psycopg2/psycopg/xid_type.c
Daniele Varrazzo 22aea9114b implement sequence behaviour, as required for transaction IDs.
By James Henstridge on 2008-07-24.

Merged from lp:~jamesh/psycopg/two-phase-commit/revision/357
2010-11-05 09:34:47 +00:00

293 lines
8.1 KiB
C

/* cursor_type.c - python interface to cursor objects
*
* Copyright (C) 2008 Canonical Ltd.
*
* This file is part of psycopg.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2,
* or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public Likcense
* along with this program; if not, write to the Free Software
* Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#define PY_SSIZE_T_CLEAN
#include <Python.h>
#include <structmember.h>
#define PSYCOPG_MODULE
#include "psycopg/config.h"
#include "psycopg/python.h"
#include "psycopg/psycopg.h"
#include "psycopg/xid.h"
static const char xid_prefix[] = "psycopg-v1";
static PyMemberDef xid_members[] = {
{ "format_id", T_OBJECT, offsetof(XidObject, format_id), RO },
{ "gtrid", T_OBJECT, offsetof(XidObject, gtrid), RO },
{ "bqual", T_OBJECT, offsetof(XidObject, bqual), RO },
{ "prepared", T_OBJECT, offsetof(XidObject, prepared), RO },
{ "owner", T_OBJECT, offsetof(XidObject, owner), RO },
{ "database", T_OBJECT, offsetof(XidObject, database), RO },
{ NULL }
};
static PyObject *
xid_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
{
XidObject *self = (XidObject *)type->tp_alloc(type, 0);
self->pg_xact_id = NULL;
Py_INCREF(Py_None);
self->format_id = Py_None;
Py_INCREF(Py_None);
self->gtrid = Py_None;
Py_INCREF(Py_None);
self->bqual = Py_None;
Py_INCREF(Py_None);
self->prepared = Py_None;
Py_INCREF(Py_None);
self->owner = Py_None;
Py_INCREF(Py_None);
self->database = Py_None;
return (PyObject *)self;
}
static int
xid_init(XidObject *self, PyObject *args, PyObject *kwargs)
{
static char *kwlist[] = {"format_id", "gtrid", "bqual", NULL};
int format_id, i, gtrid_len, bqual_len, xid_len;
const char *gtrid, *bqual;
PyObject *tmp;
if (!PyArg_ParseTupleAndKeywords(args, kwargs, "iss", kwlist,
&format_id, &gtrid, &bqual))
return -1;
if (format_id < 0 || format_id >= 0xffffffff) {
PyErr_SetString(PyExc_ValueError,
"format_id must be a non-negative 32-bit integer");
return -1;
}
/* make sure that gtrid is no more than 64 characters long and
made of printable characters (which we're defining as those
between 0x20 and 0x7f). */
gtrid_len = strlen(gtrid);
if (gtrid_len > 64) {
PyErr_SetString(PyExc_ValueError,
"gtrid must be a string no longer than 64 characters");
return -1;
}
for (i = 0; i < gtrid_len; i++) {
if (gtrid[i] < 0x20 || gtrid[i] >= 0x7f) {
PyErr_SetString(PyExc_ValueError,
"gtrid must contain only printable characters.");
return -1;
}
}
/* Same for bqual */
bqual_len = strlen(bqual);
if (bqual_len > 64) {
PyErr_SetString(PyExc_ValueError,
"bqual must be a string no longer than 64 characters");
return -1;
}
for (i = 0; i < bqual_len; i++) {
if (bqual[i] < 0x20 || bqual[i] >= 0x7f) {
PyErr_SetString(PyExc_ValueError,
"bqual must contain only printable characters.");
return -1;
}
}
/* Now we can construct the PostgreSQL transaction ID, which is of
the following form:
psycopg-v1:$FORMAT_ID:$GTRID_LEN:$GTRID$BQUAL
Where $FORMAT_ID is eight hex digits and $GTRID_LEN is 2 hex digits.
*/
