| /* List object implementation */ |
| |
| #include "Python.h" |
| #include "pycore_abstract.h" // _PyIndex_Check() |
| #include "pycore_interp.h" // PyInterpreterState.list |
| #include "pycore_list.h" // struct _Py_list_state, _PyListIterObject |
| #include "pycore_long.h" // _PyLong_DigitCount |
| #include "pycore_object.h" // _PyObject_GC_TRACK() |
| #include "pycore_tuple.h" // _PyTuple_FromArray() |
| #include <stddef.h> |
| |
| /*[clinic input] |
| class list "PyListObject *" "&PyList_Type" |
| [clinic start generated code]*/ |
| /*[clinic end generated code: output=da39a3ee5e6b4b0d input=f9b222678f9f71e0]*/ |
| |
| #include "clinic/listobject.c.h" |
| |
| _Py_DECLARE_STR(list_err, "list index out of range"); |
| |
| #if PyList_MAXFREELIST > 0 |
| static struct _Py_list_state * |
| get_list_state(void) |
| { |
| PyInterpreterState *interp = _PyInterpreterState_GET(); |
| return &interp->list; |
| } |
| #endif |
| |
| |
| /* Ensure ob_item has room for at least newsize elements, and set |
| * ob_size to newsize. If newsize > ob_size on entry, the content |
| * of the new slots at exit is undefined heap trash; it's the caller's |
| * responsibility to overwrite them with sane values. |
| * The number of allocated elements may grow, shrink, or stay the same. |
| * Failure is impossible if newsize <= self.allocated on entry, although |
| * that partly relies on an assumption that the system realloc() never |
| * fails when passed a number of bytes <= the number of bytes last |
| * allocated (the C standard doesn't guarantee this, but it's hard to |
| * imagine a realloc implementation where it wouldn't be true). |
| * Note that self->ob_item may change, and even if newsize is less |
| * than ob_size on entry. |
| */ |
| static int |
| list_resize(PyListObject *self, Py_ssize_t newsize) |
| { |
| PyObject **items; |
| size_t new_allocated, num_allocated_bytes; |
| Py_ssize_t allocated = self->allocated; |
| |
| /* Bypass realloc() when a previous overallocation is large enough |
| to accommodate the newsize. If the newsize falls lower than half |
| the allocated size, then proceed with the realloc() to shrink the list. |
| */ |
| if (allocated >= newsize && newsize >= (allocated >> 1)) { |
| assert(self->ob_item != NULL || newsize == 0); |
| Py_SET_SIZE(self, newsize); |
| return 0; |
| } |
| |
| /* This over-allocates proportional to the list size, making room |
| * for additional growth. The over-allocation is mild, but is |
| * enough to give linear-time amortized behavior over a long |
| * sequence of appends() in the presence of a poorly-performing |
| * system realloc(). |
| * Add padding to make the allocated size multiple of 4. |
| * The growth pattern is: 0, 4, 8, 16, 24, 32, 40, 52, 64, 76, ... |
| * Note: new_allocated won't overflow because the largest possible value |
| * is PY_SSIZE_T_MAX * (9 / 8) + 6 which always fits in a size_t. |
| */ |
| new_allocated = ((size_t)newsize + (newsize >> 3) + 6) & ~(size_t)3; |
| /* Do not overallocate if the new size is closer to overallocated size |
| * than to the old size. |
| */ |
| if (newsize - Py_SIZE(self) > (Py_ssize_t)(new_allocated - newsize)) |
| new_allocated = ((size_t)newsize + 3) & ~(size_t)3; |
| |
| if (newsize == 0) |
| new_allocated = 0; |
| if (new_allocated <= (size_t)PY_SSIZE_T_MAX / sizeof(PyObject *)) { |
| num_allocated_bytes = new_allocated * sizeof(PyObject *); |
| items = (PyObject **)PyMem_Realloc(self->ob_item, num_allocated_bytes); |
| } |
| else { |
| // integer overflow |
| items = NULL; |
| } |
| if (items == NULL) { |
| PyErr_NoMemory(); |
| return -1; |
| } |
| self->ob_item = items; |
| Py_SET_SIZE(self, newsize); |
| self->allocated = new_allocated; |
| return 0; |
| } |
| |
| static int |
| list_preallocate_exact(PyListObject *self, Py_ssize_t size) |
| { |
| assert(self->ob_item == NULL); |
| assert(size > 0); |
| |
| /* Since the Python memory allocator has granularity of 16 bytes on 64-bit |
| * platforms (8 on 32-bit), there is no benefit of allocating space for |
| * the odd number of items, and there is no drawback of rounding the |
| * allocated size up to the nearest even number. |
| */ |
| size = (size + 1) & ~(size_t)1; |
| PyObject **items = PyMem_New(PyObject*, size); |
| if (items == NULL) { |
| PyErr_NoMemory(); |
| return -1; |
| } |
| self->ob_item = items; |
| self->allocated = size; |
| return 0; |
| } |
| |
| void |
| _PyList_ClearFreeList(PyInterpreterState *interp) |
| { |
| #if PyList_MAXFREELIST > 0 |
| struct _Py_list_state *state = &interp->list; |
| while (state->numfree) { |
| PyListObject *op = state->free_list[--state->numfree]; |
| assert(PyList_CheckExact(op)); |
| PyObject_GC_Del(op); |
| } |
| #endif |
| } |
| |
| void |
| _PyList_Fini(PyInterpreterState *interp) |
| { |
| _PyList_ClearFreeList(interp); |
| #if defined(Py_DEBUG) && PyList_MAXFREELIST > 0 |
| struct _Py_list_state *state = &interp->list; |
| state->numfree = -1; |
| #endif |
| } |
| |
| /* Print summary info about the state of the optimized allocator */ |
| void |
| _PyList_DebugMallocStats(FILE *out) |
| { |
| #if PyList_MAXFREELIST > 0 |
| struct _Py_list_state *state = get_list_state(); |
| _PyDebugAllocatorStats(out, |
| "free PyListObject", |
| state->numfree, sizeof(PyListObject)); |
| #endif |
| } |
| |
| PyObject * |
| PyList_New(Py_ssize_t size) |
| { |
| PyListObject *op; |
| |
| if (size < 0) { |
| PyErr_BadInternalCall(); |
| return NULL; |
| } |
| |
| #if PyList_MAXFREELIST > 0 |
| struct _Py_list_state *state = get_list_state(); |
| #ifdef Py_DEBUG |
| // PyList_New() must not be called after _PyList_Fini() |
| assert(state->numfree != -1); |
| #endif |
| if (PyList_MAXFREELIST && state->numfree) { |
| state->numfree--; |
| op = state->free_list[state->numfree]; |
| OBJECT_STAT_INC(from_freelist); |
| _Py_NewReference((PyObject *)op); |
| } |
| else |
| #endif |
| { |
| op = PyObject_GC_New(PyListObject, &PyList_Type); |
| if (op == NULL) { |
| return NULL; |
| } |
| } |
| if (size <= 0) { |
| op->ob_item = NULL; |
| } |
| else { |
| op->ob_item = (PyObject **) PyMem_Calloc(size, sizeof(PyObject *)); |
| if (op->ob_item == NULL) { |
| Py_DECREF(op); |
| return PyErr_NoMemory(); |
| } |
| } |
| Py_SET_SIZE(op, size); |
| op->allocated = size; |
| _PyObject_GC_TRACK(op); |
| return (PyObject *) op; |
| } |
| |
| static PyObject * |
| list_new_prealloc(Py_ssize_t size) |
| { |
| assert(size > 0); |
| PyListObject *op = (PyListObject *) PyList_New(0); |
| if (op == NULL) { |
| return NULL; |
| } |
| assert(op->ob_item == NULL); |
| op->ob_item = PyMem_New(PyObject *, size); |
| if (op->ob_item == NULL) { |
| Py_DECREF(op); |
| return PyErr_NoMemory(); |
| } |
| op->allocated = size; |
| return (PyObject *) op; |
| } |
| |
| Py_ssize_t |
| PyList_Size(PyObject *op) |
| { |
| if (!PyList_Check(op)) { |
| PyErr_BadInternalCall(); |
| return -1; |
| } |
| else |
| return Py_SIZE(op); |
| } |
| |
| static inline int |
| valid_index(Py_ssize_t i, Py_ssize_t limit) |
| { |
| /* The cast to size_t lets us use just a single comparison |
| to check whether i is in the range: 0 <= i < limit. |
| |
| See: Section 14.2 "Bounds Checking" in the Agner Fog |
| optimization manual found at: |
| https://www.agner.org/optimize/optimizing_cpp.pdf |
| */ |
| return (size_t) i < (size_t) limit; |
| } |
| |
| PyObject * |
| PyList_GetItem(PyObject *op, Py_ssize_t i) |
| { |
| if (!PyList_Check(op)) { |
| PyErr_BadInternalCall(); |
| return NULL; |
| } |
| if (!valid_index(i, Py_SIZE(op))) { |
| _Py_DECLARE_STR(list_err, "list index out of range"); |
| PyErr_SetObject(PyExc_IndexError, &_Py_STR(list_err)); |
| return NULL; |
| } |
| return ((PyListObject *)op) -> ob_item[i]; |
| } |
| |
| int |
| PyList_SetItem(PyObject *op, Py_ssize_t i, |
| PyObject *newitem) |
| { |
| PyObject **p; |
| if (!PyList_Check(op)) { |
| Py_XDECREF(newitem); |
| PyErr_BadInternalCall(); |
| return -1; |
| } |
| if (!valid_index(i, Py_SIZE(op))) { |
| Py_XDECREF(newitem); |
| PyErr_SetString(PyExc_IndexError, |
| "list assignment index out of range"); |
| return -1; |
| } |
| p = ((PyListObject *)op) -> ob_item + i; |
| Py_XSETREF(*p, newitem); |
| return 0; |
| } |
| |
| static int |
| ins1(PyListObject *self, Py_ssize_t where, PyObject *v) |
| { |
| Py_ssize_t i, n = Py_SIZE(self); |
| PyObject **items; |
| if (v == NULL) { |
| PyErr_BadInternalCall(); |
| return -1; |
| } |
| |
| assert((size_t)n + 1 < PY_SSIZE_T_MAX); |
| if (list_resize(self, n+1) < 0) |
| return -1; |
| |
| if (where < 0) { |
| where += n; |
| if (where < 0) |
| where = 0; |
| } |
| if (where > n) |
| where = n; |
| items = self->ob_item; |
| for (i = n; --i >= where; ) |
| items[i+1] = items[i]; |
| items[where] = Py_NewRef(v); |
| return 0; |
| } |
| |
| int |
| PyList_Insert(PyObject *op, Py_ssize_t where, PyObject *newitem) |
| { |
| if (!PyList_Check(op)) { |
| PyErr_BadInternalCall(); |
| return -1; |
| } |
| return ins1((PyListObject *)op, where, newitem); |
| } |
| |
| /* internal, used by _PyList_AppendTakeRef */ |
| int |
| _PyList_AppendTakeRefListResize(PyListObject *self, PyObject *newitem) |
| { |
| Py_ssize_t len = PyList_GET_SIZE(self); |
| assert(self->allocated == -1 || self->allocated == len); |
| if (list_resize(self, len + 1) < 0) { |
| Py_DECREF(newitem); |
| return -1; |
| } |
| PyList_SET_ITEM(self, len, newitem); |
| return 0; |
| } |
| |
| int |
| PyList_Append(PyObject *op, PyObject *newitem) |
| { |
| if (PyList_Check(op) && (newitem != NULL)) { |
| return _PyList_AppendTakeRef((PyListObject *)op, Py_NewRef(newitem)); |
| } |
| PyErr_BadInternalCall(); |
| return -1; |
| } |
| |
| /* Methods */ |
| |
| static void |
| list_dealloc(PyListObject *op) |
| { |
| Py_ssize_t i; |
| PyObject_GC_UnTrack(op); |
| Py_TRASHCAN_BEGIN(op, list_dealloc) |
| if (op->ob_item != NULL) { |
| /* Do it backwards, for Christian Tismer. |
| There's a simple test case where somehow this reduces |
| thrashing when a *very* large list is created and |
| immediately deleted. */ |
| i = Py_SIZE(op); |
| while (--i >= 0) { |
| Py_XDECREF(op->ob_item[i]); |
| } |
| PyMem_Free(op->ob_item); |
| } |
| #if PyList_MAXFREELIST > 0 |
| struct _Py_list_state *state = get_list_state(); |
| #ifdef Py_DEBUG |
| // list_dealloc() must not be called after _PyList_Fini() |
| assert(state->numfree != -1); |
| #endif |
| if (state->numfree < PyList_MAXFREELIST && PyList_CheckExact(op)) { |
