Merge pull request #68 from alimanfoo/issue_59

implement TempStore; resolves #59

Author: alimanfoo

docs/api/storage.rst

@@ -11,6 +11,7 @@ can be used as a Zarr array store.
 
 .. autoclass:: DictStore
 .. autoclass:: DirectoryStore
+.. autoclass:: TempStore
 .. autoclass:: ZipStore
 
     .. automethod:: close

docs/release.rst

@@ -1,6 +1,9 @@
 Release notes
 =============
 
+* Added :class:`zarr.storage.TempStore` class for convenience to provide
+  storage via a temporary directory
+  (`#59 <https://github.com/alimanfoo/zarr/issues/59>`_)
 * Fixed performance issues with ``ZipStore`` class
   (`#66 <https://github.com/alimanfoo/zarr/issues/27>`_)
 * The Blosc extension has been modified to return bytes instead of array

zarr/__init__.py

@@ -6,7 +6,7 @@
 from zarr.core import Array
 from zarr.creation import empty, zeros, ones, full, array, empty_like, \
     zeros_like, ones_like, full_like, open, open_array, open_like, create
-from zarr.storage import DictStore, DirectoryStore, ZipStore
+from zarr.storage import DictStore, DirectoryStore, ZipStore, TempStore
 from zarr.hierarchy import group, open_group, Group
 from zarr.sync import ThreadSynchronizer, ProcessSynchronizer
 from zarr.codecs import *

zarr/storage.py

@@ -6,6 +6,7 @@
 import json
 import zipfile
 import shutil
+import atexit
 
 
 import numpy as np
@@ -717,6 +718,23 @@ def getsize(self, path=None):
             err_path_not_found(path)
 
 
+def _atexit_rmtree(path,
+                   isdir=os.path.isdir,
+                   rmtree=shutil.rmtree):  # pragma: no cover
+    """Ensure directory removal at interpreter exit."""
+    if isdir(path):
+        rmtree(path)
+
+
+class TempStore(DirectoryStore):
+    """Directory store using a temporary directory for storage."""
+
+    def __init__(self, suffix='', prefix='zarr', dir=None):
+        path = tempfile.mkdtemp(suffix=suffix, prefix=prefix, dir=dir)
+        atexit.register(_atexit_rmtree, path)
+        super(TempStore, self).__init__(path)
+
+
 # noinspection PyPep8Naming
 class ZipStore(MutableMapping):
     """Mutable Mapping interface to a Zip file. Keys must be strings,

zarr/tests/test_storage.py

@@ -15,7 +15,8 @@
 
 
 from zarr.storage import init_array, array_meta_key, attrs_key, DictStore, \
-    DirectoryStore, ZipStore, init_group, group_meta_key, getsize, migrate_1to2
+    DirectoryStore, ZipStore, init_group, group_meta_key, getsize, \
+    migrate_1to2, TempStore
 from zarr.meta import decode_array_metadata, encode_array_metadata, \
     ZARR_FORMAT, decode_group_metadata, encode_group_metadata
 from zarr.compat import text_type
@@ -619,6 +620,16 @@ def test_setdel(self):
         setdel_hierarchy_checks(store)
 
 
+class TestTempStore(StoreTests, unittest.TestCase):
+
+    def create_store(self):
+        return TempStore()
+
+    def test_setdel(self):
+        store = self.create_store()
+        setdel_hierarchy_checks(store)
+
+
 class TestZipStore(StoreTests, unittest.TestCase):
 
     def create_store(self):