zeroinstall/injector/model.py

   1 """In-memory representation of interfaces and other data structures.
   2
   3 The objects in this module are used to build a representation of an XML interface
   4 file in memory.
   5
   6 @see: L{reader} constructs these data-structures
   7 @see: U{http://0install.net/interface-spec.html} description of the domain model
   8
   9 @var defaults: Default values for the 'default' attribute for <environment> bindings of
  10 well-known variables.
  11 """
  12
  13 # Copyright (C) 2009, Thomas Leonard
  14 # See the README file for details, or visit http://0install.net.
  15
  16 from zeroinstall import _
  17 import os, re, locale
  18 from logging import info, debug, warn
  19 from zeroinstall import SafeException, version
  20 from zeroinstall.injector.namespaces import XMLNS_IFACE
  21 from zeroinstall.injector import qdom
  22
  23 # Element names for bindings in feed files
  24 binding_names = frozenset(['environment', 'overlay'])
  25
  26 network_offline = 'off-line'
  27 network_minimal = 'minimal'
  28 network_full = 'full'
  29 network_levels = (network_offline, network_minimal, network_full)
  30
  31 stability_levels = {}   # Name -> Stability
  32
  33 defaults = {
  34         'PATH': '/bin:/usr/bin',
  35         'XDG_CONFIG_DIRS': '/etc/xdg',
  36         'XDG_DATA_DIRS': '/usr/local/share:/usr/share',
  37 }
  38
  39 class InvalidInterface(SafeException):
  40         """Raised when parsing an invalid feed."""
  41         feed_url = None
  42
  43         def __init__(self, message, ex = None):
  44                 if ex:
  45                         try:
  46                                 message += "\n\n(exact error: %s)" % ex
  47                         except:
  48                                 # Some Python messages have type str but contain UTF-8 sequences.
  49                                 # (e.g. IOException). Adding these to a Unicode 'message' (e.g.
  50                                 # after gettext translation) will cause an error.
  51                                 import codecs
  52                                 decoder = codecs.lookup('utf-8')
  53                                 decex = decoder.decode(str(ex), errors = 'replace')[0]
  54                                 message += "\n\n(exact error: %s)" % decex
  55
  56                 SafeException.__init__(self, message)
  57
  58         def __str__(self):
  59                 if self.feed_url:
  60                         return SafeException.__str__(self) + ' in ' + self.feed_url
  61                 return SafeException.__str__(self)
  62
  63 def _split_arch(arch):
  64         """Split an arch into an (os, machine) tuple. Either or both parts may be None."""
  65         if not arch:
  66                 return None, None
  67         elif '-' not in arch:
  68                 raise SafeException(_("Malformed arch '%s'") % arch)
  69         else:
  70                 osys, machine = arch.split('-', 1)
  71                 if osys == '*': osys = None
  72                 if machine == '*': machine = None
  73                 return osys, machine
  74
  75 def _join_arch(osys, machine):
  76         if osys == machine == None: return None
  77         return "%s-%s" % (osys or '*', machine or '*')
  78
  79 def _best_language_match(options):
  80         (language, encoding) = locale.getlocale(locale.LC_ALL)
  81         return (options.get(language, None) or
  82                 (language and options.get(language.split('_', 1)[0], None)) or
  83                 options.get(None, None))
  84
  85 class Stability(object):
  86         """A stability rating. Each implementation has an upstream stability rating and,
  87         optionally, a user-set rating."""
  88         __slots__ = ['level', 'name', 'description']
  89         def __init__(self, level, name, description):
  90                 self.level = level
  91                 self.name = name
  92                 self.description = description
  93                 assert name not in stability_levels
  94                 stability_levels[name] = self
  95
  96         def __cmp__(self, other):
  97                 return cmp(self.level, other.level)
  98
  99         def __str__(self):
 100                 return self.name
 101
 102         def __repr__(self):
 103                 return _("<Stability: %s>") % self.description
 104
 105 def process_binding(e):
 106         """Internal"""
 107         if e.name == 'environment':
 108                 mode = {
 109                         None: EnvironmentBinding.PREPEND,
 110                         'prepend': EnvironmentBinding.PREPEND,
 111                         'append': EnvironmentBinding.APPEND,
 112                         'replace': EnvironmentBinding.REPLACE,
 113                 }[e.getAttribute('mode')]
 114
 115                 binding = EnvironmentBinding(e.getAttribute('name'),
 116                                              insert = e.getAttribute('insert'),
 117                                              default = e.getAttribute('default'),
 118                                              value = e.getAttribute('value'),
 119                                              mode = mode)
 120                 if not binding.name: raise InvalidInterface(_("Missing 'name' in binding"))
 121                 if binding.insert is None and binding.value is None:
 122                         raise InvalidInterface(_("Missing 'insert' or 'value' in binding"))
 123                 if binding.insert is not None and binding.value is not None:
 124                         raise InvalidInterface(_("Binding contains both 'insert' and 'value'"))
 125                 return binding
 126         elif e.name == 'overlay':
 127                 return OverlayBinding(e.getAttribute('src'), e.getAttribute('mount-point'))
 128         else:
 129                 raise Exception(_("Unknown binding type '%s'") % e.name)
 130
 131 def process_depends(item, local_feed_dir):
 132         """Internal"""
 133         # Note: also called from selections
 134         attrs = item.attrs
 135         dep_iface = item.getAttribute('interface')
 136         if not dep_iface:
 137                 raise InvalidInterface(_("Missing 'interface' on <%s>") % item.name)
 138         if dep_iface.startswith('./'):
 139                 if local_feed_dir:
 140                         dep_iface = os.path.abspath(os.path.join(local_feed_dir, dep_iface))
 141                         # (updates the element too, in case we write it out again)
 142                         attrs['interface'] = dep_iface
 143                 else:
 144                         raise InvalidInterface(_('Relative interface URI "%s" in non-local feed') % dep_iface)
 145         dependency = InterfaceDependency(dep_iface, element = item)
 146
 147         for e in item.childNodes:
 148                 if e.uri != XMLNS_IFACE: continue
 149                 if e.name in binding_names:
 150                         dependency.bindings.append(process_binding(e))
 151                 elif e.name == 'version':
 152                         dependency.restrictions.append(
 153                                 VersionRangeRestriction(not_before = parse_version(e.getAttribute('not-before')),
 154                                                         before = parse_version(e.getAttribute('before'))))
 155         return dependency
 156
 157 def N_(message): return message
 158
 159 insecure = Stability(0, N_('insecure'), _('This is a security risk'))
 160 buggy = Stability(5, N_('buggy'), _('Known to have serious bugs'))
 161 developer = Stability(10, N_('developer'), _('Work-in-progress - bugs likely'))
 162 testing = Stability(20, N_('testing'), _('Stability unknown - please test!'))
