tests/testsat.py

   1 #!/usr/bin/env python
   2 from basetest import BaseTest
   3 import sys, os
   4 import unittest
   5
   6 sys.path.insert(0, '..')
   7 from zeroinstall.injector import model, arch, qdom
   8 from zeroinstall.injector.namespaces import XMLNS_IFACE
   9
  10 from zeroinstall.injector.solver import SATSolver as Solver
  11 from zeroinstall.injector import sat
  12
  13 import logging
  14 logger = logging.getLogger()
  15
  16 class Stores:
  17         def lookup_any(self, digests):
  18                 return "/"
  19
  20 stores = Stores()
  21
  22 uri_prefix = 'http://localhost/tests/'
  23
  24 class Version:
  25         def __init__(self, n):
  26                 self.n = n
  27                 self.requires = []
  28                 self.arch = None
  29
  30         def add_requires(self, lib, min_v, max_v):
  31                 self.requires.append((lib, min_v, max_v))
  32
  33 class Program:
  34         def __init__(self, name):
  35                 self.name = name
  36                 self.versions = {}
  37
  38         def get_version(self, version):
  39                 if version not in self.versions:
  40                         self.versions[version] = Version(version)
  41                 return self.versions[version]
  42
  43         def build_feed(self):
  44                 def child(parent, name, attrs = None):
  45                         new = qdom.Element(XMLNS_IFACE, name, attrs or {})
  46                         parent.childNodes.append(new)
  47                         return new
  48
  49                 root = qdom.Element(XMLNS_IFACE, 'interface', {'uri' : uri_prefix + self.name})
  50                 child(root, 'name').content = self.name
  51                 child(root, 'summary').content = self.name
  52
  53                 i = 0
  54                 for version in self.versions.values():
  55                         attrs = {
  56                                 'id': str(i),
  57                                 'version': str(version.n),
  58                         }
  59                         if version.arch:
  60                                 attrs['arch'] = version.arch
  61                         impl = child(root, 'implementation', attrs)
  62                         child(impl, 'manifest-digest', {'sha1new': '1234'})
  63                         for lib, min_v, max_v in version.requires:
  64                                 req = child(impl, 'requires', {'interface': uri_prefix + lib})
  65                                 child(req, 'version', {
  66                                         'before': str(int(max_v) + 1),
  67                                         'not-before': min_v})
  68                         i += 1
  69
  70                 feed = model.ZeroInstallFeed(root)
  71                 feed.last_modified = 1
  72                 return feed
  73
  74 class TestCache:
  75         def __init__(self):
  76                 self.progs = {}
  77                 self.interfaces = {}
  78                 self.feeds = {}
  79
  80         def get_prog(self, prog):
  81                 if not prog in self.progs:
  82                         self.progs[prog] = Program(prog)
  83                 return self.progs[prog]
  84
  85         def get_interface(self, uri):
  86                 if uri not in self.interfaces:
  87                         iface = model.Interface(uri)
  88                         self.interfaces[uri] = iface
  89                 return self.interfaces[uri]
  90
  91         def get_feed(self, url):
  92                 if url not in self.feeds:
  93                         feed = self.progs[url.rsplit('/', 1)[1]].build_feed()
  94                         self.feeds[url] = feed
  95                 return self.feeds[url]
  96
  97 def assertSelection(expected, repo):
  98         cache = TestCache()
  99
 100         expected = [tuple(e.strip().split('-')) for e in expected.split(",")]
 101
 102         for line in repo.split('\n'):
 103                 line = line.strip()
 104                 if not line: continue
 105                 if ':' in line:
 106                         prog, versions = line.split(':')
 107                         prog = prog.strip()
 108                         if ' ' in prog:
 109                                 prog, prog_arch = prog.split()
 110                         else:
 111                                 prog_arch = None
 112                         for v in versions.split():
 113                                 cache.get_prog(prog).get_version(v).arch = prog_arch
