formats.py

   1 import os, sys
   2 from support import pipe_through_command
   3 import rox
   4
   5 operations = []
   6 class Operation:
   7         add_extension = 0
   8
   9         def __init__(self, extension):
  10                 operations.append(self)
  11                 self.extension = extension
  12
  13         def can_handle(self, data):
  14                 return isinstance(data, FileData)
  15
  16         def save_to_stream(self, data, stream):
  17                 pipe_through_command(self.command, data.source, stream)
  18
  19 class Compress(Operation):
  20         "Compress a stream into another stream."
  21         add_extension = 1
  22
  23         def __init__(self, extension, command, type):
  24                 Operation.__init__(self, extension)
  25                 self.command = command
  26                 self.type = type
  27
  28         def __str__(self):
  29                 return 'Compress as .%s' % self.extension
  30
  31 class Decompress(Operation):
  32         "Decompress a stream into another stream."
  33         type = 'text/plain'
  34
  35         def __init__(self, extension, command):
  36                 Operation.__init__(self, extension)
  37                 self.command = command
  38
  39         def __str__(self):
  40                 return 'Decompress .%s' % self.extension
  41
  42 class Extract(Operation):
  43         "Extract an archive to a directory."
  44         type = 'inode/directory'
  45
  46         def __init__(self, extension, command):
  47                 "If command has a %s then the source path is inserted, else uses stdin."
  48                 Operation.__init__(self, extension)
  49                 self.command = command
  50
  51         def __str__(self):
  52                 return 'Extract from a .%s' % self.extension
  53
  54         def save_to_stream(self, data, stream):
  55                 raise Exception('This operation creates a directory, so you have '
  56                                 'to drag to a filer window on the local machine')
  57
  58         def save_to_file(self, data, path):
  59                 if os.path.exists(path):
  60                         if not os.path.isdir(path):
  61                                 raise Exception("'%s' already exists and is not a directory!" %
  62                                                 path)
  63                         if not rox.confirm('Directory already exists; extract into it?',
  64                                            g.STOCK_YES):
  65                                 raise Exception('Extraction aborted... try somewhere else')
  66                 if not os.path.exists(path):
  67                         os.mkdir(path)
  68                 os.chdir(path)
  69                 command = self.command
  70                 if command.find('%s') != -1:
  71                         # TODO: Handle path being '-'
  72                         command = command % data.path
  73                 pipe_through_command(command, data.source, None)
  74
  75 class Archive(Operation):
  76         "Create an archive from a directory."
  77         add_extension = 1
  78
  79         def __init__(self, extension, command, type):
  80                 assert command.find("'%s'") != -1
  81
  82                 Operation.__init__(self, extension)
  83                 self.command = command
  84                 self.type = type
  85
  86         def __str__(self):
  87                 return 'Create .%s archive' % self.extension
  88
  89         def can_handle(self, data):
  90                 return isinstance(data, DirData)
  91
  92         def save_to_stream(self, data, stream):
  93                 os.chdir(os.path.dirname(data.path))
  94                 command = self.command % os.path.basename(data.path)
  95                 pipe_through_command(command, None, stream)
  96
  97 tgz = Extract('tgz',    "gunzip -c - | tar xf -")
  98 tbz = Extract('tar.bz2', "bunzip2 -c - | tar xf -")
  99 jar = Extract('jar',    "unzip -q -")
 100 rar = Extract('rar',    "rar x -")
 101 tar = Extract('tar',    "tar xf -")
 102 rpm = Extract('rpm',    "rpm2cpio - | cpio -id --quiet")
 103 cpio = Extract('cpio',  "cpio -id --quiet")
 104 deb = Extract('deb', "ar x '%s'")
 105 zip = Extract('zip', "unzip -q '%s'")
 106
 107 make_tgz = Archive('tgz', "tar cf - '%s' | gzip", 'application/x-compressed-tar')
 108 Archive('tar.gz',  "tar cf - '%s' | gzip", 'application/x-compressed-tar')
 109 Archive('tar.bz',  "tar cf - '%s' | bzip2", 'application/x-bzip-compressed-tar')
 110 Archive('tar.bz2', "tar cf - '%s' | bzip2", 'application/x-bzip-compressed-tar')
 111 Archive('zip',     "zip -qr - '%s'", 'application/zip'),
 112 Archive('jar',     "zip -qr - '%s'", 'application/x-jar')
 113 Archive('tar',     "tar cf - '%s'", 'application/x-tar')
 114
 115 # Note: these go afterwards so that .tar.gz matches before .gz
 116 make_gz = Compress('gz', "gzip -c -", 'application/x-gzip')
 117 Compress('bz2', "bzip2 -c -", 'application/x-bzip')
 118
 119 gz = Decompress('gz',   "gunzip -c -")
 120 bz2 = Decompress('bz2',  "bunzip2 -ck -")
 121
 122
 123 # Can bzip2 read bzip files?
