Skip to content

Commit

Permalink
Merge pull request #332 from dictation-toolbox/engine-init-changes
Browse files Browse the repository at this point in the history 
get_engine() function changes
  • Loading branch information
@drmfinlay
drmfinlay committed Apr 25, 2021
2 parents e16e72f + 07b318c commit 82e1e3e
Showing 1 changed file with 86 additions and 53 deletions.
139 changes: 86 additions & 53 deletions dragonfly/engines/__init__.py
View file
Original file line number Diff line number Diff line change
Expand Up @@ -18,9 +18,11 @@
# <http://www.gnu.org/licenses/>.
#

# pylint: disable=global-statement

import logging
import os
import traceback

from .base import EngineBase, EngineError, MimicFailure


Expand All @@ -34,121 +36,152 @@ def get_engine(name=None, **kwargs):
"""
Get the engine implementation.
This function will initialize an engine object using the
This function will initialize an engine instance using the
``get_engine`` and ``is_engine_available`` functions in the engine
packages and return an instance of the first available engine. If
packages and return an instance of the first available engine. If
one has already been initialized, it will be returned instead.
If no specific engine is requested and no engine has already been
initialized, this function will initialize and return an instance of
the first available engine in the following order:
======================= =========================================
SR engine back-end Engine name string(s)
======================= =========================================
1. Dragon/Natlink ``"natlink"``
2. Kaldi ``"kaldi"``
3. WSR/SAPI 5 ``"sapi5", "sapi5inproc", "sapi5shared"``
4. CMU Pocket Sphinx ``"sphinx"``
======================= =========================================
The :ref:`Text-input engine <RefTextEngine>` can be initialized by
specifying ``"text"`` as the engine name. This back-end will
**not** be initialized if no specific engine is requested because
the back-end is not a real SR engine and is used mostly for testing.
**Arguments**:
:param name: optional human-readable name of the engine to return.
:type name: str
:param \\**kwargs: optional keyword arguments passed through to the
engine for engine-specific configuration.
:rtype: EngineBase
:returns: engine object
:returns: engine instance
:raises: EngineError
"""
# pylint: disable=too-many-statements,too-many-branches
global _default_engine, _engines_by_name
log = logging.getLogger("engine")

if name and name in _engines_by_name:
# If the requested engine has already been loaded, return it.
if kwargs is not None and len(kwargs) > 0:
message = ("Error: Passing get_engine arguments to an engine "
"that has already been created, hence these "
"arguments are ignored.")
print(message)
raise EngineError(message)
return _engines_by_name[name]
# If the requested engine has already been initialized, return it.
engine = _engines_by_name[name]
elif not name and _default_engine:
# If no specific engine is requested and an engine has already
# been loaded, return it.
if kwargs is not None and len(kwargs) > 0:
message = ("Error: Passing get_engine arguments to an engine "
"that has already been created, hence these "
"arguments are ignored.")
print(message)
raise EngineError(message)
return _default_engine

# Check if we're on Windows. If name is None and we're not on Windows,
# then we don't evaluate Windows-only engines like natlink.
# been initialized, return it.
engine = _default_engine
else:
# No engine has been initialized yet.
engine = None

# Check if there is an already initialized engine *and* custom engine
# initialization arguments. This is not allowed.
if engine and kwargs is not None and len(kwargs) > 0:
message = ("Error: Passing get_engine arguments to an engine "
"that has already been initialized, hence these "
"arguments are ignored.")
log.error(message)
raise EngineError(message)

# If there is a relevant initialized engine already, then return it.
if engine:
return engine

# Check if we're on Windows. If we're not on Windows, then we don't
# evaluate Windows-only engines like natlink.
windows = os.name == 'nt'

if (windows and not name) or name == "natlink":
if not engine and windows and name in (None, "natlink"):
# Attempt to retrieve the natlink back-end.
try:
from .backend_natlink import is_engine_available
from .backend_natlink import get_engine as get_specific_engine
if is_engine_available(**kwargs):
return get_specific_engine(**kwargs)
engine = get_specific_engine(**kwargs)
except Exception as e:
message = ("Exception while initializing natlink engine:"
" %s" % (e,))
print(message)
log.warning(message)
if name:
raise EngineError(message)

sapi5_names = ["sapi5shared", "sapi5inproc", "sapi5"]
if (windows and not name) or name in sapi5_names:
if not engine and name in (None, "kaldi"):
# Attempt to retrieve the Kaldi back-end.
try:
from .backend_kaldi import is_engine_available
from .backend_kaldi import get_engine as get_specific_engine
if is_engine_available(**kwargs):
engine = get_specific_engine(**kwargs)
except Exception as e:
message = ("Exception while initializing kaldi engine:"
" %s" % (e,))
log.warning(message)
if name:
raise EngineError(message)

sapi5_names = (None, "sapi5shared", "sapi5inproc", "sapi5")
if not engine and windows and name in sapi5_names:
# Attempt to retrieve the sapi5 back-end.
try:
from .backend_sapi5 import is_engine_available
from .backend_sapi5 import get_engine as get_specific_engine
if is_engine_available(name, **kwargs):
return get_specific_engine(name, **kwargs)
engine = get_specific_engine(name, **kwargs)
except Exception as e:
message = ("Exception while initializing sapi5 engine:"
" %s" % (e,))
print(message)
log.warning(message)
if name:
raise EngineError(message)

if not name or name == "sphinx":
if not engine and name in (None, "sphinx"):
# Attempt to retrieve the CMU Sphinx back-end.
try:
from .backend_sphinx import is_engine_available
from .backend_sphinx import get_engine as get_specific_engine
if is_engine_available(**kwargs):
return get_specific_engine(**kwargs)
engine = get_specific_engine(**kwargs)
except Exception as e:
message = ("Exception while initializing sphinx engine:"
" %s" % (e,))
log.exception(message)
if name:
raise EngineError(message)

if not name or name == "kaldi":
# Attempt to retrieve the Kaldi back-end.
try:
from .backend_kaldi import is_engine_available
from .backend_kaldi import get_engine as get_specific_engine
if is_engine_available(**kwargs):
return get_specific_engine(**kwargs)
except Exception as e:
message = ("Exception while initializing kaldi engine:"
" %s" % (e,))
print(message)
log.warning(message)
if name:
raise EngineError(message)

# Only retrieve the text input engine if explicitly specified; it is not
# an actual SR engine implementation and is mostly intended to be used
# for testing.
if name == "text":
# an actual SR engine implementation and is mostly intended to be used
# for testing.
if not engine and name == "text":
# Attempt to retrieve the TextInput engine instance.
try:
from .backend_text import is_engine_available
from .backend_text import get_engine as get_specific_engine
if is_engine_available(**kwargs):
return get_specific_engine(**kwargs)
engine = get_specific_engine(**kwargs)
except Exception as e:
message = ("Exception while initializing text-input engine:"
" %s" % (e,))
print(message)
log.warning(message)
if name:
raise EngineError(message)

if not name:
# Return the engine instance, if one has been initialized. Log a
# message about which SR engine back-end was used.
if engine:
message = "Initialized %r SR engine: %r." % (engine.name, engine)
log.info(message)
return engine
elif not name:
raise EngineError("No usable engines found.")
else:
valid_names = ["natlink", "kaldi", "sphinx", "sapi5shared",
Expand Down

0 comments on commit 82e1e3e

Please sign in to comment.