| state->free_list[state->numfree++] = op; |
| OBJECT_STAT_INC(to_freelist); |
| } |
| else |
| #endif |
| { |
| Py_TYPE(op)->tp_free((PyObject *)op); |
| } |
| Py_TRASHCAN_END |
| } |
| |
| static PyObject * |
| list_repr(PyListObject *v) |
| { |
| Py_ssize_t i; |
| PyObject *s; |
| _PyUnicodeWriter writer; |
| |
| if (Py_SIZE(v) == 0) { |
| return PyUnicode_FromString("[]"); |
| } |
| |
| i = Py_ReprEnter((PyObject*)v); |
| if (i != 0) { |
| return i > 0 ? PyUnicode_FromString("[...]") : NULL; |
| } |
| |
| _PyUnicodeWriter_Init(&writer); |
| writer.overallocate = 1; |
| /* "[" + "1" + ", 2" * (len - 1) + "]" */ |
| writer.min_length = 1 + 1 + (2 + 1) * (Py_SIZE(v) - 1) + 1; |
| |
| if (_PyUnicodeWriter_WriteChar(&writer, '[') < 0) |
| goto error; |
| |
| /* Do repr() on each element. Note that this may mutate the list, |
| so must refetch the list size on each iteration. */ |
| for (i = 0; i < Py_SIZE(v); ++i) { |
| if (i > 0) { |
| if (_PyUnicodeWriter_WriteASCIIString(&writer, ", ", 2) < 0) |
| goto error; |
| } |
| |
| s = PyObject_Repr(v->ob_item[i]); |
| if (s == NULL) |
| goto error; |
| |
| if (_PyUnicodeWriter_WriteStr(&writer, s) < 0) { |
| Py_DECREF(s); |
| goto error; |
| } |
| Py_DECREF(s); |
| } |
| |
| writer.overallocate = 0; |
| if (_PyUnicodeWriter_WriteChar(&writer, ']') < 0) |
| goto error; |
| |
| Py_ReprLeave((PyObject *)v); |
| return _PyUnicodeWriter_Finish(&writer); |
| |
| error: |
| _PyUnicodeWriter_Dealloc(&writer); |
| Py_ReprLeave((PyObject *)v); |
| return NULL; |
| } |
| |
| static Py_ssize_t |
| list_length(PyListObject *a) |
| { |
| return Py_SIZE(a); |
| } |
| |
| static int |
| list_contains(PyListObject *a, PyObject *el) |
| { |
| PyObject *item; |
| Py_ssize_t i; |
| int cmp; |
| |
| for (i = 0, cmp = 0 ; cmp == 0 && i < Py_SIZE(a); ++i) { |
| item = PyList_GET_ITEM(a, i); |
| Py_INCREF(item); |
| cmp = PyObject_RichCompareBool(item, el, Py_EQ); |
| Py_DECREF(item); |
| } |
| return cmp; |
| } |
| |
| static PyObject * |
| list_item(PyListObject *a, Py_ssize_t i) |
| { |
| if (!valid_index(i, Py_SIZE(a))) { |
| PyErr_SetObject(PyExc_IndexError, &_Py_STR(list_err)); |
| return NULL; |
| } |
| return Py_NewRef(a->ob_item[i]); |
| } |
| |
| static PyObject * |
| list_slice(PyListObject *a, Py_ssize_t ilow, Py_ssize_t ihigh) |
| { |
| PyListObject *np; |
| PyObject **src, **dest; |
| Py_ssize_t i, len; |
| len = ihigh - ilow; |
| if (len <= 0) { |
| return PyList_New(0); |
| } |
| np = (PyListObject *) list_new_prealloc(len); |
| if (np == NULL) |
| return NULL; |
| |
| src = a->ob_item + ilow; |
| dest = np->ob_item; |
| for (i = 0; i < len; i++) { |
| PyObject *v = src[i]; |
| dest[i] = Py_NewRef(v); |
| } |
| Py_SET_SIZE(np, len); |
| return (PyObject *)np; |
| } |
| |
| PyObject * |
| PyList_GetSlice(PyObject *a, Py_ssize_t ilow, Py_ssize_t ihigh) |
| { |
| if (!PyList_Check(a)) { |
| PyErr_BadInternalCall(); |
| return NULL; |
| } |
| if (ilow < 0) { |
| ilow = 0; |
| } |
| else if (ilow > Py_SIZE(a)) { |
| ilow = Py_SIZE(a); |
| } |
| if (ihigh < ilow) { |
| ihigh = ilow; |
| } |
| else if (ihigh > Py_SIZE(a)) { |
| ihigh = Py_SIZE(a); |
| } |
| return list_slice((PyListObject *)a, ilow, ihigh); |
| } |
| |
| static PyObject * |
| list_concat(PyListObject *a, PyObject *bb) |
| { |
| Py_ssize_t size; |
| Py_ssize_t i; |
| PyObject **src, **dest; |
| PyListObject *np; |
| if (!PyList_Check(bb)) { |
| PyErr_Format(PyExc_TypeError, |
| "can only concatenate list (not \"%.200s\") to list", |
| Py_TYPE(bb)->tp_name); |
| return NULL; |
| } |
| #define b ((PyListObject *)bb) |
| assert((size_t)Py_SIZE(a) + (size_t)Py_SIZE(b) < PY_SSIZE_T_MAX); |
| size = Py_SIZE(a) + Py_SIZE(b); |
| if (size == 0) { |
| return PyList_New(0); |
| } |
| np = (PyListObject *) list_new_prealloc(size); |
| if (np == NULL) { |
| return NULL; |
| } |
| src = a->ob_item; |
| dest = np->ob_item; |
| for (i = 0; i < Py_SIZE(a); i++) { |
| PyObject *v = src[i]; |
| dest[i] = Py_NewRef(v); |
| } |
| src = b->ob_item; |
| dest = np->ob_item + Py_SIZE(a); |
| for (i = 0; i < Py_SIZE(b); i++) { |
| PyObject *v = src[i]; |
| dest[i] = Py_NewRef(v); |
| } |
| Py_SET_SIZE(np, size); |
| return (PyObject *)np; |
| #undef b |
| } |
| |
| static PyObject * |
| list_repeat(PyListObject *a, Py_ssize_t n) |
| { |
| const Py_ssize_t input_size = Py_SIZE(a); |
| if (input_size == 0 || n <= 0) |
| return PyList_New(0); |
| assert(n > 0); |
| |
| if (input_size > PY_SSIZE_T_MAX / n) |
| return PyErr_NoMemory(); |
| Py_ssize_t output_size = input_size * n; |
| |
| PyListObject *np = (PyListObject *) list_new_prealloc(output_size); |
| if (np == NULL) |
| return NULL; |
| |
| PyObject **dest = np->ob_item; |
| if (input_size == 1) { |
| PyObject *elem = a->ob_item[0]; |
| _Py_RefcntAdd(elem, n); |
| PyObject **dest_end = dest + output_size; |
| while (dest < dest_end) { |
| *dest++ = elem; |
| } |
| } |
| else { |
| PyObject **src = a->ob_item; |
| PyObject **src_end = src + input_size; |
| while (src < src_end) { |
| _Py_RefcntAdd(*src, n); |
| *dest++ = *src++; |
| } |
| |
| _Py_memory_repeat((char *)np->ob_item, sizeof(PyObject *)*output_size, |
| sizeof(PyObject *)*input_size); |
| } |
| |
| Py_SET_SIZE(np, output_size); |
| return (PyObject *) np; |
| } |
| |
| static int |
| _list_clear(PyListObject *a) |
| { |
| Py_ssize_t i; |
| PyObject **item = a->ob_item; |
| if (item != NULL) { |
| /* Because XDECREF can recursively invoke operations on |
| this list, we make it empty first. */ |
| i = Py_SIZE(a); |
| Py_SET_SIZE(a, 0); |
| a->ob_item = NULL; |
| a->allocated = 0; |
| while (--i >= 0) { |
| Py_XDECREF(item[i]); |
| } |
| PyMem_Free(item); |
| } |
| /* Never fails; the return value can be ignored. |
| Note that there is no guarantee that the list is actually empty |
| at this point, because XDECREF may have populated it again! */ |
| return 0; |
| } |
| |
| /* a[ilow:ihigh] = v if v != NULL. |
| * del a[ilow:ihigh] if v == NULL. |
| * |
| * Special speed gimmick: when v is NULL and ihigh - ilow <= 8, it's |
| * guaranteed the call cannot fail. |
| */ |
| static int |
| list_ass_slice(PyListObject *a, Py_ssize_t ilow, Py_ssize_t ihigh, PyObject *v) |
| { |
| /* Because [X]DECREF can recursively invoke list operations on |
| this list, we must postpone all [X]DECREF activity until |
| after the list is back in its canonical shape. Therefore |
| we must allocate an additional array, 'recycle', into which |
| we temporarily copy the items that are deleted from the |
| list. :-( */ |
| PyObject *recycle_on_stack[8]; |
| PyObject **recycle = recycle_on_stack; /* will allocate more if needed */ |
| PyObject **item; |
| PyObject **vitem = NULL; |
| PyObject *v_as_SF = NULL; /* PySequence_Fast(v) */ |
| Py_ssize_t n; /* # of elements in replacement list */ |
| Py_ssize_t norig; /* # of elements in list getting replaced */ |
| Py_ssize_t d; /* Change in size */ |
| Py_ssize_t k; |
| size_t s; |
| int result = -1; /* guilty until proved innocent */ |
| #define b ((PyListObject *)v) |
| if (v == NULL) |
| n = 0; |
| else { |
| if (a == b) { |
| /* Special case "a[i:j] = a" -- copy b first */ |
| v = list_slice(b, 0, Py_SIZE(b)); |
| if (v == NULL) |
| return result; |
| result = list_ass_slice(a, ilow, ihigh, v); |
| Py_DECREF(v); |
| return result; |
| } |
| v_as_SF = PySequence_Fast(v, "can only assign an iterable"); |
| if(v_as_SF == NULL) |
| goto Error; |
| n = PySequence_Fast_GET_SIZE(v_as_SF); |
| vitem = PySequence_Fast_ITEMS(v_as_SF); |
| } |
| if (ilow < 0) |
| ilow = 0; |
| else if (ilow > Py_SIZE(a)) |
| ilow = Py_SIZE(a); |
| |
| if (ihigh < ilow) |
| ihigh = ilow; |
| else if (ihigh > Py_SIZE(a)) |
| ihigh = Py_SIZE(a); |
| |
| norig = ihigh - ilow; |
| assert(norig >= 0); |
| d = n - norig; |
| if (Py_SIZE(a) + d == 0) { |
| Py_XDECREF(v_as_SF); |
| return _list_clear(a); |
| } |
| item = a->ob_item; |
| /* recycle the items that we are about to remove */ |
| s = norig * sizeof(PyObject *); |
| /* If norig == 0, item might be NULL, in which case we may not memcpy from it. */ |
| if (s) { |
| if (s > sizeof(recycle_on_stack)) { |
| recycle = (PyObject **)PyMem_Malloc(s); |
| if (recycle == NULL) { |
| PyErr_NoMemory(); |
| goto Error; |
| } |
| } |
| memcpy(recycle, &item[ilow], s); |
| } |
| |
| if (d < 0) { /* Delete -d items */ |
| Py_ssize_t tail; |
| tail = (Py_SIZE(a) - ihigh) * sizeof(PyObject *); |
| memmove(&item[ihigh+d], &item[ihigh], tail); |
| if (list_resize(a, Py_SIZE(a) + d) < 0) { |
| memmove(&item[ihigh], &item[ihigh+d], tail); |
| memcpy(&item[ilow], recycle, s); |
| goto Error; |
| } |
| item = a->ob_item; |
| } |
| else if (d > 0) { /* Insert d items */ |
| k = Py_SIZE(a); |
| if (list_resize(a, k+d) < 0) |
| goto Error; |
| item = a->ob_item; |
| memmove(&item[ihigh+d], &item[ihigh], |
| (k - ihigh)*sizeof(PyObject *)); |
| } |
| for (k = 0; k < n; k++, ilow++) { |
| PyObject *w = vitem[k]; |
| item[ilow] = Py_XNewRef(w); |
| } |
| for (k = norig - 1; k >= 0; --k) |
| Py_XDECREF(recycle[k]); |
| result = 0; |
| Error: |
| if (recycle != recycle_on_stack) |
| PyMem_Free(recycle); |
| Py_XDECREF(v_as_SF); |
| return result; |
| #undef b |
| } |
| |
| int |
| PyList_SetSlice(PyObject *a, Py_ssize_t ilow, Py_ssize_t ihigh, PyObject *v) |
| { |
| if (!PyList_Check(a)) { |
| PyErr_BadInternalCall(); |
| return -1; |
| } |
| return list_ass_slice((PyListObject *)a, ilow, ihigh, v); |
| } |
| |
| static PyObject * |
| list_inplace_repeat(PyListObject *self, Py_ssize_t n) |
| { |
| Py_ssize_t input_size = PyList_GET_SIZE(self); |
| if (input_size == 0 || n == 1) { |
| return Py_NewRef(self); |
| } |
| |
| if (n < 1) { |
| (void)_list_clear(self); |
| return Py_NewRef(self); |
| } |
| |
| if (input_size > PY_SSIZE_T_MAX / n) { |
| return PyErr_NoMemory(); |
| } |
| Py_ssize_t output_size = input_size * n; |
| |
| if (list_resize(self, output_size) < 0) |
| return NULL; |
| |
| PyObject **items = self->ob_item; |
| for (Py_ssize_t j = 0; j < input_size; j++) { |
| _Py_RefcntAdd(items[j], n-1); |
| } |
| _Py_memory_repeat((char *)items, sizeof(PyObject *)*output_size, |
| sizeof(PyObject *)*input_size); |
| |
| return Py_NewRef(self); |
| } |
| |
| static int |
| list_ass_item(PyListObject *a, Py_ssize_t i, PyObject *v) |
| { |
| if (!valid_index(i, Py_SIZE(a))) { |
| PyErr_SetString(PyExc_IndexError, |
