| Ahmad Sharif | 0dcbc4b | 2012-02-02 16:37:18 -0800 | [diff] [blame^] | 1 | #!/usr/bin/python |
| 2 | |
| 3 | # Copyright 2011 Google Inc. All Rights Reserved. |
| 4 | |
| 5 | |
| 6 | class Settings(object): |
| 7 | """Class representing settings (a set of fields) from an experiment file.""" |
| 8 | |
| 9 | def __init__(self, name, settings_type): |
| 10 | self.name = name |
| 11 | self.settings_type = settings_type |
| 12 | self.fields = {} |
| 13 | self.parent = None |
| 14 | |
| 15 | def SetParentSettings(self, settings): |
| 16 | """Set the parent settings which these settings can inherit from.""" |
| 17 | self.parent = settings |
| 18 | |
| 19 | def AddField(self, field): |
| 20 | name = field.name |
| 21 | if name in self.fields: |
| 22 | raise Exception("Field %s defined previously." % name) |
| 23 | self.fields[name] = field |
| 24 | |
| 25 | def SetField(self, name, value, append=False): |
| 26 | if name not in self.fields: |
| 27 | raise Exception("'%s' is not a valid field in '%s' settings" |
| 28 | % (name, self.settings_type)) |
| 29 | if append: |
| 30 | self.fields[name].Append(value) |
| 31 | else: |
| 32 | self.fields[name].Set(value) |
| 33 | |
| 34 | def GetField(self, name): |
| 35 | """Get the value of a field with a given name.""" |
| 36 | if name not in self.fields: |
| 37 | raise Exception("Field '%s' not a valid field in '%s' settings." % |
| 38 | (name, self.name)) |
| 39 | field = self.fields[name] |
| 40 | if not field.assigned and field.required: |
| 41 | raise Exception("Required field '%s' not defined in '%s' settings." % |
| 42 | (name, self.name)) |
| 43 | return self.fields[name].Get() |
| 44 | |
| 45 | def Inherit(self): |
| 46 | """Inherit any unset values from the parent settings.""" |
| 47 | for name in self.fields: |
| 48 | if (not self.fields[name].assigned and self.parent and |
| 49 | name in self.parent.fields and self.parent.fields[name].assigned): |
| 50 | self.fields[name].Set(self.parent.GetField(name), parse=False) |
| 51 | |
| 52 | def Override(self, settings): |
| 53 | """Override settings with settings from a different object.""" |
| 54 | for name in settings.fields: |
| 55 | if name in self.fields and settings.fields[name].assigned: |
| 56 | self.fields[name].Set(settings.GetField(name), parse=False) |
| 57 | |
| 58 | def Validate(self): |
| 59 | """Check that all required fields have been set.""" |
| 60 | for name in self.fields: |
| 61 | if not self.fields[name].assigned and self.fields[name].required: |
| 62 | raise Exception("Field %s is invalid." % name) |