fluree.errors
=============

.. py:module:: fluree.errors

.. autoapi-nested-parse::

   Exceptions raised by Fluree.

   Every error derives from :class:`FlureeError`. Where a Python builtin
   exception means the same thing, the Fluree error derives from it too, so
   ``except LookupError`` catches a missing ledger and ``except ValueError``
   catches a malformed query.





Module Contents
---------------

.. py:exception:: FlureeError

   Bases: :py:obj:`Exception`


   Base class for all Fluree errors.

   ``status`` is the HTTP-style status code the engine assigned the error,
   or ``None`` when the error did not come from the engine.


   .. py:attribute:: status
      :type:  int | None
      :value: None



.. py:exception:: InvalidRequestError

   Bases: :py:obj:`FlureeError`, :py:obj:`ValueError`


   The query, transaction, or argument is malformed or invalid.


.. py:exception:: ShaclViolationError

   Bases: :py:obj:`InvalidRequestError`


   A write that would leave data breaking the ledger's SHACL shapes.

   ``violations`` lists each way it would, as the same
   :class:`ValidationResult` objects :meth:`Ledger.validate` reports, so a
   rejected write is handled like a failed validation.


   .. py:property:: violations
      :type: list[fluree._records.ValidationResult]


      Each way the write breaks the shapes, as :class:`ValidationResult` objects.



.. py:exception:: UniqueConstraintError

   Bases: :py:obj:`InvalidRequestError`


   A write that would give two subjects the same value of a property the
   ledger requires to be unique (``f:enforceUnique``).

   ``value`` is the value as text; ``graph`` is the named graph's IRI, or
   ``None`` for the default graph.


   .. py:attribute:: property
      :type:  fluree._terms.IRI


   .. py:attribute:: value
      :type:  str


   .. py:attribute:: graph
      :type:  fluree._terms.IRI | None


   .. py:attribute:: existing_subject
      :type:  fluree._terms.IRI


   .. py:attribute:: new_subject
      :type:  fluree._terms.IRI


.. py:exception:: NotFoundError

   Bases: :py:obj:`FlureeError`, :py:obj:`LookupError`


   A ledger, branch, commit, or graph does not exist.


.. py:exception:: PermissionDeniedError

   Bases: :py:obj:`FlureeError`, :py:obj:`PermissionError`


   Policy denied the operation.


.. py:exception:: ConflictError

   Bases: :py:obj:`FlureeError`


   A concurrent change won; retrying against the new state may succeed.

   When a commit lost a race, ``expected_t`` is the ledger ``t`` it was
   built on and ``head_t`` the ``t`` another commit had moved it to; both
   are ``None`` for other conflicts.


   .. py:attribute:: expected_t
      :type:  int | None
      :value: None



   .. py:attribute:: head_t
      :type:  int | None
      :value: None



.. py:exception:: QueryTimeoutError

   Bases: :py:obj:`FlureeError`, :py:obj:`TimeoutError`


   The operation ran past its time limit.


.. py:exception:: ResourceLimitError

   Bases: :py:obj:`FlureeError`


   The operation exceeded a fuel, memory, or size limit.


.. py:exception:: DatabaseInUseError

   Bases: :py:obj:`FlureeError`


   The database directory is open in another process.

   One process opens a directory at a time, and its threads share that
   connection. To use the same data from several processes, run
   ``fluree server`` on the directory and send requests to it. ``pid`` is
   the other process's id, or ``None`` when it could not be read.


   .. py:attribute:: pid
      :type:  int | None
      :value: None