| "list assignment index out of range"); |
| return -1; |
| } |
| if (v == NULL) |
| return list_ass_slice(a, i, i+1, v); |
| Py_SETREF(a->ob_item[i], Py_NewRef(v)); |
| return 0; |
| } |
| |
| /*[clinic input] |
| list.insert |
| |
| index: Py_ssize_t |
| object: object |
| / |
| |
| Insert object before index. |
| [clinic start generated code]*/ |
| |
| static PyObject * |
| list_insert_impl(PyListObject *self, Py_ssize_t index, PyObject *object) |
| /*[clinic end generated code: output=7f35e32f60c8cb78 input=858514cf894c7eab]*/ |
| { |
| if (ins1(self, index, object) == 0) |
| Py_RETURN_NONE; |
| return NULL; |
| } |
| |
| /*[clinic input] |
| list.clear |
| |
| Remove all items from list. |
| [clinic start generated code]*/ |
| |
| static PyObject * |
| list_clear_impl(PyListObject *self) |
| /*[clinic end generated code: output=67a1896c01f74362 input=ca3c1646856742f6]*/ |
| { |
| _list_clear(self); |
| Py_RETURN_NONE; |
| } |
| |
| /*[clinic input] |
| list.copy |
| |
| Return a shallow copy of the list. |
| [clinic start generated code]*/ |
| |
| static PyObject * |
| list_copy_impl(PyListObject *self) |
| /*[clinic end generated code: output=ec6b72d6209d418e input=6453ab159e84771f]*/ |
| { |
| return list_slice(self, 0, Py_SIZE(self)); |
| } |
| |
| /*[clinic input] |
| list.append |
| |
| object: object |
| / |
| |
| Append object to the end of the list. |
| [clinic start generated code]*/ |
| |
| static PyObject * |
| list_append(PyListObject *self, PyObject *object) |
| /*[clinic end generated code: output=7c096003a29c0eae input=43a3fe48a7066e91]*/ |
| { |
| if (_PyList_AppendTakeRef(self, Py_NewRef(object)) < 0) { |
| return NULL; |
| } |
| Py_RETURN_NONE; |
| } |
| |
| /*[clinic input] |
| list.extend |
| |
| iterable: object |
| / |
| |
| Extend list by appending elements from the iterable. |
| [clinic start generated code]*/ |
| |
| static PyObject * |
| list_extend(PyListObject *self, PyObject *iterable) |
| /*[clinic end generated code: output=630fb3bca0c8e789 input=9ec5ba3a81be3a4d]*/ |
| { |
| PyObject *it; /* iter(v) */ |
| Py_ssize_t m; /* size of self */ |
| Py_ssize_t n; /* guess for size of iterable */ |
| Py_ssize_t i; |
| PyObject *(*iternext)(PyObject *); |
| |
| /* Special cases: |
| 1) lists and tuples which can use PySequence_Fast ops |
| 2) extending self to self requires making a copy first |
| */ |
| if (PyList_CheckExact(iterable) || PyTuple_CheckExact(iterable) || |
| (PyObject *)self == iterable) { |
| PyObject **src, **dest; |
| iterable = PySequence_Fast(iterable, "argument must be iterable"); |
| if (!iterable) |
| return NULL; |
| n = PySequence_Fast_GET_SIZE(iterable); |
| if (n == 0) { |
| /* short circuit when iterable is empty */ |
| Py_DECREF(iterable); |
| Py_RETURN_NONE; |
| } |
| m = Py_SIZE(self); |
| /* It should not be possible to allocate a list large enough to cause |
| an overflow on any relevant platform */ |
| assert(m < PY_SSIZE_T_MAX - n); |
| if (self->ob_item == NULL) { |
| if (list_preallocate_exact(self, n) < 0) { |
| return NULL; |
| } |
| Py_SET_SIZE(self, n); |
| } |
| else if (list_resize(self, m + n) < 0) { |
| Py_DECREF(iterable); |
| return NULL; |
| } |
| /* note that we may still have self == iterable here for the |
| * situation a.extend(a), but the following code works |
| * in that case too. Just make sure to resize self |
| * before calling PySequence_Fast_ITEMS. |
| */ |
| /* populate the end of self with iterable's items */ |
| src = PySequence_Fast_ITEMS(iterable); |
| dest = self->ob_item + m; |
| for (i = 0; i < n; i++) { |
| PyObject *o = src[i]; |
| dest[i] = Py_NewRef(o); |
| } |
| Py_DECREF(iterable); |
| Py_RETURN_NONE; |
| } |
| |
| it = PyObject_GetIter(iterable); |
| if (it == NULL) |
| return NULL; |
| iternext = *Py_TYPE(it)->tp_iternext; |
| |
| /* Guess a result list size. */ |
| n = PyObject_LengthHint(iterable, 8); |
| if (n < 0) { |
| Py_DECREF(it); |
| return NULL; |
| } |
| m = Py_SIZE(self); |
| if (m > PY_SSIZE_T_MAX - n) { |
| /* m + n overflowed; on the chance that n lied, and there really |
| * is enough room, ignore it. If n was telling the truth, we'll |
| * eventually run out of memory during the loop. |
| */ |
| } |
| else if (self->ob_item == NULL) { |
| if (n && list_preallocate_exact(self, n) < 0) |
| goto error; |
| } |
| else { |
| /* Make room. */ |
| if (list_resize(self, m + n) < 0) |
| goto error; |
| /* Make the list sane again. */ |
| Py_SET_SIZE(self, m); |
| } |
| |
| /* Run iterator to exhaustion. */ |
| for (;;) { |
| PyObject *item = iternext(it); |
| if (item == NULL) { |
| if (PyErr_Occurred()) { |
| if (PyErr_ExceptionMatches(PyExc_StopIteration)) |
| PyErr_Clear(); |
| else |
| goto error; |
| } |
| break; |
| } |
| if (Py_SIZE(self) < self->allocated) { |
| /* steals ref */ |
| PyList_SET_ITEM(self, Py_SIZE(self), item); |
| Py_SET_SIZE(self, Py_SIZE(self) + 1); |
| } |
| else { |
| if (_PyList_AppendTakeRef(self, item) < 0) |
| goto error; |
| } |
| } |
| |
| /* Cut back result list if initial guess was too large. */ |
| if (Py_SIZE(self) < self->allocated) { |
| if (list_resize(self, Py_SIZE(self)) < 0) |
| goto error; |
| } |
| |
| Py_DECREF(it); |
| Py_RETURN_NONE; |
| |
| error: |
| Py_DECREF(it); |
| return NULL; |
| } |
| |
| PyObject * |
| _PyList_Extend(PyListObject *self, PyObject *iterable) |
| { |
| return list_extend(self, iterable); |
| } |
| |
| static PyObject * |
| list_inplace_concat(PyListObject *self, PyObject *other) |
| { |
| PyObject *result; |
| |
| result = list_extend(self, other); |
| if (result == NULL) |
| return result; |
| Py_DECREF(result); |
| return Py_NewRef(self); |
| } |
| |
| /*[clinic input] |
| list.pop |
| |
| index: Py_ssize_t = -1 |
| / |
| |
| Remove and return item at index (default last). |
| |
| Raises IndexError if list is empty or index is out of range. |
| [clinic start generated code]*/ |
| |
| static PyObject * |
| list_pop_impl(PyListObject *self, Py_ssize_t index) |
| /*[clinic end generated code: output=6bd69dcb3f17eca8 input=b83675976f329e6f]*/ |
| { |
| PyObject *v; |
| int status; |
| |
| if (Py_SIZE(self) == 0) { |
| /* Special-case most common failure cause */ |
| PyErr_SetString(PyExc_IndexError, "pop from empty list"); |
| return NULL; |
| } |
| if (index < 0) |
| index += Py_SIZE(self); |
| if (!valid_index(index, Py_SIZE(self))) { |
| PyErr_SetString(PyExc_IndexError, "pop index out of range"); |
| return NULL; |
| } |
| |
| PyObject **items = self->ob_item; |
| v = items[index]; |
| const Py_ssize_t size_after_pop = Py_SIZE(self) - 1; |
| if (size_after_pop == 0) { |
| Py_INCREF(v); |
| status = _list_clear(self); |
| } |
| else { |
| if ((size_after_pop - index) > 0) { |
| memmove(&items[index], &items[index+1], (size_after_pop - index) * sizeof(PyObject *)); |
| } |
| status = list_resize(self, size_after_pop); |
| } |
| if (status >= 0) { |
| return v; // and v now owns the reference the list had |
| } |
| else { |
| // list resize failed, need to restore |
| memmove(&items[index+1], &items[index], (size_after_pop - index)* sizeof(PyObject *)); |
| items[index] = v; |
| return NULL; |
| } |
| } |
| |
| /* Reverse a slice of a list in place, from lo up to (exclusive) hi. */ |
| static void |
| reverse_slice(PyObject **lo, PyObject **hi) |
| { |
| assert(lo && hi); |
| |
| --hi; |
| while (lo < hi) { |
| PyObject *t = *lo; |
| *lo = *hi; |
| *hi = t; |
| ++lo; |
| --hi; |
| } |
| } |
| |
| /* Lots of code for an adaptive, stable, natural mergesort. There are many |
| * pieces to this algorithm; read listsort.txt for overviews and details. |
| */ |
| |
| /* A sortslice contains a pointer to an array of keys and a pointer to |
| * an array of corresponding values. In other words, keys[i] |
| * corresponds with values[i]. If values == NULL, then the keys are |
| * also the values. |
| * |
| * Several convenience routines are provided here, so that keys and |
| * values are always moved in sync. |
| */ |
| |
| typedef struct { |
| PyObject **keys; |
| PyObject **values; |
| } sortslice; |
| |
| Py_LOCAL_INLINE(void) |
| sortslice_copy(sortslice *s1, Py_ssize_t i, sortslice *s2, Py_ssize_t j) |
| { |
| s1->keys[i] = s2->keys[j]; |
| if (s1->values != NULL) |
| s1->values[i] = s2->values[j]; |
| } |
| |
| Py_LOCAL_INLINE(void) |
| sortslice_copy_incr(sortslice *dst, sortslice *src) |
| { |
| *dst->keys++ = *src->keys++; |
| if (dst->values != NULL) |
| *dst->values++ = *src->values++; |
| } |
| |
| Py_LOCAL_INLINE(void) |
| sortslice_copy_decr(sortslice *dst, sortslice *src) |
| { |
| *dst->keys-- = *src->keys--; |
| if (dst->values != NULL) |
| *dst->values-- = *src->values--; |
| } |
| |
| |
| Py_LOCAL_INLINE(void) |
| sortslice_memcpy(sortslice *s1, Py_ssize_t i, sortslice *s2, Py_ssize_t j, |
| Py_ssize_t n) |
| { |
| memcpy(&s1->keys[i], &s2->keys[j], sizeof(PyObject *) * n); |
| if (s1->values != NULL) |
| memcpy(&s1->values[i], &s2->values[j], sizeof(PyObject *) * n); |
| } |
| |
| Py_LOCAL_INLINE(void) |
| sortslice_memmove(sortslice *s1, Py_ssize_t i, sortslice *s2, Py_ssize_t j, |
| Py_ssize_t n) |
| { |
| memmove(&s1->keys[i], &s2->keys[j], sizeof(PyObject *) * n); |
| if (s1->values != NULL) |
| memmove(&s1->values[i], &s2->values[j], sizeof(PyObject *) * n); |
| } |
| |
| Py_LOCAL_INLINE(void) |
| sortslice_advance(sortslice *slice, Py_ssize_t n) |
| { |
| slice->keys += n; |
| if (slice->values != NULL) |
| slice->values += n; |
| } |
| |
| /* Comparison function: ms->key_compare, which is set at run-time in |
| * listsort_impl to optimize for various special cases. |
| * Returns -1 on error, 1 if x < y, 0 if x >= y. |
| */ |
| |
| #define ISLT(X, Y) (*(ms->key_compare))(X, Y, ms) |
| |
| /* Compare X to Y via "<". Goto "fail" if the comparison raises an |
| error. Else "k" is set to true iff X<Y, and an "if (k)" block is |
| started. It makes more sense in context <wink>. X and Y are PyObject*s. |
| */ |
| #define IFLT(X, Y) if ((k = ISLT(X, Y)) < 0) goto fail; \ |
| if (k) |
| |
| /* The maximum number of entries in a MergeState's pending-runs stack. |
| * For a list with n elements, this needs at most floor(log2(n)) + 1 entries |
| * even if we didn't force runs to a minimal length. So the number of bits |
| * in a Py_ssize_t is plenty large enough for all cases. |
| */ |
| #define MAX_MERGE_PENDING (SIZEOF_SIZE_T * 8) |
| |
| /* When we get into galloping mode, we stay there until both runs win less |