 114                 elif '=>' in line:
 115                         prog, requires = line.split('=>')
 116                         prog, version_range = prog.strip().split('[')
 117                         lib, min_v, max_v = requires.split()
 118                         assert version_range.endswith(']')
 119                         version_range = version_range[:-1]
 120                         if ',' in version_range:
 121                                 min_p, max_p = map(int, version_range.split(','))
 122                                 prog_versions = range(min_p, max_p + 1)
 123                         else:
 124                                 prog_versions = [int(version_range)]
 125                         for prog_version in prog_versions:
 126                                 cache.get_prog(prog).get_version(str(prog_version)).add_requires(lib, min_v, max_v)
 127
 128         root = uri_prefix + expected[0][0]
 129         s = Solver(model.network_offline, cache, stores)
 130         s.solve(root, arch.get_architecture('Linux', 'x86_64'))
 131
 132         if expected[0][1] == 'FAIL':
 133                 assert not s.ready
 134         else:
 135                 assert s.ready
 136
 137                 actual = []
 138                 for iface, impl in s.selections.iteritems():
 139                         actual.append(((iface.uri.rsplit('/', 1)[1]), impl.get_version()))
 140
 141                 expected.sort()
 142                 actual.sort()
 143                 if expected != actual:
 144                         raise Exception("Solve failed:\nExpected: %s\n  Actual: %s" % (expected, actual))
 145         return s
 146
 147 class TestSAT(BaseTest):
 148         def testTrivial(self):
 149                 assertSelection("prog-2", """
 150                         prog: 1 2
 151                         """)
 152
 153         def testSimple(self):
 154                 assertSelection("prog-5, liba-5", """
 155                         prog: 1 2 3 4 5
 156                         liba: 1 2 3 4 5
 157                         prog[1] => liba 0 4
 158                         prog[2] => liba 1 5
 159                         prog[5] => liba 4 5
 160                         """)
 161
 162         def testBestImpossible(self):
 163                 assertSelection("prog-1", """
 164                         prog: 1 2
 165                         liba: 1
 166                         prog[2] => liba 3 4
 167                         """)
 168
 169         def testSlow(self):
 170                 assertSelection("prog-1", """
 171                         prog: 1 2 3 4 5 6 7 8 9
 172                         liba: 1 2 3 4 5 6 7 8 9
 173                         libb: 1 2 3 4 5 6 7 8 9
 174                         libc: 1 2 3 4 5 6 7 8 9
 175                         libd: 1 2 3 4 5 6 7 8 9
 176                         libe: 1
 177                         prog[2,9] => liba 1 9
 178                         liba[1,9] => libb 1 9
 179                         libb[1,9] => libc 1 9
 180                         libc[1,9] => libd 1 9
 181                         libd[1,9] => libe 0 0
 182                         """)
 183
 184         def testNoSolution(self):
 185                 assertSelection("prog-FAIL", """
 186                         prog: 1 2 3
 187                         liba: 1
 188                         prog[1,3] => liba 2 3
 189                         """)
 190
 191         def testBacktrackSimple(self):
 192                 # We initially try liba-3 before learning that it
 193                 # is incompatible and backtracking.
 194                 # We learn that liba-3 doesn't work ever.
 195                 assertSelection("prog-1, liba-2", """
 196                         prog: 1
 197                         liba: 1 2 3
 198                         prog[1] => liba 1 2
 199                         """)
 200
 201         def testBacktrackLocal(self):
 202                 # We initially try liba-3 before learning that it
 203                 # is incompatible and backtracking.
 204                 # We learn that liba-3 doesn't work with prog-1.
 205                 assertSelection("prog-2, liba-2", """
 206                         prog: 1 2
 207                         liba: 1 2 3
 208                         prog[1,2] => liba 1 2
 209                         """)
 210
 211         def testLearning(self):
 212                 # Prog-2 depends on libb and libz, but we can't have both
 213                 # at once. The learning means we don't have to explore every
 214                 # possible combination of liba and libb.
