lakesuperior.api package¶

Submodules¶

lakesuperior.api.admin module¶

Admin API.

This module contains maintenance utilities and stats.

lakesuperior.api.admin.fixity_check(uid)[source]¶

Check fixity of a resource.

This calculates the checksum of a resource and validates it against the checksum stored in its metadata (premis:hasMessageDigest).

Parameters:	uid (str) – UID of the resource to be checked.
Return type:	None
Raises:	lakesuperior.exceptions.ChecksumValidationError: the cecksums do not match. This indicates corruption.
Raises:	lakesuperior.exceptions.IncompatibleLdpTypeError: if the resource is not an LDP-NR.

lakesuperior.api.admin.integrity_check()[source]¶

Check integrity of the data set.

At the moment this is limited to referential integrity. Other checks can be added and triggered by different argument flags.

lakesuperior.api.admin.migrate(src, dest, start_pts=None, list_file=None, **kwargs)[source]¶

Migrate an LDP repository to a new Lakesuperior instance.

See Migrator.__init__().

lakesuperior.api.admin.stats()[source]¶

Get repository statistics.

Return type:	dict
Returns:	Store statistics, resource statistics.

lakesuperior.api.query module¶

lakesuperior.api.query.fulltext_lookup(pattern)[source]¶

Look up one term by partial match.

TODO: reserved for future use. A `Whoosh <https://whoosh.readthedocs.io/>`__ or similar full-text index is necessary for this.

lakesuperior.api.query.operands = ('_id', '=', '!=', '<', '>', '<=', '>=')¶

Available term comparators for term query.

The _uri term is used to match URIRef terms, all other comparators are used against literals.

lakesuperior.api.query.sparql_query(qry_str, fmt)[source]¶

Send a SPARQL query to the triplestore.

Parameters:	qry_str (str) – SPARQL query string. SPARQL 1.1 Query Language (https://www.w3.org/TR/sparql11-query/) is supported. fmt (str) – Serialization format. This varies depending on the query type (SELECT, ASK, CONSTRUCT, etc.). [TODO Add reference to RDFLib serialization formats]
Return type:	BytesIO
Returns:	Serialized SPARQL results.

lakesuperior.api.query.term_query(terms, or_logic=False)[source]¶

Query resources by predicates, comparators and values.

Comparators can be against literal or URIRef objects. For a list of comparators and their meanings, see the documentation and source for operands.

Parameters:	terms (list(tuple{3})) – List of 3-tuples containing: Predicate URI (rdflib.URIRef) Comparator value (str) Value to compare to (rdflib.URIRef or rdflib.Literal or str) or_logic (bool) – Whether to concatenate multiple query terms with OR logic (uses SPARQL `UNION` statements). The default is False (i.e. terms are concatenated as standard SPARQL statements).

lakesuperior.api.query.triple_match(s=None, p=None, o=None, return_full=False)[source]¶

Query store by matching triple patterns.

Any of the s, p or o terms can be None to represent a wildcard.

This method is for triple matching only; it does not allow to query, nor exposes to the caller, any context.

Parameters:	s (rdflib.term.Identifier) – Subject term. p (rdflib.term.Identifier) – Predicate term. o (rdflib.term.Identifier) – Object term. return_full (bool) – if `False` (the default), the returned values in the set are the URIs of the resources found. If True, the full set of matching triples is returned.
Return type:	set(tuple(rdflib.term.Identifier){3}) or set(rdflib.URIRef)
Returns:	Matching resource URIs if `return_full` is false, or matching triples otherwise.

lakesuperior.api.resource module¶

Primary API for resource manipulation.

Quickstart:

>>> # First import default configuration and globals—only done once.
>>> from lakesuperior import env
>>> env.setup()
>>> from lakesuperior.api import resource
>>> # Get root resource.
>>> rsrc = resource.get('/')
>>> # Dump graph.
>>> with rsrc.imr.store.txn_ctx():
>>>     print({*rsrc.imr.as_rdflib()})
{(rdflib.term.URIRef('info:fcres/'),
  rdflib.term.URIRef('http://purl.org/dc/terms/title'),
  rdflib.term.Literal('Repository Root')),
 (rdflib.term.URIRef('info:fcres/'),
  rdflib.term.URIRef('http://www.w3.org/1999/02/22-rdf-syntax-ns#type'),
  rdflib.term.URIRef('http://fedora.info/definitions/fcrepo#Container')),
 (rdflib.term.URIRef('info:fcres/'),
  rdflib.term.URIRef('http://www.w3.org/1999/02/22-rdf-syntax-ns#type'),
  rdflib.term.URIRef('http://fedora.info/definitions/fcrepo#RepositoryRoot')),
 (rdflib.term.URIRef('info:fcres/'),
  rdflib.term.URIRef('http://www.w3.org/1999/02/22-rdf-syntax-ns#type'),
  rdflib.term.URIRef('http://fedora.info/definitions/fcrepo#Resource')),
 (rdflib.term.URIRef('info:fcres/'),
  rdflib.term.URIRef('http://www.w3.org/1999/02/22-rdf-syntax-ns#type'),
  rdflib.term.URIRef('http://www.w3.org/ns/ldp#BasicContainer')),
 (rdflib.term.URIRef('info:fcres/'),
  rdflib.term.URIRef('http://www.w3.org/1999/02/22-rdf-syntax-ns#type'),
  rdflib.term.URIRef('http://www.w3.org/ns/ldp#Container')),
 (rdflib.term.URIRef('info:fcres/'),
  rdflib.term.URIRef('http://www.w3.org/1999/02/22-rdf-syntax-ns#type'),
  rdflib.term.URIRef('http://www.w3.org/ns/ldp#RDFSource'))}

lakesuperior.api.resource.create(parent, slug=None, **kwargs)[source]¶

Mint a new UID and create a resource.