| * often than MIN_GALLOP consecutive times. See listsort.txt for more info. |
| */ |
| #define MIN_GALLOP 7 |
| |
| /* Avoid malloc for small temp arrays. */ |
| #define MERGESTATE_TEMP_SIZE 256 |
| |
| /* One MergeState exists on the stack per invocation of mergesort. It's just |
| * a convenient way to pass state around among the helper functions. |
| */ |
| struct s_slice { |
| sortslice base; |
| Py_ssize_t len; /* length of run */ |
| int power; /* node "level" for powersort merge strategy */ |
| }; |
| |
| typedef struct s_MergeState MergeState; |
| struct s_MergeState { |
| /* This controls when we get *into* galloping mode. It's initialized |
| * to MIN_GALLOP. merge_lo and merge_hi tend to nudge it higher for |
| * random data, and lower for highly structured data. |
| */ |
| Py_ssize_t min_gallop; |
| |
| Py_ssize_t listlen; /* len(input_list) - read only */ |
| PyObject **basekeys; /* base address of keys array - read only */ |
| |
| /* 'a' is temp storage to help with merges. It contains room for |
| * alloced entries. |
| */ |
| sortslice a; /* may point to temparray below */ |
| Py_ssize_t alloced; |
| |
| /* A stack of n pending runs yet to be merged. Run #i starts at |
| * address base[i] and extends for len[i] elements. It's always |
| * true (so long as the indices are in bounds) that |
| * |
| * pending[i].base + pending[i].len == pending[i+1].base |
| * |
| * so we could cut the storage for this, but it's a minor amount, |
| * and keeping all the info explicit simplifies the code. |
| */ |
| int n; |
| struct s_slice pending[MAX_MERGE_PENDING]; |
| |
| /* 'a' points to this when possible, rather than muck with malloc. */ |
| PyObject *temparray[MERGESTATE_TEMP_SIZE]; |
| |
| /* This is the function we will use to compare two keys, |
| * even when none of our special cases apply and we have to use |
| * safe_object_compare. */ |
| int (*key_compare)(PyObject *, PyObject *, MergeState *); |
| |
| /* This function is used by unsafe_object_compare to optimize comparisons |
| * when we know our list is type-homogeneous but we can't assume anything else. |
| * In the pre-sort check it is set equal to Py_TYPE(key)->tp_richcompare */ |
| PyObject *(*key_richcompare)(PyObject *, PyObject *, int); |
| |
| /* This function is used by unsafe_tuple_compare to compare the first elements |
| * of tuples. It may be set to safe_object_compare, but the idea is that hopefully |
| * we can assume more, and use one of the special-case compares. */ |
| int (*tuple_elem_compare)(PyObject *, PyObject *, MergeState *); |
| }; |
| |
| /* binarysort is the best method for sorting small arrays: it does |
| few compares, but can do data movement quadratic in the number of |
| elements. |
| [lo, hi) is a contiguous slice of a list, and is sorted via |
| binary insertion. This sort is stable. |
| On entry, must have lo <= start <= hi, and that [lo, start) is already |
| sorted (pass start == lo if you don't know!). |
| If islt() complains return -1, else 0. |
| Even in case of error, the output slice will be some permutation of |
| the input (nothing is lost or duplicated). |
| */ |
| static int |
| binarysort(MergeState *ms, sortslice lo, PyObject **hi, PyObject **start) |
| { |
| Py_ssize_t k; |
| PyObject **l, **p, **r; |
| PyObject *pivot; |
| |
| assert(lo.keys <= start && start <= hi); |
| /* assert [lo, start) is sorted */ |
| if (lo.keys == start) |
| ++start; |
| for (; start < hi; ++start) { |
| /* set l to where *start belongs */ |
| l = lo.keys; |
| r = start; |
| pivot = *r; |
| /* Invariants: |
| * pivot >= all in [lo, l). |
| * pivot < all in [r, start). |
| * The second is vacuously true at the start. |
| */ |
| assert(l < r); |
| do { |
| p = l + ((r - l) >> 1); |
| IFLT(pivot, *p) |
| r = p; |
| else |
| l = p+1; |
| } while (l < r); |
| assert(l == r); |
| /* The invariants still hold, so pivot >= all in [lo, l) and |
| pivot < all in [l, start), so pivot belongs at l. Note |
| that if there are elements equal to pivot, l points to the |
| first slot after them -- that's why this sort is stable. |
| Slide over to make room. |
| Caution: using memmove is much slower under MSVC 5; |
| we're not usually moving many slots. */ |
| for (p = start; p > l; --p) |
| *p = *(p-1); |
| *l = pivot; |
| if (lo.values != NULL) { |
| Py_ssize_t offset = lo.values - lo.keys; |
| p = start + offset; |
| pivot = *p; |
| l += offset; |
| for (p = start + offset; p > l; --p) |
| *p = *(p-1); |
| *l = pivot; |
| } |
| } |
| return 0; |
| |
| fail: |
| return -1; |
| } |
| |
| /* |
| Return the length of the run beginning at lo, in the slice [lo, hi). lo < hi |
| is required on entry. "A run" is the longest ascending sequence, with |
| |
| lo[0] <= lo[1] <= lo[2] <= ... |
| |
| or the longest descending sequence, with |
| |
| lo[0] > lo[1] > lo[2] > ... |
| |
| Boolean *descending is set to 0 in the former case, or to 1 in the latter. |
| For its intended use in a stable mergesort, the strictness of the defn of |
| "descending" is needed so that the caller can safely reverse a descending |
| sequence without violating stability (strict > ensures there are no equal |
| elements to get out of order). |
| |
| Returns -1 in case of error. |
| */ |
| static Py_ssize_t |
| count_run(MergeState *ms, PyObject **lo, PyObject **hi, int *descending) |
| { |
| Py_ssize_t k; |
| Py_ssize_t n; |
| |
| assert(lo < hi); |
| *descending = 0; |
| ++lo; |
| if (lo == hi) |
| return 1; |
| |
| n = 2; |
| IFLT(*lo, *(lo-1)) { |
| *descending = 1; |
| for (lo = lo+1; lo < hi; ++lo, ++n) { |
| IFLT(*lo, *(lo-1)) |
| ; |
| else |
| break; |
| } |
| } |
| else { |
| for (lo = lo+1; lo < hi; ++lo, ++n) { |
| IFLT(*lo, *(lo-1)) |
| break; |
| } |
| } |
| |
| return n; |
| fail: |
| return -1; |
| } |
| |
| /* |
| Locate the proper position of key in a sorted vector; if the vector contains |
| an element equal to key, return the position immediately to the left of |
| the leftmost equal element. [gallop_right() does the same except returns |
| the position to the right of the rightmost equal element (if any).] |
| |
| "a" is a sorted vector with n elements, starting at a[0]. n must be > 0. |
| |
| "hint" is an index at which to begin the search, 0 <= hint < n. The closer |
| hint is to the final result, the faster this runs. |
| |
| The return value is the int k in 0..n such that |
| |
| a[k-1] < key <= a[k] |
| |
| pretending that *(a-1) is minus infinity and a[n] is plus infinity. IOW, |
| key belongs at index k; or, IOW, the first k elements of a should precede |
| key, and the last n-k should follow key. |
| |
| Returns -1 on error. See listsort.txt for info on the method. |
| */ |
| static Py_ssize_t |
| gallop_left(MergeState *ms, PyObject *key, PyObject **a, Py_ssize_t n, Py_ssize_t hint) |
| { |
| Py_ssize_t ofs; |
| Py_ssize_t lastofs; |
| Py_ssize_t k; |
| |
| assert(key && a && n > 0 && hint >= 0 && hint < n); |
| |
| a += hint; |
| lastofs = 0; |
| ofs = 1; |
| IFLT(*a, key) { |
| /* a[hint] < key -- gallop right, until |
| * a[hint + lastofs] < key <= a[hint + ofs] |
| */ |
| const Py_ssize_t maxofs = n - hint; /* &a[n-1] is highest */ |
| while (ofs < maxofs) { |
| IFLT(a[ofs], key) { |
| lastofs = ofs; |
| assert(ofs <= (PY_SSIZE_T_MAX - 1) / 2); |
| ofs = (ofs << 1) + 1; |
| } |
| else /* key <= a[hint + ofs] */ |
| break; |
| } |
| if (ofs > maxofs) |
| ofs = maxofs; |
| /* Translate back to offsets relative to &a[0]. */ |
| lastofs += hint; |
| ofs += hint; |
| } |
| else { |
| /* key <= a[hint] -- gallop left, until |
| * a[hint - ofs] < key <= a[hint - lastofs] |
| */ |
| const Py_ssize_t maxofs = hint + 1; /* &a[0] is lowest */ |
| while (ofs < maxofs) { |
| IFLT(*(a-ofs), key) |
| break; |
| /* key <= a[hint - ofs] */ |
| lastofs = ofs; |
| assert(ofs <= (PY_SSIZE_T_MAX - 1) / 2); |
| ofs = (ofs << 1) + 1; |
| } |
| if (ofs > maxofs) |
| ofs = maxofs; |
| /* Translate back to positive offsets relative to &a[0]. */ |
| k = lastofs; |
| lastofs = hint - ofs; |
| ofs = hint - k; |
| } |
| a -= hint; |
| |
| assert(-1 <= lastofs && lastofs < ofs && ofs <= n); |
| /* Now a[lastofs] < key <= a[ofs], so key belongs somewhere to the |
| * right of lastofs but no farther right than ofs. Do a binary |
| * search, with invariant a[lastofs-1] < key <= a[ofs]. |
| */ |
| ++lastofs; |
| while (lastofs < ofs) { |
| Py_ssize_t m = lastofs + ((ofs - lastofs) >> 1); |
| |
| IFLT(a[m], key) |
| lastofs = m+1; /* a[m] < key */ |
| else |
| ofs = m; /* key <= a[m] */ |
| } |
| assert(lastofs == ofs); /* so a[ofs-1] < key <= a[ofs] */ |
| return ofs; |
| |
| fail: |
| return -1; |
| } |
| |
| /* |
| Exactly like gallop_left(), except that if key already exists in a[0:n], |
| finds the position immediately to the right of the rightmost equal value. |
| |
| The return value is the int k in 0..n such that |
| |
| a[k-1] <= key < a[k] |
| |
| or -1 if error. |
| |
| The code duplication is massive, but this is enough different given that |
| we're sticking to "<" comparisons that it's much harder to follow if |
| written as one routine with yet another "left or right?" flag. |
| */ |
| static Py_ssize_t |
| gallop_right(MergeState *ms, PyObject *key, PyObject **a, Py_ssize_t n, Py_ssize_t hint) |
| { |
| Py_ssize_t ofs; |
| Py_ssize_t lastofs; |
| Py_ssize_t k; |
| |
| assert(key && a && n > 0 && hint >= 0 && hint < n); |
| |
| a += hint; |
| lastofs = 0; |
| ofs = 1; |
| IFLT(key, *a) { |
| /* key < a[hint] -- gallop left, until |
| * a[hint - ofs] <= key < a[hint - lastofs] |
| */ |
| const Py_ssize_t maxofs = hint + 1; /* &a[0] is lowest */ |
| while (ofs < maxofs) { |
| IFLT(key, *(a-ofs)) { |
| lastofs = ofs; |
| assert(ofs <= (PY_SSIZE_T_MAX - 1) / 2); |
| ofs = (ofs << 1) + 1; |
| } |
| else /* a[hint - ofs] <= key */ |
| break; |
| } |
| if (ofs > maxofs) |
| ofs = maxofs; |
| /* Translate back to positive offsets relative to &a[0]. */ |
| k = lastofs; |
| lastofs = hint - ofs; |
| ofs = hint - k; |
| } |
| else { |
| /* a[hint] <= key -- gallop right, until |
| * a[hint + lastofs] <= key < a[hint + ofs] |
| */ |
| const Py_ssize_t maxofs = n - hint; /* &a[n-1] is highest */ |
| while (ofs < maxofs) { |
| IFLT(key, a[ofs]) |
| break; |
| /* a[hint + ofs] <= key */ |
| lastofs = ofs; |
| assert(ofs <= (PY_SSIZE_T_MAX - 1) / 2); |
| ofs = (ofs << 1) + 1; |
| } |
| if (ofs > maxofs) |