 163 stable = Stability(30, N_('stable'), _('Tested - no serious problems found'))
 164 packaged = Stability(35, N_('packaged'), _('Supplied by the local package manager'))
 165 preferred = Stability(40, N_('preferred'), _('Best of all - must be set manually'))
 166
 167 del N_
 168
 169 class Restriction(object):
 170         """A Restriction limits the allowed implementations of an Interface."""
 171         __slots__ = []
 172
 173         def meets_restriction(self, impl):
 174                 """Called by the L{solver.Solver} to check whether a particular implementation is acceptable.
 175                 @return: False if this implementation is not a possibility
 176                 @rtype: bool
 177                 """
 178                 raise NotImplementedError(_("Abstract"))
 179
 180 class VersionRestriction(Restriction):
 181         """Only select implementations with a particular version number.
 182         @since: 0.40"""
 183
 184         def __init__(self, version):
 185                 """@param version: the required version number
 186                 @see: L{parse_version}; use this to pre-process the version number
 187                 """
 188                 self.version = version
 189
 190         def meets_restriction(self, impl):
 191                 return impl.version == self.version
 192
 193         def __str__(self):
 194                 return _("(restriction: version = %s)") % format_version(self.version)
 195
 196 class VersionRangeRestriction(Restriction):
 197         """Only versions within the given range are acceptable"""
 198         __slots__ = ['before', 'not_before']
 199
 200         def __init__(self, before, not_before):
 201                 """@param before: chosen versions must be earlier than this
 202                 @param not_before: versions must be at least this high
 203                 @see: L{parse_version}; use this to pre-process the versions
 204                 """
 205                 self.before = before
 206                 self.not_before = not_before
 207
 208         def meets_restriction(self, impl):
 209                 if self.not_before and impl.version < self.not_before:
 210                         return False
 211                 if self.before and impl.version >= self.before:
 212                         return False
 213                 return True
 214
 215         def __str__(self):
 216                 if self.not_before is not None or self.before is not None:
 217                         range = ''
 218                         if self.not_before is not None:
 219                                 range += format_version(self.not_before) + ' <= '
 220                         range += 'version'
 221                         if self.before is not None:
 222                                 range += ' < ' + format_version(self.before)
 223                 else:
 224                         range = 'none'
 225                 return _("(restriction: %s)") % range
 226
 227 class Binding(object):
 228         """Information about how the choice of a Dependency is made known
 229         to the application being run."""
 230
 231 class EnvironmentBinding(Binding):
 232         """Indicate the chosen implementation using an environment variable."""
 233         __slots__ = ['name', 'insert', 'default', 'mode', 'value']
 234
 235         PREPEND = 'prepend'
 236         APPEND = 'append'
 237         REPLACE = 'replace'
 238
 239         def __init__(self, name, insert, default = None, mode = PREPEND, value=None):
 240                 """
 241                 mode argument added in version 0.28
 242                 value argument added in version 0.52
 243                 """
 244                 self.name = name
 245                 self.insert = insert
 246                 self.default = default
 247                 self.mode = mode
 248                 self.value = value
 249
 250         def __str__(self):
 251                 return _("<environ %(name)s %(mode)s %(insert)s %(value)s>") % {'name': self.name,'mode':  self.mode, 'insert': self.insert, 'value': self.value}
 252
 253         __repr__ = __str__
 254
 255         def get_value(self, path, old_value):
 256                 """Calculate the new value of the environment variable after applying this binding.
 257                 @param path: the path to the selected implementation
 258                 @param old_value: the current value of the environment variable
 259                 @return: the new value for the environment variable"""
 260
 261                 if self.insert is not None:
 262                         extra = os.path.join(path, self.insert)
 263                 else:
 264                         assert self.value is not None
 265                         extra = self.value
 266
 267                 if self.mode == EnvironmentBinding.REPLACE:
 268                         return extra
 269
 270                 if old_value is None:
 271                         old_value = self.default or defaults.get(self.name, None)
 272                 if old_value is None:
 273                         return extra
 274                 if self.mode == EnvironmentBinding.PREPEND:
 275                         return extra + os.pathsep + old_value
 276                 else:
 277                         return old_value + os.pathsep + extra
 278
 279         def _toxml(self, doc):
 280                 """Create a DOM element for this binding.
 281                 @param doc: document to use to create the element
 282                 @return: the new element
 283                 """
 284                 env_elem = doc.createElementNS(XMLNS_IFACE, 'environment')
 285                 env_elem.setAttributeNS(None, 'name', self.name)
 286                 if self.insert is not None:
 287                         env_elem.setAttributeNS(None, 'insert', self.insert)
 288                 else:
 289                         env_elem.setAttributeNS(None, 'value', self.value)
 290                 if self.default:
 291                         env_elem.setAttributeNS(None, 'default', self.default)
 292                 return env_elem
 293
 294 class OverlayBinding(Binding):
 295         """Make the chosen implementation available by overlaying it onto another part of the file-system.
 296         This is to support legacy programs which use hard-coded paths."""
 297         __slots__ = ['src', 'mount_point']
 298
 299         def __init__(self, src, mount_point):
 300                 self.src = src
 301                 self.mount_point = mount_point
 302
 303         def __str__(self):
 304                 return _("<overlay %(src)s on %(mount_point)s>") % {'src': self.src or '.', 'mount_point': self.mount_point or '/'}
 305
 306         __repr__ = __str__
 307
 308         def _toxml(self, doc):
 309                 """Create a DOM element for this binding.
