CodernityDB python 3

libs/CodernityDB3/storage.py

@@ -0,0 +1,162 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2011-2013 Codernity (http://codernity.com)
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import os
+import struct
+import shutil
+import marshal
+import io
+
+
+try:
+    from CodernityDB3 import __version__
+except ImportError:
+    from .__init__ import __version__
+
+
+class StorageException(Exception):
+    pass
+
+
+class DummyStorage(object):
+    """
+    Storage mostly used to fake real storage
+    """
+
+    def create(self, *args, **kwargs):
+        pass
+
+    def open(self, *args, **kwargs):
+        pass
+
+    def close(self, *args, **kwargs):
+        pass
+
+    def data_from(self, *args, **kwargs):
+        pass
+
+    def data_to(self, *args, **kwargs):
+        pass
+
+    def save(self, *args, **kwargs):
+        return 0, 0
+
+    def insert(self, *args, **kwargs):
+        return self.save(*args, **kwargs)
+
+    def update(self, *args, **kwargs):
+        return 0, 0
+
+    def get(self, *args, **kwargs):
+        return None
+
+    # def compact(self, *args, **kwargs):
+    #     pass
+
+    def fsync(self, *args, **kwargs):
+        pass
+
+    def flush(self, *args, **kwargs):
+        pass
+
+
+class IU_Storage(object):
+
+    __version__ = __version__
+
+    def __init__(self, db_path, name='main'):
+        if isinstance(db_path, bytes):
+            db_path = db_path.decode()
+        if isinstance(name, bytes):
+            name = name.decode()
+
+        self.db_path = db_path
+        self.name = name
+        self._header_size = 100
+
+    def create(self):
+        if os.path.exists(os.path.join(self.db_path, self.name + "_stor")):
+            raise IOError("Storage already exists!")
+        with io.open(os.path.join(self.db_path, self.name + "_stor"), 'wb') as f:
+            if isinstance(self.__version__, str):
+                new_version = self.__version__.encode()
+            else:
+                new_version = self.__version__
+            f.write(struct.pack(b'10s90s', new_version, b'|||||'))
+            f.close()
+        self._f = io.open(os.path.join(
+            self.db_path, self.name + "_stor"), 'r+b', buffering=0)
+        self.flush()
+        self._f.seek(0, 2)
+
+    def open(self):
+        if not os.path.exists(os.path.join(self.db_path, self.name + "_stor")):
+            raise IOError("Storage doesn't exists!")
+        self._f = io.open(os.path.join(
+            self.db_path, self.name + "_stor"), 'r+b', buffering=0)
+        self.flush()
+        self._f.seek(0, 2)
+
+    def destroy(self):
+        os.unlink(os.path.join(self.db_path, self.name + '_stor'))
+
+    def close(self):
+        self._f.close()
+        # self.flush()
+        # self.fsync()
+
+    def data_from(self, data):
+        return marshal.loads(data)
+
+    def data_to(self, data):
+        return marshal.dumps(data)
+
+    def save(self, data):
+        s_data = self.data_to(data)
+        self._f.seek(0, 2)
+        start = self._f.tell()
+        size = len(s_data)
+        self._f.write(s_data)
+        self.flush()
+        return start, size
+
+    def insert(self, data):
+        return self.save(data)
+
+    def update(self, data):
+        return self.save(data)
+
+    def get(self, start, size, status='c'):
+        if status == 'd':
+            return None
+        else:
+            self._f.seek(start)
+            return self.data_from(self._f.read(size))
+
+    def flush(self):
+        self._f.flush()
+
+    def fsync(self):
+        os.fsync(self._f.fileno())
+
+
+# classes for public use, done in this way because of
+# generation static files with indexes (_index directory)
+
+
+class Storage(IU_Storage):
+    pass