| ofs = maxofs; |
| /* Translate back to offsets relative to &a[0]. */ |
| lastofs += hint; |
| ofs += hint; |
| } |
| a -= hint; |
| |
| assert(-1 <= lastofs && lastofs < ofs && ofs <= n); |
| /* Now a[lastofs] <= key < a[ofs], so key belongs somewhere to the |
| * right of lastofs but no farther right than ofs. Do a binary |
| * search, with invariant a[lastofs-1] <= key < a[ofs]. |
| */ |
| ++lastofs; |
| while (lastofs < ofs) { |
| Py_ssize_t m = lastofs + ((ofs - lastofs) >> 1); |
| |
| IFLT(key, a[m]) |
| ofs = m; /* key < a[m] */ |
| else |
| lastofs = m+1; /* a[m] <= key */ |
| } |
| assert(lastofs == ofs); /* so a[ofs-1] <= key < a[ofs] */ |
| return ofs; |
| |
| fail: |
| return -1; |
| } |
| |
| /* Conceptually a MergeState's constructor. */ |
| static void |
| merge_init(MergeState *ms, Py_ssize_t list_size, int has_keyfunc, |
| sortslice *lo) |
| { |
| assert(ms != NULL); |
| if (has_keyfunc) { |
| /* The temporary space for merging will need at most half the list |
| * size rounded up. Use the minimum possible space so we can use the |
| * rest of temparray for other things. In particular, if there is |
| * enough extra space, listsort() will use it to store the keys. |
| */ |
| ms->alloced = (list_size + 1) / 2; |
| |
| /* ms->alloced describes how many keys will be stored at |
| ms->temparray, but we also need to store the values. Hence, |
| ms->alloced is capped at half of MERGESTATE_TEMP_SIZE. */ |
| if (MERGESTATE_TEMP_SIZE / 2 < ms->alloced) |
| ms->alloced = MERGESTATE_TEMP_SIZE / 2; |
| ms->a.values = &ms->temparray[ms->alloced]; |
| } |
| else { |
| ms->alloced = MERGESTATE_TEMP_SIZE; |
| ms->a.values = NULL; |
| } |
| ms->a.keys = ms->temparray; |
| ms->n = 0; |
| ms->min_gallop = MIN_GALLOP; |
| ms->listlen = list_size; |
| ms->basekeys = lo->keys; |
| } |
| |
| /* Free all the temp memory owned by the MergeState. This must be called |
| * when you're done with a MergeState, and may be called before then if |
| * you want to free the temp memory early. |
| */ |
| static void |
| merge_freemem(MergeState *ms) |
| { |
| assert(ms != NULL); |
| if (ms->a.keys != ms->temparray) { |
| PyMem_Free(ms->a.keys); |
| ms->a.keys = NULL; |
| } |
| } |
| |
| /* Ensure enough temp memory for 'need' array slots is available. |
| * Returns 0 on success and -1 if the memory can't be gotten. |
| */ |
| static int |
| merge_getmem(MergeState *ms, Py_ssize_t need) |
| { |
| int multiplier; |
| |
| assert(ms != NULL); |
| if (need <= ms->alloced) |
| return 0; |
| |
| multiplier = ms->a.values != NULL ? 2 : 1; |
| |
| /* Don't realloc! That can cost cycles to copy the old data, but |
| * we don't care what's in the block. |
| */ |
| merge_freemem(ms); |
| if ((size_t)need > PY_SSIZE_T_MAX / sizeof(PyObject *) / multiplier) { |
| PyErr_NoMemory(); |
| return -1; |
| } |
| ms->a.keys = (PyObject **)PyMem_Malloc(multiplier * need |
| * sizeof(PyObject *)); |
| if (ms->a.keys != NULL) { |
| ms->alloced = need; |
| if (ms->a.values != NULL) |
| ms->a.values = &ms->a.keys[need]; |
| return 0; |
| } |
| PyErr_NoMemory(); |
| return -1; |
| } |
| #define MERGE_GETMEM(MS, NEED) ((NEED) <= (MS)->alloced ? 0 : \ |
| merge_getmem(MS, NEED)) |
| |
| /* Merge the na elements starting at ssa with the nb elements starting at |
| * ssb.keys = ssa.keys + na in a stable way, in-place. na and nb must be > 0. |
| * Must also have that ssa.keys[na-1] belongs at the end of the merge, and |
| * should have na <= nb. See listsort.txt for more info. Return 0 if |
| * successful, -1 if error. |
| */ |
| static Py_ssize_t |
| merge_lo(MergeState *ms, sortslice ssa, Py_ssize_t na, |
| sortslice ssb, Py_ssize_t nb) |
| { |
| Py_ssize_t k; |
| sortslice dest; |
| int result = -1; /* guilty until proved innocent */ |
| Py_ssize_t min_gallop; |
| |
| assert(ms && ssa.keys && ssb.keys && na > 0 && nb > 0); |
| assert(ssa.keys + na == ssb.keys); |
| if (MERGE_GETMEM(ms, na) < 0) |
| return -1; |
| sortslice_memcpy(&ms->a, 0, &ssa, 0, na); |
| dest = ssa; |
| ssa = ms->a; |
| |
| sortslice_copy_incr(&dest, &ssb); |
| --nb; |
| if (nb == 0) |
| goto Succeed; |
| if (na == 1) |
| goto CopyB; |
| |
| min_gallop = ms->min_gallop; |
| for (;;) { |
| Py_ssize_t acount = 0; /* # of times A won in a row */ |
| Py_ssize_t bcount = 0; /* # of times B won in a row */ |
| |
| /* Do the straightforward thing until (if ever) one run |
| * appears to win consistently. |
| */ |
| for (;;) { |
| assert(na > 1 && nb > 0); |
| k = ISLT(ssb.keys[0], ssa.keys[0]); |
| if (k) { |
| if (k < 0) |
| goto Fail; |
| sortslice_copy_incr(&dest, &ssb); |
| ++bcount; |
| acount = 0; |
| --nb; |
| if (nb == 0) |
| goto Succeed; |
| if (bcount >= min_gallop) |
| break; |
| } |
| else { |
| sortslice_copy_incr(&dest, &ssa); |
| ++acount; |
| bcount = 0; |
| --na; |
| if (na == 1) |
| goto CopyB; |
| if (acount >= min_gallop) |
| break; |
| } |
| } |
| |
| /* One run is winning so consistently that galloping may |
| * be a huge win. So try that, and continue galloping until |
| * (if ever) neither run appears to be winning consistently |
| * anymore. |
| */ |
| ++min_gallop; |
| do { |
| assert(na > 1 && nb > 0); |
| min_gallop -= min_gallop > 1; |
| ms->min_gallop = min_gallop; |
| k = gallop_right(ms, ssb.keys[0], ssa.keys, na, 0); |
| acount = k; |
| if (k) { |
| if (k < 0) |
| goto Fail; |
| sortslice_memcpy(&dest, 0, &ssa, 0, k); |
| sortslice_advance(&dest, k); |
| sortslice_advance(&ssa, k); |
| na -= k; |
| if (na == 1) |
| goto CopyB; |
| /* na==0 is impossible now if the comparison |
| * function is consistent, but we can't assume |
| * that it is. |
| */ |
| if (na == 0) |
| goto Succeed; |
| } |
| sortslice_copy_incr(&dest, &ssb); |
| --nb; |
| if (nb == 0) |
| goto Succeed; |
| |
| k = gallop_left(ms, ssa.keys[0], ssb.keys, nb, 0); |
| bcount = k; |
| if (k) { |
| if (k < 0) |
| goto Fail; |
| sortslice_memmove(&dest, 0, &ssb, 0, k); |
| sortslice_advance(&dest, k); |
| sortslice_advance(&ssb, k); |
| nb -= k; |
| if (nb == 0) |
| goto Succeed; |
| } |
| sortslice_copy_incr(&dest, &ssa); |
| --na; |
| if (na == 1) |
| goto CopyB; |
| } while (acount >= MIN_GALLOP || bcount >= MIN_GALLOP); |
| ++min_gallop; /* penalize it for leaving galloping mode */ |
| ms->min_gallop = min_gallop; |
| } |
| Succeed: |
| result = 0; |
| Fail: |
| if (na) |
| sortslice_memcpy(&dest, 0, &ssa, 0, na); |
| return result; |
| CopyB: |
| assert(na == 1 && nb > 0); |
| /* The last element of ssa belongs at the end of the merge. */ |
| sortslice_memmove(&dest, 0, &ssb, 0, nb); |
| sortslice_copy(&dest, nb, &ssa, 0); |
| return 0; |
| } |
| |
| /* Merge the na elements starting at pa with the nb elements starting at |
| * ssb.keys = ssa.keys + na in a stable way, in-place. na and nb must be > 0. |
| * Must also have that ssa.keys[na-1] belongs at the end of the merge, and |
| * should have na >= nb. See listsort.txt for more info. Return 0 if |
| * successful, -1 if error. |
| */ |
| static Py_ssize_t |
| merge_hi(MergeState *ms, sortslice ssa, Py_ssize_t na, |
| sortslice ssb, Py_ssize_t nb) |
| { |
| Py_ssize_t k; |
| sortslice dest, basea, baseb; |
| int result = -1; /* guilty until proved innocent */ |
| Py_ssize_t min_gallop; |
| |
| assert(ms && ssa.keys && ssb.keys && na > 0 && nb > 0); |
| assert(ssa.keys + na == ssb.keys); |
| if (MERGE_GETMEM(ms, nb) < 0) |
| return -1; |
| dest = ssb; |
| sortslice_advance(&dest, nb-1); |
| sortslice_memcpy(&ms->a, 0, &ssb, 0, nb); |
| basea = ssa; |
| baseb = ms->a; |
| ssb.keys = ms->a.keys + nb - 1; |
| if (ssb.values != NULL) |
| ssb.values = ms->a.values + nb - 1; |
| sortslice_advance(&ssa, na - 1); |
| |
| sortslice_copy_decr(&dest, &ssa); |
| --na; |
| if (na == 0) |
| goto Succeed; |
| if (nb == 1) |
| goto CopyA; |
| |
| min_gallop = ms->min_gallop; |
| for (;;) { |
| Py_ssize_t acount = 0; /* # of times A won in a row */ |
| Py_ssize_t bcount = 0; /* # of times B won in a row */ |
| |
| /* Do the straightforward thing until (if ever) one run |
| * appears to win consistently. |
| */ |
| for (;;) { |
| assert(na > 0 && nb > 1); |
| k = ISLT(ssb.keys[0], ssa.keys[0]); |
| if (k) { |
| if (k < 0) |
| goto Fail; |
| sortslice_copy_decr(&dest, &ssa); |
| ++acount; |
| bcount = 0; |
| --na; |
| if (na == 0) |
| goto Succeed; |
| if (acount >= min_gallop) |
| break; |
| } |
| else { |
| sortslice_copy_decr(&dest, &ssb); |
| ++bcount; |
| acount = 0; |
| --nb; |
| if (nb == 1) |
| goto CopyA; |
| if (bcount >= min_gallop) |
| break; |
| } |
| } |
| |
| /* One run is winning so consistently that galloping may |
| * be a huge win. So try that, and continue galloping until |
| * (if ever) neither run appears to be winning consistently |
| * anymore. |
| */ |
| ++min_gallop; |
| do { |
| assert(na > 0 && nb > 1); |
| min_gallop -= min_gallop > 1; |
| ms->min_gallop = min_gallop; |
| k = gallop_right(ms, ssb.keys[0], basea.keys, na, na-1); |
| if (k < 0) |
| goto Fail; |
| k = na - k; |
| acount = k; |
| if (k) { |
| sortslice_advance(&dest, -k); |
| sortslice_advance(&ssa, -k); |
| sortslice_memmove(&dest, 1, &ssa, 1, k); |
| na -= k; |
| if (na == 0) |
| goto Succeed; |
| } |
| sortslice_copy_decr(&dest, &ssb); |
| --nb; |
| if (nb == 1) |
| goto CopyA; |
| |
| k = gallop_left(ms, ssa.keys[0], baseb.keys, nb, nb-1); |
| if (k < 0) |
| goto Fail; |
| k = nb - k; |
| bcount = k; |
| if (k) { |
| sortslice_advance(&dest, -k); |
| sortslice_advance(&ssb, -k); |
| sortslice_memcpy(&dest, 1, &ssb, 1, k); |
| nb -= k; |
| if (nb == 1) |
| goto CopyA; |
| /* nb==0 is impossible now if the comparison |
| * function is consistent, but we can't assume |
| * that it is. |
| */ |
| if (nb == 0) |
| goto Succeed; |
| } |
| sortslice_copy_decr(&dest, &ssa); |
| --na; |
| if (na == 0) |
| goto Succeed; |
| } while (acount >= MIN_GALLOP || bcount >= MIN_GALLOP); |
| ++min_gallop; /* penalize it for leaving galloping mode */ |
| ms->min_gallop = min_gallop; |
| } |
| Succeed: |
| result = 0; |
| Fail: |
| if (nb) |
| sortslice_memcpy(&dest, -(nb-1), &baseb, 0, nb); |
| return result; |
| CopyA: |
| assert(nb == 1 && na > 0); |
| /* The first element of ssb belongs at the front of the merge. */ |
| sortslice_memmove(&dest, 1-na, &ssa, 1-na, na); |
| sortslice_advance(&dest, -na); |
| sortslice_advance(&ssa, -na); |
| sortslice_copy(&dest, 0, &ssb, 0); |
| return 0; |
| } |
| |
| /* Merge the two runs at stack indices i and i+1. |
