Adding support for stack.ArrayStack in C++ backend (#512)

Co-authored-by: Gagandeep Singh <[email protected]>

pydatastructs/miscellaneous_data_structures/__init__.py

@@ -5,7 +5,8 @@
     binomial_trees,
     queue,
     disjoint_set,
-    sparse_table
+    sparse_table,
+    _extensions,
 )
 
 from .binomial_trees import (

pydatastructs/miscellaneous_data_structures/_backend/cpp/stack/ArrayStack.hpp

@@ -0,0 +1,177 @@
+#ifndef MISCELLANEOUS_DATA_STRUCTURES_ARRAYSTACK_HPP
+#define MISCELLANEOUS_DATA_STRUCTURES_ARRAYSTACK_HPP
+
+#define PY_SSIZE_T_CLEAN
+#include <Python.h>
+#include <cstdlib>
+#include <iostream>
+#include <structmember.h>
+#include "../../../../linear_data_structures/_backend/cpp/arrays/DynamicOneDimensionalArray.hpp"
+
+typedef struct {
+    PyObject_HEAD
+    DynamicOneDimensionalArray* _items;
+} ArrayStack;
+
+static void ArrayStack_dealloc(ArrayStack *self) {
+    DynamicOneDimensionalArray_dealloc(self->_items);
+    Py_TYPE(self)->tp_free(reinterpret_cast<PyObject*>(self));
+}
+
+static PyObject* ArrayStack__new__(PyTypeObject *type, PyObject *args, PyObject *kwds) {
+    ArrayStack *self = reinterpret_cast<ArrayStack*>(type->tp_alloc(type, 0));
+
+    static char *kwlist[] = {"items", "dtype", NULL};
+    PyObject *initial_values = Py_None, *dtype = Py_None;
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "|OO", kwlist, &initial_values, &dtype)) {
+        PyErr_SetString(PyExc_ValueError, "Error creating ArrayStack");
+        return NULL;
+    }
+
+    if (initial_values != Py_None && PyType_Check(initial_values)) {
+        PyErr_SetString(PyExc_TypeError, "`items` must be an instance of list or tuple, received a type instead\n"
+                                         "Did you mean to instantiate an ArrayStack with only the data type? "
+                                         "if so, send the type parameter as a named argument "
+                                         "for example: dtype=int");
+        return NULL;
+    }
+
+    PyObject* items = NULL;
+    PyObject* doda_kwds = Py_BuildValue("{}");
+    if (initial_values == Py_None) {
+        // If the only argument is the dtype, redefine the args as a tuple (dtype, 0)
+        // where 0 is the initial array size
+        PyObject* extended_args = PyTuple_Pack(2, dtype, PyLong_FromLong(0));
+
+        items = DynamicOneDimensionalArray___new__(&DynamicOneDimensionalArrayType, extended_args, doda_kwds);
+    } else {
+        // If the user provides dtype and initial values list, let the array initializer handle the checks.
+        PyObject* doda_args = PyTuple_Pack(2, dtype, initial_values);
+        items = DynamicOneDimensionalArray___new__(&DynamicOneDimensionalArrayType, doda_args, doda_kwds);
+    }
+
+    if (!items) {
+        return NULL;
+    }
+
+    DynamicOneDimensionalArray* tmp = self->_items;
+    self->_items = reinterpret_cast<DynamicOneDimensionalArray*>(items);
+
+    return reinterpret_cast<PyObject*>(self);
+}
+
+static PyObject* ArrayStack_is_empty(ArrayStack *self) {
+    bool is_empty = self->_items->_last_pos_filled == -1;
+
+    if (is_empty) {
+        Py_RETURN_TRUE;
+    }
+
+    Py_RETURN_FALSE;
+}
+
+static PyObject* ArrayStack_push(ArrayStack *self, PyObject* args) {
+    size_t len_args = PyObject_Length(args);
+    if (len_args != 1) {
+        PyErr_SetString(PyExc_ValueError, "Expected one argument");
+        return NULL;
+    }
+
+    if (PyObject_IsTrue(ArrayStack_is_empty(self))) {
+        self->_items->_one_dimensional_array->_dtype = reinterpret_cast<PyObject*>(
+            Py_TYPE(PyObject_GetItem(args, PyZero))
+        );
+    }
+
+    DynamicOneDimensionalArray_append(self->_items, args);
+
+    Py_RETURN_NONE;
+}
+
+static PyObject* ArrayStack_pop(ArrayStack *self) {
+    if (PyObject_IsTrue(ArrayStack_is_empty(self))) {
+        PyErr_SetString(PyExc_IndexError, "Stack is empty");
+        return NULL;
+    }
+
+    PyObject *top_element = DynamicOneDimensionalArray___getitem__(
+        self->_items, PyLong_FromLong(self->_items->_last_pos_filled)
+    );
+
+    PyObject* last_pos_arg = PyTuple_Pack(1, PyLong_FromLong(self->_items->_last_pos_filled));
+    DynamicOneDimensionalArray_delete(self->_items, last_pos_arg);
+    return top_element;
+}
+
+static PyObject* ArrayStack_peek(ArrayStack *self, void *closure) {
+    return DynamicOneDimensionalArray___getitem__(
+        self->_items, PyLong_FromLong(self->_items->_last_pos_filled)
+    );
+}
+
+static Py_ssize_t ArrayStack__len__(ArrayStack *self) {
+    return self->_items->_num;
+}
+
+static PyObject* ArrayStack__str__(ArrayStack* self){
+    return DynamicOneDimensionalArray___str__(self->_items);
+}
+
+static struct PyMethodDef ArrayStack_PyMethodDef[] = {
+    {"push", (PyCFunction) ArrayStack_push, METH_VARARGS, NULL},
+    {"pop", (PyCFunction) ArrayStack_pop, METH_VARARGS, NULL},
+    {NULL}
+};
+
+static PyMappingMethods ArrayStack_PyMappingMethods = {
+    (lenfunc) ArrayStack__len__,
+};
+
+static PyGetSetDef ArrayStack_GetterSetters[] = {
+    {"peek", (getter) ArrayStack_peek, NULL, "peek top value", NULL},
+    {"is_empty", (getter) ArrayStack_is_empty, NULL, "check if the stack is empty", NULL},
+    {NULL}  /* Sentinel */
+};
+
+static PyTypeObject ArrayStackType = {
+        /* tp_name */ PyVarObject_HEAD_INIT(NULL, 0) "ArrayStack",
+        /* tp_basicsize */ sizeof(ArrayStack),
+        /* tp_itemsize */ 0,
+        /* tp_dealloc */ (destructor) ArrayStack_dealloc,
+        /* tp_print */ 0,
+        /* tp_getattr */ 0,
+        /* tp_setattr */ 0,
+        /* tp_reserved */ 0,
+        /* tp_repr */ 0,
+        /* tp_as_number */ 0,
+        /* tp_as_sequence */ 0,
+        /* tp_as_mapping */ &ArrayStack_PyMappingMethods,
+        /* tp_hash  */ 0,
+        /* tp_call */ 0,
+        /* tp_str */ (reprfunc) ArrayStack__str__,
+        /* tp_getattro */ 0,
+        /* tp_setattro */ 0,
+        /* tp_as_buffer */ 0,
+        /* tp_flags */ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
+        /* tp_doc */ 0,
+        /* tp_traverse */ 0,
+        /* tp_clear */ 0,
+        /* tp_richcompare */ 0,
+        /* tp_weaklistoffset */ 0,
+        /* tp_iter */ 0,
+        /* tp_iternext */ 0,
+        /* tp_methods */ ArrayStack_PyMethodDef,
+        /* tp_members */ 0,
+        /* tp_getset */ ArrayStack_GetterSetters,
+        /* tp_base */ 0,
+        /* tp_dict */ 0,
+        /* tp_descr_get */ 0,
+        /* tp_descr_set */ 0,
+        /* tp_dictoffset */ 0,
+        /* tp_init */ 0,
+        /* tp_alloc */ 0,
+        /* tp_new */ ArrayStack__new__,
+};
+
+
+#endif

