Deserialize appose_type "shm" and "ndarray"

src/appose/types.py

@@ -29,6 +29,7 @@
 
 import json
 from typing import Any, Dict
+from multiprocessing import shared_memory
 
 Args = Dict[str, Any]
 
@@ -38,4 +39,34 @@ def encode(data: Args) -> str:
 
 
 def decode(the_json: str) -> Args:
-    return json.loads(the_json)
+    return json.loads(the_json, object_hook=_appose_object_hook)
+
+
+class ShmNDArray:
+
+    def __init__(self, shm: shared_memory.SharedMemory, dtype: str, shape ):
+        self.shm = shm
+        self.dtype = dtype
+        self.shape = shape
+
+    def __str__(self):
+        return f"ShmNDArray(shm='{self.shm.name}' ({self.shm.size}), dtype='{self.dtype}', shape={self.shape})"
+
+    def ndarray(self):
+        try:
+            import math
+            import numpy
+            num_elements = math.prod(self.shape)
+            return numpy.ndarray(num_elements, dtype=self.dtype, buffer=self.shm.buf).reshape(self.shape)
+        except ModuleNotFoundError:
+            raise ImportError("NumPy is not available.")
+
+
+def _appose_object_hook(obj: Dict):
+    type = obj.get('appose_type')
+    if type == 'shm':
+        return shared_memory.SharedMemory(name=(obj['name']), size=(obj['size']))
+    elif type == 'ndarray':
+        return ShmNDArray(obj['shm'], obj['dtype'], obj['shape'])
+    else:
+        return obj