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cpython/Modules/_testbuffer.c

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/* C Extension module to test all aspects of PEP-3118.
Written by Stefan Krah. */
#include "Python.h"
/* struct module */
static PyObject *structmodule = NULL;
static PyObject *Struct = NULL;
static PyObject *calcsize = NULL;
/* cache simple format string */
static const char *simple_fmt = "B";
static PyObject *simple_format = NULL;
#define SIMPLE_FORMAT(fmt) (fmt == NULL || strcmp(fmt, "B") == 0)
#define FIX_FORMAT(fmt) (fmt == NULL ? "B" : fmt)
/**************************************************************************/
/* NDArray Object */
/**************************************************************************/
static PyTypeObject NDArray_Type;
#define NDArray_Check(v) Py_IS_TYPE(v, &NDArray_Type)
#define CHECK_LIST_OR_TUPLE(v) \
if (!PyList_Check(v) && !PyTuple_Check(v)) { \
PyErr_SetString(PyExc_TypeError, \
#v " must be a list or a tuple"); \
return NULL; \
} \
#define PyMem_XFree(v) \
do { if (v) PyMem_Free(v); } while (0)
/* Maximum number of dimensions. */
#define ND_MAX_NDIM (2 * PyBUF_MAX_NDIM)
/* Check for the presence of suboffsets in the first dimension. */
#define HAVE_PTR(suboffsets) (suboffsets && suboffsets[0] >= 0)
/* Adjust ptr if suboffsets are present. */
#define ADJUST_PTR(ptr, suboffsets) \
(HAVE_PTR(suboffsets) ? *((char**)ptr) + suboffsets[0] : ptr)
/* Default: NumPy style (strides), read-only, no var-export, C-style layout */
#define ND_DEFAULT 0x000
/* User configurable flags for the ndarray */
#define ND_VAREXPORT 0x001 /* change layout while buffers are exported */
/* User configurable flags for each base buffer */
#define ND_WRITABLE 0x002 /* mark base buffer as writable */
#define ND_FORTRAN 0x004 /* Fortran contiguous layout */
#define ND_SCALAR 0x008 /* scalar: ndim = 0 */
#define ND_PIL 0x010 /* convert to PIL-style array (suboffsets) */
#define ND_REDIRECT 0x020 /* redirect buffer requests */
#define ND_GETBUF_FAIL 0x040 /* trigger getbuffer failure */
#define ND_GETBUF_UNDEFINED 0x080 /* undefined view.obj */
/* Internal flags for the base buffer */
#define ND_C 0x100 /* C contiguous layout (default) */
#define ND_OWN_ARRAYS 0x200 /* consumer owns arrays */
/* ndarray properties */
#define ND_IS_CONSUMER(nd) \
(((NDArrayObject *)nd)->head == &((NDArrayObject *)nd)->staticbuf)
/* ndbuf->flags properties */
#define ND_C_CONTIGUOUS(flags) (!!(flags&(ND_SCALAR|ND_C)))
#define ND_FORTRAN_CONTIGUOUS(flags) (!!(flags&(ND_SCALAR|ND_FORTRAN)))
#define ND_ANY_CONTIGUOUS(flags) (!!(flags&(ND_SCALAR|ND_C|ND_FORTRAN)))
/* getbuffer() requests */
#define REQ_INDIRECT(flags) ((flags&PyBUF_INDIRECT) == PyBUF_INDIRECT)
#define REQ_C_CONTIGUOUS(flags) ((flags&PyBUF_C_CONTIGUOUS) == PyBUF_C_CONTIGUOUS)
#define REQ_F_CONTIGUOUS(flags) ((flags&PyBUF_F_CONTIGUOUS) == PyBUF_F_CONTIGUOUS)
#define REQ_ANY_CONTIGUOUS(flags) ((flags&PyBUF_ANY_CONTIGUOUS) == PyBUF_ANY_CONTIGUOUS)
#define REQ_STRIDES(flags) ((flags&PyBUF_STRIDES) == PyBUF_STRIDES)
#define REQ_SHAPE(flags) ((flags&PyBUF_ND) == PyBUF_ND)
#define REQ_WRITABLE(flags) (flags&PyBUF_WRITABLE)