 310                 @param doc: document to use to create the element
 311                 @return: the new element
 312                 """
 313                 env_elem = doc.createElementNS(XMLNS_IFACE, 'overlay')
 314                 if self.src is not None:
 315                         env_elem.setAttributeNS(None, 'src', self.src)
 316                 if self.mount_point is not None:
 317                         env_elem.setAttributeNS(None, 'mount-point', self.mount_point)
 318                 return env_elem
 319
 320 class Feed(object):
 321         """An interface's feeds are other interfaces whose implementations can also be
 322         used as implementations of this interface."""
 323         __slots__ = ['uri', 'os', 'machine', 'user_override', 'langs']
 324         def __init__(self, uri, arch, user_override, langs = None):
 325                 self.uri = uri
 326                 # This indicates whether the feed comes from the user's overrides
 327                 # file. If true, writer.py will write it when saving.
 328                 self.user_override = user_override
 329                 self.os, self.machine = _split_arch(arch)
 330                 self.langs = langs
 331
 332         def __str__(self):
 333                 return "<Feed from %s>" % self.uri
 334         __repr__ = __str__
 335
 336         arch = property(lambda self: _join_arch(self.os, self.machine))
 337
 338 class Dependency(object):
 339         """A Dependency indicates that an Implementation requires some additional
 340         code to function. This is an abstract base class.
 341         @ivar qdom: the XML element for this Dependency (since 0launch 0.51)
 342         @type qdom: L{qdom.Element}
 343         @ivar metadata: any extra attributes from the XML element
 344         @type metadata: {str: str}
 345         """
 346         __slots__ = ['qdom']
 347
 348         def __init__(self, element):
 349                 assert isinstance(element, qdom.Element), type(element) # Use InterfaceDependency instead!
 350                 self.qdom = element
 351
 352         @property
 353         def metadata(self):
 354                 return self.qdom.attrs
 355
 356 class InterfaceDependency(Dependency):
 357         """A Dependency on a Zero Install interface.
 358         @ivar interface: the interface required by this dependency
 359         @type interface: str
 360         @ivar restrictions: a list of constraints on acceptable implementations
 361         @type restrictions: [L{Restriction}]
 362         @ivar bindings: how to make the choice of implementation known
 363         @type bindings: [L{Binding}]
 364         @since: 0.28
 365         """
 366         __slots__ = ['interface', 'restrictions', 'bindings']
 367
 368         def __init__(self, interface, restrictions = None, element = None):
 369                 Dependency.__init__(self, element)
 370                 assert isinstance(interface, (str, unicode))
 371                 assert interface
 372                 self.interface = interface
 373                 if restrictions is None:
 374                         self.restrictions = []
 375                 else:
 376                         self.restrictions = restrictions
 377                 self.bindings = []
 378
 379         def __str__(self):
 380                 return _("<Dependency on %(interface)s; bindings: %(bindings)s%(restrictions)s>") % {'interface': self.interface, 'bindings': self.bindings, 'restrictions': self.restrictions}
 381
 382 class RetrievalMethod(object):
 383         """A RetrievalMethod provides a way to fetch an implementation."""
 384         __slots__ = []
 385
 386 class DownloadSource(RetrievalMethod):
 387         """A DownloadSource provides a way to fetch an implementation."""
 388         __slots__ = ['implementation', 'url', 'size', 'extract', 'start_offset', 'type']
 389
 390         def __init__(self, implementation, url, size, extract, start_offset = 0, type = None):
 391                 self.implementation = implementation
 392                 self.url = url
 393                 self.size = size
 394                 self.extract = extract
 395                 self.start_offset = start_offset
 396                 self.type = type                # MIME type - see unpack.py
 397
 398 class Recipe(RetrievalMethod):
 399         """Get an implementation by following a series of steps.
 400         @ivar size: the combined download sizes from all the steps
 401         @type size: int
 402         @ivar steps: the sequence of steps which must be performed
 403         @type steps: [L{RetrievalMethod}]"""
 404         __slots__ = ['steps']
 405
 406         def __init__(self):
 407                 self.steps = []
 408
 409         size = property(lambda self: sum([x.size for x in self.steps]))
 410
 411 class DistributionSource(RetrievalMethod):
 412         """A package that is installed using the distribution's tools (including PackageKit).
 413         @ivar install: a function to call to install this package
 414         @type install: (L{handler.Handler}) -> L{tasks.Blocker}
 415         @ivar package_id: the package name, in a form recognised by the distribution's tools
 416         @type package_id: str
 417         @ivar size: the download size in bytes
 418         @type size: int
 419         @ivar needs_confirmation: whether the user should be asked to confirm before calling install()
 420         @type needs_confirmation: bool"""
 421
 422         __slots__ = ['package_id', 'size', 'install', 'needs_confirmation']
 423
 424         def __init__(self, package_id, size, install, needs_confirmation = True):
 425                 RetrievalMethod.__init__(self)
 426                 self.package_id = package_id
 427                 self.size = size
 428                 self.install = install
 429                 self.needs_confirmation = needs_confirmation
 430
 431 class Command(object):
 432         """A Command is a way of running an Implementation as a program."""
 433
 434         __slots__ = ['qdom', '_depends', '_local_dir', '_runner']
 435
 436         def __init__(self, qdom, local_dir):
 437                 """@param qdom: the <command> element
 438                 @param local_dir: the directory containing the feed (for relative dependencies), or None if not local
 439                 """
 440                 assert qdom.name == 'command', 'not <command>: %s' % qdom
 441                 self.qdom = qdom
 442                 self._local_dir = local_dir
 443                 self._depends = None
 444
 445         path = property(lambda self: self.qdom.attrs.get("path", None))
 446
 447         def _toxml(self, doc, prefixes):
 448                 return self.qdom.toDOM(doc, prefixes)
 449
 450         @property
 451         def requires(self):
 452                 if self._depends is None:
 453                         self._runner = None
 454                         depends = []
 455                         for child in self.qdom.childNodes:
 456                                 if child.name == 'requires':
 457                                         dep = process_depends(child, self._local_dir)
 458                                         depends.append(dep)
 459                                 elif child.name == 'runner':
 460                                         if self._runner:
 461                                                 raise InvalidInterface(_("Multiple <runner>s in <command>!"))
