working - but extremly primitive - method to sample and batch arrayse…

…t groups

src/hangar/__init__.py

@@ -8,13 +8,15 @@
 def raise_ImportError(message, *args, **kwargs):  # pragma: no cover
     raise ImportError(message)
 
+from .dataloaders.tfloader import make_tf_dataset
+from .dataloaders.torchloader import make_torch_dataset
 
-try:                 # pragma: no cover
-    from .dataloaders.tfloader import make_tf_dataset
-except ImportError:  # pragma: no cover
-    make_tf_dataset = partial(raise_ImportError, "Could not import tensorflow. Install dependencies")
+# try:                 # pragma: no cover
+#     from .dataloaders.tfloader import make_tf_dataset
+# except ImportError:  # pragma: no cover
+#     make_tf_dataset = partial(raise_ImportError, "Could not import tensorflow. Install dependencies")
 
-try:                 # pragma: no cover
-    from .dataloaders.torchloader import make_torch_dataset
-except ImportError:  # pragma: no cover
-    make_torch_dataset = partial(raise_ImportError, "Could not import torch. Install dependencies")
+# try:                 # pragma: no cover
+#     from .dataloaders.torchloader import make_torch_dataset
+# except ImportError:  # pragma: no cover
+#     make_torch_dataset = partial(raise_ImportError, "Could not import torch. Install dependencies")

src/hangar/arrayset.py

@@ -27,8 +27,9 @@
 from .records.parsing import arrayset_record_schema_db_val_from_raw_val
 
 
-CompatibleArray = NamedTuple(
-    'CompatibleArray', [('compatible', bool), ('reason', str)])
+CompatibleArray = NamedTuple('CompatibleArray', [
+    ('compatible', bool),
+    ('reason', str)])
 
 
 class ArraysetDataReader(object):
@@ -305,18 +306,6 @@ def backend_opts(self):
         """
         return self._dflt_backend_opts
 
-    @property
-    def sample_classes(self):
-        grouped_spec_names = defaultdict(list)
-        for name, bespec in self._sspecs.items():
-            grouped_spec_names[bespec].append(name)
-
-        grouped_data_names = {}
-        for spec, names in grouped_spec_names.items():
-            data = self._fs[spec.backend].read_data(spec)
-            grouped_data_names[tuple(data.tolist())] = names
-        return grouped_data_names
-
     def keys(self, local: bool = False) -> Iterator[Union[str, int]]:
         """generator which yields the names of every sample in the arrayset
 

src/hangar/dataloaders/__init__.py

@@ -0,0 +1,3 @@
+from .grouper import GroupedArraysetDataReader
+
+__all__ = ['GroupedArraysetDataReader']

src/hangar/dataloaders/grouper.py

@@ -0,0 +1,125 @@
+import numpy as np
+
+from ..arrayset import ArraysetDataReader
+
+from collections import defaultdict
+import hashlib
+from typing import Sequence, Union, Iterable, NamedTuple
+import struct
+
+
+# -------------------------- typehints ---------------------------------------
+
+
+ArraysetSampleNames = Sequence[Union[str, int]]
+
+SampleGroup = NamedTuple('SampleGroup', [
+    ('group', np.ndarray),
+    ('samples', Union[str, int])])
+
+
+# ------------------------------------------------------------------------------
+
+
+def _calculate_hash_digest(data: np.ndarray) -> str:
+    hasher = hashlib.blake2b(data, digest_size=20)
+    hasher.update(struct.pack(f'<{len(data.shape)}QB', *data.shape, data.dtype.num))
+    digest = hasher.hexdigest()
+    return digest
+
+
+class FakeNumpyKeyDict(object):
+    def __init__(self, group_spec_samples, group_spec_value, group_digest_spec):
+        self._group_spec_samples = group_spec_samples
+        self._group_spec_value = group_spec_value
+        self._group_digest_spec = group_digest_spec
+
+    def __getitem__(self, key: np.ndarray) -> ArraysetSampleNames:
+        digest = _calculate_hash_digest(key)
+        spec = self._group_digest_spec[digest]
+        samples = self._group_spec_samples[spec]
+        return samples
+
+    def get(self, key: np.ndarray) -> ArraysetSampleNames:
+        return self.__getitem__(key)
+
+    def __setitem__(self, key, val):
+        raise PermissionError('Not User Editable')
+
+    def __delitem__(self, key):
+        raise PermissionError('Not User Editable')
+
+    def __len__(self) -> int:
+        return len(self._group_digest_spec)
+
+    def __contains__(self, key: np.ndarray) -> bool:
+        digest = _calculate_hash_digest(key)
+        res = True if digest in self._group_digest_spec else False
+        return res
+
+    def __iter__(self) -> Iterable[np.ndarray]:
+        for spec in self._group_digest_spec.values():
+            yield self._group_spec_value[spec]
+
+    def keys(self) -> Iterable[np.ndarray]:
+        for spec in self._group_digest_spec.values():
+            yield self._group_spec_value[spec]
+
+    def values(self) -> Iterable[ArraysetSampleNames]:
+        for spec in self._group_digest_spec.values():
+            yield self._group_spec_samples[spec]
+
+    def items(self) -> Iterable[ArraysetSampleNames]:
+        for spec in self._group_digest_spec.values():
+            yield (self._group_spec_value[spec], self._group_spec_samples[spec])
+
+    def __repr__(self):
+        print('Mapping: Group Data Value -> Sample Name')
+        for k, v in self.items():
+            print(k, v)
+
+    def _repr_pretty_(self, p, cycle):
+        res = f'Mapping: Group Data Value -> Sample Name \n'
+        for k, v in self.items():
+            res += f'\n {k} :: {v}'
+        p.text(res)
+
+
+
+# ---------------------------- MAIN METHOD ------------------------------------
+
+
+class GroupedArraysetDataReader(object):
+    '''Pass in an arrayset and automatically find sample groups.
+    '''
+
+    def __init__(self, arrayset: ArraysetDataReader, *args, **kwargs):
+
+        self.__arrayset = arrayset  # TODO: Do we actually need to keep this around?
+        self._group_spec_samples = defaultdict(list)
+        self._group_spec_value = {}
+        self._group_digest_spec = {}
+
+        self._setup()
+        self._group_samples = FakeNumpyKeyDict(
+            self._group_spec_samples,
+            self._group_spec_value,
+            self._group_digest_spec)
+
+    def _setup(self):
+        for name, bespec in self.__arrayset._sspecs.items():
+            self._group_spec_samples[bespec].append(name)
+        for spec, names in self._group_spec_samples.items():
+            data = self.__arrayset._fs[spec.backend].read_data(spec)
+            self._group_spec_value[spec] = data
+            digest = _calculate_hash_digest(data)
+            self._group_digest_spec[digest] = spec
+
+    @property
+    def groups(self) -> Iterable[np.ndarray]:
+        for spec in self._group_digest_spec.values():
+            yield self._group_spec_value[spec]
+
+    @property
+    def group_samples(self):
+        return self._group_samples