ButlerAttributeManager¶
- class lsst.daf.butler.registry.interfaces.ButlerAttributeManager(*, registry_schema_version: VersionTuple | None = None)¶
Bases:
VersionedExtension
An interface for managing butler attributes in a
Registry
.Attributes are represented in registry as a set of name-value pairs, both have string type. Any non-string data types (e.g. integers) need to be converted to/from strings on client side. Attribute names can be arbitrary strings, no particular structure is enforced by this interface. Attribute names are globally unique, to avoid potential collision clients should follow some common convention for attribute names, e.g. dot-separated components (
config.managers.opaque
).One of the critical pieces of information that will be stored as attribute is the version of database schema which needs to be known before registry can do any operations on database. For that reasons it is likely there will be only one implementation of this interface which uses database table with a stable schema.
Methods Summary
checkCompatibility
(registry_schema_version, ...)Check that schema version defined in registry is compatible with current implementation.
checkNewSchemaVersion
(schema_version)Verify that requested schema version can be created by an extension.
clsNewSchemaVersion
(schema_version)Class method which returns schema version to use for newly created registry database.
Return schema version(s) supported by this extension class.
delete
(name)Delete an attribute.
empty
()Check whether attributes set is empty.
Return full name of the extension.
get
(name[, default])Retrieve value of a given attribute.
initialize
(db, context[, ...])Construct an instance of the manager.
items
()Iterate over attributes and yield their names and values.
Return schema version for newly created registry.
set
(name, value, *[, force])Set value for a given attribute.
Methods Documentation
- classmethod checkCompatibility(registry_schema_version: VersionTuple, update: bool) None ¶
Check that schema version defined in registry is compatible with current implementation.
- Parameters:
- registry_schema_version
VersionTuple
Schema version that exists in registry or defined in a configuration for a registry to be created.
- update
bool
If True then read-write access is expected.
- registry_schema_version
- Raises:
- IncompatibleVersionError
Raised if schema version is not supported by implementation.
Notes
Default implementation uses
VersionTuple.checkCompatibility
on the versions returned fromcurrentVersions
method. Subclasses that support different compatibility model will overwrite this method.
- classmethod checkNewSchemaVersion(schema_version: VersionTuple) None ¶
Verify that requested schema version can be created by an extension.
- Parameters:
- schema_version
VersionTuple
Schema version that this extension is asked to create.
- schema_version
Notes
This method may be used only occasionally when a specific schema version is given in a regisitry config file. This can be used with an extension that supports multiple schem versions to make it create new schema with a non-default version number. Default implementation compares requested version with one of the version returned from
currentVersions
.
- classmethod clsNewSchemaVersion(schema_version: VersionTuple | None) VersionTuple | None ¶
Class method which returns schema version to use for newly created registry database.
- Parameters:
- schema_version
VersionTuple
orNone
Configured schema version or
None
if default schema version should be created. If notNone
then it is guaranteed to be compatible withcurrentVersions
.
- schema_version
- Returns:
- version
VersionTuple
orNone
Schema version created by this extension.
None
is returned if an extension does not require its version to be saved or checked.
- version
Notes
Default implementation of this method can work in simple cases. If the extension only supports single schema version than that version is returned. If the extension supports multiple schema versions and
schema_version
is notNone
thenschema_version
is returned. If the extension supports multiple schema versions, butschema_version
isNone
it calls_newDefaultSchemaVersion
method which needs to be reimplemented in a subsclass.
- abstract classmethod currentVersions() list[lsst.daf.butler.registry.interfaces._versioning.VersionTuple] ¶
Return schema version(s) supported by this extension class.
- Returns:
- version
list
[VersionTuple
] Schema versions for this extension. Empty list is returned if an extension does not require its version to be saved or checked.
- version
- abstract empty() bool ¶
Check whether attributes set is empty.
- Returns:
- empty
bool
True if there are no any attributes defined.
- empty
- classmethod extensionName() str ¶
Return full name of the extension.
This name should match the name defined in registry configuration. It is also stored in registry attributes. Default implementation returns full class name.
- Returns:
- name
str
Full extension name.
- name
- abstract get(name: str, default: str | None = None) str | None ¶
Retrieve value of a given attribute.
- abstract classmethod initialize(db: Database, context: StaticTablesContext, registry_schema_version: VersionTuple | None = None) ButlerAttributeManager ¶
Construct an instance of the manager.
- Parameters:
- db
Database
Interface to the underlying database engine and namespace.
- context
StaticTablesContext
Context object obtained from
Database.declareStaticTables
; used to declare any tables that should always be present in a layer implemented with this manager.- registry_schema_version
VersionTuple
orNone
Schema version of this extension as defined in registry.
- db
- Returns:
- manager
ButlerAttributeManager
An instance of
ButlerAttributeManager
.
- manager
- abstract items() Iterable[tuple[str, str]] ¶
Iterate over attributes and yield their names and values.
- newSchemaVersion() VersionTuple | None ¶
Return schema version for newly created registry.
- Returns:
- version
VersionTuple
orNone
Schema version created by this extension.
None
is returned if an extension does not require its version to be saved or checked.
- version
Notes
Extension classes that support multiple schema versions need to override
_newDefaultSchemaVersion
method.
- abstract set(name: str, value: str, *, force: bool = False) None ¶
Set value for a given attribute.
- Parameters:
- name
str
Attribute name, arbitrary non-empty string.
- value
str
New value for an attribute, an arbitrary string. Due to deficiencies of some database engines we are not allowing empty strings to be stored in the database, and
value
cannot be an empty string.- force
bool
, optional Controls handling of existing attributes. With default
False
value an exception is raised if attributename
already exists, ifTrue
is passed then value of the existing attribute will be updated.
- name
- Raises:
- ButlerAttributeExistsError
Raised if attribute already exists but
force
option is false.- ValueError
Raised if name or value parameters are empty.