 462                                         dep = process_depends(child, self._local_dir)
 463                                         depends.append(dep)
 464                                         self._runner = dep
 465                         self._depends = depends
 466                 return self._depends
 467
 468         def get_runner(self):
 469                 self.requires           # (sets _runner)
 470                 return self._runner
 471
 472 class Implementation(object):
 473         """An Implementation is a package which implements an Interface.
 474         @ivar download_sources: list of methods of getting this implementation
 475         @type download_sources: [L{RetrievalMethod}]
 476         @ivar feed: the feed owning this implementation (since 0.32)
 477         @type feed: [L{ZeroInstallFeed}]
 478         @ivar bindings: how to tell this component where it itself is located (since 0.31)
 479         @type bindings: [Binding]
 480         @ivar upstream_stability: the stability reported by the packager
 481         @type upstream_stability: [insecure | buggy | developer | testing | stable | packaged]
 482         @ivar user_stability: the stability as set by the user
 483         @type upstream_stability: [insecure | buggy | developer | testing | stable | packaged | preferred]
 484         @ivar langs: natural languages supported by this package
 485         @type langs: str
 486         @ivar requires: interfaces this package depends on
 487         @type requires: [L{Dependency}]
 488         @ivar commands: ways to execute as a program
 489         @type commands: {str: Command}
 490         @ivar metadata: extra metadata from the feed
 491         @type metadata: {"[URI ]localName": str}
 492         @ivar id: a unique identifier for this Implementation
 493         @ivar version: a parsed version number
 494         @ivar released: release date
 495         @ivar local_path: the directory containing this local implementation, or None if it isn't local (id isn't a path)
 496         @type local_path: str | None
 497         @ivar requires_root_install: whether the user will need admin rights to use this
 498         @type requires_root_install: bool
 499         """
 500
 501         # Note: user_stability shouldn't really be here
 502
 503         __slots__ = ['upstream_stability', 'user_stability', 'langs',
 504                      'requires', 'metadata', 'download_sources', 'commands',
 505                      'id', 'feed', 'version', 'released', 'bindings', 'machine']
 506
 507         def __init__(self, feed, id):
 508                 assert id
 509                 self.feed = feed
 510                 self.id = id
 511                 self.user_stability = None
 512                 self.upstream_stability = None
 513                 self.metadata = {}      # [URI + " "] + localName -> value
 514                 self.requires = []
 515                 self.version = None
 516                 self.released = None
 517                 self.download_sources = []
 518                 self.langs = ""
 519                 self.machine = None
 520                 self.bindings = []
 521                 self.commands = {}
 522
 523         def get_stability(self):
 524                 return self.user_stability or self.upstream_stability or testing
 525
 526         def __str__(self):
 527                 return self.id
 528
 529         def __repr__(self):
 530                 return "v%s (%s)" % (self.get_version(), self.id)
 531
 532         def __cmp__(self, other):
 533                 """Newer versions come first"""
 534                 d = cmp(other.version, self.version)
 535                 if d: return d
 536                 # If the version number is the same, just give a stable sort order, and
 537                 # ensure that two different implementations don't compare equal.
 538                 d = cmp(other.feed.url, self.feed.url)
 539                 if d: return d
 540                 return cmp(other.id, self.id)
 541
 542         def get_version(self):
 543                 """Return the version as a string.
 544                 @see: L{format_version}
 545                 """
 546                 return format_version(self.version)
 547
 548         arch = property(lambda self: _join_arch(self.os, self.machine))
 549
 550         os = None
 551         local_path = None
 552         digests = None
 553         requires_root_install = False
 554
 555         def _get_main(self):
 556                 """"@deprecated: use commands["run"] instead"""
 557                 main = self.commands.get("run", None)
 558                 if main is not None:
 559                         return main.path
 560                 return None
 561         def _set_main(self, path):
 562                 """"@deprecated: use commands["run"] instead"""
 563                 if path is None:
 564                         if "run" in self.commands:
 565                                 del self.commands["run"]
 566                 else:
 567                         self.commands["run"] = Command(qdom.Element(XMLNS_IFACE, 'command', {'path': path}), None)
 568         main = property(_get_main, _set_main)
 569
 570         def is_available(self, stores):
 571                 """Is this Implementation available locally?
 572                 (a local implementation, an installed distribution package, or a cached ZeroInstallImplementation)
 573                 @rtype: bool
 574                 @since: 0.53
 575                 """
 576                 raise NotImplementedError("abstract")
 577
 578 class DistributionImplementation(Implementation):
 579         """An implementation provided by the distribution. Information such as the version
 580         comes from the package manager.
 581         @since: 0.28"""
 582         __slots__ = ['distro', 'installed']
 583
 584         def __init__(self, feed, id, distro):
 585                 assert id.startswith('package:')
 586                 Implementation.__init__(self, feed, id)
 587                 self.distro = distro
 588                 self.installed = False
 589
 590         @property
 591         def requires_root_install(self):
 592                 return not self.installed
 593
 594         def is_available(self, stores):
 595                 return self.installed
 596
 597 class ZeroInstallImplementation(Implementation):
 598         """An implementation where all the information comes from Zero Install.
 599         @ivar digests: a list of "algorith=value" strings (since 0.45)
 600         @type digests: [str]
 601         @since: 0.28"""
 602         __slots__ = ['os', 'size', 'digests', 'local_path']
 603
 604         def __init__(self, feed, id, local_path):
 605                 """id can be a local path (string starting with /) or a manifest hash (eg "sha1=XXX")"""
 606                 assert not id.startswith('package:'), id
 607                 Implementation.__init__(self, feed, id)
 608                 self.size = None
 609                 self.os = None
 610                 self.digests = []
 611                 self.local_path = local_path
 612
 613         # Deprecated
 614         dependencies = property(lambda self: dict([(x.interface, x) for x in self.requires
 615                                                    if isinstance(x, InterfaceDependency)]))
 616
 617         def add_download_source(self, url, size, extract, start_offset = 0, type = None):
 618                 """Add a download source."""