 215                 assertSelection("prog-1", """
 216                         prog: 1 2
 217                         liba: 1 2 3
 218                         libb Linux-i486: 1 2 3
 219                         libz Linux-x86_64: 1 2
 220                         prog[2] => liba 1 3
 221                         prog[2] => libz 1 2
 222                         liba[1,3] => libb 1 3
 223                         """)
 224
 225         def testToplevelConflict(self):
 226                 # We don't detect the conflict until we start solving, but the
 227                 # conflict is top-level so we abort immediately without
 228                 # backtracking.
 229                 assertSelection("prog-FAIL", """
 230                         prog Linux-i386: 1
 231                         liba Linux-x86_64: 1
 232                         prog[1] => liba 1 1
 233                         """)
 234
 235         def testDiamondConflict(self):
 236                 # prog depends on liba and libb, which depend on incompatible
 237                 # versions of libc.
 238                 assertSelection("prog-FAIL", """
 239                         prog: 1
 240                         liba: 1
 241                         libb: 1
 242                         libc: 1 2
 243                         prog[1] => liba 1 1
 244                         prog[1] => libb 1 1
 245                         liba[1] => libc 1 1
 246                         libb[1] => libc 2 3
 247                         """)
 248
 249         def testCoverage(self):
 250                 # Try to trigger some edge cases...
 251
 252                 # An at_most_one clause must be analysed for causing
 253                 # a conflict.
 254                 solver = sat.SATProblem()
 255                 v1 = solver.add_variable("v1")
 256                 v2 = solver.add_variable("v2")
 257                 v3 = solver.add_variable("v3")
 258                 solver.at_most_one([v1, v2])
 259                 solver.add_clause([v1, sat.neg(v3)])
 260                 solver.add_clause([v2, sat.neg(v3)])
 261                 solver.add_clause([v1, v3])
 262                 solver.run_solver(lambda: v3)
 263
 264         def testFailState(self):
 265                 # If we can't select a valid combination,
 266                 # try to select as many as we can.
 267                 s = assertSelection("prog-FAIL", """
 268                         prog: 1 2
 269                         liba: 1 2
 270                         libb: 1 2
 271                         libc: 5
 272                         prog[1,2] => liba 1 2
 273                         liba[1,2] => libb 1 2
 274                         libb[1,2] => libc 0 0
 275                         """)
 276                 assert not s.ready
 277                 selected = {}
 278                 for iface, impl in s.selections.iteritems():
 279                         if impl is not None: impl = impl.get_version()
 280                         selected[iface.uri.rsplit('/', 1)[1]] = impl
 281                 self.assertEquals({
 282                         'prog': '2',
 283                         'liba': '2',
 284                         'libb': '2',
 285                         'libc': None
 286                 }, selected)
 287
 288         def testWatch(self):
 289                 solver = sat.SATProblem()
 290
 291                 a = solver.add_variable('a')
 292                 b = solver.add_variable('b')
 293                 c = solver.add_variable('c')
 294
 295                 # Add a clause. It starts watching the first two variables (a and b).
 296                 # (use the internal function to avoid variable reordering)
 297                 solver._add_clause([a, b, c], False)
 298
 299                 # b is False, so it switches to watching a and c
 300                 solver.add_clause([sat.neg(b)])
 301
 302                 # Try to trigger bug.
 303                 solver.add_clause([c])
 304
 305                 decisions = [a]
 306                 solver.run_solver(lambda: decisions.pop())
 307                 assert not decisions    # All used up
 308
 309                 assert solver.assigns[a].value == True
 310
 311         def testOverbacktrack(self):
 312                 # After learning that prog-3 => m0 we backtrack all the way up to the prog-3
 313                 # assignment, unselecting liba-3, and then select it again.
 314                 assertSelection("prog-3, liba-3, libb-3, libc-1, libz-2", """
 315                         prog: 1 2 3
 316                         liba: 1 2 3
 317                         libb: 1 2 3
 318                         libc Linux-x86_64: 2 3
 319                         libc Linux-i486: 1
 320                         libz Linux-i386: 1 2
 321                         prog[2,3] => liba 1 3
 322                         prog[2,3] => libz 1 2
 323                         liba[1,3] => libb 1 3
 324                         libb[1,3] => libc 1 3
 325                         """)
 326
 327 if __name__ == '__main__':
 328         unittest.main()