 124
 125 aliases = {
 126         'tar.gz': 'tgz',
 127         'tar.bz': 'tar.bz2',
 128         'bz': 'bz2'
 129 }
 130
 131 known_extensions = {}
 132 for x in operations:
 133         try:
 134                 known_extensions[x.extension] = None
 135         except AttributeError:
 136                 pass
 137
 138 def guess_format(data):
 139         "Return a good default Operation, judging by the first 300 bytes or so."
 140         l = len(data)
 141         def string(offset, match):
 142                 return data[offset:offset + len(match)] == match
 143         def short(offset, match):
 144                 if l > offset + 1:
 145                         a = data[offset]
 146                         b = data[offset + 1]
 147                         return ((a == match & 0xff) and (b == (match >> 8))) or \
 148                                 (b == match & 0xff) and (a == (match >> 8))
 149                 return 0
 150
 151         # Archives
 152         if string(257, 'ustar\0') or string(257, 'ustar\040\040\0'):
 153                 return tar
 154         if short(0, 070707) or short(0, 0143561) or string(0, '070707') or \
 155            string(0, '070701') or string(0, '070702'):
 156                 return cpio
 157         if string(0, '!<arch>') or string(0, '\\<ar>') or string(0, '<ar>'):
 158                 if string(7, '\ndebian'):
 159                         return deb
 160         if string(0, 'Rar!'): return rar
 161         if string(0, 'PK\003\004'): return zip
 162
 163         # Compressed streams
 164         if string(0, '\037\213'): return gz
 165         if string(0, 'BZh'): return bz2
 166         if string(0, 'BZ'): return bz2  # bzip, but maybe bzip2 can cope?
 167
 168         return make_gz
 169
 170 class FileData:
 171         "A file on the local filesystem."
 172         def __init__(self, path):
 173                 self.path = path
 174
 175                 if path == '-':
 176                         source = sys.stdin
 177                 else:
 178                         try:
 179                                 source = file(path)
 180                         except:
 181                                 rox.report_exception()
 182                                 sys.exit(1)
 183
 184                 self.path = path
 185                 start = source.read(300)
 186                 try:
 187                         source.seek(0)
 188                         self.source = source
 189                 except:
 190                         print "(unseekable)"
 191                         # Input is not a regular, local, seekable file, so copy it
 192                         # to a local temp file.
 193                         import shutil
 194                         tmp = Tmp()
 195                         tmp.write(start)
 196                         shutil.copyfileobj(source, tmp)
 197                         self.source = tmp
 198                 self.default = guess_format(start)
 199
 200                 if path == '-':
 201                         name = 'Data'
 202                 else:
 203                         name = path
 204                         for ext in known_extensions:
 205                                 if path.endswith('.' + ext):
 206                                         new = path[:-len(ext)-1]
 207                                         if len(new) < len(name):
 208                                                 name = new
 209                 self.default_name = name
 210
 211 class DirData:
 212         def __init__(self, path):
 213                 self.path = path
 214                 self.default = make_tgz
 215                 self.default_name = path + '.' + self.default.extension