Import m_lib/hash

[m_lib.git] / m_lib / hash / ZODBhash.py

diff --git a/m_lib/hash/ZODBhash.py b/m_lib/hash/ZODBhash.py
new file mode 100644 (file)
index 0000000..13073c5
--- /dev/null
+++ b/m_lib/hash/ZODBhash.py
@@ -0,0 +1,81 @@
+"""Provide a (g)dbm-compatible interface to ZODB.
+Author: Oleg Broytman <phd@phd.pp.ru>
+Copyright (C) 2001-2002 PhiloSoft Design
+License: Python"""
+
+
+import sys
+try:
+    from ZODB import FileStorage, DB, POSException
+except ImportError:
+    # prevent a second import of this module from spuriously succeeding
+    del sys.modules[__name__]
+    raise
+
+
+__all__ = ["error", "open"]
+
+error = POSException.POSError                     # Exported for anydbm
+
+
+class ZODBhash:
+    def __init__(self, file, flag, mode=0666, trans_threshold=1000):
+        create = (flag == 'n') # force recreation
+        # if flag == 'w' or 'c' and file does not exist FileStorage will set it to 1 for us 
+
+        self.read_only = read_only = (flag == 'r')
+        self._closed = 0
+
+        self.trans_threshold = trans_threshold
+        self._transcount = 0 # transactions counter - for commiting transactions
+
+        storage = FileStorage.FileStorage(file, create=create, read_only = read_only)
+        db = DB(storage)
+        self.conn = conn = db.open()
+        self.dbroot = conn.root()
+
+    def __del__(self):
+        self.close()
+
+    def keys(self):
+        return self.dbroot.keys()
+
+    def __len__(self):
+        return len(self.dbroot)
+
+    def has_key(self, key):
+        return self.dbroot.has_key(key)
+
+    def get(self, key, default=None):
+        if self.dbroot.has_key(key):
+            return self[key]
+        return default
+
+    def __getitem__(self, key):
+        return self.dbroot[key]
+
+    def __setitem__(self, key, value):
+        self.dbroot[key] = value
+        self._add_tran()
+
+    def __delitem__(self, key):
+        del self.dbroot[key]
+        self._add_tran()
+
+    def close(self):
+        if self._closed: return
+        if not self.read_only:
+            get_transaction().commit()
+            self.conn.db().close()
+        self.conn.close()
+        self._closed = 1
+
+    def _add_tran(self):
+        self._transcount = self._transcount + 1
+        if self._transcount == self.trans_threshold:
+            self._transcount = 0
+            get_transaction().commit()
+
+
+def open(file, flag, mode=0666):
+    return ZODBhash(file, flag, mode)