xid_len = strlen(xid_prefix) + 1 + 8 + 1 + 2 + 1 + gtrid_len + bqual_len + 1;
if (self->pg_xact_id)
free(self->pg_xact_id);
self->pg_xact_id = malloc(xid_len);
memset(self->pg_xact_id, '\0', xid_len);
snprintf(self->pg_xact_id, xid_len, "%s:%08X:%02X:%s%s",
xid_prefix, format_id, gtrid_len, gtrid, bqual);
tmp = self->format_id;
self->format_id = PyInt_FromLong(format_id);
Py_XDECREF(tmp);
tmp = self->gtrid;
self->gtrid = PyString_FromString(gtrid);
Py_XDECREF(tmp);
tmp = self->bqual;
self->bqual = PyString_FromString(bqual);
Py_XDECREF(tmp);
return 0;
}
static int
xid_traverse(XidObject *self, visitproc visit, void *arg)
{
Py_VISIT(self->format_id);
Py_VISIT(self->gtrid);
Py_VISIT(self->bqual);
Py_VISIT(self->prepared);
Py_VISIT(self->owner);
Py_VISIT(self->database);
return 0;
}
static void
xid_dealloc(XidObject *self)
{
if (self->pg_xact_id) {
free(self->pg_xact_id);
self->pg_xact_id = NULL;
}
Py_CLEAR(self->format_id);
Py_CLEAR(self->gtrid);
Py_CLEAR(self->bqual);
Py_CLEAR(self->prepared);
Py_CLEAR(self->owner);
Py_CLEAR(self->database);
self->ob_type->tp_free((PyObject *)self);
}
static void
xid_del(PyObject *self)
{
PyObject_GC_Del(self);
}
static PyObject *
xid_repr(XidObject *self)
{
return PyString_FromFormat("<Xid \"%s\">",
self->pg_xact_id ? self->pg_xact_id : "(null)");
}
static Py_ssize_t
xid_len(XidObject *self)
{
return 3;
}
static PyObject *
xid_getitem(XidObject *self, Py_ssize_t item)
{
if (item < 0)
item += 3;
switch (item) {
case 0:
Py_INCREF(self->format_id);
return self->format_id;
case 1:
Py_INCREF(self->gtrid);
return self->gtrid;
case 2:
Py_INCREF(self->bqual);
return self->bqual;
default:
PyErr_SetString(PyExc_IndexError, "index out of range");
return NULL;
}
}
static PySequenceMethods xid_sequence = {
(lenfunc)xid_len, /* sq_length */
0, /* sq_concat */
0, /* sq_repeat */
(ssizeargfunc)xid_getitem, /* sq_item */
0, /* sq_slice */
0, /* sq_ass_item */
0, /* sq_ass_slice */
0, /* sq_contains */
0, /* sq_inplace_concat */
0, /* sq_inplace_repeat */
};
static const char xid_doc[] =
"A transaction identifier used for two phase commit.";
PyTypeObject XidType = {
PyObject_HEAD_INIT(NULL)
0,
"psycopg2.extensions.Xid",
sizeof(XidObject),
0,
(destructor)xid_dealloc, /* tp_dealloc */
0, /*tp_print*/
0, /*tp_getattr*/
0, /*tp_setattr*/
0, /*tp_compare*/
(reprfunc)xid_repr, /*tp_repr*/
0, /*tp_as_number*/
&xid_sequence, /*tp_as_sequence*/
0, /*tp_as_mapping*/
0, /*tp_hash */
0, /*tp_call*/
0, /*tp_str*/
0, /*tp_getattro*/
0, /*tp_setattro*/
0, /*tp_as_buffer*/
Py_TPFLAGS_DEFAULT|Py_TPFLAGS_BASETYPE|Py_TPFLAGS_HAVE_GC, /*tp_flags*/
xid_doc, /*tp_doc*/
(traverseproc)xid_traverse, /*tp_traverse*/
0, /*tp_clear*/
0, /*tp_richcompare*/
0, /*tp_weaklistoffset*/
0, /*tp_iter*/
0, /*tp_iternext*/
/* Attribute descriptor and subclassing stuff */
0, /*tp_methods*/
xid_members, /*tp_members*/
0, /*tp_getset*/
0, /*tp_base*/
0, /*tp_dict*/
0, /*tp_descr_get*/
0, /*tp_descr_set*/
0, /*tp_dictoffset*/
(initproc)xid_init, /*tp_init*/
0, /*tp_alloc will be set to PyType_GenericAlloc in module init*/
xid_new, /*tp_new*/
(freefunc)xid_del, /*tp_free Low-level free-memory routine */
0, /*tp_is_gc For PyObject_IS_GC */
0, /*tp_bases*/
0, /*tp_mro method resolution order */
0, /*tp_cache*/
0, /*tp_subclasses*/
0 /*tp_weaklist*/
};