The UID is computed from a given parent UID and a “slug”, a proposed path relative to the parent. The application will attempt to use the suggested path but it may use a different one if a conflict with an existing resource arises.

Parameters:	parent (str) – UID of the parent resource. slug (str) – Tentative path relative to the parent UID. **kwargs – Other parameters are passed to the `from_provided()` method.
Return type:	tuple(str, lakesuperior.model.ldp.ldpr.Ldpr)
Returns:	A tuple of: 1. Event type (str): whether the resource was created or updated. 2. Resource (lakesuperior.model.ldp.ldpr.Ldpr): The new or updated resource.

lakesuperior.api.resource.create_or_replace(uid, **kwargs)[source]¶

Create or replace a resource with a specified UID.

Parameters:

uid (string) – UID of the resource to be created or updated.
**kwargs – Other parameters are passed to the from_provided() method.

Return type:

tuple(str, lakesuperior.model.ldp.ldpr.Ldpr)

Returns:

A tuple of: 1. Event type (str): whether the resource was created or updated. 2. Resource (lakesuperior.model.ldp.ldpr.Ldpr): The new or updated

resource.

lakesuperior.api.resource.create_version(uid, ver_uid)[source]¶

Create a resource version.

Parameters:	uid (string) – Resource UID. ver_uid (string) – Version UID to be appended to the resource URI. NOTE: this is a “slug”, i.e. the version URI is not guaranteed to be the one indicated.
Return type:	str
Returns:	Version UID.

lakesuperior.api.resource.delete(uid, soft=True, inbound=True)[source]¶

Delete a resource.

Parameters:	uid (string) – Resource UID. soft (bool) – Whether to perform a soft-delete and leave a tombstone resource, or wipe any memory of the resource.

lakesuperior.api.resource.exists(uid)[source]¶

Return whether a resource exists (is stored) in the repository.

Parameters:	uid (string) – Resource UID.

lakesuperior.api.resource.get(uid, repr_options={})[source]¶

Get an LDPR resource.

The resource comes preloaded with user data and metadata as indicated by the repr_options argument. Any further handling of this resource is done outside of a transaction.

Parameters:	uid (string) – Resource UID. repr_options – (dict(bool)) Representation options. This is a dict that is unpacked downstream in the process. The default empty dict results in default values. The accepted dict keys are:

incl_inbound: include inbound references. Default: False.
incl_children: include children URIs. Default: True.
embed_children: Embed full graph of all child resources. Default: False

lakesuperior.api.resource.get_metadata(uid)[source]¶

Get metadata (admin triples) of an LDPR resource.

Parameters:	uid (string) – Resource UID.

lakesuperior.api.resource.get_version(uid, ver_uid)[source]¶: Get version metadata (fcr:versions).

lakesuperior.api.resource.get_version_info(uid)[source]¶: Get version metadata (fcr:versions).

lakesuperior.api.resource.resurrect(uid)[source]¶

Reinstate a buried (soft-deleted) resource.

Parameters:	uid (str) – Resource UID.

lakesuperior.api.resource.revert_to_version(uid, ver_uid)[source]¶

Restore a resource to a previous version state.

Parameters:	uid (str) – Resource UID. ver_uid (str) – Version UID.

lakesuperior.api.resource.transaction(write=False)[source]¶

Handle atomic operations in a store.

This wrapper ensures that a write operation is performed atomically. It also takes care of sending a message for each resource changed in the transaction.

ALL write operations on the LDP-RS and LDP-NR stores go through this wrapper.

lakesuperior.api.resource.update(uid, update_str, is_metadata=False, handling='strict')[source]¶

Update a resource with a SPARQL-Update string.

Parameters:

uid (string) – Resource UID.
update_str (string) – SPARQL-Update statements.
is_metadata (bool) – Whether the resource metadata are being updated.
handling (str) – How to handle server-managed triples. strict (the default) rejects the update with an exception if server-managed triples are being changed. lenient modifies the update graph so offending triples are removed and the update can be applied.

Raises:

InvalidResourceError – If is_metadata is False and the resource being updated is a LDP-NR.

lakesuperior.api.resource.update_delta(uid, remove_trp, add_trp)[source]¶

Update a resource graph (LDP-RS or LDP-NR) with sets of add/remove triples.

A set of triples to add and/or a set of triples to remove may be provided.

Parameters:	uid (string) – Resource UID. remove_trp (set(tuple(rdflib.term.Identifier))) – Triples to remove, as 3-tuples of RDFLib terms. add_trp (set(tuple(rdflib.term.Identifier))) – Triples to add, as 3-tuples of RDFLib terms.