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Persistency.py
Go to the documentation of this file.
1 """
2 Module to configure the persistency type in GaudiPython.
3 """
4 __author__ = "Marco Clemencic <marco.clemencic@cern.ch>"
5
6 class PersistencyError(RuntimeError):
7 """
8 Base class for exceptions in PersistencyHelper.
9 """
10 pass
11
12 class UnknownPersistency(PersistencyError):
13 """
14 Exception raised if the persistency type is not known to the module.
15 """
16 def __init__(self, type_):
17 super(UnknownPersistency, self).__init__("Unknown persistency type %r" % type_)
18 self.type = type_
19
20 # internal storage for the persistency helpers
21 _implementations = []
22
23 def get(type_):
24 """
25 Return the PersistencyHerper implementing the given persistency type.
26 """
27 for i in _implementations:
28 if i.handle(type_):
29 return i
30 raise UnknownPersistency(type_)
31
32 def add(instance):
33 """
34 Function to extend the list of known helpers.
35
36 New helpers are added to the top of the list.
37 """
38 _implementations.insert(0, instance)
39
40 class FileDescription(object):
41 def __init__(self, filename, opt, svc, sel=None, collection=None, fun=None):
42 '''
43 Class to hold/manipulate the file description.
44
45 @param filename: name of the file
46 @param opt: option (READ/CREATE/RECREATE/WRITE)
47 @param svc: conversion service (or selector)
48 @param sel: selection expression
49 @param collection: collection
50 @param fun: selection class
51 '''
52 self.filename = filename
53 self.opt = opt
54 self.svc = svc
55 self.sel = sel
56 self.collection = collection
57 self.fun = fun
58 def __data__(self):
59 '''
60 Return a list of pairs describing the instance.
61 '''
62 return [("DATAFILE", self.filename),
63 ("OPT", self.opt),
64 ("SVC", self.svc),
65 ("SEL", self.sel),
66 ("COLLECTION", self.collection),
67 ("FUN", self.fun)]
68 def __str__(self):
69 """
70 Return the string representation of the file description to be passed
71 to the application.
72 """
73 return " ".join(["%s='%s'" % (k, v) for k, v in self.__data__() if v])
74
75 class PersistencyHelper(object):
76 """
77 Base class for extensions to persistency configuration in GaudiPython.
78 """
79 def __init__(self, types):
80 """
81 Define the type of persistencies supported by the instance.
82 """
83 self.types = set(types)
84 def handle(self, typ):
85 """
86 Returns True if the current instance understands the requested
87 persistency type.
88 """
89 return typ in self.types
90
91 class RootPersistency(PersistencyHelper):
92 """
93 Implementation of PersistencyHelper based on Gaudi::RootCnvSvc.
94 """
95 def __init__(self):
96 """
97 Constructor.
98
99 Declare the type of supported persistencies to the base class.
100 """
101 super(RootPersistency, self).__init__(["ROOT", "POOL_ROOT",
102 "RootCnvSvc", "Gaudi::RootCnvSvc"])
103 self.configured = False
104
105 def configure(self, appMgr):
106 """
107 Basic configuration.
108 """
109 if not self.configured:
110 # instantiate the required services
111 appMgr.service('Gaudi::RootCnvSvc/RootCnvSvc')
112 eps = appMgr.service ( 'EventPersistencySvc' )
113 eps.CnvServices += ['RootCnvSvc']
114 self.configured = True
115
116 def formatInput(self, filenames, **kwargs):
117 '''
118 Translate a list of file names in a list of input descriptions.
119
120 The optional parameters 'collection', 'sel' and 'fun' should be used to
121 configure Event Tag Collection inputs.
122
123 @param filenames: the list of files
124 '''
125 if not self.configured:
126 raise PersistencyError("Persistency not configured")
127 if type(filenames) is str:
128 filenames = [filenames]
129 fileargs = {}
130 # check if we are accessing a collection
131 fileargs = dict([(k, kwargs[k])
132 for k in ["collection", "sel", "fun"]
133 if k in kwargs])
134 if fileargs:
135 # is a collection
136 svc = 'Gaudi::RootCnvSvc'
137 else:
138 svc = 'Gaudi::RootEvtSelector'
139 return map(str,
140 [FileDescription(f, 'READ', svc, **fileargs)
141 for f in filenames])
142
143 def formatOutput(self, filename, **kwargs):
144 '''
145 Translate a filename in an output description.
146
147 @param filenames: the list of files
148 @param lun: Logical Unit for Event Tag Collection outputs (optional)
149 '''
150 if not self.configured:
151 raise PersistencyError("Persistency not configured")
152 retval = str(FileDescription(filename, 'RECREATE', 'Gaudi::RootCnvSvc'))
153 if 'lun' in kwargs:
154 retval = "%s %s" % (kwargs['lun'], retval)
155 return retval
156
157 # Adding the know instances to the list of helpers
158 add(RootPersistency())
GaudiPython.Persistency.PersistencyHelper.handle
def handle(self, typ)
Definition: Persistency.py:84
GaudiPython.Persistency.FileDescription.collection
collection
Definition: Persistency.py:56
GaudiPython.Persistency.UnknownPersistency.type
type
Definition: Persistency.py:18
GaudiPython.Persistency.FileDescription.__data__
def __data__(self)
Definition: Persistency.py:58
GaudiPython.Persistency.PersistencyHelper.__init__
def __init__(self, types)
Definition: Persistency.py:79
GaudiPython.Persistency.FileDescription.filename
filename
Definition: Persistency.py:52
GaudiPython.Persistency.FileDescription.__str__
def __str__(self)
Definition: Persistency.py:68
GaudiPython.Persistency.PersistencyHelper.types
types
Definition: Persistency.py:83
GaudiPython.Persistency.RootPersistency.formatOutput
def formatOutput(self, filename, kwargs)
Definition: Persistency.py:143
GaudiPython.Persistency.UnknownPersistency.__init__
def __init__(self, type_)
Definition: Persistency.py:16
GaudiPython.Persistency.RootPersistency.formatInput
def formatInput(self, filenames, kwargs)
Definition: Persistency.py:116
GaudiPython.Persistency.FileDescription.svc
svc
Definition: Persistency.py:54
GaudiPython.Persistency.add
def add(instance)
Definition: Persistency.py:32
GaudiPython.Persistency.PersistencyHelper
Definition: Persistency.py:75
gaudirun.type
string type
Definition: gaudirun.py:151
Containers::map
struct GAUDI_API map
Parametrisation class for map-like implementation.
Definition: KeyedObjectManager.h:25
GaudiPython.Persistency.RootPersistency.configure
def configure(self, appMgr)
Definition: Persistency.py:105
GaudiPython.Persistency.UnknownPersistency
Definition: Persistency.py:12
GaudiPython.Persistency.RootPersistency
Definition: Persistency.py:91
GaudiPython.Persistency.FileDescription.__init__
def __init__
Definition: Persistency.py:41
GaudiPython.Persistency.RootPersistency.configured
configured
Definition: Persistency.py:103
GaudiPython.Persistency.get
def get(type_)
Definition: Persistency.py:23
GaudiPython.Persistency.FileDescription.opt
opt
Definition: Persistency.py:53
GaudiPython.Persistency.FileDescription.sel
sel
Definition: Persistency.py:55
GaudiPython.Persistency.PersistencyError
Definition: Persistency.py:6
GaudiPython.Persistency.FileDescription
Definition: Persistency.py:40
GaudiPython.Persistency.FileDescription.fun
fun
Definition: Persistency.py:57
GaudiPython.Persistency.RootPersistency.__init__
def __init__(self)
Definition: Persistency.py:95