| * Returns 0 on success, -1 on error. |
| */ |
| static Py_ssize_t |
| merge_at(MergeState *ms, Py_ssize_t i) |
| { |
| sortslice ssa, ssb; |
| Py_ssize_t na, nb; |
| Py_ssize_t k; |
| |
| assert(ms != NULL); |
| assert(ms->n >= 2); |
| assert(i >= 0); |
| assert(i == ms->n - 2 || i == ms->n - 3); |
| |
| ssa = ms->pending[i].base; |
| na = ms->pending[i].len; |
| ssb = ms->pending[i+1].base; |
| nb = ms->pending[i+1].len; |
| assert(na > 0 && nb > 0); |
| assert(ssa.keys + na == ssb.keys); |
| |
| /* Record the length of the combined runs; if i is the 3rd-last |
| * run now, also slide over the last run (which isn't involved |
| * in this merge). The current run i+1 goes away in any case. |
| */ |
| ms->pending[i].len = na + nb; |
| if (i == ms->n - 3) |
| ms->pending[i+1] = ms->pending[i+2]; |
| --ms->n; |
| |
| /* Where does b start in a? Elements in a before that can be |
| * ignored (already in place). |
| */ |
| k = gallop_right(ms, *ssb.keys, ssa.keys, na, 0); |
| if (k < 0) |
| return -1; |
| sortslice_advance(&ssa, k); |
| na -= k; |
| if (na == 0) |
| return 0; |
| |
| /* Where does a end in b? Elements in b after that can be |
| * ignored (already in place). |
| */ |
| nb = gallop_left(ms, ssa.keys[na-1], ssb.keys, nb, nb-1); |
| if (nb <= 0) |
| return nb; |
| |
| /* Merge what remains of the runs, using a temp array with |
| * min(na, nb) elements. |
| */ |
| if (na <= nb) |
| return merge_lo(ms, ssa, na, ssb, nb); |
| else |
| return merge_hi(ms, ssa, na, ssb, nb); |
| } |
| |
| /* Two adjacent runs begin at index s1. The first run has length n1, and |
| * the second run (starting at index s1+n1) has length n2. The list has total |
| * length n. |
| * Compute the "power" of the first run. See listsort.txt for details. |
| */ |
| static int |
| powerloop(Py_ssize_t s1, Py_ssize_t n1, Py_ssize_t n2, Py_ssize_t n) |
| { |
| int result = 0; |
| assert(s1 >= 0); |
| assert(n1 > 0 && n2 > 0); |
| assert(s1 + n1 + n2 <= n); |
| /* midpoints a and b: |
| * a = s1 + n1/2 |
| * b = s1 + n1 + n2/2 = a + (n1 + n2)/2 |
| * |
| * Those may not be integers, though, because of the "/2". So we work with |
| * 2*a and 2*b instead, which are necessarily integers. It makes no |
| * difference to the outcome, since the bits in the expansion of (2*i)/n |
| * are merely shifted one position from those of i/n. |
| */ |
| Py_ssize_t a = 2 * s1 + n1; /* 2*a */ |
| Py_ssize_t b = a + n1 + n2; /* 2*b */ |
| /* Emulate a/n and b/n one bit a time, until bits differ. */ |
| for (;;) { |
| ++result; |
| if (a >= n) { /* both quotient bits are 1 */ |
| assert(b >= a); |
| a -= n; |
| b -= n; |
| } |
| else if (b >= n) { /* a/n bit is 0, b/n bit is 1 */ |
| break; |
| } /* else both quotient bits are 0 */ |
| assert(a < b && b < n); |
| a <<= 1; |
| b <<= 1; |
| } |
| return result; |
| } |
| |
| /* The next run has been identified, of length n2. |
| * If there's already a run on the stack, apply the "powersort" merge strategy: |
| * compute the topmost run's "power" (depth in a conceptual binary merge tree) |
| * and merge adjacent runs on the stack with greater power. See listsort.txt |
| * for more info. |
| * |
| * It's the caller's responsibility to push the new run on the stack when this |
| * returns. |
| * |
| * Returns 0 on success, -1 on error. |
| */ |
| static int |
| found_new_run(MergeState *ms, Py_ssize_t n2) |
| { |
| assert(ms); |
| if (ms->n) { |
| assert(ms->n > 0); |
| struct s_slice *p = ms->pending; |
| Py_ssize_t s1 = p[ms->n - 1].base.keys - ms->basekeys; /* start index */ |
| Py_ssize_t n1 = p[ms->n - 1].len; |
| int power = powerloop(s1, n1, n2, ms->listlen); |
| while (ms->n > 1 && p[ms->n - 2].power > power) { |
| if (merge_at(ms, ms->n - 2) < 0) |
| return -1; |
| } |
| assert(ms->n < 2 || p[ms->n - 2].power < power); |
| p[ms->n - 1].power = power; |
| } |
| return 0; |
| } |
| |
| /* Regardless of invariants, merge all runs on the stack until only one |
| * remains. This is used at the end of the mergesort. |
| * |
| * Returns 0 on success, -1 on error. |
| */ |
| static int |
| merge_force_collapse(MergeState *ms) |
| { |
| struct s_slice *p = ms->pending; |
| |
| assert(ms); |
| while (ms->n > 1) { |
| Py_ssize_t n = ms->n - 2; |
| if (n > 0 && p[n-1].len < p[n+1].len) |
| --n; |
| if (merge_at(ms, n) < 0) |
| return -1; |
| } |
| return 0; |
| } |
| |
| /* Compute a good value for the minimum run length; natural runs shorter |
| * than this are boosted artificially via binary insertion. |
| * |
| * If n < 64, return n (it's too small to bother with fancy stuff). |
| * Else if n is an exact power of 2, return 32. |
| * Else return an int k, 32 <= k <= 64, such that n/k is close to, but |
| * strictly less than, an exact power of 2. |
| * |
| * See listsort.txt for more info. |
| */ |
| static Py_ssize_t |
| merge_compute_minrun(Py_ssize_t n) |
| { |
| Py_ssize_t r = 0; /* becomes 1 if any 1 bits are shifted off */ |
| |
| assert(n >= 0); |
| while (n >= 64) { |
| r |= n & 1; |
| n >>= 1; |
| } |
| return n + r; |
| } |
| |
| static void |
| reverse_sortslice(sortslice *s, Py_ssize_t n) |
| { |
| reverse_slice(s->keys, &s->keys[n]); |
| if (s->values != NULL) |
| reverse_slice(s->values, &s->values[n]); |
| } |
| |
| /* Here we define custom comparison functions to optimize for the cases one commonly |
| * encounters in practice: homogeneous lists, often of one of the basic types. */ |
| |
| /* This struct holds the comparison function and helper functions |
| * selected in the pre-sort check. */ |
| |
| /* These are the special case compare functions. |
| * ms->key_compare will always point to one of these: */ |
| |
| /* Heterogeneous compare: default, always safe to fall back on. */ |
| static int |
| safe_object_compare(PyObject *v, PyObject *w, MergeState *ms) |
| { |
| /* No assumptions necessary! */ |
| return PyObject_RichCompareBool(v, w, Py_LT); |
| } |
| |
| /* Homogeneous compare: safe for any two comparable objects of the same type. |
| * (ms->key_richcompare is set to ob_type->tp_richcompare in the |
| * pre-sort check.) |
| */ |
| static int |
| unsafe_object_compare(PyObject *v, PyObject *w, MergeState *ms) |
| { |
| PyObject *res_obj; int res; |
| |
| /* No assumptions, because we check first: */ |
| if (Py_TYPE(v)->tp_richcompare != ms->key_richcompare) |
| return PyObject_RichCompareBool(v, w, Py_LT); |
| |
| assert(ms->key_richcompare != NULL); |
| res_obj = (*(ms->key_richcompare))(v, w, Py_LT); |
| |
| if (res_obj == Py_NotImplemented) { |
| Py_DECREF(res_obj); |
| return PyObject_RichCompareBool(v, w, Py_LT); |
| } |
| if (res_obj == NULL) |
| return -1; |
| |
| if (PyBool_Check(res_obj)) { |
| res = (res_obj == Py_True); |
| } |
| else { |
| res = PyObject_IsTrue(res_obj); |
| } |
| Py_DECREF(res_obj); |
| |
| /* Note that we can't assert |
| * res == PyObject_RichCompareBool(v, w, Py_LT); |
| * because of evil compare functions like this: |
| * lambda a, b: int(random.random() * 3) - 1) |
| * (which is actually in test_sort.py) */ |
| return res; |
| } |
| |
| /* Latin string compare: safe for any two latin (one byte per char) strings. */ |
| static int |
| unsafe_latin_compare(PyObject *v, PyObject *w, MergeState *ms) |
| { |
| Py_ssize_t len; |
| int res; |
| |
| /* Modified from Objects/unicodeobject.c:unicode_compare, assuming: */ |
| assert(Py_IS_TYPE(v, &PyUnicode_Type)); |
| assert(Py_IS_TYPE(w, &PyUnicode_Type)); |
| assert(PyUnicode_KIND(v) == PyUnicode_KIND(w)); |
| assert(PyUnicode_KIND(v) == PyUnicode_1BYTE_KIND); |
| |
| len = Py_MIN(PyUnicode_GET_LENGTH(v), PyUnicode_GET_LENGTH(w)); |
| res = memcmp(PyUnicode_DATA(v), PyUnicode_DATA(w), len); |
| |
| res = (res != 0 ? |
| res < 0 : |
| PyUnicode_GET_LENGTH(v) < PyUnicode_GET_LENGTH(w)); |
| |
| assert(res == PyObject_RichCompareBool(v, w, Py_LT));; |
| return res; |
| } |
| |
| /* Bounded int compare: compare any two longs that fit in a single machine word. */ |
| static int |
| unsafe_long_compare(PyObject *v, PyObject *w, MergeState *ms) |
| { |
| PyLongObject *vl, *wl; |
| intptr_t v0, w0; |
| int res; |
| |
| /* Modified from Objects/longobject.c:long_compare, assuming: */ |
| assert(Py_IS_TYPE(v, &PyLong_Type)); |
| assert(Py_IS_TYPE(w, &PyLong_Type)); |
| assert(_PyLong_IsCompact((PyLongObject *)v)); |
| assert(_PyLong_IsCompact((PyLongObject *)w)); |
| |
| vl = (PyLongObject*)v; |
| wl = (PyLongObject*)w; |
| |
| v0 = _PyLong_CompactValue(vl); |
| w0 = _PyLong_CompactValue(wl); |
| |
| res = v0 < w0; |
| assert(res == PyObject_RichCompareBool(v, w, Py_LT)); |
| return res; |
| } |
| |
| /* Float compare: compare any two floats. */ |
| static int |
| unsafe_float_compare(PyObject *v, PyObject *w, MergeState *ms) |
| { |
| int res; |
| |
| /* Modified from Objects/floatobject.c:float_richcompare, assuming: */ |
| assert(Py_IS_TYPE(v, &PyFloat_Type)); |
| assert(Py_IS_TYPE(w, &PyFloat_Type)); |
| |
| res = PyFloat_AS_DOUBLE(v) < PyFloat_AS_DOUBLE(w); |
| assert(res == PyObject_RichCompareBool(v, w, Py_LT)); |
| return res; |
| } |
| |
| /* Tuple compare: compare *any* two tuples, using |
| * ms->tuple_elem_compare to compare the first elements, which is set |
| * using the same pre-sort check as we use for ms->key_compare, |
| * but run on the list [x[0] for x in L]. This allows us to optimize compares |
| * on two levels (as long as [x[0] for x in L] is type-homogeneous.) The idea is |
| * that most tuple compares don't involve x[1:]. */ |
| static int |
| unsafe_tuple_compare(PyObject *v, PyObject *w, MergeState *ms) |
| { |
| PyTupleObject *vt, *wt; |
| Py_ssize_t i, vlen, wlen; |
| int k; |
| |
| /* Modified from Objects/tupleobject.c:tuplerichcompare, assuming: */ |
| assert(Py_IS_TYPE(v, &PyTuple_Type)); |
| assert(Py_IS_TYPE(w, &PyTuple_Type)); |
| assert(Py_SIZE(v) > 0); |
| assert(Py_SIZE(w) > 0); |
| |
| vt = (PyTupleObject *)v; |
| wt = (PyTupleObject *)w; |
| |
| vlen = Py_SIZE(vt); |
| wlen = Py_SIZE(wt); |
| |
| for (i = 0; i < vlen && i < wlen; i++) { |
| k = PyObject_RichCompareBool(vt->ob_item[i], wt->ob_item[i], Py_EQ); |
| if (k < 0) |
| return -1; |
| if (!k) |
| break; |
| } |
| |
| if (i >= vlen || i >= wlen) |
| return vlen < wlen; |
| |
| if (i == 0) |
| return ms->tuple_elem_compare(vt->ob_item[i], wt->ob_item[i], ms); |
| else |
| return PyObject_RichCompareBool(vt->ob_item[i], wt->ob_item[i], Py_LT); |
| } |
| |
