psycopg2/psycopg/adapter_list.c

/* adapter_list.c - python list objects
 *
 * Copyright (C) 2004-2010 Federico Di Gregorio <fog@debian.org>
 *
 * This file is part of psycopg.
 *
 * psycopg2 is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * In addition, as a special exception, the copyright holders give
 * permission to link this program with the OpenSSL library (or with
 * modified versions of OpenSSL that use the same license as OpenSSL),
 * and distribute linked combinations including the two.
 *
 * You must obey the GNU Lesser General Public License in all respects for
 * all of the code used other than OpenSSL.
 *
 * psycopg2 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 Lesser General Public
 * License for more details.
 */

#define PSYCOPG_MODULE
#include "psycopg/psycopg.h"

#include "psycopg/adapter_list.h"
#include "psycopg/microprotocols.h"
#include "psycopg/microprotocols_proto.h"


/* list_str, list_getquoted - return result of quoting */

static PyObject *
list_quote(listObject *self)
{
    /*  adapt the list by calling adapt() recursively and then wrapping
        everything into "ARRAY[]" */
    PyObject *tmp = NULL, *str = NULL, *joined = NULL, *res = NULL;

    /*  list consisting of only NULL don't work with the ARRAY[] construct
     *  so we use the {NULL,...} syntax. Note however that list of lists where
     *  some element is a list of only null still fails: for that we should use
     *  the '{...}' syntax uniformly but we cannot do it in the current
     *  infrastructure. TODO in psycopg3 */
    int all_nulls = 1;

    Py_ssize_t i, len;

    len = PyList_GET_SIZE(self->wrapped);

    /* empty arrays are converted to NULLs (still searching for a way to
       insert an empty array in postgresql */
    if (len == 0) return Bytes_FromString("'{}'");

    tmp = PyTuple_New(len);

    for (i=0; i<len; i++) {
        PyObject *quoted;
        PyObject *wrapped = PyList_GET_ITEM(self->wrapped, i);
        if (wrapped == Py_None) {
            Py_INCREF(psyco_null);
            quoted = psyco_null;
        }
        else {
            quoted = microprotocol_getquoted(wrapped,
                                       (connectionObject*)self->connection);
            if (quoted == NULL) goto error;
            all_nulls = 0;
        }

        /* here we don't loose a refcnt: SET_ITEM does not change the
           reference count and we are just transferring ownership of the tmp
           object to the tuple */
        PyTuple_SET_ITEM(tmp, i, quoted);
    }

    /* now that we have a tuple of adapted objects we just need to join them
       and put "ARRAY[] around the result */
    str = Bytes_FromString(", ");
    joined = PyObject_CallMethod(str, "join", "(O)", tmp);
    if (joined == NULL) goto error;

    /* PG doesn't like ARRAY[NULL..] */
    if (!all_nulls) {
        res = Bytes_FromFormat("ARRAY[%s]", Bytes_AsString(joined));
    } else {
        res = Bytes_FromFormat("'{%s}'", Bytes_AsString(joined));
    }

 error:
    Py_XDECREF(tmp);
    Py_XDECREF(str);
    Py_XDECREF(joined);
    return res;
}

static PyObject *
list_str(listObject *self)
{
    return psycopg_ensure_text(list_quote(self));
}

static PyObject *
list_getquoted(listObject *self, PyObject *args)
{
    return list_quote(self);
}

static PyObject *
list_prepare(listObject *self, PyObject *args)
{
    PyObject *conn;

    if (!PyArg_ParseTuple(args, "O!", &connectionType, &conn))
        return NULL;

    Py_CLEAR(self->connection);
    Py_INCREF(conn);
    self->connection = conn;

    Py_RETURN_NONE;
}

static PyObject *
list_conform(listObject *self, PyObject *args)
{
    PyObject *res, *proto;

    if (!PyArg_ParseTuple(args, "O", &proto)) return NULL;

    if (proto == (PyObject*)&isqlquoteType)
        res = (PyObject*)self;
    else
        res = Py_None;

    Py_INCREF(res);
    return res;
}

/** the DateTime wrapper object **/

/* object member list */

static struct PyMemberDef listObject_members[] = {
    {"adapted", T_OBJECT, offsetof(listObject, wrapped), READONLY},
    {NULL}
};

/* object method table */

static PyMethodDef listObject_methods[] = {
    {"getquoted", (PyCFunction)list_getquoted, METH_NOARGS,
     "getquoted() -> wrapped object value as SQL date/time"},
    {"prepare", (PyCFunction)list_prepare, METH_VARARGS,
     "prepare(conn) -> set encoding to conn->encoding"},
    {"__conform__", (PyCFunction)list_conform, METH_VARARGS, NULL},
    {NULL}  /* Sentinel */
};

/* initialization and finalization methods */

static int
list_setup(listObject *self, PyObject *obj)
{
    Dprintf("list_setup: init list object at %p, refcnt = "
        FORMAT_CODE_PY_SSIZE_T,
        self, Py_REFCNT(self)
      );

    if (!PyList_Check(obj))
        return -1;

    self->connection = NULL;
    Py_INCREF(obj);
    self->wrapped = obj;

    Dprintf("list_setup: good list object at %p, refcnt = "
        FORMAT_CODE_PY_SSIZE_T,
        self, Py_REFCNT(self)
      );
    return 0;
}

static int
list_traverse(listObject *self, visitproc visit, void *arg)
{
    Py_VISIT(self->wrapped);
    Py_VISIT(self->connection);
    return 0;
}

static int
list_clear(listObject *self)
{
    Py_CLEAR(self->wrapped);
    Py_CLEAR(self->connection);
    return 0;
}

static void
list_dealloc(listObject* self)
{
    PyObject_GC_UnTrack((PyObject *)self);
    list_clear(self);

    Dprintf("list_dealloc: deleted list object at %p, "
            "refcnt = " FORMAT_CODE_PY_SSIZE_T, self, Py_REFCNT(self));

    Py_TYPE(self)->tp_free((PyObject *)self);
}

static int
list_init(PyObject *obj, PyObject *args, PyObject *kwds)
{
    PyObject *l;

    if (!PyArg_ParseTuple(args, "O", &l))
        return -1;

    return list_setup((listObject *)obj, l);
}

static PyObject *
list_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
    return type->tp_alloc(type, 0);
}


/* object type */

#define listType_doc \
"List(list) -> new list wrapper object"

PyTypeObject listType = {
    PyVarObject_HEAD_INIT(NULL, 0)
    "psycopg2._psycopg.List",
    sizeof(listObject), 0,
    (destructor)list_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*/
    (reprfunc)list_str, /*tp_str*/
    0,          /*tp_getattro*/
    0,          /*tp_setattro*/
    0,          /*tp_as_buffer*/
    Py_TPFLAGS_DEFAULT|Py_TPFLAGS_BASETYPE|Py_TPFLAGS_HAVE_GC, /*tp_flags*/
    listType_doc, /*tp_doc*/
    (traverseproc)list_traverse, /*tp_traverse*/
    (inquiry)list_clear, /*tp_clear*/
    0,          /*tp_richcompare*/
    0,          /*tp_weaklistoffset*/
    0,          /*tp_iter*/
    0,          /*tp_iternext*/
    listObject_methods, /*tp_methods*/
    listObject_members, /*tp_members*/
    0,          /*tp_getset*/
    0,          /*tp_base*/
    0,          /*tp_dict*/
    0,          /*tp_descr_get*/
    0,          /*tp_descr_set*/
    0,          /*tp_dictoffset*/
    list_init, /*tp_init*/
    0,          /*tp_alloc*/
    list_new, /*tp_new*/
};