Split plpython.c into smaller pieces

This moves the code around from one huge file into hopefully logical
and more manageable modules.  For the most part, the code itself was
not touched, except: PLy_function_handler and PLy_trigger_handler were
renamed to PLy_exec_function and PLy_exec_trigger, because they were
not actually handlers in the PL handler sense, and it makes the naming
more similar to the way PL/pgSQL is organized.  The initialization of
the procedure caches was separated into a new function
init_procedure_caches to keep the hash tables private to
plpy_procedures.c.

Jan Urbański and Peter Eisentraut

1 files changed, 217 insertions, 0 deletions

diff --git a/src/pl/plpython/plpy_subxactobject.c b/src/pl/plpython/plpy_subxactobject.c
new file mode 100644
index 00000000000..6c3cc69adfa
--- /dev/null
+++ b/src/pl/plpython/plpy_subxactobject.c
@@ -0,0 +1,217 @@
+/*
+ * the PLySubtransaction class
+ *
+ * src/pl/plpython/plpy_subxactobject.c
+ */
+
+#include "postgres.h"
+
+#include "access/xact.h"
+#include "executor/spi.h"
+
+#include "plpython.h"
+
+#include "plpy_subxactobject.h"
+
+#include "plpy_elog.h"
+
+
+List *explicit_subtransactions = NIL;
+
+
+static void PLy_subtransaction_dealloc(PyObject *);
+static PyObject *PLy_subtransaction_enter(PyObject *, PyObject *);
+static PyObject *PLy_subtransaction_exit(PyObject *, PyObject *);
+
+static char PLy_subtransaction_doc[] = {
+	"PostgreSQL subtransaction context manager"
+};
+
+static PyMethodDef PLy_subtransaction_methods[] = {
+	{"__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}
+};
+
+static PyTypeObject PLy_SubtransactionType = {
+	PyVarObject_HEAD_INIT(NULL, 0)
+	"PLySubtransaction",		/* tp_name */
+	sizeof(PLySubtransactionObject),	/* tp_size */
+	0,							/* tp_itemsize */
+
+	/*
+	 * methods
+	 */
+	PLy_subtransaction_dealloc, /* tp_dealloc */
+	0,							/* tp_print */
+	0,							/* tp_getattr */
+	0,							/* tp_setattr */
+	0,							/* tp_compare */
+	0,							/* tp_repr */
+	0,							/* tp_as_number */
+	0,							/* 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,	/* tp_flags */
+	PLy_subtransaction_doc,		/* tp_doc */
+	0,							/* tp_traverse */
+	0,							/* tp_clear */
+	0,							/* tp_richcompare */
+	0,							/* tp_weaklistoffset */
+	0,							/* tp_iter */
+	0,							/* tp_iternext */
+	PLy_subtransaction_methods, /* tp_tpmethods */
+};
+
+
+void
+PLy_subtransaction_init_type(void)
+{
+	if (PyType_Ready(&PLy_SubtransactionType) < 0)
+		elog(ERROR, "could not initialize PLy_SubtransactionType");
+}
+
+/* s = plpy.subtransaction() */
+PyObject *
+PLy_subtransaction_new(PyObject *self, PyObject *unused)
+{
+	PLySubtransactionObject *ob;
+
+	ob = PyObject_New(PLySubtransactionObject, &PLy_SubtransactionType);
+
+	if (ob == NULL)
+		return NULL;
+
+	ob->started = false;
+	ob->exited = false;
+
+	return (PyObject *) ob;
+}
+
+/* Python requires a dealloc function to be defined */
+static void
+PLy_subtransaction_dealloc(PyObject *subxact)
+{
+}
+
+/*
+ * subxact.__enter__() or subxact.enter()
+ *
+ * Start an explicit subtransaction.  SPI calls within an explicit
+ * subtransaction will not start another one, so you can atomically
+ * execute many SPI calls and still get a controllable exception if
+ * one of them fails.
+ */
+static PyObject *
+PLy_subtransaction_enter(PyObject *self, PyObject *unused)
+{
+	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 = PLy_malloc(sizeof(*subxactdata));
+	subxactdata->oldcontext = oldcontext;
+	subxactdata->oldowner = CurrentResourceOwner;
+
+	BeginInternalSubTransaction(NULL);
+	/* Do not want to leave the previous memory context */
+	MemoryContextSwitchTo(oldcontext);
+
+	explicit_subtransactions = lcons(subxactdata, explicit_subtransactions);
+
+	Py_INCREF(self);
+	return self;
+}
+
+/*
+ * subxact.__exit__(exc_type, exc, tb) or subxact.exit(exc_type, exc, tb)
+ *
+ * Exit an explicit subtransaction. exc_type is an exception type, exc
+ * is the exception object, tb is the traceback.  If exc_type is None,
+ * commit the subtransactiony, if not abort it.
+ *
+ * The method signature is chosen to allow subtransaction objects to
+ * be used as context managers as described in
+ * <http://www.python.org/dev/peps/pep-0343/>.
+ */
+static PyObject *
+PLy_subtransaction_exit(PyObject *self, PyObject *args)
+{
+	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;
+	PLy_free(subxactdata);
+
+	/*
+	 * AtEOSubXact_SPI() should not have popped any SPI context, but just in
+	 * case it did, make sure we remain connected.
+	 */
+	SPI_restore_connection();
+
+	Py_INCREF(Py_None);
+	return Py_None;
+}