First draft for leases
[plcapi.git] / PLC / PostgreSQL.py
index 6286a1a..09132e2 100644 (file)
@@ -5,7 +5,8 @@
 # Mark Huang <mlhuang@cs.princeton.edu>
 # Copyright (C) 2006 The Trustees of Princeton University
 #
-# $Id: PostgreSQL.py,v 1.10 2006/11/09 19:34:04 mlhuang Exp $
+# $Id$
+# $URL$
 #
 
 import psycopg2
@@ -24,60 +25,46 @@ from pprint import pformat
 from PLC.Debug import profile, log
 from PLC.Faults import *
 
-if not psycopg2:
-    is8bit = re.compile("[\x80-\xff]").search
-
-    def unicast(typecast):
-        """
-        pgdb returns raw UTF-8 strings. This function casts strings that
-        appear to contain non-ASCII characters to unicode objects.
-        """
-    
-        def wrapper(*args, **kwds):
-            value = typecast(*args, **kwds)
-
-            # pgdb always encodes unicode objects as UTF-8 regardless of
-            # the DB encoding (and gives you no option for overriding
-            # the encoding), so always decode 8-bit objects as UTF-8.
-            if isinstance(value, str) and is8bit(value):
-                value = unicode(value, "utf-8")
-
-            return value
-
-        return wrapper
-
-    pgdb.pgdbTypeCache.typecast = unicast(pgdb.pgdbTypeCache.typecast)
-
 class PostgreSQL:
     def __init__(self, api):
         self.api = api
+        self.debug = False
+#        self.debug = True
+        self.connection = None
 
-        # Initialize database connection
-        if psycopg2:
+    def cursor(self):
+        if self.connection is None:
+            # (Re)initialize database connection
             try:
                 # Try UNIX socket first
-                self.db = psycopg2.connect(user = api.config.PLC_DB_USER,
-                                           password = api.config.PLC_DB_PASSWORD,
-                                           database = api.config.PLC_DB_NAME)
+                self.connection = psycopg2.connect(user = self.api.config.PLC_DB_USER,
+                                                   password = self.api.config.PLC_DB_PASSWORD,
+                                                   database = self.api.config.PLC_DB_NAME)
             except psycopg2.OperationalError:
                 # Fall back on TCP
-                self.db = psycopg2.connect(user = api.config.PLC_DB_USER,
-                                           password = api.config.PLC_DB_PASSWORD,
-                                           database = api.config.PLC_DB_NAME,
-                                           host = api.config.PLC_DB_HOST,
-                                           port = api.config.PLC_DB_PORT)
-            self.db.set_client_encoding("UNICODE")
-        else:
-            self.db = pgdb.connect(user = api.config.PLC_DB_USER,
-                                   password = api.config.PLC_DB_PASSWORD,
-                                   host = "%s:%d" % (api.config.PLC_DB_HOST, api.config.PLC_DB_PORT),
-                                   database = api.config.PLC_DB_NAME)
-
-        self.cursor = self.db.cursor()
+                self.connection = psycopg2.connect(user = self.api.config.PLC_DB_USER,
+                                                   password = self.api.config.PLC_DB_PASSWORD,
+                                                   database = self.api.config.PLC_DB_NAME,
+                                                   host = self.api.config.PLC_DB_HOST,
+                                                   port = self.api.config.PLC_DB_PORT)
+            self.connection.set_client_encoding("UNICODE")
 
         (self.rowcount, self.description, self.lastrowid) = \
                         (None, None, None)
 
+        return self.connection.cursor()
+
+    def close(self):
+        if self.connection is not None:
+            self.connection.close()
+            self.connection = None
+
+    # join insists on getting strings
+    @classmethod
+    def quote_string(self, value):
+        return str(PostgreSQL.quote(value))
+
+    @classmethod
     def quote(self, value):
         """
         Returns quoted version of the specified value.
@@ -86,12 +73,11 @@ class PostgreSQL:
         # The pgdb._quote function is good enough for general SQL
         # quoting, except for array types.
         if isinstance(value, (list, tuple, set)):
-            return "ARRAY[%s]" % ", ".join(map, self.quote, value)
+            return "ARRAY[%s]" % ", ".join(map (PostgreSQL.quote_string, value))
         else:
             return pgdb._quote(value)
 
-    quote = classmethod(quote)
-
+    @classmethod
     def param(self, name, value):
         # None is converted to the unquoted string NULL
         if isinstance(value, NoneType):
@@ -108,22 +94,30 @@ class PostgreSQL:
 
         return '%(' + name + ')' + conversion
 
-    param = classmethod(param)
-
     def begin_work(self):
         # Implicit in pgdb.connect()
         pass
 
     def commit(self):
-        self.db.commit()
+        self.connection.commit()
 
     def rollback(self):
-        self.db.rollback()
+        self.connection.rollback()
 
     def do(self, query, params = None):
-        self.execute(query, params)
+        cursor = self.execute(query, params)
+        cursor.close()
         return self.rowcount
 
