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