 619                 self.download_sources.append(DownloadSource(self, url, size, extract, start_offset, type))
 620
 621         def set_arch(self, arch):
 622                 self.os, self.machine = _split_arch(arch)
 623         arch = property(lambda self: _join_arch(self.os, self.machine), set_arch)
 624
 625         def is_available(self, stores):
 626                 if self.local_path is not None:
 627                         return os.path.exists(self.local_path)
 628                 if self.digests:
 629                         path = stores.lookup_maybe(self.digests)
 630                         return path is not None
 631                 return False    # (0compile creates fake entries with no digests)
 632
 633 class Interface(object):
 634         """An Interface represents some contract of behaviour.
 635         @ivar uri: the URI for this interface.
 636         @ivar stability_policy: user's configured policy.
 637         Implementations at this level or higher are preferred.
 638         Lower levels are used only if there is no other choice.
 639         """
 640         __slots__ = ['uri', 'stability_policy', 'extra_feeds']
 641
 642         implementations = property(lambda self: self._main_feed.implementations)
 643         name = property(lambda self: self._main_feed.name)
 644         description = property(lambda self: self._main_feed.description)
 645         summary = property(lambda self: self._main_feed.summary)
 646         last_modified = property(lambda self: self._main_feed.last_modified)
 647         feeds = property(lambda self: self.extra_feeds + self._main_feed.feeds)
 648         metadata = property(lambda self: self._main_feed.metadata)
 649
 650         last_checked = property(lambda self: self._main_feed.last_checked)
 651
 652         def __init__(self, uri):
 653                 assert uri
 654                 if uri.startswith('http:') or uri.startswith('https:') or os.path.isabs(uri):
 655                         self.uri = uri
 656                 else:
 657                         raise SafeException(_("Interface name '%s' doesn't start "
 658                                             "with 'http:' or 'https:'") % uri)
 659                 self.reset()
 660
 661         def _get_feed_for(self):
 662                 retval = {}
 663                 for key in self._main_feed.feed_for:
 664                         retval[key] = True
 665                 return retval
 666         feed_for = property(_get_feed_for)      # Deprecated (used by 0publish)
 667
 668         def reset(self):
 669                 self.extra_feeds = []
 670                 self.stability_policy = None
 671
 672         def get_name(self):
 673                 from zeroinstall.injector.iface_cache import iface_cache
 674                 feed = iface_cache.get_feed(self.uri)
 675                 if feed:
 676                         return feed.get_name()
 677                 return '(' + os.path.basename(self.uri) + ')'
 678
 679         def __repr__(self):
 680                 return _("<Interface %s>") % self.uri
 681
 682         def set_stability_policy(self, new):
 683                 assert new is None or isinstance(new, Stability)
 684                 self.stability_policy = new
 685
 686         def get_feed(self, url):
 687                 #import warnings
 688                 #warnings.warn("use iface_cache.get_feed instead", DeprecationWarning, 2)
 689                 for x in self.extra_feeds:
 690                         if x.uri == url:
 691                                 return x
 692                 #return self._main_feed.get_feed(url)
 693                 return None
 694
 695         def get_metadata(self, uri, name):
 696                 return self._main_feed.get_metadata(uri, name)
 697
 698         @property
 699         def _main_feed(self):
 700                 #import warnings
 701                 #warnings.warn("use the feed instead", DeprecationWarning, 3)
 702                 from zeroinstall.injector import policy
 703                 iface_cache = policy.get_deprecated_singleton_config().iface_cache
 704                 feed = iface_cache.get_feed(self.uri)
 705                 if feed is None:
 706                         return _dummy_feed
 707                 return feed
 708
 709 def _merge_attrs(attrs, item):
 710         """Add each attribute of item to a copy of attrs and return the copy.
 711         @type attrs: {str: str}
 712         @type item: L{qdom.Element}
 713         @rtype: {str: str}
 714         """
 715         new = attrs.copy()
 716         for a in item.attrs:
 717                 new[str(a)] = item.attrs[a]
 718         return new
 719
 720 def _get_long(elem, attr_name):
 721         val = elem.getAttribute(attr_name)
 722         if val is not None:
 723                 try:
 724                         val = long(val)
 725                 except ValueError:
 726                         raise SafeException(_("Invalid value for integer attribute '%(attribute_name)s': %(value)s") % {'attribute_name': attr_name, 'value': val})
 727         return val
 728
 729 class ZeroInstallFeed(object):
 730         """A feed lists available implementations of an interface.
 731         @ivar url: the URL for this feed
 732         @ivar implementations: Implementations in this feed, indexed by ID
 733         @type implementations: {str: L{Implementation}}
 734         @ivar name: human-friendly name
 735         @ivar summaries: short textual description (in various languages, since 0.49)
 736         @type summaries: {str: str}
 737         @ivar descriptions: long textual description (in various languages, since 0.49)
 738         @type descriptions: {str: str}
 739         @ivar last_modified: timestamp on signature
 740         @ivar last_checked: time feed was last successfully downloaded and updated
 741         @ivar feeds: list of <feed> elements in this feed
 742         @type feeds: [L{Feed}]
 743         @ivar feed_for: interfaces for which this could be a feed
 744         @type feed_for: set(str)
 745         @ivar metadata: extra elements we didn't understand
 746         """
 747         # _main is deprecated
 748         __slots__ = ['url', 'implementations', 'name', 'descriptions', 'summaries', '_package_implementations',
 749                      'last_checked', 'last_modified', 'feeds', 'feed_for', 'metadata']
 750
 751         def __init__(self, feed_element, local_path = None, distro = None):
 752                 """Create a feed object from a DOM.
 753                 @param feed_element: the root element of a feed file
 754                 @type feed_element: L{qdom.Element}
 755                 @param local_path: the pathname of this local feed, or None for remote feeds"""
 756                 self.implementations = {}
 757                 self.name = None
 758                 self.summaries = {}     # { lang: str }
 759                 self.descriptions = {}  # { lang: str }
 760                 self.last_modified = None
 761                 self.feeds = []
 762                 self.feed_for = set()
 763                 self.metadata = []
 764                 self.last_checked = None
 765                 self._package_implementations = []
 766
 767                 if distro is not None:
 768                         import warnings
 769                         warnings.warn("distro argument is now ignored", DeprecationWarning, 2)
 770
 771                 if feed_element is None:
 772                         return                  # XXX subclass?
