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 _
13 from logging
import info
, debug
15 from zeroinstall
.injector
import arch
, model
16 from zeroinstall
.injector
.model
import network_offline
17 from zeroinstall
.support
import tasks
20 """Chooses a set of implementations based on a policy.
22 1. Create a Driver object, giving it the requirements about the program to be run.
23 2. Call L{solve_with_downloads}. If more information is needed, a L{fetch.Fetcher} will be used to download it.
24 3. When all downloads are complete, the L{solver} contains the chosen versions.
25 4. Use L{get_uncached_implementations} to find where to get these versions and download them
26 using L{download_uncached_implementations}.
28 @ivar target_arch: target architecture for binaries
29 @type target_arch: L{arch.Architecture}
30 @ivar solver: solver used to choose a set of implementations
31 @type solver: L{solve.Solver}
32 @ivar watchers: callbacks to invoke after solving
34 __slots__
= ['watchers', 'requirements', 'config', 'target_arch', 'solver']
36 def __init__(self
, config
, requirements
):
38 @param config: The configuration settings to use
39 @type config: L{config.Config}
40 @param requirements: Details about the program we want to run
41 @type requirements: L{requirements.Requirements}
50 self
.requirements
= requirements
52 self
.target_arch
= arch
.get_architecture(requirements
.os
, requirements
.cpu
)
54 from zeroinstall
.injector
.solver
import DefaultSolver
55 self
.solver
= DefaultSolver(self
.config
)
57 debug(_("Supported systems: '%s'"), arch
.os_ranks
)
58 debug(_("Supported processors: '%s'"), arch
.machine_ranks
)
60 if requirements
.before
or requirements
.not_before
:
61 self
.solver
.extra_restrictions
[config
.iface_cache
.get_interface(requirements
.interface_uri
)] = [
62 model
.VersionRangeRestriction(model
.parse_version(requirements
.before
),
63 model
.parse_version(requirements
.not_before
))]
65 def get_uncached_implementations(self
):
66 """List all chosen implementations which aren't yet available locally.
67 @rtype: [(L{model.Interface}, L{model.Implementation})]"""
68 iface_cache
= self
.config
.iface_cache
69 stores
= self
.config
.stores
71 for uri
, selection
in self
.solver
.selections
.selections
.iteritems():
73 assert impl
, self
.solver
.selections
74 if not impl
.is_available(stores
):
75 uncached
.append((iface_cache
.get_interface(uri
), impl
))
79 def solve_with_downloads(self
, force
= False, update_local
= False):
80 """Run the solver, then download any feeds that are missing or
81 that need to be updated. Each time a new feed is imported into
82 the cache, the solver is run again, possibly adding new downloads.
83 @param force: whether to download even if we're already ready to run.
84 @param update_local: fetch PackageKit feeds even if we're ready to run."""
86 downloads_finished
= set() # Successful or otherwise
87 downloads_in_progress
= {} # URL -> Download
89 host_arch
= self
.target_arch
90 if self
.requirements
.source
:
91 host_arch
= arch
.SourceArchitecture(host_arch
)
93 # There are three cases:
94 # 1. We want to run immediately if possible. If not, download all the information we can.
95 # (force = False, update_local = False)
96 # 2. We're in no hurry, but don't want to use the network unnecessarily.
97 # We should still update local information (from PackageKit).
98 # (force = False, update_local = True)
99 # 3. The user explicitly asked us to refresh everything.
102 try_quick_exit
= not (force
or update_local
)
105 self
.solver
.solve(self
.requirements
.interface_uri
, host_arch
, command_name
= self
.requirements
.command
)
106 for w
in self
.watchers
: w()
108 if try_quick_exit
and self
.solver
.ready
:
110 try_quick_exit
= False
112 if not self
.solver
.ready
:
115 for f
in self
.solver
.feeds_used
:
116 if f
in downloads_finished
or f
in downloads_in_progress
:
120 self
.config
.iface_cache
.get_feed(f
, force
= True)
121 downloads_in_progress
[f
] = tasks
.IdleBlocker('Refresh local feed')
123 elif f
.startswith('distribution:'):
124 if force
or update_local
:
125 downloads_in_progress
[f
] = self
.config
.fetcher
.download_and_import_feed(f
, self
.config
.iface_cache
)
126 elif force
and self
.config
.network_use
!= network_offline
:
127 downloads_in_progress
[f
] = self
.config
.fetcher
.download_and_import_feed(f
, self
.config
.iface_cache
)
128 # Once we've starting downloading some things,
129 # we might as well get them all.
132 if not downloads_in_progress
:
133 if self
.config
.network_use
== network_offline
:
134 info(_("Can't choose versions and in off-line mode, so aborting"))
137 # Wait for at least one download to finish
138 blockers
= downloads_in_progress
.values()
143 tasks
.check(blockers
, self
.config
.handler
.report_error
)
145 for f
in downloads_in_progress
.keys():
146 if f
in downloads_in_progress
and downloads_in_progress
[f
].happened
:
147 del downloads_in_progress
[f
]
148 downloads_finished
.add(f
)
150 # Need to refetch any "distribution" feed that
151 # depends on this one
152 distro_feed_url
= 'distribution:' + f
153 if distro_feed_url
in downloads_finished
:
154 downloads_finished
.remove(distro_feed_url
)
155 if distro_feed_url
in downloads_in_progress
:
156 del downloads_in_progress
[distro_feed_url
]
159 def solve_and_download_impls(self
, refresh
= False, select_only
= False):
160 """Run L{solve_with_downloads} and then get the selected implementations too.
161 @raise SafeException: if we couldn't select a set of implementations
163 refreshed
= self
.solve_with_downloads(refresh
)
167 if not self
.solver
.ready
:
168 raise self
.solver
.get_failure_reason()
171 downloaded
= self
.download_uncached_implementations()
175 def need_download(self
):
176 """Decide whether we need to download anything (but don't do it!)
177 @return: true if we MUST download something (feeds or implementations)
179 host_arch
= self
.target_arch
180 if self
.requirements
.source
:
181 host_arch
= arch
.SourceArchitecture(host_arch
)
182 self
.solver
.solve(self
.requirements
.interface_uri
, host_arch
, command_name
= self
.requirements
.command
)
183 for w
in self
.watchers
: w()
185 if not self
.solver
.ready
:
186 return True # Maybe a newer version will work?
188 if self
.get_uncached_implementations():
193 def download_uncached_implementations(self
):
194 """Download all implementations chosen by the solver that are missing from the cache."""
195 assert self
.solver
.ready
, "Solver is not ready!\n%s" % self
.solver
.selections
196 stores
= self
.config
.stores
197 return self
.config
.fetcher
.download_impls([impl
for impl
in self
.solver
.selections
.values() if not impl
.is_available(stores
)],