Test covers accessor output

model_server/base/api.py

@@ -3,7 +3,7 @@ from typing import Union
 
 from fastapi import FastAPI, HTTPException
 from .accessors import generate_file_accessor
-from .session import session, AccessorIdError, InvalidPathError
+from .session import session, AccessorIdError, InvalidPathError, WriteAccessorError
 
 app = FastAPI(debug=True)
 
@@ -86,5 +86,11 @@ def read_accessor_from_file(filename: str, accessor_id: Union[str, None] = None)
     acc = generate_file_accessor(fp)
     return session.add_accessor(acc, accessor_id=accessor_id)
 
-
-
+@app.put('/accessors/write_to_file/{accessor_id}')
+def write_accessor_to_file(accessor_id: str, filename: Union[str, None] = None) -> str:
+    try:
+        return session.write_accessor(accessor_id, filename)
+    except AccessorIdError as e:
+        raise HTTPException(404, f'Did not find accessor with ID {accessor_id}')
+    except WriteAccessorError as e:
+        raise HTTPException(409, str(e))
\ No newline at end of file

model_server/base/session.py

@@ -118,7 +118,10 @@ class _Session(object):
         """
         List information about all accessors in JSON-readable format
         """
-        return pd.DataFrame(self.accessors).drop('object').to_dict()
+        if len(self.accessors):
+            return pd.DataFrame(self.accessors).drop('object').to_dict()
+        else:
+            return {}
 
     def get_accessor_info(self, acc_id: str) -> dict:
         """
@@ -142,6 +145,26 @@ class _Session(object):
             self.del_accessor(acc_id)
         return acc
 
+    def write_accessor(self, acc_id: str, filename: Union[str, None] = None) -> str:
+        """
+        Write an accessor to file and unload it from the session
+        """
+        if filename is None:
+            fp = self.paths['outbound_images'] / f'{acc_id}.tif'
+        else:
+            fp = self.paths['outbound_images'] / filename
+        acc = self.get_accessor(acc_id, pop=True)
+
+        old_fp = self.accessors[acc_id]['filepath']
+        if old_fp != '':
+            raise WriteAccessorError(
+                f'Cannot overwrite accessor that is already written to {old_fp}'
+            )
+
+        acc.write(fp)
+        self.accessors[acc_id]['filepath'] = fp.__str__()
+        return fp.__str__()
+
     @staticmethod
     def make_paths(root: str = None) -> dict:
         """
@@ -273,6 +296,9 @@ class CouldNotInstantiateModelError(Error):
 class AccessorIdError(Error):
     pass
 
+class WriteAccessorError(Error):
+    pass
+
 class CouldNotCreateDirectory(Error):
     pass
 

tests/base/test_api.py

 from pathlib import Path
 
 from fastapi import APIRouter
+import numpy as np
 from pydantic import BaseModel
 
 import model_server.conf.testing as conf
+from model_server.base.accessors import InMemoryDataAccessor, generate_file_accessor
 from model_server.base.api import app
 from model_server.base.session import session
 from tests.base.test_model import DummyInstanceSegmentationModel, DummySemanticSegmentationModel
@@ -24,6 +26,18 @@ class BounceBackParams(BaseModel):
 def list_bounce_back(params: BounceBackParams):
     return {'success': True, 'params': {'par1': params.par1, 'par2': params.par2}}
 
+@router.put('/accessors/dummy_accessor/load')
+def load_dummy_accessor() -> str:
+    acc = InMemoryDataAccessor(
+        np.random.randint(
+            0,
+            2 ** 8,
+            size=(512, 256, 3, 7),
+            dtype='uint8'
+        )
+    )
+    return session.add_accessor(acc)
+
 @router.put('/models/dummy_semantic/load/')
 def load_dummy_model() -> dict:
     mid = session.load_model(DummySemanticSegmentationModel)
@@ -220,3 +234,25 @@ class TestApiFromAutomatedClient(TestServerTestCase):
         # and try a non-existent accessor ID
         resp_wrong_acc = self._get('accessors/auto_123456')
         self.assertEqual(resp_wrong_acc.status_code, 404)
+
+    def test_empty_accessor_list(self):
+        resp_list_acc = self._get(
+            f'accessors',
+        )
+        self.assertEqual(len(resp_list_acc.json()), 0)
+
+    def test_write_accessor(self):
+        acc_id = self._put('/testing/accessors/dummy_accessor/load').json()
+        self.assertTrue(self._get(f'accessors/{acc_id}').json()['loaded'])
+        sd = self._get(f'accessors/{acc_id}').json()['shape_dict']
+        self.assertEqual(self._get(f'accessors/{acc_id}').json()['filepath'], '')
+
+        filename = 'test_output.tif'
+        self._put(f'/accessors/write_to_file/{acc_id}', query={'filename': filename})
+        where_out = self._get('paths').json()['outbound_images']
+        fp_out = (Path(where_out) / filename)
+
+        self.assertTrue(fp_out.exists())
+
+        acc_out = generate_file_accessor(fp_out)
+        self.assertEqual(sd, acc_out.shape_dict)
\ No newline at end of file