#define REQ_FORMAT(flags) (flags&PyBUF_FORMAT)
/* Single node of a list of base buffers. The list is needed to implement
changes in memory layout while exported buffers are active. */
static PyTypeObject NDArray_Type;
struct ndbuf;
typedef struct ndbuf {
struct ndbuf *next;
struct ndbuf *prev;
Py_ssize_t len; /* length of data */
Py_ssize_t offset; /* start of the array relative to data */
char *data; /* raw data */
int flags; /* capabilities of the base buffer */
Py_ssize_t exports; /* number of exports */
Py_buffer base; /* base buffer */
} ndbuf_t;
typedef struct {
PyObject_HEAD
int flags; /* ndarray flags */
ndbuf_t staticbuf; /* static buffer for re-exporting mode */
ndbuf_t *head; /* currently active base buffer */
} NDArrayObject;
static ndbuf_t *
ndbuf_new(Py_ssize_t nitems, Py_ssize_t itemsize, Py_ssize_t offset, int flags)
{
ndbuf_t *ndbuf;
Py_buffer *base;
Py_ssize_t len;
len = nitems * itemsize;
if (offset % itemsize) {
PyErr_SetString(PyExc_ValueError,
"offset must be a multiple of itemsize");
return NULL;
}
if (offset < 0 || offset+itemsize > len) {
PyErr_SetString(PyExc_ValueError, "offset out of bounds");
return NULL;
}
ndbuf = PyMem_Malloc(sizeof *ndbuf);
if (ndbuf == NULL) {
PyErr_NoMemory();
return NULL;
}
ndbuf->next = NULL;
ndbuf->prev = NULL;
ndbuf->len = len;
ndbuf->offset= offset;
ndbuf->data = PyMem_Malloc(len);
if (ndbuf->data == NULL) {
PyErr_NoMemory();
PyMem_Free(ndbuf);
return NULL;
}
ndbuf->flags = flags;
ndbuf->exports = 0;
base = &ndbuf->base;
base->obj = NULL;
base->buf = ndbuf->data;
base->len = len;
base->itemsize = 1;
base->readonly = 0;
base->format = NULL;
base->ndim = 1;
base->shape = NULL;
base->strides = NULL;
base->suboffsets = NULL;
base->internal = ndbuf;
return ndbuf;
}
static void
ndbuf_free(ndbuf_t *ndbuf)
{
Py_buffer *base = &ndbuf->base;
PyMem_XFree(ndbuf->data);
PyMem_XFree(base->format);
PyMem_XFree(base->shape);
PyMem_XFree(base->strides);
PyMem_XFree(base->suboffsets);
PyMem_Free(ndbuf);
}
static void
ndbuf_push(NDArrayObject *nd, ndbuf_t *elt)
{
elt->next = nd->head;
if (nd->head) nd->head->prev = elt;
nd->head = elt;
elt->prev = NULL;
}
static void
ndbuf_delete(NDArrayObject *nd, ndbuf_t *elt)
{
if (elt->prev)
elt->prev->next = elt->next;
else
nd->head = elt->next;
if (elt->next)
elt->next->prev = elt->prev;
ndbuf_free(elt);
}
static void
ndbuf_pop(NDArrayObject *nd)
{
ndbuf_delete(nd, nd->head);
}
static PyObject *
ndarray_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
NDArrayObject *nd;
nd = PyObject_New(NDArrayObject, &NDArray_Type);
if (nd == NULL)
return NULL;
nd->flags = 0;
nd->head = NULL;
return (PyObject *)nd;
}
static void
ndarray_dealloc(NDArrayObject *self)
{
if (self->head) {
if (ND_IS_CONSUMER(self)) {
Py_buffer *base = &self->head->base;
if (self->head->flags & ND_OWN_ARRAYS) {
PyMem_XFree(base->shape);
PyMem_XFree(base->strides);
PyMem_XFree(base->suboffsets);
}
PyBuffer_Release(base);
}
else {
while (self->head)
ndbuf_pop(self);
}
}
PyObject_Free(self);
}
static int
ndarray_init_staticbuf(PyObject *exporter, NDArrayObject *nd, int flags)
{
Py_buffer *base = &nd->staticbuf.base;
if (PyObject_GetBuffer(exporter, base, flags) < 0)
