Isolation level changes.

ChangeLog

@@ -1,3 +1,16 @@
+2005-10-08 Federico Di Gregorio <fog@initd.org>
+
+	* lib/psycopg1.py: explicitly set isolation level to 2 on .connect()
+	to mimic psycopg 1 behaviour.
+
+	* psycopg/connection_int.c: now set isolation level from
+	default_transaction_isolation backend environment value.
+
+	* psycopg/pqpath.c: removed serialization level 3: now everybody
+	(except me) has to use the mnemonics defined in psycopg2.extensions.
+
+	* lib/extensions.py: Added mnemonics for serialization levels.
+
 2005-10-02  Federico Di Gregorio  <fog@debian.org>
 
 	* psycopg/cursor_type.c (psyco_curs_callproc): applied callproc

lib/extensions.py

@@ -41,6 +41,15 @@ from _psycopg import adapt, adapters, encodings, connection, cursor
 from _psycopg import string_types, binary_types, new_type, register_type
 from _psycopg import ISQLQuote
 
+"""Isolation level values."""
+ISOLATION_LEVEL_AUTOCOMMIT    = 0
+ISOLATION_LEVEL_READ_COMMITED = 1 
+ISOLATION_LEVEL_SERIALIZABLE  = 2
+
+# Postgresql maps the the other standard values to already defined levels
+ISOLATION_LEVEL_REPEATABLE_READ  = ISOLATION_LEVEL_SERIALIZABLE
+ISOLATION_LEVEL_READ UNCOMMITTED = ISOLATION_LEVEL_READ_COMMITED
+
 
 def register_adapter(typ, callable):
     """Register 'callable' as an ISQLQuote adapter for type 'typ'."""

lib/psycopg1.py

@@ -31,8 +31,9 @@ del connect
 def connect(*args, **kwargs):
     """connect(dsn, ...) -> new psycopg 1.1.x compatible connection object"""
     kwargs['connection_factory'] = connection
-    return _2psycopg.connect(*args, **kwargs)
-
+    conn = _2psycopg.connect(*args, **kwargs)
+    conn.set_isolation_level(2)
+    return conn
     
 class connection(_2connection):
     """psycopg 1.1.x connection."""

psycopg/connection_int.c

@@ -53,11 +53,18 @@ conn_connect(connectionObject *self)
 {
     PGconn *pgconn;
     PGresult *pgres;
-
+    char *data;
+    
     /* we need the initial date style to be ISO, for typecasters; if the user
        later change it, she must know what she's doing... */
     const char *datestyle = "SET DATESTYLE TO 'ISO'";
     const char *encoding  = "SHOW client_encoding";
+    const char *isolevel  = "SHOW default_transaction_isolation";
+    
+    const char *lvl1a = "read uncommitted";
+    const char *lvl1b = "read committed";
+    const char *lvl2a = "repeatable read";
+    const char *lvl2b = "serializable";
     
     Py_BEGIN_ALLOW_THREADS;
     pgconn = PQconnectdb(self->dsn);
@@ -86,7 +93,6 @@ conn_connect(connectionObject *self)
     Py_END_ALLOW_THREADS;
 
     if (pgres == NULL || PQresultStatus(pgres) != PGRES_COMMAND_OK ) {
-        Dprintf("conn_connect: setting datestyle to iso FAILED");
         PyErr_SetString(OperationalError, "can't set datestyle to ISO");
         PQfinish(pgconn);
         IFCLEARPGRES(pgres);
@@ -99,7 +105,6 @@ conn_connect(connectionObject *self)
     Py_END_ALLOW_THREADS;
 
     if (pgres == NULL || PQresultStatus(pgres) != PGRES_TUPLES_OK) {
-        Dprintf("conn_connect: fetching current client_encoding FAILED");
         PyErr_SetString(OperationalError, "can't fetch client_encoding");
         PQfinish(pgconn);
         IFCLEARPGRES(pgres);
@@ -107,6 +112,26 @@ conn_connect(connectionObject *self)
     }
     self->encoding = strdup(PQgetvalue(pgres, 0, 0));
     CLEARPGRES(pgres);
+    
+    Py_BEGIN_ALLOW_THREADS;
+    pgres = PQexec(pgconn, isolevel);
+    Py_END_ALLOW_THREADS;
+
+    if (pgres == NULL || PQresultStatus(pgres) != PGRES_TUPLES_OK) {
+        PyErr_SetString(OperationalError,
+                         "can't fetch default_isolation_level");
+        PQfinish(pgconn);
+        IFCLEARPGRES(pgres);
+        return -1;
+    }
+    data = PQgetvalue(pgres, 0, 0);
+    if ((strncmp(lvl1a, data, strlen(lvl1a)) == 0)
+        || (strncmp(lvl1b, data, strlen(lvl1b)) == 0))
+        self->isolation_level = 1;
+    else if ((strncmp(lvl2a, data, strlen(lvl2a)) == 0)
+        || (strncmp(lvl2b, data, strlen(lvl2b)) == 0))
+        self->isolation_level = 2;
+    CLEARPGRES(pgres);
 
     if (PQsetnonblocking(pgconn, 1) != 0) {
         Dprintf("conn_connect: PQsetnonblocking() FAILED");

psycopg/connection_type.c

@@ -257,7 +257,6 @@ connection_setup(connectionObject *self, char *dsn)
     self->dsn = strdup(dsn);
     self->notice_list = PyList_New(0);
     self->closed = 0;
-    self->isolation_level = 1;
     self->status = CONN_STATUS_READY;
     self->critical = NULL;
     self->async_cursor = NULL;

psycopg/pqpath.c

@@ -186,7 +186,6 @@ pq_begin(connectionObject *conn)
     const char *query[] = {
         NULL,
         "BEGIN; SET TRANSACTION ISOLATION LEVEL READ COMMITTED",
-        "BEGIN; SET TRANSACTION ISOLATION LEVEL SERIALIZABLE",
         "BEGIN; SET TRANSACTION ISOLATION LEVEL SERIALIZABLE"};
     
     int pgstatus, retvalue = -1;

setup.py

@@ -55,7 +55,7 @@ from distutils.command.build_ext import build_ext
 from distutils.sysconfig import get_python_inc
 from distutils.ccompiler import get_default_compiler
 
-PSYCOPG_VERSION = '2.0b4'
+PSYCOPG_VERSION = '2.0rc1'
 version_flags   = []
 
 # to work around older distutil limitations