+    def next_id(self, table_name, primary_key):
+       sequence = "%(table_name)s_%(primary_key)s_seq" % locals()      
+       sql = "SELECT nextval('%(sequence)s')" % locals()
+       rows = self.selectall(sql, hashref = False)
+       if rows: 
+           return rows[0][0]
+               
+       return None 
+
     def last_insert_id(self, table_name, primary_key):
         if isinstance(self.lastrowid, int):
             sql = "SELECT %s FROM %s WHERE oid = %d" % \
@@ -134,18 +128,44 @@ class PostgreSQL:
 
         return None
 
+    # modified for psycopg2-2.0.7 
+    # executemany is undefined for SELECT's
+    # see http://www.python.org/dev/peps/pep-0249/
+    # accepts either None, a single dict, a tuple of single dict - in which case it execute's
+    # or a tuple of several dicts, in which case it executemany's
     def execute(self, query, params = None):
-        self.execute_array(query, (params,))
 
-    def execute_array(self, query, param_seq):
-        cursor = self.cursor
+        cursor = self.cursor()
         try:
+
             # psycopg2 requires %()s format for all parameters,
             # regardless of type.
+            # this needs to be done carefully though as with pattern-based filters
+            # we might have percents embedded in the query
+            # so e.g. GetPersons({'email':'*fake*'}) was resulting in .. LIKE '%sake%'
             if psycopg2:
                 query = re.sub(r'(%\([^)]*\)|%)[df]', r'\1s', query)
-
-            cursor.executemany(query, param_seq)
+            # rewrite wildcards set by Filter.py as '***' into '%'
+            query = query.replace ('***','%')
+
+            if not params:
+                if self.debug:
+                    print >> log,'execute0',query
+                cursor.execute(query)
+            elif isinstance(params,dict):
+                if self.debug:
+                    print >> log,'execute-dict: params',params,'query',query%params
+                cursor.execute(query,params)
+            elif isinstance(params,tuple) and len(params)==1:
+                if self.debug:
+                    print >> log,'execute-tuple',query%params[0]
+                cursor.execute(query,params[0])
+            else:
+                param_seq=(params,)
+                if self.debug:
+                    for params in param_seq:
+                        print >> log,'executemany',query%params
+                cursor.executemany(query, param_seq)
             (self.rowcount, self.description, self.lastrowid) = \
                             (cursor.rowcount, cursor.description, cursor.lastrowid)
         except Exception, e:
@@ -159,12 +179,14 @@ class PostgreSQL:
             print >> log, "Query:"
             print >> log, query
             print >> log, "Params:"
-            print >> log, pformat(param_seq[0])
+            print >> log, pformat(params)
             raise PLCDBError("Please contact " + \
                              self.api.config.PLC_NAME + " Support " + \
                              "<" + self.api.config.PLC_MAIL_SUPPORT_ADDRESS + ">" + \
                              " and reference " + uuid)
 
+        return cursor
+
     def selectall(self, query, params = None, hashref = True, key_field = None):
         """
         Return each row as a dictionary keyed on field name (like DBI
@@ -173,13 +195,13 @@ class PostgreSQL:
         selectall_hashref()).
 
         If params is specified, the specified parameters will be bound
-        to the query (see PLC.DB.parameterize() and
-        pgdb.cursor.execute()).
+        to the query.
         """
 
-        self.execute(query, params)
-        rows = self.cursor.fetchall()
-
+        cursor = self.execute(query, params)
+        rows = cursor.fetchall()
+        cursor.close()
+        self.commit()
         if hashref or key_field is not None:
             # Return each row as a dictionary keyed on field name
             # (like DBI selectrow_hashref()).
@@ -198,6 +220,12 @@ class PostgreSQL:
         Return the names of the fields of the specified table.
         """
 
+        if hasattr(self, 'fields_cache'):
+            if self.fields_cache.has_key((table, notnull, hasdef)):
+                return self.fields_cache[(table, notnull, hasdef)]
+        else:
+            self.fields_cache = {}
+
         sql = "SELECT attname FROM pg_attribute, pg_class" \
               " WHERE pg_class.oid = attrelid" \
               " AND attnum > 0 AND relname = %(table)s"
@@ -210,4 +238,6 @@ class PostgreSQL:
 
         rows = self.selectall(sql, locals(), hashref = False)
 
-        return [row[0] for row in rows]
+        self.fields_cache[(table, notnull, hasdef)] = [row[0] for row in rows]
+
+        return self.fields_cache[(table, notnull, hasdef)]