 773
 774                 assert feed_element.name in ('interface', 'feed'), "Root element should be <interface>, not %s" % feed_element
 775                 assert feed_element.uri == XMLNS_IFACE, "Wrong namespace on root element: %s" % feed_element.uri
 776
 777                 main = feed_element.getAttribute('main')
 778                 #if main: warn("Setting 'main' on the root element is deprecated. Put it on a <group> instead")
 779
 780                 if local_path:
 781                         self.url = local_path
 782                         local_dir = os.path.dirname(local_path)
 783                 else:
 784                         self.url = feed_element.getAttribute('uri')
 785                         if not self.url:
 786                                 raise InvalidInterface(_("<interface> uri attribute missing"))
 787                         local_dir = None        # Can't have relative paths
 788
 789                 min_injector_version = feed_element.getAttribute('min-injector-version')
 790                 if min_injector_version:
 791                         if parse_version(min_injector_version) > parse_version(version):
 792                                 raise InvalidInterface(_("This feed requires version %(min_version)s or later of "
 793                                                         "Zero Install, but I am only version %(version)s. "
 794                                                         "You can get a newer version from http://0install.net") %
 795                                                         {'min_version': min_injector_version, 'version': version})
 796
 797                 for x in feed_element.childNodes:
 798                         if x.uri != XMLNS_IFACE:
 799                                 self.metadata.append(x)
 800                                 continue
 801                         if x.name == 'name':
 802                                 self.name = x.content
 803                         elif x.name == 'description':
 804                                 self.descriptions[x.attrs.get("http://www.w3.org/XML/1998/namespace lang", None)] = x.content
 805                         elif x.name == 'summary':
 806                                 self.summaries[x.attrs.get("http://www.w3.org/XML/1998/namespace lang", None)] = x.content
 807                         elif x.name == 'feed-for':
 808                                 feed_iface = x.getAttribute('interface')
 809                                 if not feed_iface:
 810                                         raise InvalidInterface(_('Missing "interface" attribute in <feed-for>'))
 811                                 self.feed_for.add(feed_iface)
 812                                 # Bug report from a Debian/stable user that --feed gets the wrong value.
 813                                 # Can't reproduce (even in a Debian/stable chroot), but add some logging here
 814                                 # in case it happens again.
 815                                 debug(_("Is feed-for %s"), feed_iface)
 816                         elif x.name == 'feed':
 817                                 feed_src = x.getAttribute('src')
 818                                 if not feed_src:
 819                                         raise InvalidInterface(_('Missing "src" attribute in <feed>'))
 820                                 if feed_src.startswith('http:') or feed_src.startswith('https:') or local_path:
 821                                         self.feeds.append(Feed(feed_src, x.getAttribute('arch'), False, langs = x.getAttribute('langs')))
 822                                 else:
 823                                         raise InvalidInterface(_("Invalid feed URL '%s'") % feed_src)
 824                         else:
 825                                 self.metadata.append(x)
 826
 827                 if not self.name:
 828                         raise InvalidInterface(_("Missing <name> in feed"))
 829                 if not self.summary:
 830                         raise InvalidInterface(_("Missing <summary> in feed"))
 831
 832                 def process_group(group, group_attrs, base_depends, base_bindings, base_commands):
 833                         for item in group.childNodes:
 834                                 if item.uri != XMLNS_IFACE: continue
 835
 836                                 if item.name not in ('group', 'implementation', 'package-implementation'):
 837                                         continue
 838
 839                                 depends = base_depends[:]
 840                                 bindings = base_bindings[:]
 841                                 commands = base_commands.copy()
 842
 843                                 item_attrs = _merge_attrs(group_attrs, item)
 844
 845                                 # We've found a group or implementation. Scan for dependencies
 846                                 # and bindings. Doing this here means that:
 847                                 # - We can share the code for groups and implementations here.
 848                                 # - The order doesn't matter, because these get processed first.
 849                                 # A side-effect is that the document root cannot contain
 850                                 # these.
 851                                 for child in item.childNodes:
 852                                         if child.uri != XMLNS_IFACE: continue
 853                                         if child.name == 'requires':
 854                                                 dep = process_depends(child, local_dir)
 855                                                 depends.append(dep)
 856                                         elif child.name == 'command':
 857                                                 command_name = child.attrs.get('name', None)
 858                                                 if not command_name:
 859                                                         raise InvalidInterface('Missing name for <command>')
 860                                                 commands[command_name] = Command(child, local_dir)
 861                                         elif child.name in binding_names:
 862                                                 bindings.append(process_binding(child))
 863
 864                                 for attr, command in [('main', 'run'),
 865                                                       ('self-test', 'test')]:
 866                                         value = item.attrs.get(attr, None)
 867                                         if value is not None:
 868                                                 commands[command] = Command(qdom.Element(XMLNS_IFACE, 'command', {'path': value}), None)
 869
 870                                 compile_command = item.attrs.get('http://zero-install.sourceforge.net/2006/namespaces/0compile command')
 871                                 if compile_command is not None:
 872                                         commands['compile'] = Command(qdom.Element(XMLNS_IFACE, 'command', {'shell-command': compile_command}), None)
 873
 874                                 if item.name == 'group':
 875                                         process_group(item, item_attrs, depends, bindings, commands)
 876                                 elif item.name == 'implementation':
 877                                         process_impl(item, item_attrs, depends, bindings, commands)
 878                                 elif item.name == 'package-implementation':
 879                                         if depends:
 880                                                 warn("A <package-implementation> with dependencies in %s!", self.url)
 881                                         self._package_implementations.append((item, item_attrs))
 882                                 else:
 883                                         assert 0
 884
 885                 def process_impl(item, item_attrs, depends, bindings, commands):
 886                         id = item.getAttribute('id')
 887                         if id is None:
 888                                 raise InvalidInterface(_("Missing 'id' attribute on %s") % item)
 889                         local_path = item_attrs.get('local-path')
 890                         if local_dir and local_path:
 891                                 abs_local_path = os.path.abspath(os.path.join(local_dir, local_path))
 892                                 impl = ZeroInstallImplementation(self, id, abs_local_path)
 893                         elif local_dir and (id.startswith('/') or id.startswith('.')):
 894                                 # For old feeds
 895                                 id = os.path.abspath(os.path.join(local_dir, id))
