bpo-31265: Compact OrderedDict (wip)

Include/dictobject.h

@@ -25,6 +25,8 @@ typedef struct {
 
     /* Number of items in the dictionary */
     Py_ssize_t ma_used;
+    // Number of free entries in front of dk_entries.
+    Py_ssize_t ma_offset;
 
     /* Dictionary version: globally unique, value change each time
        the dictionary is modified */

Lib/test/test_ordered_dict.py

@@ -520,14 +520,23 @@ def __hash__(self):
             od[key] = i
 
         # These should not crash.
-        with self.assertRaises(KeyError):
+        # Pure Python implementation raises KeyError, C implementation not.
+        try:
             list(od.values())
-        with self.assertRaises(KeyError):
+        except KeyError:
+            pass
+        try:
             list(od.items())
-        with self.assertRaises(KeyError):
+        except KeyError:
+            pass
+        try:
             repr(od)
-        with self.assertRaises(KeyError):
+        except KeyError:
+            pass
+        try:
             od.copy()
+        except KeyError:
+            pass
 
     def test_issue24348(self):
         OrderedDict = self.OrderedDict
@@ -578,8 +587,11 @@ def test_dict_delitem(self):
         od['spam'] = 1
         od['ham'] = 2
         dict.__delitem__(od, 'spam')
-        with self.assertRaises(KeyError):
+        # Pure Python implementation raises KeyError, C implementation not.
+        try:
             repr(od)
+        except KeyError:
+            pass
 
     def test_dict_clear(self):
         OrderedDict = self.OrderedDict
@@ -595,17 +607,23 @@ def test_dict_pop(self):
         od['spam'] = 1
         od['ham'] = 2
         dict.pop(od, 'spam')
-        with self.assertRaises(KeyError):
+        # Pure Python implementation raises KeyError, C implementation not.
+        try:
             repr(od)
+        except KeyError:
+            pass
 
     def test_dict_popitem(self):
         OrderedDict = self.OrderedDict
         od = OrderedDict()
         od['spam'] = 1
         od['ham'] = 2
         dict.popitem(od)
-        with self.assertRaises(KeyError):
+        # Pure Python implementation raises KeyError, C implementation not.
+        try:
             repr(od)
+        except KeyError:
+            pass
 
     def test_dict_setdefault(self):
         OrderedDict = self.OrderedDict
@@ -676,26 +694,25 @@ def test_sizeof_exact(self):
         size = support.calcobjsize
         check = self.check_sizeof
 
-        basicsize = size('nQ2P' + '3PnPn2P') + calcsize('2nP2n')
+        basicsize = size('n2Q2P' + '2Pn') + calcsize('2nP2n')
 
         entrysize = calcsize('n2P')
         p = calcsize('P')
-        nodesize = calcsize('Pn2P')
 
         od = OrderedDict()
-        check(od, basicsize + 8*p + 8 + 5*entrysize)  # 8byte indicies + 8*2//3 * entry table
+        check(od, basicsize + 8 + 5*entrysize)  # 8byte indicies + 8*2//3 * entry table
         od.x = 1
-        check(od, basicsize + 8*p + 8 + 5*entrysize)
+        check(od, basicsize + 8 + 5*entrysize)
         od.update([(i, i) for i in range(3)])
-        check(od, basicsize + 8*p + 8 + 5*entrysize + 3*nodesize)
+        check(od, basicsize + 8 + 5*entrysize)
         od.update([(i, i) for i in range(3, 10)])
-        check(od, basicsize + 16*p + 16 + 10*entrysize + 10*nodesize)
+        check(od, basicsize + 16 + 10*entrysize)
 
         check(od.keys(), size('P'))
         check(od.items(), size('P'))
         check(od.values(), size('P'))
 
-        itersize = size('iP2n2P')
+        itersize = size('i2P3nP')
         check(iter(od), itersize)
         check(iter(od.keys()), itersize)
         check(iter(od.items()), itersize)