pydatastructs/miscellaneous_data_structures/_backend/cpp/stack/stack.cpp

@@ -0,0 +1,48 @@
+#include <Python.h>
+#include "ArrayStack.hpp"
+
+static struct PyModuleDef stack_struct = {
+    PyModuleDef_HEAD_INIT,
+    "_stack",
+    0,
+    -1,
+    NULL,
+};
+
+PyMODINIT_FUNC PyInit__stack(void) {
+    Py_Initialize();
+    PyObject *stack = PyModule_Create(&stack_struct);
+
+    if (PyType_Ready(&ArrayStackType) < 0) {
+        return NULL;
+    }
+    Py_INCREF(&ArrayStackType);
+    PyModule_AddObject(stack, "ArrayStack", reinterpret_cast<PyObject*>(&ArrayStackType));
+
+    if (PyType_Ready(&ArrayType) < 0) {
+        return NULL;
+    }
+    Py_INCREF(&ArrayType);
+    PyModule_AddObject(stack, "Array", reinterpret_cast<PyObject*>(&ArrayType));
+
+    if (PyType_Ready(&OneDimensionalArrayType) < 0) {
+        return NULL;
+    }
+    Py_INCREF(&OneDimensionalArrayType);
+    PyModule_AddObject(stack, "OneDimensionalArray", reinterpret_cast<PyObject*>(&OneDimensionalArrayType));
+
+    if (PyType_Ready(&DynamicArrayType) < 0) {
+        return NULL;
+    }
+    Py_INCREF(&DynamicArrayType);
+    PyModule_AddObject(stack, "DynamicArray", reinterpret_cast<PyObject*>(&DynamicArrayType));
+
+    if (PyType_Ready(&DynamicOneDimensionalArrayType) < 0) {
+        return NULL;
+    }
+    Py_INCREF(&DynamicOneDimensionalArrayType);
+    PyModule_AddObject(stack, "DynamicOneDimensionalArray", reinterpret_cast<PyObject*>(&DynamicOneDimensionalArrayType));
+
+
+    return stack;
+}