 896                                 impl = ZeroInstallImplementation(self, id, id)
 897                         else:
 898                                 impl = ZeroInstallImplementation(self, id, None)
 899                                 if '=' in id:
 900                                         # In older feeds, the ID was the (single) digest
 901                                         impl.digests.append(id)
 902                         if id in self.implementations:
 903                                 warn(_("Duplicate ID '%(id)s' in feed '%(feed)s'"), {'id': id, 'feed': self})
 904                         self.implementations[id] = impl
 905
 906                         impl.metadata = item_attrs
 907                         try:
 908                                 version_mod = item_attrs.get('version-modifier', None)
 909                                 if version_mod:
 910                                         item_attrs['version'] += version_mod
 911                                         del item_attrs['version-modifier']
 912                                 version = item_attrs['version']
 913                         except KeyError:
 914                                 raise InvalidInterface(_("Missing version attribute"))
 915                         impl.version = parse_version(version)
 916
 917                         impl.commands = commands
 918
 919                         impl.released = item_attrs.get('released', None)
 920                         impl.langs = item_attrs.get('langs', '')
 921
 922                         size = item.getAttribute('size')
 923                         if size:
 924                                 impl.size = long(size)
 925                         impl.arch = item_attrs.get('arch', None)
 926                         try:
 927                                 stability = stability_levels[str(item_attrs['stability'])]
 928                         except KeyError:
 929                                 stab = str(item_attrs['stability'])
 930                                 if stab != stab.lower():
 931                                         raise InvalidInterface(_('Stability "%s" invalid - use lower case!') % item_attrs.stability)
 932                                 raise InvalidInterface(_('Stability "%s" invalid') % item_attrs['stability'])
 933                         if stability >= preferred:
 934                                 raise InvalidInterface(_("Upstream can't set stability to preferred!"))
 935                         impl.upstream_stability = stability
 936
 937                         impl.bindings = bindings
 938                         impl.requires = depends
 939
 940                         for elem in item.childNodes:
 941                                 if elem.uri != XMLNS_IFACE: continue
 942                                 if elem.name == 'archive':
 943                                         url = elem.getAttribute('href')
 944                                         if not url:
 945                                                 raise InvalidInterface(_("Missing href attribute on <archive>"))
 946                                         size = elem.getAttribute('size')
 947                                         if not size:
 948                                                 raise InvalidInterface(_("Missing size attribute on <archive>"))
 949                                         impl.add_download_source(url = url, size = long(size),
 950                                                         extract = elem.getAttribute('extract'),
 951                                                         start_offset = _get_long(elem, 'start-offset'),
 952                                                         type = elem.getAttribute('type'))
 953                                 elif elem.name == 'manifest-digest':
 954                                         for aname, avalue in elem.attrs.iteritems():
 955                                                 if ' ' not in aname:
 956                                                         impl.digests.append('%s=%s' % (aname, avalue))
 957                                 elif elem.name == 'recipe':
 958                                         recipe = Recipe()
 959                                         for recipe_step in elem.childNodes:
 960                                                 if recipe_step.uri == XMLNS_IFACE and recipe_step.name == 'archive':
 961                                                         url = recipe_step.getAttribute('href')
 962                                                         if not url:
 963                                                                 raise InvalidInterface(_("Missing href attribute on <archive>"))
 964                                                         size = recipe_step.getAttribute('size')
 965                                                         if not size:
 966                                                                 raise InvalidInterface(_("Missing size attribute on <archive>"))
 967                                                         recipe.steps.append(DownloadSource(None, url = url, size = long(size),
 968                                                                         extract = recipe_step.getAttribute('extract'),
 969                                                                         start_offset = _get_long(recipe_step, 'start-offset'),
 970                                                                         type = recipe_step.getAttribute('type')))
 971                                                 else:
 972                                                         info(_("Unknown step '%s' in recipe; skipping recipe"), recipe_step.name)
 973                                                         break
 974                                         else:
 975                                                 impl.download_sources.append(recipe)
 976
 977                 root_attrs = {'stability': 'testing'}
 978                 root_commands = {}
 979                 if main:
 980                         info("Note: @main on document element is deprecated in %s", self)
 981                         root_commands['run'] = Command(qdom.Element(XMLNS_IFACE, 'command', {'path': main}), None)
 982                 process_group(feed_element, root_attrs, [], [], root_commands)
 983
 984         def get_distro_feed(self):
 985                 """Does this feed contain any <pacakge-implementation> elements?
 986                 i.e. is it worth asking the package manager for more information?
 987                 @return: the URL of the virtual feed, or None
 988                 @since: 0.49"""
 989                 if self._package_implementations:
 990                         return "distribution:" + self.url
 991                 return None
 992
 993         def get_package_impls(self, distro):
 994                 """Find the best <pacakge-implementation> element(s) for the given distribution.
 995                 @param distro: the distribution to use to rate them
 996                 @type distro: L{distro.Distribution}
 997                 @return: a list of tuples for the best ranked elements
 998                 @rtype: [str]
 999                 @since: 0.49"""
1000                 best_score = 0
1001                 best_impls = []
1002
1003                 for item, item_attrs in self._package_implementations:
1004                         distro_names = item_attrs.get('distributions', '')
1005                         for distro_name in distro_names.split(' '):
1006                                 score = distro.get_score(distro_name)
1007                                 if score > best_score:
1008                                         best_score = score
1009                                         best_impls = []
1010                                 if score == best_score:
1011                                         best_impls.append((item, item_attrs))
1012                 return best_impls
1013
1014         def get_name(self):
1015                 return self.name or '(' + os.path.basename(self.url) + ')'
1016
1017         def __repr__(self):
1018                 return _("<Feed %s>") % self.url
1019
1020         def set_stability_policy(self, new):
1021                 assert new is None or isinstance(new, Stability)
1022                 self.stability_policy = new
1023
1024         def get_feed(self, url):
1025                 for x in self.feeds:
1026                         if x.uri == url:
1027                                 return x
1028                 return None
1029
1030         def add_metadata(self, elem):
1031                 self.metadata.append(elem)
1032
1033         def get_metadata(self, uri, name):
1034                 """Return a list of interface metadata elements with this name and namespace URI."""