Lib/test/test_sys.py

@@ -949,9 +949,9 @@ def inner():
         # method-wrapper (descriptor object)
         check({}.__iter__, size('2P'))
         # dict
-        check({}, size('nQ2P') + calcsize('2nP2n') + 8 + (8*2//3)*calcsize('n2P'))
+        check({}, size('2nQ2P') + calcsize('2nP2n') + 8 + (8*2//3)*calcsize('n2P'))
         longdict = {1:1, 2:2, 3:3, 4:4, 5:5, 6:6, 7:7, 8:8}
-        check(longdict, size('nQ2P') + calcsize('2nP2n') + 16 + (16*2//3)*calcsize('n2P'))
+        check(longdict, size('2nQ2P') + calcsize('2nP2n') + 16 + (16*2//3)*calcsize('n2P'))
         # dictionary-keyview
         check({}.keys(), size('P'))
         # dictionary-valueview
@@ -1115,7 +1115,7 @@ def delx(self): del self.__x
         class newstyleclass(object): pass
         check(newstyleclass, s)
         # dict with shared keys
-        check(newstyleclass().__dict__, size('nQ2P' + '2nP2n'))
+        check(newstyleclass().__dict__, size('n2Q2P' + '2nP2n'))
         # unicode
         # each tuple contains a string and its expected character size
         # don't put any static strings here, as they may contain

Makefile.pre.in

@@ -395,7 +395,6 @@ OBJECT_OBJS=	\
 		Objects/listobject.o \
 		Objects/longobject.o \
 		Objects/dictobject.o \
-		Objects/odictobject.o \
 		Objects/memoryobject.o \
 		Objects/methodobject.o \
 		Objects/moduleobject.o \
@@ -854,8 +853,7 @@ Objects/bytearrayobject.o: $(srcdir)/Objects/bytearrayobject.c $(BYTESTR_DEPS)
 
 Objects/unicodeobject.o: $(srcdir)/Objects/unicodeobject.c $(UNICODE_DEPS)
 
-Objects/odictobject.o: $(srcdir)/Objects/dict-common.h
-Objects/dictobject.o: $(srcdir)/Objects/stringlib/eq.h $(srcdir)/Objects/dict-common.h
+Objects/dictobject.o: $(srcdir)/Objects/stringlib/eq.h
 Objects/setobject.o: $(srcdir)/Objects/stringlib/eq.h
 
