plpy_subxactobject.c File Reference

#include "postgres.h"
#include "access/xact.h"
#include "plpy_elog.h"
#include "plpy_subxactobject.h"
#include "plpy_util.h"
#include "utils/memutils.h"

Include dependency graph for plpy_subxactobject.c:

Go to the source code of this file.

Functions
static PyObject *	PLy_subtransaction_enter (PyObject *self, PyObject *unused)
static PyObject *	PLy_subtransaction_exit (PyObject *self, PyObject *args)
void	PLy_subtransaction_init_type (void)
PyObject *	PLy_subtransaction_new (PyObject *self, PyObject *unused)

Variables
List *	explicit_subtransactions = NIL
static char	PLy_subtransaction_doc []
static PyMethodDef	PLy_subtransaction_methods []
static PyType_Slot	PLySubtransaction_slots []
static PyType_Spec	PLySubtransaction_spec
static PyTypeObject *	PLy_SubtransactionType

Function Documentation

PLy_subtransaction_enter()

static PyObject * PLy_subtransaction_enter ( PyObject *  self, PyObject *  unused  )

static

Definition at line 94 of file plpy_subxactobject.c.

{
    PLySubtransactionData *subxactdata;
    MemoryContext oldcontext;
    PLySubtransactionObject *subxact = (PLySubtransactionObject *) self;
 
    if (subxact->started)
    {
        PLy_exception_set(PyExc_ValueError, "this subtransaction has already been entered");
        return NULL;
    }
 
    if (subxact->exited)
    {
        PLy_exception_set(PyExc_ValueError, "this subtransaction has already been exited");
        return NULL;
    }
 
    subxact->started = true;
    oldcontext = CurrentMemoryContext;
 
    subxactdata = (PLySubtransactionData *)
        MemoryContextAlloc(TopTransactionContext,
                           sizeof(PLySubtransactionData));
 
    subxactdata->oldcontext = oldcontext;
    subxactdata->oldowner = CurrentResourceOwner;
 
    BeginInternalSubTransaction(NULL);
 
    /* Be sure that cells of explicit_subtransactions list are long-lived */
    MemoryContextSwitchTo(TopTransactionContext);
    explicit_subtransactions = lcons(subxactdata, explicit_subtransactions);
 
    /* Caller wants to stay in original memory context */
    MemoryContextSwitchTo(oldcontext);
 
    Py_INCREF(self);
    return self;
}

References BeginInternalSubTransaction(), CurrentMemoryContext, CurrentResourceOwner, explicit_subtransactions, fb(), lcons(), MemoryContextAlloc(), MemoryContextSwitchTo(), PLy_exception_set(), and TopTransactionContext.

PLy_subtransaction_exit()

static PyObject * PLy_subtransaction_exit ( PyObject *  self, PyObject *  args  )

static

Definition at line 147 of file plpy_subxactobject.c.

{
    PyObject   *type;
    PyObject   *value;
    PyObject   *traceback;
    PLySubtransactionData *subxactdata;
    PLySubtransactionObject *subxact = (PLySubtransactionObject *) self;
 
    if (!PyArg_ParseTuple(args, "OOO", &type, &value, &traceback))
        return NULL;
 
    if (!subxact->started)
    {
        PLy_exception_set(PyExc_ValueError, "this subtransaction has not been entered");
        return NULL;
    }
 
    if (subxact->exited)
    {
        PLy_exception_set(PyExc_ValueError, "this subtransaction has already been exited");
        return NULL;
    }
 
    if (explicit_subtransactions == NIL)
    {
        PLy_exception_set(PyExc_ValueError, "there is no subtransaction to exit from");
        return NULL;
    }
 
    subxact->exited = true;
 
    if (type != Py_None)
    {
        /* Abort the inner transaction */
        RollbackAndReleaseCurrentSubTransaction();
    }
    else
    {
        ReleaseCurrentSubTransaction();
    }
 
    subxactdata = (PLySubtransactionData *) linitial(explicit_subtransactions);
    explicit_subtransactions = list_delete_first(explicit_subtransactions);
 
    MemoryContextSwitchTo(subxactdata->oldcontext);
    CurrentResourceOwner = subxactdata->oldowner;
    pfree(subxactdata);
 
    Py_RETURN_NONE;
}

References CurrentResourceOwner, explicit_subtransactions, fb(), linitial, list_delete_first(), MemoryContextSwitchTo(), NIL, pfree(), PLy_exception_set(), ReleaseCurrentSubTransaction(), RollbackAndReleaseCurrentSubTransaction(), type, and value.

