Archive('tgz', "tar cf - '%s' | gzip", 'application/x-compressed-tar')
 100 Archive('tar.gz',  "tar cf - '%s' | gzip", 'application/x-compressed-tar')
 101 Archive('tar.bz',  "tar cf - '%s' | bzip2", 'application/x-bzip-compressed-tar')
 102 Archive('tar.bz2', "tar cf - '%s' | bzip2", 'application/x-bzip-compressed-tar')
 103 Archive('zip',     "zip -r - '%s'", 'application/zip'),
 104 Archive('jar',     "zip -r - '%s'", 'application/x-jar')
 105 Archive('rar',     "rar a - '%s'", 'application/x-rar'),
 106 Archive('tar',     "tar cf - '%s'", 'application/x-tar')
 107
 108 # Note: these go afterwards so that .tar.gz matches before .gz
 109 make_gz = Compress('gz', "gzip -c -", 'application/x-gzip')
 110 Compress('bz2', "bzip2 -c -", 'application/x-bzip')
 111
 112 gz = Decompress('gz',   "gunzip -c -")
 113 bz2 = Decompress('bz2',  "bunzip2 -ck -")
 114
 115
 116 # Can bzip2 read bzip files?
 117
 118 aliases = {
 119         'tar.gz': 'tgz',
 120         'tar.bz': 'tar.bz2',
 121         'bz': 'bz2'
 122 }
 123
 124 known_extensions = {}
 125 for x in operations:
 126         try:
 127                 known_extensions[x.extension] = None
 128         except AttributeError:
 129                 pass
 130
 131 def guess_format(data):
 132         "Return a good default Operation, judging by the first 300 bytes or so."
 133         l = len(data)
 134         def string(offset, match):
 135                 return data[offset:offset + len(match)] == match
 136         def short(offset, match):
 137                 if l > offset + 1:
 138                         a = data[offset]
 139                         b = data[offset + 1]
 140                         return ((a == match & 0xff) and (b == (match >> 8))) or \
 141                                 (b == match & 0xff) and (a == (match >> 8))
 142                 return 0
 143
 144         # Archives
 145         if string(257, 'ustar\0') or string(257, 'ustar\040\040\0'):
 146                 return tar
 147         if short(0, 070707) or short(0, 0143561) or string(0, '070707') or \
 148            string(0, '070701') or string(0, '070702'):
 149                 return cpio
 150         if string(0, '!<arch>') or string(0, '\\<ar>') or string(0, '<ar>'):
 151                 if string(7, '\ndebian'):
 152                         return deb
 153         if string(0, 'Rar!'): return rar
 154         if string(0, 'PK\003\004'): return zip
 155
 156         # Compressed streams
 157         if string(0, '\037\213'): return gz
 158         if string(0, 'BZh'): return bz2
 159         if string(0, 'BZ'): return bz2  # bzip, but maybe bzip2 can cope?
 160
 161         return make_gz
 162
 163 class FileData:
 164         "A file on the local filesystem."
 165         def __init__(self, path):
 166                 self.path = path
 167
 168                 if path == '-':
 169                         source = sys.stdin
 170                 else:
 171                         try:
 172                                 source = file(path)
 173                         except:
 174                                 rox.report_exception()
 175                                 sys.exit(1)
 176
 177                 self.path = path
 178                 start = source.read(300)
 179                 try:
 180                         source.seek(0)
 181                         self.source = source
 182                 except:
 183                         print "(unseekable)"
 184                         # Input is not a regular, local, seekable file, so copy it
 185                         # to a local temp file.
 186                         import shutil
 187                         tmp = Tmp()
 188                         tmp.write(start)
 189                         shutil.copyfileobj(source, tmp)
 190                         self.source = tmp
 191                 self.default = guess_format(start)
 192
 193                 if path == '-':
 194                         name = 'Data'
 195                 else:
 196                         name = path
 197                         for ext in known_extensions:
 198                                 if path.endswith('.' + ext):
 199                                         new = path[:-len(ext)-1]
 200                                         if len(new) < len(name):
 201                                                 name = new
 202                 self.default_name = name
 203
 204 class DirData:
 205         def __init__(self, path):
 206                 self.path = path
 207                 self.default = make_tgz
 208                 self.default_name = path + self.default.extension