bpo-42862: Use functools.lru_cache iso. _sqlite.Cache in sqlite3 module (GH-24203)

Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>

1 files changed, 0 insertions, 344 deletions

diff --git a/Modules/_sqlite/cache.c b/Modules/_sqlite/cache.c
deleted file mode 100644
index 8196e3c5783..00000000000
--- a/Modules/_sqlite/cache.c
+++ /dev/null
@@ -1,344 +0,0 @@
-/* cache .c - a LRU cache
- *
- * Copyright (C) 2004-2010 Gerhard Häring <gh@ghaering.de>
- *
- * This file is part of pysqlite.
- *
- * This software is provided 'as-is', without any express or implied
- * warranty.  In no event will the authors be held liable for any damages
- * arising from the use of this software.
- *
- * Permission is granted to anyone to use this software for any purpose,
- * including commercial applications, and to alter it and redistribute it
- * freely, subject to the following restrictions:
- *
- * 1. The origin of this software must not be misrepresented; you must not
- *    claim that you wrote the original software. If you use this software
- *    in a product, an acknowledgment in the product documentation would be
- *    appreciated but is not required.
- * 2. Altered source versions must be plainly marked as such, and must not be
- *    misrepresented as being the original software.
- * 3. This notice may not be removed or altered from any source distribution.
- */
-
-#include "cache.h"
-#include <limits.h>
-
-/* only used internally */
-static pysqlite_Node *
-pysqlite_new_node(PyObject *key, PyObject *data)
-{
-    pysqlite_Node* node;
-
-    node = (pysqlite_Node*) (pysqlite_NodeType->tp_alloc(pysqlite_NodeType, 0));
-    if (!node) {
-        return NULL;
-    }
-
-    node->key = Py_NewRef(key);
-    node->data = Py_NewRef(data);
-
-    node->prev = NULL;
-    node->next = NULL;
-
-    return node;
-}
-
-static int
-node_traverse(pysqlite_Node *self, visitproc visit, void *arg)
-{
-    Py_VISIT(Py_TYPE(self));
-    Py_VISIT(self->key);
-    Py_VISIT(self->data);
-    return 0;
-}
-
-static int
-node_clear(pysqlite_Node *self)
-{
-    Py_CLEAR(self->key);
-    Py_CLEAR(self->data);
-    return 0;
-}
-
-static void
-pysqlite_node_dealloc(pysqlite_Node *self)
-{
-    PyTypeObject *tp = Py_TYPE(self);
-    PyObject_GC_UnTrack(self);
-    tp->tp_clear((PyObject *)self);
-    tp->tp_free(self);
-    Py_DECREF(tp);
-}
-
-static int
-pysqlite_cache_init(pysqlite_Cache *self, PyObject *args, PyObject *kwargs)
-{
-    PyObject* factory;
-    int size = 10;
-
-    self->factory = NULL;
-
-    if (!PyArg_ParseTuple(args, "O|i", &factory, &size)) {
-        return -1;
-    }
-
-    /* minimum cache size is 5 entries */
-    if (size < 5) {
-        size = 5;
-    }
-    self->size = size;
-    self->first = NULL;
-    self->last = NULL;
-
-    self->mapping = PyDict_New();
-    if (!self->mapping) {
-        return -1;
-    }
-
-    self->factory = Py_NewRef(factory);
-    return 0;
-}
-
-static int
-cache_traverse(pysqlite_Cache *self, visitproc visit, void *arg)
-{
-    Py_VISIT(Py_TYPE(self));
-    Py_VISIT(self->mapping);
-    Py_VISIT(self->factory);
-
-    pysqlite_Node *node = self->first;
-    while (node) {
-        Py_VISIT(node);
-        node = node->next;
-    }
-    return 0;
-}
-
-static int
-cache_clear(pysqlite_Cache *self)
-{
-    Py_CLEAR(self->mapping);
-    Py_CLEAR(self->factory);
-
-    /* iterate over all nodes and deallocate them */
-    pysqlite_Node *node = self->first;
-    self->first = NULL;
-    while (node) {
-        pysqlite_Node *delete_node = node;
-        node = node->next;
-        Py_CLEAR(delete_node);
-    }
-    return 0;
-}
-
-static void
-pysqlite_cache_dealloc(pysqlite_Cache *self)
-{
-    if (!self->factory) {
-        /* constructor failed, just get out of here */
-        return;
-    }
-
-    PyObject_GC_UnTrack(self);
-    PyTypeObject *tp = Py_TYPE(self);
-    tp->tp_clear((PyObject *)self);
-    tp->tp_free(self);
-    Py_DECREF(tp);
-}
-
-PyObject* pysqlite_cache_get(pysqlite_Cache* self, PyObject* key)
-{
-    pysqlite_Node* node;
-    pysqlite_Node* ptr;
-    PyObject* data;
-
-    node = (pysqlite_Node*)PyDict_GetItemWithError(self->mapping, key);
-    if (node) {
-        /* an entry for this key already exists in the cache */
-
-        /* increase usage counter of the node found */
-        if (node->count < LONG_MAX) {
-            node->count++;
-        }
-
-        /* if necessary, reorder entries in the cache by swapping positions */
-        if (node->prev && node->count > node->prev->count) {
-            ptr = node->prev;
-
-            while (ptr->prev && node->count > ptr->prev->count) {
-                ptr = ptr->prev;
-            }
-
