introduce abstract base class for backends

doc/_templates/better-apidoc/package.rst

@@ -32,11 +32,11 @@
     {%- endif -%}
 {%- endfor -%}
 
-{# Bypass the automatic discovery of simulators at qiskit.simulators #}
-{%- if fullname == 'qiskit.simulators' -%}
-    {%- set imported_modules = ['_localsimulator', '_qasm_cpp_simulator',
+{# Bypass the automatic discovery of simulators at qiskit.backends #}
+{%- if fullname == 'qiskit.backends' -%}
+    {%- set imported_modules = ['_qasm_cpp_simulator',
                                 '_qasmsimulator', '_unitarysimulator'] -%}
-    {%- set imported_classes = [] -%}
+    {%- set imported_classes = ['BaseBackend'] -%}
 {%- endif -%}
 
 {% if imported_modules %}

doc/dev_introduction.rst

@@ -36,7 +36,7 @@ The directory also contains internal modules that are still under development:
   graphs
 - a :py:mod:`mapper <qiskit.mapper>` module for mapping all-to-all circuits to
   run on devices with fixed couplings
-- a :py:mod:`simulators <qiskit.simulators>` module contains quantum circuit
+- a :py:mod:`backends <qiskit.backends>` module contains quantum circuit
   simulators
 - a *tools* directory contains methods for applications, analysis, and visualization
 

qiskit/__init__.py

@@ -14,6 +14,4 @@
 from ._quantumprogram import QuantumProgram
 from ._result import Result
 
-
 __version__ = '0.4.0'
-

qiskit/_jobprocessor.py

@@ -3,18 +3,15 @@
 import sys
 import time
 
-from IBMQuantumExperience import IBMQuantumExperience
-
+import qiskit.backends as backends
 from qiskit._result import Result
 from qiskit._resulterror import ResultError
-# Stable Modules
 from qiskit import QISKitError
-# Local Simulator Modules
-from qiskit import simulators
-# compiler module
 from qiskit import _openquantumcompiler as openquantumcompiler
+from IBMQuantumExperience.IBMQuantumExperience import (IBMQuantumExperience,
+                                                       ApiError)
 
-def run_local_simulator(qobj):
+def run_local_backend(qobj):
     """Run a program of compiled quantum circuits on the local machine.
 
     Args:
@@ -40,9 +37,9 @@ def run_local_simulator(qobj):
             compiled_circuit = openquantumcompiler.compile(circuit['circuit'],
                                                            format='json')
             circuit['compiled_circuit'] = compiled_circuit
-    local_simulator = simulators.LocalSimulator(qobj)
-    local_simulator.run()
-    return local_simulator.result()
+    BackendClass = backends.get_backend_class(qobj['config']['backend'])
+    backend = BackendClass(qobj)
+    return backend.run()
 
 def run_remote_backend(qobj, api, wait=5, timeout=60, silent=True):
     """
@@ -124,10 +121,6 @@ def _wait_for_job(jobid, api, wait=5, timeout=60, silent=True):
                                   'status': job_result['qasms'][index]['status']})
     return {'status': job_result['status'], 'result': job_result_return}
 
-def local_backends():
-    """Get the local backends."""
-    return simulators._localsimulator.local_backends()
-
 def remote_backends(api):
     """Get the remote backends.
 
@@ -160,7 +153,7 @@ def __init__(self, q_jobs, callback, max_workers=1, token=None, url=None, api=No
         self.q_jobs = q_jobs
         self.max_workers = max_workers
         # check whether any jobs are remote
-        self._local_backends = local_backends()
+        self._local_backends = backends.local_backends()
         self.online = any(qj.backend not in self._local_backends for qj in q_jobs)
         self.futures = {}
         self.lock = Lock()
@@ -224,7 +217,7 @@ def submit(self, wait=5, timeout=120, silent=True):
         executor = self.executor_class(max_workers=self.max_workers)
         for q_job in self.q_jobs:
             if q_job.backend in self._local_backends:
-                future = executor.submit(run_local_simulator,
+                future = executor.submit(run_local_backend,
                                          q_job.qobj)
             elif self.online and q_job.backend in self._online_backends:
                 future = executor.submit(run_remote_backend,

qiskit/_openquantumcompiler.py

@@ -3,7 +3,6 @@
 import qiskit.mapper as mapper
 from qiskit._qiskiterror import QISKitError
 
-
 def compile(qasm_circuit, basis_gates='u1,u2,u3,cx,id', coupling_map=None,
             initial_layout=None, silent=True, get_layout=False, format='dag'):
     """Compile the circuit.

