Close the underlying iterator.

Fixes #4.

Also add PyPy support.

Modernize the .travis.yml: sudo false, pip caching, same testrunner as
tox.ini.

Pin ZODB/ZEO to old versions because ServerZlibStorage is broken for
ZODB 5. Will address in a subsequent PR.

.travis.yml

@@ -1,12 +1,18 @@
+sudo: false
 language: python
 python:
     - 2.7
     - 3.4
     - 3.5
+    - 3.6
+    - pypy-5.4.1
 install:
-    - pip install zc.buildout
-    - buildout
+    - pip install -U pip setuptools
+    - pip install -U -e .[test] zope.testrunner
 script:
-    - bin/test -v1j99
+    - zope-testrunner --test-path=src -v1j99
 notifications:
     email: false
+cache: pip
+before_cache:
+  - rm -f $HOME/.cache/pip/log/debug.log

CHANGES.rst

@@ -1,8 +1,21 @@
-Changes
-=======
+=========
+ Changes
+=========
+
+1.2.0 (unreleased)
+==================
+
+- Add support for Python 3.6 and PyPy.
+
+- Restrict ZODB dependency to less than 5.0. ServerZlibStorage
+  currently doesn't work with ZEO 5.
+  (https://github.com/zopefoundation/zc.zlibstorage/issues/5).
+
+- Close the underlying iterator used by the ``iterator`` wrapper when
+  it is closed. (https://github.com/zopefoundation/zc.zlibstorage/issues/4)
 
 1.1.0 (2016-08-03)
-------------------
+==================
 
 - Fixed an incompatibility with ZODB5.  The previously optional and
   ignored version argument to the database ``invalidate`` method is now
@@ -11,16 +24,16 @@ Changes
 - Drop Python 2.6, 3.2, and 3.3 support. Added Python 3.4 and 3.5 support.
 
 1.0.0 (2015-11-11)
-------------------
+==================
 
 - Python 3 support contributed by Christian Tismer.
 
 0.1.1 (2010-05-26)
-------------------
+==================
 
 - Fixed a packaging bug.
 
 0.1.0 (2010-05-20)
-------------------
+==================
 
 Initial release

setup.py

@@ -13,8 +13,8 @@
 ##############################################################################
 name, version = 'zc.zlibstorage', '1.1.0'
 
-install_requires = ['setuptools', 'ZODB', 'zope.interface']
-extras_require = dict(test=['zope.testing', 'manuel', 'ZEO'])
+install_requires = ['setuptools', 'ZODB < 5', 'zope.interface']
+extras_require = dict(test=['zope.testing', 'manuel', 'ZEO[test] < 5'])
 
 entry_points = """
 """
@@ -41,9 +41,13 @@ def read(filename):
     long_description=long_description,
     description=long_description.split('\n')[1],
     classifiers=[
+        "Programming Language :: Python",
         'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
+        'Programming Language :: Python :: 3.6',
+        "Programming Language :: Python :: Implementation :: CPython",
+        "Programming Language :: Python :: Implementation :: PyPy",
     ],
     packages=[name.split('.')[0], name],
     namespace_packages=[name.split('.')[0]],

src/zc/zlibstorage/__init__.py

@@ -95,8 +95,7 @@ def restore(self, oid, serial, data, version, prev_txn, transaction):
             oid, serial, self._transform(data), version, prev_txn, transaction)
 
     def iterator(self, start=None, stop=None):
-        for t in self.base.iterator(start, stop):
-            yield Transaction(t)
+        return _Iterator(self.base.iterator(start, stop))
 
     def storeBlob(self, oid, oldserial, data, blobfilename, version,
                   transaction):
@@ -156,6 +155,35 @@ class ServerZlibStorage(ZlibStorage):
         'iterator', 'storeBlob', 'restoreBlob', 'record_iternext',
         )
 
+class _Iterator(object):
+    # A class that allows for proper closing of the underlying iterator
+    # as well as avoiding any GC issues.
+    # (https://github.com/zopefoundation/zc.zlibstorage/issues/4)
+
+    def __init__(self, base_it):
+        self._base_it = base_it
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        return Transaction(next(self._base_it))
+
+    next = __next__
+
+    def close(self):
+        try:
+            base_close = self._base_it.close
+        except AttributeError:
+            pass
+        else:
+            base_close()
+        finally:
+            self._base_it = iter(())
+
+    def __getattr__(self, name):
+        return getattr(self._base_it, name)
+
 class Transaction(object):
 
     def __init__(self, trans):

src/zc/zlibstorage/tests.py

@@ -38,6 +38,10 @@
 
 import zc.zlibstorage
 
+def _copy(dest, src):
+    with open(src, 'rb') as srcf:
+        with open(dest, 'wb') as destf:
+            destf.write(srcf.read())
 
 def test_config():
     r"""
@@ -185,7 +189,7 @@ def test_mixed_compressed_and_uncompressed_and_packing():
 
