2 Parses an XML feed into a Python representation. You should probably use L{iface_cache.iface_cache} rather than the functions here.
5 # Copyright (C) 2009, Thomas Leonard
6 # See the README file for details, or visit http://0install.net.
8 from zeroinstall
import _
10 from logging
import debug
, info
, warn
12 from zeroinstall
.support
import basedir
13 from zeroinstall
.injector
import qdom
14 from zeroinstall
.injector
.namespaces
import config_site
, config_prog
, XMLNS_IFACE
15 from zeroinstall
.injector
.model
import Interface
, InvalidInterface
, ZeroInstallFeed
, escape
, Feed
, stability_levels
16 from zeroinstall
.injector
import model
18 def update_from_cache(interface
, iface_cache
= None):
19 """Read a cached interface and any native feeds or user overrides.
20 @param interface: the interface object to update
21 @type interface: L{model.Interface}
22 @return: True if cached version and user overrides loaded OK.
23 False if upstream not cached. Local interfaces (starting with /) are
24 always considered to be cached, although they are not actually stored in the cache.
25 Internal: use L{iface_cache.IfaceCache.get_interface} instread.
28 if iface_cache
is None:
29 from zeroinstall
.injector
import policy
30 iface_cache
= policy
.get_deprecated_singleton_config().iface_cache
32 # Add the distribution package manager's version, if any
33 path
= basedir
.load_first_data(config_site
, 'native_feeds', model
._pretty
_escape
(interface
.uri
))
35 # Resolve any symlinks
36 info(_("Adding native packager feed '%s'"), path
)
37 interface
.extra_feeds
.append(Feed(os
.path
.realpath(path
), None, False))
39 update_user_overrides(interface
)
41 main_feed
= iface_cache
.get_feed(interface
.uri
, force
= True)
43 update_user_feed_overrides(main_feed
)
45 return main_feed
is not None
47 def load_feed_from_cache(url
, selections_ok
= False):
48 """Load a feed. If the feed is remote, load from the cache. If local, load it directly.
49 @return: the feed, or None if it's remote and not cached."""
51 if os
.path
.isabs(url
):
52 debug(_("Loading local feed file '%s'"), url
)
53 return load_feed(url
, local
= True, selections_ok
= selections_ok
)
55 cached
= basedir
.load_first_cache(config_site
, 'interfaces', escape(url
))
57 debug(_("Loading cached information for %(interface)s from %(cached)s"), {'interface': url
, 'cached': cached
})
58 return load_feed(cached
, local
= False)
61 except InvalidInterface
, ex
:
65 def update_user_feed_overrides(feed
):
66 """Update a feed with user-supplied information.
67 Sets last_checked and user_stability ratings.
68 @param feed: feed to update
71 user
= basedir
.load_first_config(config_site
, config_prog
,
72 'feeds', model
._pretty
_escape
(feed
.url
))
74 # For files saved by 0launch < 0.49
75 user
= basedir
.load_first_config(config_site
, config_prog
,
76 'user_overrides', escape(feed
.url
))
81 root
= qdom
.parse(file(user
))
83 warn(_("Error reading '%(user)s': %(exception)s"), {'user': user
, 'exception': ex
})
86 last_checked
= root
.getAttribute('last-checked')
88 feed
.last_checked
= int(last_checked
)
90 for item
in root
.childNodes
:
91 if item
.uri
!= XMLNS_IFACE
: continue
92 if item
.name
== 'implementation':
93 id = item
.getAttribute('id')
95 impl
= feed
.implementations
.get(id, None)
97 debug(_("Ignoring user-override for unknown implementation %(id)s in %(interface)s"), {'id': id, 'interface': feed
})
100 user_stability
= item
.getAttribute('user-stability')
102 impl
.user_stability
= stability_levels
[str(user_stability
)]
104 def update_user_overrides(interface
):
105 """Update an interface with user-supplied information.
