Memory improvements (1/3): Introduce new data access layer and schemas

.gitignore

@@ -88,3 +88,6 @@ node_modules/
 !.yarn/releases
 !.yarn/sdks
 !.yarn/versions
+
+# Ignore mock database
+**/*.sqlite

CHANGELOG.md

@@ -26,6 +26,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- [Significant Changes] Improving memory management part 1/3
 - Removed strict version pins on `lmdbm`, `mpire`, `orjson`, and `pennylane`
 - Changed license to Apache
 
@@ -146,6 +147,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - File transfer strategy for GCP storage
 - Add CLI status for zombie, stopped process.
 - Fix for double locking file in configurations.
+- Introduced new data access layer
+- Introduced Shutil file transfer strategy for local file transfers
 
 ### Docs
 

covalent/_file_transfer/enums.py

@@ -34,6 +34,7 @@ class FileSchemes(str, enum.Enum):
 
 
 class FileTransferStrategyTypes(str, enum.Enum):
+    Shutil = "Shutil"
     Rsync = "rsync"
     HTTP = "http"
     S3 = "s3"
@@ -43,7 +44,7 @@ class FileTransferStrategyTypes(str, enum.Enum):
 
 
 SchemeToStrategyMap = {
-    "file": FileTransferStrategyTypes.Rsync,
+    "file": FileTransferStrategyTypes.Shutil,
     "http": FileTransferStrategyTypes.HTTP,
     "https": FileTransferStrategyTypes.HTTP,
     "s3": FileTransferStrategyTypes.S3,

covalent/_file_transfer/file_transfer.py

@@ -19,7 +19,7 @@
 from .enums import FileTransferStrategyTypes, FtCallDepReturnValue, Order
 from .file import File
 from .strategies.http_strategy import HTTP
-from .strategies.rsync_strategy import Rsync
+from .strategies.shutil_strategy import Shutil
 from .strategies.transfer_strategy_base import FileTransferStrategy
 
 
@@ -59,10 +59,10 @@ def __init__(
         if strategy:
             self.strategy = strategy
         elif (
-            from_file.mapped_strategy_type == FileTransferStrategyTypes.Rsync
-            and to_file.mapped_strategy_type == FileTransferStrategyTypes.Rsync
+            from_file.mapped_strategy_type == FileTransferStrategyTypes.Shutil
+            and to_file.mapped_strategy_type == FileTransferStrategyTypes.Shutil
         ):
-            self.strategy = Rsync()
+            self.strategy = Shutil()
         elif from_file.mapped_strategy_type == FileTransferStrategyTypes.HTTP:
             self.strategy = HTTP()
         else:

covalent/_file_transfer/strategies/shutil_strategy.py

@@ -0,0 +1,59 @@
+# Copyright 2021 Agnostiq Inc.
+#
+# This file is part of Covalent.
+#
+# Licensed under the Apache License 2.0 (the "License"). A copy of the
+# License may be obtained with this software package or at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Use of this file is prohibited except in compliance with the License.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import shutil
+
+from .. import File
+from .transfer_strategy_base import FileTransferStrategy
+
+
+class Shutil(FileTransferStrategy):
+    """
+    Implements Base FileTransferStrategy class to copy files locally
+
+    The copying is done in-process using shutil.copyfile.
+    """
+
+    def __init__(
+        self,
+    ):
+        pass
+
+    # return callable to copy files in the local file system
+    def cp(self, from_file: File, to_file: File = File()) -> None:
+        """
+        Get a callable that copies a file from one location to another locally
+
+        Args:
+            from_file: File to copy from
+            to_file: File to copy to. Defaults to File().
+
+        Returns:
+            A callable that copies a file from one location to another locally
+        """
+
+        def callable():
+            shutil.copyfile(from_file.filepath, to_file.filepath)
+
+        return callable
+
+    # Local file operations only
+    def upload(self, from_file: File, to_file: File = File()) -> File:
+        raise NotImplementedError
+
+    # Local file operations only
+    def download(self, from_file: File, to_file: File) -> File:
+        raise NotImplementedError

covalent/_results_manager/result.py

@@ -16,6 +16,7 @@
 
 """Result object."""
 import os
+import re
 from datetime import datetime
 from typing import TYPE_CHECKING, Any, Dict, List, Set, Union
 