1035                 return [m for m in self.metadata if m.name == name and m.uri == uri]
1036
1037         @property
1038         def summary(self):
1039                 return _best_language_match(self.summaries)
1040
1041         @property
1042         def description(self):
1043                 return _best_language_match(self.descriptions)
1044
1045 class DummyFeed(object):
1046         """Temporary class used during API transition."""
1047         last_modified = None
1048         name = '-'
1049         last_checked = property(lambda self: None)
1050         implementations = property(lambda self: {})
1051         feeds = property(lambda self: [])
1052         summary = property(lambda self: '-')
1053         description = property(lambda self: '')
1054         def get_name(self): return self.name
1055         def get_feed(self, url): return None
1056         def get_metadata(self, uri, name): return []
1057 _dummy_feed = DummyFeed()
1058
1059 def unescape(uri):
1060         """Convert each %20 to a space, etc.
1061         @rtype: str"""
1062         uri = uri.replace('#', '/')
1063         if '%' not in uri: return uri
1064         return re.sub('%[0-9a-fA-F][0-9a-fA-F]',
1065                 lambda match: chr(int(match.group(0)[1:], 16)),
1066                 uri).decode('utf-8')
1067
1068 def escape(uri):
1069         """Convert each space to %20, etc
1070         @rtype: str"""
1071         return re.sub('[^-_.a-zA-Z0-9]',
1072                 lambda match: '%%%02x' % ord(match.group(0)),
1073                 uri.encode('utf-8'))
1074
1075 def _pretty_escape(uri):
1076         """Convert each space to %20, etc
1077         : is preserved and / becomes #. This makes for nicer strings,
1078         and may replace L{escape} everywhere in future.
1079         @rtype: str"""
1080         return re.sub('[^-_.a-zA-Z0-9:/]',
1081                 lambda match: '%%%02x' % ord(match.group(0)),
1082                 uri.encode('utf-8')).replace('/', '#')
1083
1084 def canonical_iface_uri(uri):
1085         """If uri is a relative path, convert to an absolute one.
1086         A "file:///foo" URI is converted to "/foo".
1087         An "alias:prog" URI expands to the URI in the 0alias script
1088         Otherwise, return it unmodified.
1089         @rtype: str
1090         @raise SafeException: if uri isn't valid
1091         """
1092         if uri.startswith('http://') or uri.startswith('https://'):
1093                 if uri.count("/") < 3:
1094                         raise SafeException(_("Missing / after hostname in URI '%s'") % uri)
1095                 return uri
1096         elif uri.startswith('file:///'):
1097                 return uri[7:]
1098         elif uri.startswith('alias:'):
1099                 from zeroinstall import alias, support
1100                 alias_prog = uri[6:]
1101                 if not os.path.isabs(alias_prog):
1102                         full_path = support.find_in_path(alias_prog)
1103                         if not full_path:
1104                                 raise alias.NotAnAliasScript("Not found in $PATH: " + alias_prog)
1105                 else:
1106                         full_path = alias_prog
1107                 interface_uri, main = alias.parse_script(full_path)
1108                 return interface_uri
1109         else:
1110                 iface_uri = os.path.realpath(uri)
1111                 if os.path.isfile(iface_uri):
1112                         return iface_uri
1113         raise SafeException(_("Bad interface name '%(uri)s'.\n"
1114                         "(doesn't start with 'http:', and "
1115                         "doesn't exist as a local file '%(interface_uri)s' either)") %
1116                         {'uri': uri, 'interface_uri': iface_uri})
1117
1118 _version_mod_to_value = {
1119         'pre': -2,
1120         'rc': -1,
1121         '': 0,
1122         'post': 1,
1123 }
1124
1125 # Reverse mapping
1126 _version_value_to_mod = {}
1127 for x in _version_mod_to_value: _version_value_to_mod[_version_mod_to_value[x]] = x
1128 del x
1129
1130 _version_re = re.compile('-([a-z]*)')
1131
1132 def parse_version(version_string):
1133         """Convert a version string to an internal representation.
1134         The parsed format can be compared quickly using the standard Python functions.
1135          - Version := DottedList ("-" Mod DottedList?)*
1136          - DottedList := (Integer ("." Integer)*)
1137         @rtype: tuple (opaque)
1138         @raise SafeException: if the string isn't a valid version
1139         @since: 0.24 (moved from L{reader}, from where it is still available):"""
1140         if version_string is None: return None
1141         parts = _version_re.split(version_string)
1142         if parts[-1] == '':
1143                 del parts[-1]   # Ends with a modifier
1144         else:
1145                 parts.append('')
1146         if not parts:
1147                 raise SafeException(_("Empty version string!"))
1148         l = len(parts)
1149         try:
1150                 for x in range(0, l, 2):
1151                         part = parts[x]
1152                         if part:
1153                                 parts[x] = map(int, parts[x].split('.'))
1154                         else:
1155                                 parts[x] = []   # (because ''.split('.') == [''], not [])
1156                 for x in range(1, l, 2):
1157                         parts[x] = _version_mod_to_value[parts[x]]
1158                 return parts
1159         except ValueError, ex:
1160                 raise SafeException(_("Invalid version format in '%(version_string)s': %(exception)s") % {'version_string': version_string, 'exception': ex})
1161         except KeyError, ex:
1162                 raise SafeException(_("Invalid version modifier in '%(version_string)s': %(exception)s") % {'version_string': version_string, 'exception': ex})
1163
1164 def format_version(version):
1165         """Format a parsed version for display. Undoes the effect of L{parse_version}.
1166         @see: L{Implementation.get_version}
1167         @rtype: str
1168         @since: 0.24"""
1169         version = version[:]
1170         l = len(version)
1171         for x in range(0, l, 2):
1172                 version[x] = '.'.join(map(str, version[x]))
1173         for x in range(1, l, 2):
1174                 version[x] = '-' + _version_value_to_mod[version[x]]
1175         if version[-1] == '-': del version[-1]
1176         return ''.join(version)
1177