Moved storage out of the main class and into a more extendable struct…

…ure allowing other backends to be used.

pycache/pycache.py

@@ -0,0 +1,39 @@
+from time import time
+
+class PyCache:
+    TABLE = 'PyCache'
+    KEY = 'PyCache_key'
+    VALUE = 'PyCache_value'
+    EXPIRES = 'PyCache_expires'
+
+    def __init__(self, **kwargs):
+        if 'engine' in kwargs:
+            self.storage = kwargs['engine'](**kwargs)
+
+        #One hour default expiration
+        self.default_length = 3600
+
+    def create(self):
+        self.storage.create()
+
+    def gc(self):
+        self.storage.gc()
+
+    def store(self, key, value, expires):
+        self.storage.store(key, value, expires)
+
+    def expire(self, key):
+        self.storage.expire(key)
+
+    def get(self, key):
+        result = self.storage.fetch(key)
+        if not result or result[PyCache.EXPIRES] < time():
+            return False
+        return result[PyCache.VALUE]
+
+    def __setitem__(self, key, value):
+        self.store(key, value, time() + self.default_length)
+    def __getitem__(self, key):
+        return self.get(key)
+    def __delitem__(self, key):
+        return self.storage.expire(key)

pycache/storage/__init__.py

@@ -0,0 +1 @@
+__all__ = ['storage', 'sqlite']

pycache/storage/sqlite.py

@@ -0,0 +1,38 @@
+import sqlite3
+from pycache import PyCache
+from storage import storage
+from time import time
+
+class SQLite(storage):
+    def __init__(self, **kwargs):
+        if 'file' in kwargs:
+            self.file = kwargs['file']
+        else:
+            self.file = 'PyCache.db'
+        self.conn = sqlite3.connect(self.file)
+        self.curs = self.conn.cursor()
+
+        if 'table' in kwargs:
+            self.table = kwargs['table'] + '_' + PyCache.TABLE
+        else:
+            self.table = PyCache.TABLE
+
+    def create(self):
+        self.curs.execute("CREATE TABLE %s (%s VARCHAR(32) PRIMARY KEY, %s TEXT, %s INTEGER)" % (self.table, PyCache.KEY, PyCache.VALUE, PyCache.EXPIRES))
+        self.curs.execute("CREATE INDEX %s_%s ON %s (%s)" % (self.table, PyCache.EXPIRES, self.table, PyCache.EXPIRES))
+
+    def store(self, key, value, expires):
+        self.curs.execute("REPLACE INTO %s (%s, %s, %s) VALUES (?, ?, ?)" % (self.table, PyCache.KEY, PyCache.VALUE, PyCache.EXPIRES), (key, value, expires))
+
+    def fetch(self, key):
+        self.curs.execute("SELECT %s, %s FROM %s WHERE %s=?" % (PyCache.VALUE, PyCache.EXPIRES, self.table, PyCache.KEY), (key,))
+        result = self.curs.fetchone()
+        if not result:
+            return False
+        return {PyCache.VALUE: result[0], PyCache.EXPIRES: int(result[1])}
+
+    def expire(self, key):
+        self.curs.execute("REPLACE INTO %s (%s, %s) VALUES (?, ?)" % (self.table, PyCache.KEY, PyCache.EXPIRES), (key, time()))
+
+    def gc(self):
+        self.curs.execute("DELETE FROM %s WHERE %s < ?" % (self.table, PyCache.EXPIRES), (time(),))

pycache/storage/storage.py

@@ -0,0 +1,6 @@
+class storage:
+    def create(self): pass
+    def store(self, key, value, expires): pass
+    def fetch(self, key): pass
+    def expire(self, key): pass
+    def gc(self): pass