106 Sets preferred stability and updates extra_feeds.
107 @param interface: the interface object to update
108 @type interface: L{model.Interface}
110 user
= basedir
.load_first_config(config_site
, config_prog
,
111 'interfaces', model
._pretty
_escape
(interface
.uri
))
113 # For files saved by 0launch < 0.49
114 user
= basedir
.load_first_config(config_site
, config_prog
,
115 'user_overrides', escape(interface
.uri
))
120 root
= qdom
.parse(file(user
))
121 except Exception, ex
:
122 warn(_("Error reading '%(user)s': %(exception)s"), {'user': user
, 'exception': ex
})
125 stability_policy
= root
.getAttribute('stability-policy')
127 interface
.set_stability_policy(stability_levels
[str(stability_policy
)])
129 for item
in root
.childNodes
:
130 if item
.uri
!= XMLNS_IFACE
: continue
131 if item
.name
== 'feed':
132 feed_src
= item
.getAttribute('src')
134 raise InvalidInterface(_('Missing "src" attribute in <feed>'))
135 interface
.extra_feeds
.append(Feed(feed_src
, item
.getAttribute('arch'), True, langs
= item
.getAttribute('langs')))
137 def check_readable(feed_url
, source
):
138 """Test whether a feed file is valid.
139 @param feed_url: the feed's expected URL
141 @param source: the name of the file to test
143 @return: the modification time in src (usually just the mtime of the file)
145 @raise InvalidInterface: If the source's syntax is incorrect,
148 feed
= load_feed(source
, local
= False)
150 if feed
.url
!= feed_url
:
151 raise InvalidInterface(_("Incorrect URL used for feed.\n\n"
152 "%(feed_url)s is given in the feed, but\n"
153 "%(interface_uri)s was requested") %
154 {'feed_url': feed
.url
, 'interface_uri': feed_url
})
155 return feed
.last_modified
156 except InvalidInterface
, ex
:
157 info(_("Error loading feed:\n"
158 "Interface URI: %(uri)s\n"
159 "Local file: %(source)s\n"
161 {'uri': feed_url
, 'source': source
, 'exception': ex
})
162 raise InvalidInterface(_("Error loading feed '%(uri)s':\n\n%(exception)s") % {'uri': feed_url
, 'exception': ex
})
164 def update(interface
, source
, local
= False):
165 """Read in information about an interface.
167 @param interface: the interface object to update
168 @type interface: L{model.Interface}
169 @param source: the name of the file to read
171 @param local: use file's mtime for last-modified, and uri attribute is ignored
172 @raise InvalidInterface: if the source's syntax is incorrect
173 @return: the new feed (since 0.32)
174 @see: L{update_from_cache}, which calls this"""
175 assert isinstance(interface
, Interface
)
177 feed
= load_feed(source
, local
)
180 if feed
.url
!= interface
.uri
:
181 raise InvalidInterface(_("Incorrect URL used for feed.\n\n"
182 "%(feed_url)s is given in the feed, but\n"
183 "%(interface_uri)s was requested") %
184 {'feed_url': feed
.url
, 'interface_uri': interface
.uri
})
187 from zeroinstall
.injector
import policy
188 iface_cache
= policy
.get_deprecated_singleton_config().iface_cache
189 iface_cache
._feeds
[unicode(interface
.uri
)] = feed
193 def load_feed(source
, local
= False, selections_ok
= False):
194 """Load a feed from a local file.
195 @param source: the name of the file to read
197 @param local: this is a local feed
199 @param selections_ok: if it turns out to be a local selections document, return that instead
200 @type selections_ok: bool
201 @raise InvalidInterface: if the source's syntax is incorrect
202 @return: the new feed
204 @see: L{iface_cache.iface_cache}, which uses this to load the feeds"""
206 root
= qdom
.parse(file(source
))
209 raise InvalidInterface(_("Feed not found. Perhaps this is a local feed that no longer exists? You can remove it from the list of feeds in that case."), ex
)
210 raise InvalidInterface(_("Can't read file"), ex
)
211 except Exception, ex
:
212 raise InvalidInterface(_("Invalid XML"), ex
)
215 if selections_ok
and root
.uri
== XMLNS_IFACE
and root
.name
== 'selections':
216 from zeroinstall
.injector
import selections
217 return selections
.Selections(root
)
221 feed
= ZeroInstallFeed(root
, local_path
)
222 feed
.last_modified
= int(os
.stat(source
).st_mtime
)