 - using the compressed storage:
 
-    >>> _ = open('data.fs.save', 'wb').write(open('data.fs', 'rb').read())
+    >>> _copy('data.fs.save', 'data.fs')
     >>> db = ZODB.DB(zc.zlibstorage.ZlibStorage(
     ...     ZODB.FileStorage.FileStorage('data.fs', blob_dir='blobs')))
     >>> db.pack()
@@ -195,7 +199,7 @@ def test_mixed_compressed_and_uncompressed_and_packing():
 
 - using the storage in non-compress mode:
 
-    >>> _ = open('data.fs', 'wb').write(open('data.fs.save', 'rb').read())
+    >>> _copy('data.fs', 'data.fs.save')
     >>> db = ZODB.DB(zc.zlibstorage.ZlibStorage(
     ...     ZODB.FileStorage.FileStorage('data.fs', blob_dir='blobs'),
     ...     compress=False))
@@ -207,7 +211,7 @@ def test_mixed_compressed_and_uncompressed_and_packing():
 
 - using the server storage:
 
-    >>> _ = open('data.fs', 'wb').write(open('data.fs.save', 'rb').read())
+    >>> _copy('data.fs', 'data.fs.save')
     >>> db = ZODB.DB(zc.zlibstorage.ServerZlibStorage(
     ...     ZODB.FileStorage.FileStorage('data.fs', blob_dir='blobs'),
     ...     compress=False))
@@ -219,7 +223,7 @@ def test_mixed_compressed_and_uncompressed_and_packing():
 
 - using the server storage in non-compress mode:
 
-    >>> _ = open('data.fs', 'wb').write(open('data.fs.save', 'rb').read())
+    >>> _copy('data.fs', 'data.fs.save')
     >>> db = ZODB.DB(zc.zlibstorage.ServerZlibStorage(
     ...     ZODB.FileStorage.FileStorage('data.fs', blob_dir='blobs'),
     ...     compress=False))
@@ -400,6 +404,57 @@ def getConfig(self):
         </serverzlibstorage>
         """
 
+class TestIterator(unittest.TestCase):
+
+    def test_iterator_closes_underlying_explicitly(self):
+        # https://github.com/zopefoundation/zc.zlibstorage/issues/4
+
+        class Storage(object):
+
+            storage_value = 42
+            iterator_closed = False
+
+            def registerDB(self, db):
+                pass
+
+            def iterator(self, start=None, stop=None):
+                return self
+
+            def __iter__(self):
+                return self
+
+            def __next__(self):
+                return self
+
+            next = __next__
+
+            def close(self):
+                self.iterator_closed = True
+
+        storage = Storage()
+        zstorage = zc.zlibstorage.ZlibStorage(storage)
+
+        it = zstorage.iterator()
+
+        # Make sure it proxies all attributes
+        self.assertEqual(42, getattr(it, 'storage_value'))
+
+        # Make sure it iterates (whose objects also proxy)
+        self.assertEqual(42, getattr(next(it), 'storage_value'))
+
+        # The real iterator is closed
+        it.close()
+
+        self.assertTrue(storage.iterator_closed)
+
+        # And we can't move on; the wrapper prevents it even though
+        # the underlying storage implementation is broken
+        self.assertRaises(StopIteration, next, it)
+
+        # We can keep closing it though
+        it.close()
+
+
 def test_suite():
     suite = unittest.TestSuite()
     for class_ in (
@@ -415,8 +470,10 @@ def test_suite():
             'zlibstoragetests.%s' % class_.__name__)
         suite.addTest(s)
 
+    suite.addTest(unittest.makeSuite(TestIterator))
+
     # The conflict resolution and blob tests don't exercise proper
-    # plumbing for libstorage because the sample data they use
+    # plumbing for zlibstorage because the sample data they use
     # compresses to larger than the original.  Run the tests again
     # after monkey patching zlibstorage to compress everything.
 
@@ -442,6 +499,9 @@ def tearDown(self):
         # Py3k renders bytes where Python2 used native strings...
         (re.compile(r"b'"), "'"),
         (re.compile(r'b"'), '"'),
+        # Older versions of PyPy2 (observed in PyPy2 5.4 but not 5.6)
+        # produce long integers (1L) where we expect normal ints
+        (re.compile(r"(\d)L"), r"\1")
     ])
 
     suite.addTest(doctest.DocTestSuite(
@@ -454,4 +514,3 @@ def tearDown(self):
         setUp=setupstack.setUpDirectory, tearDown=setupstack.tearDown
         ))
     return suite
-

tox.ini

@@ -1,11 +1,10 @@
 [tox]
 envlist =
-    py26,py27,py32,py33
+    py27,py34,py35,py36,pypy
 
 [testenv]
 deps =
-    zope.testing
-    manuel
-    ZEO
+    .[test]
+    zope.testrunner
 commands =
-    python setup.py test -q
+    zope-testrunner --test-path=src -v1j99