pydatastructs/miscellaneous_data_structures/_extensions.py

@@ -0,0 +1,16 @@
+from setuptools import Extension
+
+project = 'pydatastructs'
+
+module = 'miscellaneous_data_structures'
+
+backend = '_backend'
+
+cpp = 'cpp'
+
+stack = '.'.join([project, module, backend, cpp, '_stack'])
+stack_sources = ['/'.join([project, module, backend, cpp, 'stack', 'stack.cpp'])]
+
+extensions = [
+    Extension(stack, sources=stack_sources),
+]

pydatastructs/miscellaneous_data_structures/stack.py

@@ -1,4 +1,5 @@
 from pydatastructs.linear_data_structures import DynamicOneDimensionalArray, SinglyLinkedList
+from pydatastructs.miscellaneous_data_structures._backend.cpp import _stack
 from pydatastructs.utils.misc_util import (
     _check_type, NoneType, Backend,
     raise_if_backend_is_not_python)
@@ -53,18 +54,22 @@ class Stack(object):
     """
 
     def __new__(cls, implementation='array', **kwargs):
-        raise_if_backend_is_not_python(
-            cls, kwargs.get('backend', Backend.PYTHON))
+        backend = kwargs.get('backend', Backend.PYTHON)
         if implementation == 'array':
-            return ArrayStack(
-                kwargs.get('items', None),
-                kwargs.get('dtype', int))
+            items = kwargs.get('items', None)
+            dtype = kwargs.get('dtype', int)
+            if backend == Backend.CPP:
+                return _stack.ArrayStack(items, dtype)
+
+            return ArrayStack(items, dtype)
         if implementation == 'linked_list':
+            raise_if_backend_is_not_python(cls, backend)
+
             return LinkedListStack(
-                kwargs.get('items',None)
+                kwargs.get('items', None)
             )
         raise NotImplementedError(
-                "%s hasn't been implemented yet."%(implementation))
+            "%s hasn't been implemented yet."%(implementation))
 
     @classmethod
     def methods(cls):

pydatastructs/miscellaneous_data_structures/tests/test_stack.py

@@ -1,7 +1,9 @@
 from pydatastructs.miscellaneous_data_structures import Stack
 from pydatastructs.miscellaneous_data_structures.stack import ArrayStack, LinkedListStack
+from pydatastructs.miscellaneous_data_structures._backend.cpp import _stack
 from pydatastructs.utils.raises_util import raises
-from pydatastructs.utils.misc_util import _check_type
+from pydatastructs.utils.misc_util import _check_type, Backend
+
 
 def test_Stack():
     s = Stack(implementation='array')
@@ -12,6 +14,11 @@ def test_Stack():
     assert _check_type(s2, LinkedListStack) is True
     assert raises(NotImplementedError, lambda: Stack(implementation=''))
 
+    s3 = Stack(backend=Backend.CPP)
+    assert _check_type(s3, _stack.ArrayStack) is True
+    s4 = Stack(implementation="array", backend=Backend.CPP)
+    assert _check_type(s4, _stack.ArrayStack) is True
+
 def test_ArrayStack():
     s = Stack(implementation='array')
     s.push(1)
@@ -28,6 +35,22 @@ def test_ArrayStack():
     assert str(_s) == '[1, 2, 3]'
     assert len(_s) == 3
 
+    # Cpp test
+    s1 = Stack(implementation="array", backend=Backend.CPP)
+    s1.push(1)
+    s1.push(2)
+    s1.push(3)
+    assert s1.peek == 3
+    assert str(s1) == "['1', '2', '3']"
+    assert s1.pop() == 3
+    assert s1.pop() == 2
+    assert s1.pop() == 1
+    assert s1.is_empty is True
+    assert raises(IndexError, lambda : s1.pop())
+    _s1 = Stack(items=[1, 2, 3], backend=Backend.CPP)
+    assert str(_s1) == "['1', '2', '3']"
+    assert len(_s1) == 3
+
 def test_LinkedListStack():
     s = Stack(implementation='linked_list')
     s.push(1)

scripts/build/dummy_submodules_data.py

@@ -1,9 +1,9 @@
 project = 'pydatastructs'
 
-modules = ['linear_data_structures']
+modules = ['linear_data_structures', 'miscellaneous_data_structures']
 
 backend = '_backend'
 
 cpp = 'cpp'
 
-dummy_submodules_list = [('_arrays.py', '_algorithms.py')]
+dummy_submodules_list = [('_arrays.py', '_algorithms.py'), ('_stack.py',)]

setup.py

@@ -1,12 +1,14 @@
 import setuptools
 from pydatastructs import linear_data_structures
+from pydatastructs import miscellaneous_data_structures
 
 with open("README.md", "r") as fh:
     long_description = fh.read()
 
 extensions = []
 
 extensions.extend(linear_data_structures._extensions.extensions)
+extensions.extend(miscellaneous_data_structures._extensions.extensions)
 
 setuptools.setup(
     name="cz-pydatastructs",