@@ -62,6 +63,9 @@
     """
 
     NEW_OBJ = RESULT_STATUS.NEW_OBJECT
+    PENDING_REUSE = (
+        RESULT_STATUS.PENDING_REUSE
+    )  # Facilitates reuse of previous electrons in the new dispatcher design
     COMPLETED = RESULT_STATUS.COMPLETED
     POSTPROCESSING = RESULT_STATUS.POSTPROCESSING
     PENDING_POSTPROCESSING = RESULT_STATUS.PENDING_POSTPROCESSING
@@ -92,19 +96,26 @@
 
         self._num_nodes = -1
 
-        self._inputs = {"args": [], "kwargs": {}}
-        if lattice.args:
-            self._inputs["args"] = lattice.args
-        if lattice.kwargs:
-            self._inputs["kwargs"] = lattice.kwargs
-
-        self._error = None
+        self._error = ""
 
     def __str__(self):
         """String representation of the result object"""
 
-        arg_str_repr = [e.object_string for e in self.inputs["args"]]
-        kwarg_str_repr = {key: value.object_string for key, value in self.inputs["kwargs"].items()}
+        if isinstance(self.inputs, TransportableObject):
+            input_string = self.inputs.object_string
+
+            regex = r"^\{'args': \((.*)\), 'kwargs': \{(.*)\}\}$"
+            pattern = re.compile(regex)
+            m = pattern.match(input_string)
+            if m:
+                arg_str_repr = m[1].rstrip(",")
+                kwarg_str_repr = m[2]
+            else:
+                arg_str_repr = str(None)
+                kwarg_str_repr = str(None)
+        else:
+            arg_str_repr = str(None)
+            kwarg_str_repr = str(None)
 
         show_result_str = f"""
 Lattice Result
@@ -200,15 +211,18 @@
         Final result of current dispatch.
         """
 
-        return self._result.get_deserialized()
+        if self._result is not None:
+            return self._result.get_deserialized()
+        else:
+            return None
 
     @property
     def inputs(self) -> dict:
         """
         Inputs sent to the "Lattice" function for dispatching.
         """
 
-        return self._inputs
+        return self.lattice.inputs
 
     @property
     def error(self) -> str:
@@ -327,8 +341,9 @@
         with active_lattice_manager.claim(lattice):
             lattice.post_processing = True
             lattice.electron_outputs = ordered_node_outputs
-            args = [arg.get_deserialized() for arg in lattice.args]
-            kwargs = {k: v.get_deserialized() for k, v in lattice.kwargs.items()}
+            inputs = self.lattice.inputs.get_deserialized()
+            args = inputs["args"]
+            kwargs = inputs["kwargs"]
             workflow_function = lattice.workflow_function.get_deserialized()
             result = workflow_function(*args, **kwargs)
             lattice.post_processing = False
@@ -427,7 +442,7 @@
         sublattice_result: "Result" = None,
         stdout: str = None,
         stderr: str = None,
-        qelectron_data_exists: bool = False,
+        qelectron_data_exists: bool = None,
     ) -> None:
         """
         Update the node result in the transport graph.
@@ -486,7 +501,7 @@
         if stderr is not None:
             self.lattice.transport_graph.set_node_value(node_id, "stderr", stderr)
 
-        if qelectron_data_exists:
+        if qelectron_data_exists is not None:
             self.lattice.transport_graph.set_node_value(
                 node_id, "qelectron_data_exists", qelectron_data_exists
             )

covalent/_serialize/__init__.py

@@ -0,0 +1,15 @@
+# Copyright 2021 Agnostiq Inc.
+#
+# This file is part of Covalent.
+#
+# Licensed under the Apache License 2.0 (the "License"). A copy of the
+# License may be obtained with this software package or at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Use of this file is prohibited except in compliance with the License.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.