LSST Applications  21.0.0-147-g0e635eb1+1acddb5be5,22.0.0+052faf71bd,22.0.0+1ea9a8b2b2,22.0.0+6312710a6c,22.0.0+729191ecac,22.0.0+7589c3a021,22.0.0+9f079a9461,22.0.1-1-g7d6de66+b8044ec9de,22.0.1-1-g87000a6+536b1ee016,22.0.1-1-g8e32f31+6312710a6c,22.0.1-10-gd060f87+016f7cdc03,22.0.1-12-g9c3108e+df145f6f68,22.0.1-16-g314fa6d+c825727ab8,22.0.1-19-g93a5c75+d23f2fb6d8,22.0.1-19-gb93eaa13+aab3ef7709,22.0.1-2-g8ef0a89+b8044ec9de,22.0.1-2-g92698f7+9f079a9461,22.0.1-2-ga9b0f51+052faf71bd,22.0.1-2-gac51dbf+052faf71bd,22.0.1-2-gb66926d+6312710a6c,22.0.1-2-gcb770ba+09e3807989,22.0.1-20-g32debb5+b8044ec9de,22.0.1-23-gc2439a9a+fb0756638e,22.0.1-3-g496fd5d+09117f784f,22.0.1-3-g59f966b+1e6ba2c031,22.0.1-3-g849a1b8+f8b568069f,22.0.1-3-gaaec9c0+c5c846a8b1,22.0.1-32-g5ddfab5d3+60ce4897b0,22.0.1-4-g037fbe1+64e601228d,22.0.1-4-g8623105+b8044ec9de,22.0.1-5-g096abc9+d18c45d440,22.0.1-5-g15c806e+57f5c03693,22.0.1-7-gba73697+57f5c03693,master-g6e05de7fdc+c1283a92b8,master-g72cdda8301+729191ecac,w.2021.39
LSST Data Management Base Package
cachingSkyMap.py
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1 #
2 # LSST Data Management System
3 # Copyright 2008-2012 LSST Corporation.
4 #
5 # This product includes software developed by the
6 # LSST Project (http://www.lsst.org/).
7 #
8 # This program is free software: you can redistribute it and/or modify
9 # it under the terms of the GNU General Public License as published by
10 # the Free Software Foundation, either version 3 of the License, or
11 # (at your option) any later version.
12 #
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
17 #
18 # You should have received a copy of the LSST License Statement and
19 # the GNU General Public License along with this program. If not,
20 # see <http://www.lsstcorp.org/LegalNotices/>.
21 #
22 
23 __all__ = ["CachingSkyMap"]
24 
25 from .baseSkyMap import BaseSkyMap
26 
27 
29  """A SkyMap that generates its tracts on request and caches them.
30 
31  Parameters
32  ----------
33  numTracts : `int`
34  Number of tracts to create.
35  config : `lsst.skymap.BaseSkyMapConfig` (optional)
36  The configuration for this SkyMap; if None use the default config.
37  version : `int` or `tuple` of `int` (optional)
38  Software version of this class, to retain compatibility with old
39  instances.
40 
41  Notes
42  -----
43  A subclass should define
44  * __init__ to calculate the required number of tracts (and pass it up)
45  * generateTract to generate a tract
46 
47  Subclassers should also check that the arguments to the constructor are
48  consistent with the below __reduce__ method.
49  """
50 
51  def __init__(self, numTracts, config=None, version=0):
52  super(CachingSkyMap, self).__init__(config)
53  self._numTracts_numTracts = numTracts
54  self._tractCache_tractCache = [None] * self._numTracts_numTracts
55  self._tractInfo_tractInfo = None # We shouldn't need this; we will generate tracts on demand
56  self._version_version = version
57 
58  def __reduce__(self):
59  """To support pickling.
60 
61  Notes
62  -----
63  **Warning:** This method assumes that the constructor is be defined:
64  __init__(self, config, version=defaultVersion)
65  The use of 'config' is effectively set by the registry mechanism.
66  If additional optional arguments are added, this method should be
67  overridden to correspond.
68  """
69  return (self.__class__, (self.configconfig, self._version_version))
70 
71  def __iter__(self):
72  """Iterator over tracts."""
73  for i in range(self._numTracts_numTracts):
74  yield self[i]
75 
76  def __len__(self):
77  """Length is number of tracts."""
78  return self._numTracts_numTracts
79 
80  def __getitem__(self, index):
81  """Get the TractInfo for a particular index.
82 
83  The tract is returned from a cache, if available, otherwise generated
84  on the fly.
85  """
86  if index < 0 or index > self._numTracts_numTracts:
87  raise IndexError("Index out of range: %d vs %d" % (index, self._numTracts_numTracts))
88  if self._tractCache_tractCache[index] is not None:
89  return self._tractCache_tractCache[index]
90  tract = self.generateTractgenerateTract(index)
91  self._tractCache_tractCache[index] = tract
92  return tract
93 
94  def generateTract(self, index):
95  """Generate TractInfo for the specified tract index."""
96  raise NotImplementedError("Subclasses must define this method.")
def __init__(self, numTracts, config=None, version=0)