| /* An adaptive, stable, natural mergesort. See listsort.txt. |
| * Returns Py_None on success, NULL on error. Even in case of error, the |
| * list will be some permutation of its input state (nothing is lost or |
| * duplicated). |
| */ |
| /*[clinic input] |
| list.sort |
| |
| * |
| key as keyfunc: object = None |
| reverse: bool = False |
| |
| Sort the list in ascending order and return None. |
| |
| The sort is in-place (i.e. the list itself is modified) and stable (i.e. the |
| order of two equal elements is maintained). |
| |
| If a key function is given, apply it once to each list item and sort them, |
| ascending or descending, according to their function values. |
| |
| The reverse flag can be set to sort in descending order. |
| [clinic start generated code]*/ |
| |
| static PyObject * |
| list_sort_impl(PyListObject *self, PyObject *keyfunc, int reverse) |
| /*[clinic end generated code: output=57b9f9c5e23fbe42 input=a74c4cd3ec6b5c08]*/ |
| { |
| MergeState ms; |
| Py_ssize_t nremaining; |
| Py_ssize_t minrun; |
| sortslice lo; |
| Py_ssize_t saved_ob_size, saved_allocated; |
| PyObject **saved_ob_item; |
| PyObject **final_ob_item; |
| PyObject *result = NULL; /* guilty until proved innocent */ |
| Py_ssize_t i; |
| PyObject **keys; |
| |
| assert(self != NULL); |
| assert(PyList_Check(self)); |
| if (keyfunc == Py_None) |
| keyfunc = NULL; |
| |
| /* The list is temporarily made empty, so that mutations performed |
| * by comparison functions can't affect the slice of memory we're |
| * sorting (allowing mutations during sorting is a core-dump |
| * factory, since ob_item may change). |
| */ |
| saved_ob_size = Py_SIZE(self); |
| saved_ob_item = self->ob_item; |
| saved_allocated = self->allocated; |
| Py_SET_SIZE(self, 0); |
| self->ob_item = NULL; |
| self->allocated = -1; /* any operation will reset it to >= 0 */ |
| |
| if (keyfunc == NULL) { |
| keys = NULL; |
| lo.keys = saved_ob_item; |
| lo.values = NULL; |
| } |
| else { |
| if (saved_ob_size < MERGESTATE_TEMP_SIZE/2) |
| /* Leverage stack space we allocated but won't otherwise use */ |
| keys = &ms.temparray[saved_ob_size+1]; |
| else { |
| keys = PyMem_Malloc(sizeof(PyObject *) * saved_ob_size); |
| if (keys == NULL) { |
| PyErr_NoMemory(); |
| goto keyfunc_fail; |
| } |
| } |
| |
| for (i = 0; i < saved_ob_size ; i++) { |
| keys[i] = PyObject_CallOneArg(keyfunc, saved_ob_item[i]); |
| if (keys[i] == NULL) { |
| for (i=i-1 ; i>=0 ; i--) |
| Py_DECREF(keys[i]); |
| if (saved_ob_size >= MERGESTATE_TEMP_SIZE/2) |
| PyMem_Free(keys); |
| goto keyfunc_fail; |
| } |
| } |
| |
| lo.keys = keys; |
| lo.values = saved_ob_item; |
| } |
| |
| |
| /* The pre-sort check: here's where we decide which compare function to use. |
| * How much optimization is safe? We test for homogeneity with respect to |
| * several properties that are expensive to check at compare-time, and |
| * set ms appropriately. */ |
| if (saved_ob_size > 1) { |
| /* Assume the first element is representative of the whole list. */ |
| int keys_are_in_tuples = (Py_IS_TYPE(lo.keys[0], &PyTuple_Type) && |
| Py_SIZE(lo.keys[0]) > 0); |
| |
| PyTypeObject* key_type = (keys_are_in_tuples ? |
| Py_TYPE(PyTuple_GET_ITEM(lo.keys[0], 0)) : |
| Py_TYPE(lo.keys[0])); |
| |
| int keys_are_all_same_type = 1; |
| int strings_are_latin = 1; |
| int ints_are_bounded = 1; |
| |
| /* Prove that assumption by checking every key. */ |
| for (i=0; i < saved_ob_size; i++) { |
| |
| if (keys_are_in_tuples && |
| !(Py_IS_TYPE(lo.keys[i], &PyTuple_Type) && Py_SIZE(lo.keys[i]) != 0)) { |
| keys_are_in_tuples = 0; |
| keys_are_all_same_type = 0; |
| break; |
| } |
| |
| /* Note: for lists of tuples, key is the first element of the tuple |
| * lo.keys[i], not lo.keys[i] itself! We verify type-homogeneity |
| * for lists of tuples in the if-statement directly above. */ |
| PyObject *key = (keys_are_in_tuples ? |
| PyTuple_GET_ITEM(lo.keys[i], 0) : |
| lo.keys[i]); |
| |
| if (!Py_IS_TYPE(key, key_type)) { |
| keys_are_all_same_type = 0; |
| /* If keys are in tuple we must loop over the whole list to make |
| sure all items are tuples */ |
| if (!keys_are_in_tuples) { |
| break; |
| } |
| } |
| |
| if (keys_are_all_same_type) { |
| if (key_type == &PyLong_Type && |
| ints_are_bounded && |
| !_PyLong_IsCompact((PyLongObject *)key)) { |
| |
| ints_are_bounded = 0; |
| } |
| else if (key_type == &PyUnicode_Type && |
| strings_are_latin && |
| PyUnicode_KIND(key) != PyUnicode_1BYTE_KIND) { |
| |
| strings_are_latin = 0; |
| } |
| } |
| } |
| |
| /* Choose the best compare, given what we now know about the keys. */ |
| if (keys_are_all_same_type) { |
| |
| if (key_type == &PyUnicode_Type && strings_are_latin) { |
| ms.key_compare = unsafe_latin_compare; |
| } |
| else if (key_type == &PyLong_Type && ints_are_bounded) { |
| ms.key_compare = unsafe_long_compare; |
| } |
| else if (key_type == &PyFloat_Type) { |
| ms.key_compare = unsafe_float_compare; |
| } |
| else if ((ms.key_richcompare = key_type->tp_richcompare) != NULL) { |
| ms.key_compare = unsafe_object_compare; |
| } |
| else { |
| ms.key_compare = safe_object_compare; |
| } |
| } |
| else { |
| ms.key_compare = safe_object_compare; |
| } |
| |
| if (keys_are_in_tuples) { |
| /* Make sure we're not dealing with tuples of tuples |
| * (remember: here, key_type refers list [key[0] for key in keys]) */ |
| if (key_type == &PyTuple_Type) { |
| ms.tuple_elem_compare = safe_object_compare; |
| } |
| else { |
| ms.tuple_elem_compare = ms.key_compare; |
| } |
| |
| ms.key_compare = unsafe_tuple_compare; |
| } |
| } |
| /* End of pre-sort check: ms is now set properly! */ |
| |
| merge_init(&ms, saved_ob_size, keys != NULL, &lo); |
| |
| nremaining = saved_ob_size; |
| if (nremaining < 2) |
| goto succeed; |
| |
| /* Reverse sort stability achieved by initially reversing the list, |
| applying a stable forward sort, then reversing the final result. */ |
| if (reverse) { |
| if (keys != NULL) |
| reverse_slice(&keys[0], &keys[saved_ob_size]); |
| reverse_slice(&saved_ob_item[0], &saved_ob_item[saved_ob_size]); |
| } |
| |
| /* March over the array once, left to right, finding natural runs, |
| * and extending short natural runs to minrun elements. |
| */ |
| minrun = merge_compute_minrun(nremaining); |
| do { |
| int descending; |
| Py_ssize_t n; |
| |
| /* Identify next run. */ |
| n = count_run(&ms, lo.keys, lo.keys + nremaining, &descending); |
| if (n < 0) |
| goto fail; |
| if (descending) |
| reverse_sortslice(&lo, n); |
| /* If short, extend to min(minrun, nremaining). */ |
| if (n < minrun) { |
| const Py_ssize_t force = nremaining <= minrun ? |
| nremaining : minrun; |
| if (binarysort(&ms, lo, lo.keys + force, lo.keys + n) < 0) |
| goto fail; |
| n = force; |
| } |
| /* Maybe merge pending runs. */ |
| assert(ms.n == 0 || ms.pending[ms.n -1].base.keys + |
| ms.pending[ms.n-1].len == lo.keys); |
| if (found_new_run(&ms, n) < 0) |
| goto fail; |
| /* Push new run on stack. */ |
| assert(ms.n < MAX_MERGE_PENDING); |
| ms.pending[ms.n].base = lo; |
| ms.pending[ms.n].len = n; |
| ++ms.n; |
| /* Advance to find next run. */ |
| sortslice_advance(&lo, n); |
| nremaining -= n; |
| } while (nremaining); |
| |
| if (merge_force_collapse(&ms) < 0) |
| goto fail; |
| assert(ms.n == 1); |
| assert(keys == NULL |
| ? ms.pending[0].base.keys == saved_ob_item |
| : ms.pending[0].base.keys == &keys[0]); |
| assert(ms.pending[0].len == saved_ob_size); |
| lo = ms.pending[0].base; |
| |
| succeed: |
| result = Py_None; |
| fail: |
| if (keys != NULL) { |
| for (i = 0; i < saved_ob_size; i++) |
| Py_DECREF(keys[i]); |
| if (saved_ob_size >= MERGESTATE_TEMP_SIZE/2) |
| PyMem_Free(keys); |
| } |
| |
| if (self->allocated != -1 && result != NULL) { |
| /* The user mucked with the list during the sort, |
| * and we don't already have another error to report. |
| */ |
| PyErr_SetString(PyExc_ValueError, "list modified during sort"); |
| result = NULL; |
| } |
| |
| if (reverse && saved_ob_size > 1) |
| reverse_slice(saved_ob_item, saved_ob_item + saved_ob_size); |
| |
| merge_freemem(&ms); |
| |
| keyfunc_fail: |
| final_ob_item = self->ob_item; |
| i = Py_SIZE(self); |
| Py_SET_SIZE(self, saved_ob_size); |
| self->ob_item = saved_ob_item; |
| self->allocated = saved_allocated; |
| if (final_ob_item != NULL) { |
| /* we cannot use _list_clear() for this because it does not |
| guarantee that the list is really empty when it returns */ |
| while (--i >= 0) { |
| Py_XDECREF(final_ob_item[i]); |
| } |
| PyMem_Free(final_ob_item); |
| } |
| return Py_XNewRef(result); |
| } |
| #undef IFLT |
| #undef ISLT |
| |
| int |
| PyList_Sort(PyObject *v) |
| { |
| if (v == NULL || !PyList_Check(v)) { |
| PyErr_BadInternalCall(); |
| return -1; |
| } |
| v = list_sort_impl((PyListObject *)v, NULL, 0); |
| if (v == NULL) |
| return -1; |
| Py_DECREF(v); |
| return 0; |
| } |
| |
| /*[clinic input] |
| list.reverse |
| |
| Reverse *IN PLACE*. |
| [clinic start generated code]*/ |
| |
| static PyObject * |
| list_reverse_impl(PyListObject *self) |
| /*[clinic end generated code: output=482544fc451abea9 input=eefd4c3ae1bc9887]*/ |
| { |
| if (Py_SIZE(self) > 1) |
| reverse_slice(self->ob_item, self->ob_item + Py_SIZE(self)); |
| Py_RETURN_NONE; |
| } |
| |
| int |
| PyList_Reverse(PyObject *v) |
| { |
| PyListObject *self = (PyListObject *)v; |
| |
| if (v == NULL || !PyList_Check(v)) { |
| PyErr_BadInternalCall(); |
| return -1; |
| } |
| if (Py_SIZE(self) > 1) |
| reverse_slice(self->ob_item, self->ob_item + Py_SIZE(self)); |
| return 0; |
| } |
| |
| PyObject * |
| PyList_AsTuple(PyObject *v) |
| { |
| if (v == NULL || !PyList_Check(v)) { |
| PyErr_BadInternalCall(); |
| return NULL; |
| } |
| return _PyTuple_FromArray(((PyListObject *)v)->ob_item, Py_SIZE(v)); |
| } |
| |
| PyObject * |
| _PyList_FromArraySteal(PyObject *const *src, Py_ssize_t n) |
| { |
| if (n == 0) { |
| return PyList_New(0); |
| } |
| |
| PyListObject *list = (PyListObject *)PyList_New(n); |
| if (list == NULL) { |
| for (Py_ssize_t i = 0; i < n; i++) { |
| Py_DECREF(src[i]); |
| } |
| return NULL; |
| } |
| |
| PyObject **dst = list->ob_item; |
| memcpy(dst, src, n * sizeof(PyObject *)); |
| |
| return (PyObject *)list; |
| } |
| |
| /*[clinic input] |
| list.index |
| |
| value: object |
| start: slice_index(accept={int}) = 0 |
| stop: slice_index(accept={int}, c_default="PY_SSIZE_T_MAX") = sys.maxsize |
