# # PostgreSQL database interface. Sort of like DBI(3) (Database # independent interface for Perl). # # Mark Huang # Copyright (C) 2006 The Trustees of Princeton University # # $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 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) 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 of the specified value. """ # 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: return pgdb._quote(value) quote = classmethod(quote) def param(self, name, value): # None is converted to the unquoted string NULL if isinstance(value, NoneType): conversion = "s" # True and False are also converted to unquoted strings elif isinstance(value, bool): conversion = "s" elif isinstance(value, float): conversion = "f" elif not isinstance(value, StringTypes): conversion = "d" else: conversion = "s" return '%(' + name + ')' + conversion param = classmethod(param) def begin_work(self): # Implicit in pgdb.connect() pass def commit(self): self.connection.commit() def rollback(self): self.connection.rollback() def do(self, query, params = None): cursor = self.execute(query, params) cursor.close() return self.rowcount 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): return self.execute_array(query, (params,)) def execute_array(self, query, param_seq): 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 Exception, e: try: self.rollback() except: pass uuid = commands.getoutput("uuidgen") print >> log, "Database error %s:" % uuid print >> log, e print >> log, "Query:" print >> log, query print >> log, "Params:" print >> log, pformat(param_seq[0]) 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 selectrow_hashref()). If key_field is specified, return rows as a dictionary keyed on the specified field (like DBI selectall_hashref()). If params is specified, the specified parameters will be bound to the query. """ cursor = self.execute(query, params) rows = cursor.fetchall() cursor.close() 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] rows = [dict(zip(labels, row)) for row in rows] if key_field is not None and key_field in labels: # Return rows as a dictionary keyed on the specified field # (like DBI selectall_hashref()). return dict([(row[key_field], row) for row in rows]) else: return rows def fields(self, table, notnull = None, hasdef = None): """ 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" 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 self.fields_cache[(table, notnull, hasdef)]