PLy_subtransaction_init_type()

void PLy_subtransaction_init_type

(

void

)

Definition at line 58 of file plpy_subxactobject.c.

{
    PLy_SubtransactionType = (PyTypeObject *) PyType_FromSpec(&PLySubtransaction_spec);
    if (!PLy_SubtransactionType)
        elog(ERROR, "could not initialize PLy_SubtransactionType");
}

References elog, ERROR, fb(), PLy_SubtransactionType, and PLySubtransaction_spec.

Referenced by PyInit_plpy().

PLy_subtransaction_new()

PyObject * PLy_subtransaction_new	(	PyObject *	self,
		PyObject *	unused
	)

Definition at line 67 of file plpy_subxactobject.c.

{
    PLySubtransactionObject *ob;
 
    ob = PyObject_New(PLySubtransactionObject, PLy_SubtransactionType);
    if (ob == NULL)
        return NULL;
#if PY_VERSION_HEX < 0x03080000
    /* Workaround for Python issue 35810; no longer necessary in Python 3.8 */
    Py_INCREF(PLy_SubtransactionType);
#endif
 
    ob->started = false;
    ob->exited = false;
 
    return (PyObject *) ob;
}

References fb(), and PLy_SubtransactionType.

Variable Documentation

explicit_subtransactions

List* explicit_subtransactions = NIL

Definition at line 15 of file plpy_subxactobject.c.

Referenced by _PG_init(), PLy_abort_open_subtransactions(), PLy_procedure_call(), PLy_subtransaction_enter(), and PLy_subtransaction_exit().

PLy_subtransaction_doc

char PLy_subtransaction_doc[]

static

Initial value:

=
"PostgreSQL subtransaction context manager"

Definition at line 21 of file plpy_subxactobject.c.

PLy_subtransaction_methods

PyMethodDef PLy_subtransaction_methods[]

static

Initial value:

= {
    {"__enter__", PLy_subtransaction_enter, METH_VARARGS, NULL},
    {"__exit__", PLy_subtransaction_exit, METH_VARARGS, NULL},
    
    {"enter", PLy_subtransaction_enter, METH_VARARGS, NULL},
    {"exit", PLy_subtransaction_exit, METH_VARARGS, NULL},
    {NULL, NULL, 0, NULL}
}

Definition at line 24 of file plpy_subxactobject.c.

                                                  {
    {"__enter__", PLy_subtransaction_enter, METH_VARARGS, NULL},
    {"__exit__", PLy_subtransaction_exit, METH_VARARGS, NULL},
    /* user-friendly names for Python <2.6 */
    {"enter", PLy_subtransaction_enter, METH_VARARGS, NULL},
    {"exit", PLy_subtransaction_exit, METH_VARARGS, NULL},
    {NULL, NULL, 0, NULL}
};

PLy_SubtransactionType

PyTypeObject* PLy_SubtransactionType

static

Definition at line 54 of file plpy_subxactobject.c.

Referenced by PLy_subtransaction_init_type(), and PLy_subtransaction_new().

PLySubtransaction_slots

PyType_Slot PLySubtransaction_slots[]

static

Initial value:

=
{
    {
        Py_tp_doc, (char *) PLy_subtransaction_doc
    },
    {
        Py_tp_methods, PLy_subtransaction_methods
    },
    {
        0, NULL
    }
}

Definition at line 33 of file plpy_subxactobject.c.

{
    {
        Py_tp_doc, (char *) PLy_subtransaction_doc
    },
    {
        Py_tp_methods, PLy_subtransaction_methods
    },
    {
        0, NULL
    }
};

PLySubtransaction_spec

PyType_Spec PLySubtransaction_spec

static

Initial value:

=
{
    .name = "PLySubtransaction",
    .basicsize = sizeof(PLySubtransactionObject),
    .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
    .slots = PLySubtransaction_slots,
}

Definition at line 46 of file plpy_subxactobject.c.

{
    .name = "PLySubtransaction",
    .basicsize = sizeof(PLySubtransactionObject),
    .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
    .slots = PLySubtransaction_slots,
};

Referenced by PLy_subtransaction_init_type().