 .PHONY: regen-opcode-targets

Objects/clinic/dictobject.c.h

@@ -103,4 +103,134 @@ dict_setdefault(PyDictObject *self, PyObject **args, Py_ssize_t nargs)
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=8d09902e60b7ab02 input=a9049054013a1b77]*/
+
+PyDoc_STRVAR(OrderedDict_fromkeys__doc__,
+"fromkeys($type, /, iterable, value=None)\n"
+"--\n"
+"\n"
+"Create a new ordered dictionary with keys from iterable and values set to value.");
+
+#define ORDEREDDICT_FROMKEYS_METHODDEF    \
+    {"fromkeys", (PyCFunction)OrderedDict_fromkeys, METH_FASTCALL|METH_KEYWORDS|METH_CLASS, OrderedDict_fromkeys__doc__},
+
+static PyObject *
+OrderedDict_fromkeys_impl(PyTypeObject *type, PyObject *seq, PyObject *value);
+
+static PyObject *
+OrderedDict_fromkeys(PyTypeObject *type, PyObject **args, Py_ssize_t nargs, PyObject *kwnames)
+{
+    PyObject *return_value = NULL;
+    static const char * const _keywords[] = {"iterable", "value", NULL};
+    static _PyArg_Parser _parser = {"O|O:fromkeys", _keywords, 0};
+    PyObject *seq;
+    PyObject *value = Py_None;
+
+    if (!_PyArg_ParseStackAndKeywords(args, nargs, kwnames, &_parser,
+        &seq, &value)) {
+        goto exit;
+    }
+    return_value = OrderedDict_fromkeys_impl(type, seq, value);
+
+exit:
+    return return_value;
+}
+
+PyDoc_STRVAR(OrderedDict_setdefault__doc__,
+"setdefault($self, /, key, default=None)\n"
+"--\n"
+"\n"
+"Insert key with a value of default if key is not in the dictionary.\n"
+"\n"
+"Return the value for key if key is in the dictionary, else default.");
+
+#define ORDEREDDICT_SETDEFAULT_METHODDEF    \
+    {"setdefault", (PyCFunction)OrderedDict_setdefault, METH_FASTCALL|METH_KEYWORDS, OrderedDict_setdefault__doc__},
+
+static PyObject *
+OrderedDict_setdefault_impl(PyODictObject *self, PyObject *key,
+                            PyObject *default_value);
+
+static PyObject *
+OrderedDict_setdefault(PyODictObject *self, PyObject **args, Py_ssize_t nargs, PyObject *kwnames)
+{
+    PyObject *return_value = NULL;
+    static const char * const _keywords[] = {"key", "default", NULL};
+    static _PyArg_Parser _parser = {"O|O:setdefault", _keywords, 0};
+    PyObject *key;
+    PyObject *default_value = Py_None;
+
+    if (!_PyArg_ParseStackAndKeywords(args, nargs, kwnames, &_parser,
+        &key, &default_value)) {
+        goto exit;
+    }
+    return_value = OrderedDict_setdefault_impl(self, key, default_value);
+
+exit:
+    return return_value;
+}
+
+PyDoc_STRVAR(OrderedDict_popitem__doc__,
+"popitem($self, /, last=True)\n"
+"--\n"
+"\n"
+"Remove and return a (key, value) pair from the dictionary.\n"
+"\n"
+"Pairs are returned in LIFO order if last is true or FIFO order if false.");
+
+#define ORDEREDDICT_POPITEM_METHODDEF    \
+    {"popitem", (PyCFunction)OrderedDict_popitem, METH_FASTCALL|METH_KEYWORDS, OrderedDict_popitem__doc__},
+
+static PyObject *
+OrderedDict_popitem_impl(PyODictObject *self, int last);
+
+static PyObject *
+OrderedDict_popitem(PyODictObject *self, PyObject **args, Py_ssize_t nargs, PyObject *kwnames)
+{
+    PyObject *return_value = NULL;
+    static const char * const _keywords[] = {"last", NULL};
+    static _PyArg_Parser _parser = {"|p:popitem", _keywords, 0};
+    int last = 1;
+
+    if (!_PyArg_ParseStackAndKeywords(args, nargs, kwnames, &_parser,
+        &last)) {
+        goto exit;
+    }
+    return_value = OrderedDict_popitem_impl(self, last);
+
+exit:
+    return return_value;
+}
+
+PyDoc_STRVAR(OrderedDict_move_to_end__doc__,
+"move_to_end($self, /, key, last=True)\n"
+"--\n"
+"\n"
+"Move an existing element to the end (or beginning if last is false).\n"
+"\n"
+"Raise KeyError if the element does not exist.");
+
+#define ORDEREDDICT_MOVE_TO_END_METHODDEF    \
+    {"move_to_end", (PyCFunction)OrderedDict_move_to_end, METH_FASTCALL|METH_KEYWORDS, OrderedDict_move_to_end__doc__},
+
+static PyObject *
+OrderedDict_move_to_end_impl(PyODictObject *self, PyObject *key, int last);
+
+static PyObject *
+OrderedDict_move_to_end(PyODictObject *self, PyObject **args, Py_ssize_t nargs, PyObject *kwnames)
+{
+    PyObject *return_value = NULL;
+    static const char * const _keywords[] = {"key", "last", NULL};
+    static _PyArg_Parser _parser = {"O|p:move_to_end", _keywords, 0};
+    PyObject *key;
+    int last = 1;
+
+    if (!_PyArg_ParseStackAndKeywords(args, nargs, kwnames, &_parser,
+        &key, &last)) {
+        goto exit;
+    }
+    return_value = OrderedDict_move_to_end_impl(self, key, last);
+
+exit:
+    return return_value;
+}
+/*[clinic end generated code: output=c5169c4993a5a8bb input=a9049054013a1b77]*/