-            if (node->next) {
-                node->next->prev = node->prev;
-            } else {
-                self->last = node->prev;
-            }
-            if (node->prev) {
-                node->prev->next = node->next;
-            }
-            if (ptr->prev) {
-                ptr->prev->next = node;
-            } else {
-                self->first = node;
-            }
-
-            node->next = ptr;
-            node->prev = ptr->prev;
-            if (!node->prev) {
-                self->first = node;
-            }
-            ptr->prev = node;
-        }
-    }
-    else if (PyErr_Occurred()) {
-        return NULL;
-    }
-    else {
-        /* There is no entry for this key in the cache, yet. We'll insert a new
-         * entry in the cache, and make space if necessary by throwing the
-         * least used item out of the cache. */
-
-        if (PyDict_GET_SIZE(self->mapping) == self->size) {
-            if (self->last) {
-                node = self->last;
-
-                if (PyDict_DelItem(self->mapping, self->last->key) != 0) {
-                    return NULL;
-                }
-
-                if (node->prev) {
-                    node->prev->next = NULL;
-                }
-                self->last = node->prev;
-                node->prev = NULL;
-
-                Py_DECREF(node);
-            }
-        }
-
-        /* We cannot replace this by PyObject_CallOneArg() since
-         * PyObject_CallFunction() has a special case when using a
-         * single tuple as argument. */
-        data = PyObject_CallFunction(self->factory, "O", key);
-
-        if (!data) {
-            return NULL;
-        }
-
-        node = pysqlite_new_node(key, data);
-        if (!node) {
-            return NULL;
-        }
-        node->prev = self->last;
-
-        Py_DECREF(data);
-
-        if (PyDict_SetItem(self->mapping, key, (PyObject*)node) != 0) {
-            Py_DECREF(node);
-            return NULL;
-        }
-
-        if (self->last) {
-            self->last->next = node;
-        } else {
-            self->first = node;
-        }
-        self->last = node;
-    }
-
-    return Py_NewRef(node->data);
-}
-
-static PyObject *
-pysqlite_cache_display(pysqlite_Cache *self, PyObject *args)
-{
-    pysqlite_Node* ptr;
-    PyObject* prevkey;
-    PyObject* nextkey;
-    PyObject* display_str;
-
-    ptr = self->first;
-
-    while (ptr) {
-        if (ptr->prev) {
-            prevkey = ptr->prev->key;
-        } else {
-            prevkey = Py_None;
-        }
-
-        if (ptr->next) {
-            nextkey = ptr->next->key;
-        } else {
-            nextkey = Py_None;
-        }
-
-        display_str = PyUnicode_FromFormat("%S <- %S -> %S\n",
-                                           prevkey, ptr->key, nextkey);
-        if (!display_str) {
-            return NULL;
-        }
-        PyObject_Print(display_str, stdout, Py_PRINT_RAW);
-        Py_DECREF(display_str);
-
-        ptr = ptr->next;
-    }
-
-    Py_RETURN_NONE;
-}
-
-static PyType_Slot node_slots[] = {
-    {Py_tp_dealloc, pysqlite_node_dealloc},
-    {Py_tp_traverse, node_traverse},
-    {Py_tp_clear, node_clear},
-    {0, NULL},
-};
-
-static PyType_Spec node_spec = {
-    .name = MODULE_NAME ".Node",
-    .basicsize = sizeof(pysqlite_Node),
-    .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC,
-    .slots = node_slots,
-};
-PyTypeObject *pysqlite_NodeType = NULL;
-
-static PyMethodDef cache_methods[] = {
-    {"get", (PyCFunction)pysqlite_cache_get, METH_O,
-        PyDoc_STR("Gets an entry from the cache or calls the factory function to produce one.")},
-    {"display", (PyCFunction)pysqlite_cache_display, METH_NOARGS,
-        PyDoc_STR("For debugging only.")},
-    {NULL, NULL}
-};
-
-static PyType_Slot cache_slots[] = {
-    {Py_tp_dealloc, pysqlite_cache_dealloc},
-    {Py_tp_methods, cache_methods},
-    {Py_tp_init, pysqlite_cache_init},
-    {Py_tp_traverse, cache_traverse},
-    {Py_tp_clear, cache_clear},
-    {0, NULL},
-};
-
-static PyType_Spec cache_spec = {
-    .name = MODULE_NAME ".Cache",
-    .basicsize = sizeof(pysqlite_Cache),
-    .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC,
-    .slots = cache_slots,
-};
-PyTypeObject *pysqlite_CacheType = NULL;
-
-int
-pysqlite_cache_setup_types(PyObject *mod)
-{
-    pysqlite_NodeType = (PyTypeObject *)PyType_FromModuleAndSpec(mod, &node_spec, NULL);
-    if (pysqlite_NodeType == NULL) {
-        return -1;
-    }
-
-    pysqlite_CacheType = (PyTypeObject *)PyType_FromModuleAndSpec(mod, &cache_spec, NULL);
-    if (pysqlite_CacheType == NULL) {
-        return -1;
-    }
-    return 0;
-}