2 This class brings together a L{solve.Solver} to choose a set of implmentations, a
3 L{fetch.Fetcher} to download additional components, and the user's configuration
8 # Copyright (C) 2011, Thomas Leonard
9 # See the README file for details, or visit http://0install.net.
11 from zeroinstall
import _
, logger
14 from zeroinstall
.injector
import arch
, model
15 from zeroinstall
.injector
.model
import network_offline
16 from zeroinstall
.support
import tasks
19 """Chooses a set of implementations based on a policy.
21 1. Create a Driver object, giving it the requirements about the program to be run.
22 2. Call L{solve_with_downloads}. If more information is needed, a L{fetch.Fetcher} will be used to download it.
23 3. When all downloads are complete, the L{solver} contains the chosen versions.
24 4. Use L{get_uncached_implementations} to find where to get these versions and download them
25 using L{download_uncached_implementations}.
27 @ivar target_arch: target architecture for binaries (deprecated)
28 @type target_arch: L{arch.Architecture}
29 @ivar solver: solver used to choose a set of implementations
30 @type solver: L{solve.Solver}
31 @ivar watchers: callbacks to invoke after solving
33 __slots__
= ['watchers', 'requirements', 'config', 'target_arch', 'solver']
35 def __init__(self
, config
, requirements
):
37 @param config: The configuration settings to use
38 @type config: L{config.Config}
39 @param requirements: Details about the program we want to run
40 @type requirements: L{requirements.Requirements}
49 self
.requirements
= requirements
51 self
.target_arch
= arch
.get_architecture(requirements
.os
, requirements
.cpu
)
53 from zeroinstall
.injector
.solver
import DefaultSolver
54 self
.solver
= DefaultSolver(self
.config
)
56 logger
.debug(_("Supported systems: '%s'"), arch
.os_ranks
)
57 logger
.debug(_("Supported processors: '%s'"), arch
.machine_ranks
)
59 if requirements
.before
or requirements
.not_before
:
60 self
.solver
.extra_restrictions
[config
.iface_cache
.get_interface(requirements
.interface_uri
)] = [
61 model
.VersionRangeRestriction(model
.parse_version(requirements
.before
),
62 model
.parse_version(requirements
.not_before
))]
64 def get_uncached_implementations(self
):
65 """List all chosen implementations which aren't yet available locally.
66 @rtype: [(L{model.Interface}, L{model.Implementation})]"""
67 iface_cache
= self
.config
.iface_cache
68 stores
= self
.config
.stores
70 for uri
, selection
in self
.solver
.selections
.selections
.items():
72 assert impl
, self
.solver
.selections
73 if not impl
.is_available(stores
):
74 uncached
.append((iface_cache
.get_interface(uri
), impl
))
78 def solve_with_downloads(self
, force
= False, update_local
= False):
79 """Run the solver, then download any feeds that are missing or
80 that need to be updated. Each time a new feed is imported into
81 the cache, the solver is run again, possibly adding new downloads.
82 @param force: whether to download even if we're already ready to run.
83 @param update_local: fetch PackageKit feeds even if we're ready to run."""
85 downloads_finished
= set() # Successful or otherwise
86 downloads_in_progress
= {} # URL -> Download
88 # There are three cases:
89 # 1. We want to run immediately if possible. If not, download all the information we can.
90 # (force = False, update_local = False)
91 # 2. We're in no hurry, but don't want to use the network unnecessarily.
92 # We should still update local information (from PackageKit).
93 # (force = False, update_local = True)
94 # 3. The user explicitly asked us to refresh everything.
97 try_quick_exit
= not (force
or update_local
)
100 self
.solver
.solve_for(self
.requirements
)
101 for w
in self
.watchers
: w()
103 if try_quick_exit
and self
.solver
.ready
:
105 try_quick_exit
= False
107 if not self
.solver
.ready
:
110 for f
in self
.solver
.feeds_used
:
111 if f
in downloads_finished
or f
in downloads_in_progress
:
115 self
.config
.iface_cache
.get_feed(f
, force
= True)
116 downloads_in_progress
[f
] = tasks
.IdleBlocker('Refresh local feed')
118 elif f
.startswith('distribution:'):
119 if force
or update_local
:
120 downloads_in_progress
[f
] = self
.config
.fetcher
.download_and_import_feed(f
, self
.config
.iface_cache
)
121 elif force
and self
.config
.network_use
!= network_offline
:
122 downloads_in_progress
[f
] = self
.config
.fetcher
.download_and_import_feed(f
, self
.config
.iface_cache
)
123 # Once we've starting downloading some things,
124 # we might as well get them all.
127 if not downloads_in_progress
:
128 if self
.config
.network_use
== network_offline
:
129 logger
.info(_("Can't choose versions and in off-line mode, so aborting"))
132 # Wait for at least one download to finish
133 blockers
= downloads_in_progress
.values()
135 tasks
.check(blockers
, self
.config
.handler
.report_error
)
137 for f
in list(downloads_in_progress
.keys()):
138 if f
in downloads_in_progress
and downloads_in_progress
[f
].happened
:
139 del downloads_in_progress
[f
]
140 downloads_finished
.add(f
)
142 # Need to refetch any "distribution" feed that
143 # depends on this one
144 distro_feed_url
= 'distribution:' + f
145 if distro_feed_url
in downloads_finished
:
146 downloads_finished
.remove(distro_feed_url
)
147 if distro_feed_url
in downloads_in_progress
:
148 del downloads_in_progress
[distro_feed_url
]
151 def solve_and_download_impls(self
, refresh
= False, select_only
= False):
152 """Run L{solve_with_downloads} and then get the selected implementations too.
153 @raise SafeException: if we couldn't select a set of implementations
155 refreshed
= self
.solve_with_downloads(refresh
)
158 tasks
.check(refreshed
)
160 if not self
.solver
.ready
:
161 raise self
.solver
.get_failure_reason()
164 downloaded
= self
.download_uncached_implementations()
167 tasks
.check(downloaded
)
169 def need_download(self
):
170 """Decide whether we need to download anything (but don't do it!)
171 @return: true if we MUST download something (feeds or implementations)
173 self
.solver
.solve_for(self
.requirements
)
174 for w
in self
.watchers
: w()
176 if not self
.solver
.ready
:
177 return True # Maybe a newer version will work?
179 if self
.get_uncached_implementations():
184 def download_uncached_implementations(self
):
185 """Download all implementations chosen by the solver that are missing from the cache."""
186 assert self
.solver
.ready
, "Solver is not ready!\n%s" % self
.solver
.selections
187 stores
= self
.config
.stores
188 return self
.config
.fetcher
.download_impls([impl
for impl
in self
.solver
.selections
.values() if not impl
.is_available(stores
)],