Merge remote-tracking branch 'origin/pycurl' into planetlab-4_0-branch
[plcapi.git] / PLC / PostgreSQL.py
index 9eff584..c58a69f 100644 (file)
@@ -5,46 +5,99 @@
 # Mark Huang <mlhuang@cs.princeton.edu>
 # Copyright (C) 2006 The Trustees of Princeton University
 #
-# $Id: PostgreSQL.py,v 1.1 2006/09/06 15:36:07 mlhuang Exp $
+# $Id: PostgreSQL.py 5574 2007-10-25 20:33:17Z thierry $
 #
 
+import psycopg2
+import psycopg2.extensions
+psycopg2.extensions.register_type(psycopg2.extensions.UNICODE)
+# UNICODEARRAY not exported yet
+psycopg2.extensions.register_type(psycopg2._psycopg.UNICODEARRAY)
+
 import pgdb
 from types import StringTypes, NoneType
 import traceback
 import commands
+import re
 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
-
-        # Initialize database connection
-        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.debug = False
+        self.connection = None
+
+    def cursor(self):
+        if self.connection is None:
+            # (Re)initialize database connection
+            if psycopg2:
+                try:
+                    # Try UNIX socket first
+                    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.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")
+            else:
+                self.connection = pgdb.connect(user = self.api.config.PLC_DB_USER,
+                                               password = self.api.config.PLC_DB_PASSWORD,
+                                               host = "%s:%d" % (api.config.PLC_DB_HOST, api.config.PLC_DB_PORT),
+                                               database = self.api.config.PLC_DB_NAME)
 
         (self.rowcount, self.description, self.lastrowid) = \
                         (None, None, None)
 
-    def quote(self, params):
+        return self.connection.cursor()
+
+    def close(self):
+        if self.connection is not None:
+            self.connection.close()
+            self.connection = None
+
+    def quote(self, value):
         """
-        Returns quoted version(s) of the specified parameter(s).
+        Returns quoted version of the specified value.
         """
 
-        # pgdb._quote functions are good enough for general SQL quoting
-        if hasattr(params, 'has_key'):
-            params = pgdb._quoteitem(params)
-        elif isinstance(params, list) or isinstance(params, tuple):
-            params = map(pgdb._quote, params)
+        # 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)
         else:
-            params = pgdb._quote(params)
-
-        return params
+            return pgdb._quote(value)
 
     quote = classmethod(quote)
 
@@ -71,29 +124,52 @@ class PostgreSQL:
         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 last_insert_id(self):
-        return self.lastrowid
+    def last_insert_id(self, table_name, primary_key):
+        if isinstance(self.lastrowid, int):
+            sql = "SELECT %s FROM %s WHERE oid = %d" % \
+                  (primary_key, table_name, self.lastrowid)
+            rows = self.selectall(sql, hashref = False)
+            if rows:
+                return rows[0][0]
+
+        return None
 
     def execute(self, query, params = None):
-        self.execute_array(query, (params,))
+        return self.execute_array(query, (params,))
 
     def execute_array(self, query, param_seq):
-        cursor = self.cursor
+        cursor = self.cursor()
         try:
+            if self.debug:
+                for params in param_seq:
+                    if params:
+                        print >> log, query % params
+                    else:
+                        print >> log, query
+
+            # psycopg2 requires %()s format for all parameters,
+            # regardless of type.
+            if psycopg2:
+                query = re.sub(r'(%\([^)]*\)|%)[df]', r'\1s', query)
+
             cursor.executemany(query, param_seq)
             (self.rowcount, self.description, self.lastrowid) = \
                             (cursor.rowcount, cursor.description, cursor.lastrowid)
-        except pgdb.DatabaseError, e:
-            self.rollback()
+        except Exception, e:
+            try:
+                self.rollback()
+            except:
+                pass
             uuid = commands.getoutput("uuidgen")
             print >> log, "Database error %s:" % uuid
             print >> log, e
@@ -106,6 +182,8 @@ class PostgreSQL:
                              "<" + 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
@@ -114,14 +192,14 @@ 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()
 
-        if hashref:
+        if hashref or key_field is not None:
             # Return each row as a dictionary keyed on field name
             # (like DBI selectrow_hashref()).
             labels = [column[0] for column in self.description]
@@ -134,15 +212,29 @@ class PostgreSQL:
         else:
             return rows
 
-    def fields(self, table):
+    def fields(self, table, notnull = None, hasdef = None):
         """
         Return the names of the fields of the specified table.
         """
 
-        rows = self.selectall("SELECT attname FROM pg_attribute, pg_class" \
-                              " WHERE pg_class.oid = attrelid" \
-                              " AND attnum > 0 AND relname = %(table)s",
-                              locals(),
-                              hashref = False)
+        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"
+
+        if notnull is not None:
+            sql += " AND attnotnull is %(notnull)s"
+
+        if hasdef is not None:
+            sql += " AND atthasdef is %(hasdef)s"
+
+        rows = self.selectall(sql, locals(), hashref = False)
+
+        self.fields_cache[(table, notnull, hasdef)] = [row[0] for row in rows]
 
-        return [row[0] for row in rows]
+        return self.fields_cache[(table, notnull, hasdef)]