qiskit/_quantumjob.py

@@ -1,8 +1,7 @@
 import random
 import string
-
 from qiskit import _openquantumcompiler as openquantumcompiler
-from qiskit.simulators import _localsimulator as localsimulators
+import qiskit.backends as backends
 
 class QuantumJob():
     """Creates a quantum circuit job"""
@@ -73,15 +72,15 @@ def __init__(self, circuits, backend='local_qasm_simulator',
         if preformatted:
             self.qobj = circuits
         else:
-            self.qobj = self._create_qobj(circuits, circuit_config, backend, 
+            self.qobj = self._create_qobj(circuits, circuit_config, backend,
                                           seed, resources, shots, do_compile)
 
         self.backend = self.qobj['config']['backend']
         self.resources = {'max_credits': self.qobj['config']['max_credits']}
         self.seed = seed
         self.result = None
-        
-    def _create_qobj(self, circuits, circuit_config, backend, seed, 
+
+    def _create_qobj(self, circuits, circuit_config, backend, seed,
                      resources, shots, do_compile):
         # local and remote backends currently need different
         # compilied circuit formats
@@ -90,7 +89,7 @@ def _create_qobj(self, circuits, circuit_config, backend, seed,
             for circuit in circuits:
                 formatted_circuits.append(None)
         else:
-            if backend in localsimulators.local_backends():
+            if backend in backends.local_backends():
                 for circuit in self.circuits:
                     formatted_circuits.append(openquantumcompiler.dag2json(circuit))
             else:
@@ -105,7 +104,7 @@ def _create_qobj(self, circuits, circuit_config, backend, seed,
                         'layout': None,
                         'seed': seed}
             circuit_config = [config] * len(self.circuits)
-    
+
         for circuit, fcircuit, name, config in zip(self.circuits,
                                                     formatted_circuits,
                                                     self.names,
@@ -126,7 +125,7 @@ def _create_qobj(self, circuits, circuit_config, backend, seed,
                            'backend': backend
                           },
                 'circuits': circuit_records}
-    
+
     def _generate_job_id(self, length=10):
         return ''.join([random.choice(
             string.ascii_letters + string.digits) for i in range(length)])

qiskit/_quantumprogram.py

@@ -39,7 +39,7 @@
 from . import mapper
 
 # Local Simulator Modules
-from . import simulators
+import qiskit.backends
 
 from . import _openquantumcompiler as openquantumcompiler
 
@@ -99,7 +99,7 @@ def __init__(self, specs=None):
         self.__init_circuit = None  # stores the intial quantum circuit of the
         # program
         self.__ONLINE_BACKENDS = []
-        self.__LOCAL_BACKENDS = self.local_backends()
+        self.__LOCAL_BACKENDS = qiskit.backends.local_backends()
         self.mapper = mapper
         if specs:
             self.__init_specs(specs)
@@ -540,10 +540,6 @@ def available_backends(self):
         """All the backends that are seen by QISKIT."""
         return self.__ONLINE_BACKENDS + self.__LOCAL_BACKENDS
 
-    def local_backends(self):
-        """Get the local backends."""
-        return simulators._localsimulator.local_backends()
-
     def online_backends(self):
         """Get the online backends.
 
@@ -660,11 +656,8 @@ def get_backend_configuration(self, backend, list_format=False):
                                     cmap = configuration[key]
                                 configuration_edit[new_key] = cmap
                     return configuration_edit
-        for configuration in simulators.local_configuration:
-            if configuration['name'] == backend:
-                return configuration
-        raise LookupError(
-            'backend configuration for "{0}" not found'.format(backend))
+        else:
+            return qiskit.backends.get_backend_configuration(backend)
 
     def get_backend_calibration(self, backend):
         """Return the online backend calibrations.

qiskit/_result.py

@@ -90,6 +90,14 @@ def circuit_statuses(self):
         return [circuit_result['status']
                 for circuit_result in self.__result['result']]
 
+    def get_circuit_status(self, icircuit):
+        """Return the status of circuit at index icircuit.
+
+        Args:
+            icircuit (int): index of circuit
+        """
+        return self.__result['result'][icircuit]['status']
+
     def get_ran_qasm(self, name):
         """Get the ran qasm for the named circuit and backend.
 

qiskit/backends/__init__.py

@@ -0,0 +1,6 @@
+from ._basebackend import BaseBackend
+from ._backendutils import (get_backend_class,
+                            get_backend_configuration,
+                            local_backends,
+                            register_backend,
+                            remote_backends)