| / |
| |
| Return first index of value. |
| |
| Raises ValueError if the value is not present. |
| [clinic start generated code]*/ |
| |
| static PyObject * |
| list_index_impl(PyListObject *self, PyObject *value, Py_ssize_t start, |
| Py_ssize_t stop) |
| /*[clinic end generated code: output=ec51b88787e4e481 input=40ec5826303a0eb1]*/ |
| { |
| Py_ssize_t i; |
| |
| if (start < 0) { |
| start += Py_SIZE(self); |
| if (start < 0) |
| start = 0; |
| } |
| if (stop < 0) { |
| stop += Py_SIZE(self); |
| if (stop < 0) |
| stop = 0; |
| } |
| for (i = start; i < stop && i < Py_SIZE(self); i++) { |
| PyObject *obj = self->ob_item[i]; |
| Py_INCREF(obj); |
| int cmp = PyObject_RichCompareBool(obj, value, Py_EQ); |
| Py_DECREF(obj); |
| if (cmp > 0) |
| return PyLong_FromSsize_t(i); |
| else if (cmp < 0) |
| return NULL; |
| } |
| PyErr_Format(PyExc_ValueError, "%R is not in list", value); |
| return NULL; |
| } |
| |
| /*[clinic input] |
| list.count |
| |
| value: object |
| / |
| |
| Return number of occurrences of value. |
| [clinic start generated code]*/ |
| |
| static PyObject * |
| list_count(PyListObject *self, PyObject *value) |
| /*[clinic end generated code: output=b1f5d284205ae714 input=3bdc3a5e6f749565]*/ |
| { |
| Py_ssize_t count = 0; |
| Py_ssize_t i; |
| |
| for (i = 0; i < Py_SIZE(self); i++) { |
| PyObject *obj = self->ob_item[i]; |
| if (obj == value) { |
| count++; |
| continue; |
| } |
| Py_INCREF(obj); |
| int cmp = PyObject_RichCompareBool(obj, value, Py_EQ); |
| Py_DECREF(obj); |
| if (cmp > 0) |
| count++; |
| else if (cmp < 0) |
| return NULL; |
| } |
| return PyLong_FromSsize_t(count); |
| } |
| |
| /*[clinic input] |
| list.remove |
| |
| value: object |
| / |
| |
| Remove first occurrence of value. |
| |
| Raises ValueError if the value is not present. |
| [clinic start generated code]*/ |
| |
| static PyObject * |
| list_remove(PyListObject *self, PyObject *value) |
| /*[clinic end generated code: output=f087e1951a5e30d1 input=2dc2ba5bb2fb1f82]*/ |
| { |
| Py_ssize_t i; |
| |
| for (i = 0; i < Py_SIZE(self); i++) { |
| PyObject *obj = self->ob_item[i]; |
| Py_INCREF(obj); |
| int cmp = PyObject_RichCompareBool(obj, value, Py_EQ); |
| Py_DECREF(obj); |
| if (cmp > 0) { |
| if (list_ass_slice(self, i, i+1, |
| (PyObject *)NULL) == 0) |
| Py_RETURN_NONE; |
| return NULL; |
| } |
| else if (cmp < 0) |
| return NULL; |
| } |
| PyErr_SetString(PyExc_ValueError, "list.remove(x): x not in list"); |
| return NULL; |
| } |
| |
| static int |
| list_traverse(PyListObject *o, visitproc visit, void *arg) |
| { |
| Py_ssize_t i; |
| |
| for (i = Py_SIZE(o); --i >= 0; ) |
| Py_VISIT(o->ob_item[i]); |
| return 0; |
| } |
| |
| static PyObject * |
| list_richcompare(PyObject *v, PyObject *w, int op) |
| { |
| PyListObject *vl, *wl; |
| Py_ssize_t i; |
| |
| if (!PyList_Check(v) || !PyList_Check(w)) |
| Py_RETURN_NOTIMPLEMENTED; |
| |
| vl = (PyListObject *)v; |
| wl = (PyListObject *)w; |
| |
| if (Py_SIZE(vl) != Py_SIZE(wl) && (op == Py_EQ || op == Py_NE)) { |
| /* Shortcut: if the lengths differ, the lists differ */ |
| if (op == Py_EQ) |
| Py_RETURN_FALSE; |
| else |
| Py_RETURN_TRUE; |
| } |
| |
| /* Search for the first index where items are different */ |
| for (i = 0; i < Py_SIZE(vl) && i < Py_SIZE(wl); i++) { |
| PyObject *vitem = vl->ob_item[i]; |
| PyObject *witem = wl->ob_item[i]; |
| if (vitem == witem) { |
| continue; |
| } |
| |
| Py_INCREF(vitem); |
| Py_INCREF(witem); |
| int k = PyObject_RichCompareBool(vitem, witem, Py_EQ); |
| Py_DECREF(vitem); |
| Py_DECREF(witem); |
| if (k < 0) |
| return NULL; |
| if (!k) |
| break; |
| } |
| |
| if (i >= Py_SIZE(vl) || i >= Py_SIZE(wl)) { |
| /* No more items to compare -- compare sizes */ |
| Py_RETURN_RICHCOMPARE(Py_SIZE(vl), Py_SIZE(wl), op); |
| } |
| |
| /* We have an item that differs -- shortcuts for EQ/NE */ |
| if (op == Py_EQ) { |
| Py_RETURN_FALSE; |
| } |
| if (op == Py_NE) { |
| Py_RETURN_TRUE; |
| } |
| |
| /* Compare the final item again using the proper operator */ |
| return PyObject_RichCompare(vl->ob_item[i], wl->ob_item[i], op); |
| } |
| |
| /*[clinic input] |
| list.__init__ |
| |
| iterable: object(c_default="NULL") = () |
| / |
| |
| Built-in mutable sequence. |
| |
| If no argument is given, the constructor creates a new empty list. |
| The argument must be an iterable if specified. |
| [clinic start generated code]*/ |
| |
| static int |
| list___init___impl(PyListObject *self, PyObject *iterable) |
| /*[clinic end generated code: output=0f3c21379d01de48 input=b3f3fe7206af8f6b]*/ |
| { |
| /* Verify list invariants established by PyType_GenericAlloc() */ |
| assert(0 <= Py_SIZE(self)); |
| assert(Py_SIZE(self) <= self->allocated || self->allocated == -1); |
| assert(self->ob_item != NULL || |
| self->allocated == 0 || self->allocated == -1); |
| |
| /* Empty previous contents */ |
| if (self->ob_item != NULL) { |
| (void)_list_clear(self); |
| } |
| if (iterable != NULL) { |
| PyObject *rv = list_extend(self, iterable); |
| if (rv == NULL) |
| return -1; |
| Py_DECREF(rv); |
| } |
| return 0; |
| } |
| |
| static PyObject * |
| list_vectorcall(PyObject *type, PyObject * const*args, |
| size_t nargsf, PyObject *kwnames) |
| { |
| if (!_PyArg_NoKwnames("list", kwnames)) { |
| return NULL; |
| } |
| Py_ssize_t nargs = PyVectorcall_NARGS(nargsf); |
| if (!_PyArg_CheckPositional("list", nargs, 0, 1)) { |
| return NULL; |
| } |
| |
| PyObject *list = PyType_GenericAlloc(_PyType_CAST(type), 0); |
| if (list == NULL) { |
| return NULL; |
| } |
| if (nargs) { |
| if (list___init___impl((PyListObject *)list, args[0])) { |
| Py_DECREF(list); |
| return NULL; |
| } |
| } |
| return list; |
| } |
| |
| |
| /*[clinic input] |
| list.__sizeof__ |
| |
| Return the size of the list in memory, in bytes. |
| [clinic start generated code]*/ |
| |
| static PyObject * |
| list___sizeof___impl(PyListObject *self) |
| /*[clinic end generated code: output=3417541f95f9a53e input=b8030a5d5ce8a187]*/ |
| { |
| size_t res = _PyObject_SIZE(Py_TYPE(self)); |
| res += (size_t)self->allocated * sizeof(void*); |
| return PyLong_FromSize_t(res); |
| } |
| |
| static PyObject *list_iter(PyObject *seq); |
| static PyObject *list_subscript(PyListObject*, PyObject*); |
| |
| static PyMethodDef list_methods[] = { |
| {"__getitem__", (PyCFunction)list_subscript, METH_O|METH_COEXIST, |
| PyDoc_STR("__getitem__($self, index, /)\n--\n\nReturn self[index].")}, |
| LIST___REVERSED___METHODDEF |
| LIST___SIZEOF___METHODDEF |
| LIST_CLEAR_METHODDEF |
| LIST_COPY_METHODDEF |
| LIST_APPEND_METHODDEF |
| LIST_INSERT_METHODDEF |
| LIST_EXTEND_METHODDEF |
| LIST_POP_METHODDEF |
| LIST_REMOVE_METHODDEF |
| LIST_INDEX_METHODDEF |
| LIST_COUNT_METHODDEF |
| LIST_REVERSE_METHODDEF |
| LIST_SORT_METHODDEF |
| {"__class_getitem__", Py_GenericAlias, METH_O|METH_CLASS, PyDoc_STR("See PEP 585")}, |
| {NULL, NULL} /* sentinel */ |
| }; |
| |
| static PySequenceMethods list_as_sequence = { |
| (lenfunc)list_length, /* sq_length */ |
| (binaryfunc)list_concat, /* sq_concat */ |
| (ssizeargfunc)list_repeat, /* sq_repeat */ |
| (ssizeargfunc)list_item, /* sq_item */ |
| 0, /* sq_slice */ |
| (ssizeobjargproc)list_ass_item, /* sq_ass_item */ |
| 0, /* sq_ass_slice */ |
| (objobjproc)list_contains, /* sq_contains */ |
| (binaryfunc)list_inplace_concat, /* sq_inplace_concat */ |
| (ssizeargfunc)list_inplace_repeat, /* sq_inplace_repeat */ |
| }; |
| |
| static PyObject * |
| list_subscript(PyListObject* self, PyObject* item) |
| { |
| if (_PyIndex_Check(item)) { |
| Py_ssize_t i; |
| i = PyNumber_AsSsize_t(item, PyExc_IndexError); |
| if (i == -1 && PyErr_Occurred()) |
| return NULL; |
| if (i < 0) |
| i += PyList_GET_SIZE(self); |
| return list_item(self, i); |
| } |
| else if (PySlice_Check(item)) { |
| Py_ssize_t start, stop, step, slicelength, i; |
| size_t cur; |
| PyObject* result; |
| PyObject* it; |
| PyObject **src, **dest; |
| |
| if (PySlice_Unpack(item, &start, &stop, &step) < 0) { |
| return NULL; |
| } |
| slicelength = PySlice_AdjustIndices(Py_SIZE(self), &start, &stop, |
| step); |
| |
| if (slicelength <= 0) { |
| return PyList_New(0); |
| } |
| else if (step == 1) { |
| return list_slice(self, start, stop); |
| } |
| else { |
| result = list_new_prealloc(slicelength); |
| if (!result) return NULL; |
| |
| src = self->ob_item; |
| dest = ((PyListObject *)result)->ob_item; |
| for (cur = start, i = 0; i < slicelength; |
| cur += (size_t)step, i++) { |
| it = Py_NewRef(src[cur]); |
| dest[i] = it; |
| } |
| Py_SET_SIZE(result, slicelength); |
| return result; |
| } |
| } |
| else { |
| PyErr_Format(PyExc_TypeError, |
| "list indices must be integers or slices, not %.200s", |
| Py_TYPE(item)->tp_name); |
| return NULL; |
| } |
| } |
| |
| static int |
| list_ass_subscript(PyListObject* self, PyObject* item, PyObject* value) |
| { |
| if (_PyIndex_Check(item)) { |
| Py_ssize_t i = PyNumber_AsSsize_t(item, PyExc_IndexError); |
| if (i == -1 && PyErr_Occurred()) |
| return -1; |
| if (i < 0) |
| i += PyList_GET_SIZE(self); |
| return list_ass_item(self, i, value); |
| } |
| else if (PySlice_Check(item)) { |
| Py_ssize_t start, stop, step, slicelength; |
| |
| if (PySlice_Unpack(item, &start, &stop, &step) < 0) { |
| return -1; |
| } |
| slicelength = PySlice_AdjustIndices(Py_SIZE(self), &start, &stop, |
| step); |
| |
| if (step == 1) |
| return list_ass_slice(self, start, stop, value); |
| |
| /* Make sure s[5:2] = [..] inserts at the right place: |
| before 5, not before 2. */ |
| if ((step < 0 && start < stop) || |
| (step > 0 && start > stop)) |
| stop = start; |
| |
| if (value == NULL) { |
| /* delete slice */ |
| PyObject **garbage; |
| size_t cur; |
| Py_ssize_t i; |
| int res; |
| |
| if (slicelength <= 0) |
| return 0; |
| |
| if (step < 0) { |
| stop = start + 1; |
| start = stop + step*(slicelength - 1) - 1; |
| step = -step; |
| } |
| |
| garbage = (PyObject**) |
| PyMem_Malloc(slicelength*sizeof(PyObject*)); |
| if (!garbage) { |
| PyErr_NoMemory(); |
| return -1; |
| } |
| |
| /* drawing pictures might help understand these for |
| loops. Basically, we memmove the parts of the |
| list that are *not* part of the slice: step-1 |
| items for each item that is part of the slice, |
| and then tail end of the list that was not |
| covered by the slice */ |
| for (cur = start, i = 0; |
| cur < (size_t)stop; |