return -1;
nd->head = &nd->staticbuf;
nd->head->next = NULL;
nd->head->prev = NULL;
nd->head->len = -1;
nd->head->offset = -1;
nd->head->data = NULL;
nd->head->flags = base->readonly ? 0 : ND_WRITABLE;
nd->head->exports = 0;
return 0;
}
static void
init_flags(ndbuf_t *ndbuf)
{
if (ndbuf->base.ndim == 0)
ndbuf->flags |= ND_SCALAR;
if (ndbuf->base.suboffsets)
ndbuf->flags |= ND_PIL;
if (PyBuffer_IsContiguous(&ndbuf->base, 'C'))
ndbuf->flags |= ND_C;
if (PyBuffer_IsContiguous(&ndbuf->base, 'F'))
ndbuf->flags |= ND_FORTRAN;
}
/****************************************************************************/
/* Buffer/List conversions */
/****************************************************************************/
static Py_ssize_t *strides_from_shape(const ndbuf_t *, int flags);
/* Get number of members in a struct: see issue #12740 */
typedef struct {
PyObject_HEAD
Py_ssize_t s_size;
Py_ssize_t s_len;
} PyPartialStructObject;
static Py_ssize_t
get_nmemb(PyObject *s)
{
return ((PyPartialStructObject *)s)->s_len;
}
/* Pack all items into the buffer of 'obj'. The 'format' parameter must be
in struct module syntax. For standard C types, a single item is an integer.
For compound types, a single item is a tuple of integers. */
static int
pack_from_list(PyObject *obj, PyObject *items, PyObject *format,
Py_ssize_t itemsize)
{
PyObject *structobj, *pack_into;
PyObject *args, *offset;
PyObject *item, *tmp;
Py_ssize_t nitems; /* number of items */
Py_ssize_t nmemb; /* number of members in a single item */
Py_ssize_t i, j;
int ret = 0;
assert(PyObject_CheckBuffer(obj));
assert(PyList_Check(items) || PyTuple_Check(items));
structobj = PyObject_CallFunctionObjArgs(Struct, format, NULL);
if (structobj == NULL)
return -1;
nitems = PySequence_Fast_GET_SIZE(items);
nmemb = get_nmemb(structobj);
assert(nmemb >= 1);
pack_into = PyObject_GetAttrString(structobj, "pack_into");
if (pack_into == NULL) {
Py_DECREF(structobj);
return -1;
}
/* nmemb >= 1 */
args = PyTuple_New(2 + nmemb);
if (args == NULL) {
Py_DECREF(pack_into);
Py_DECREF(structobj);
return -1;
}
offset = NULL;
for (i = 0; i < nitems; i++) {
/* Loop invariant: args[j] are borrowed references or NULL. */
PyTuple_SET_ITEM(args, 0, obj);
for (j = 1; j < 2+nmemb; j++)
PyTuple_SET_ITEM(args, j, NULL);
Py_XDECREF(offset);
offset = PyLong_FromSsize_t(i*itemsize);
if (offset == NULL) {
ret = -1;
break;
}
PyTuple_SET_ITEM(args, 1, offset);
item = PySequence_Fast_GET_ITEM(items, i);
if ((PyBytes_Check(item) || PyLong_Check(item) ||
PyFloat_Check(item)) && nmemb == 1) {
PyTuple_SET_ITEM(args, 2, item);
}
else if ((PyList_Check(item) || PyTuple_Check(item)) &&
PySequence_Length(item) == nmemb) {
for (j = 0; j < nmemb; j++) {
tmp = PySequence_Fast_GET_ITEM(item, j);
PyTuple_SET_ITEM(args, 2+j, tmp);
}
}
else {
PyErr_SetString(PyExc_ValueError,
"mismatch between initializer element and format string");
ret = -1;
break;
}
tmp = PyObject_CallObject(pack_into, args);
if (tmp == NULL) {
ret = -1;
break;
}
Py_DECREF(tmp);
}
Py_INCREF(obj); /* args[0] */
/* args[1]: offset is either NULL or should be dealloc'd */
for (i = 2; i < 2+nmemb; i++) {
tmp = PyTuple_GET_ITEM(args, i);
Py_XINCREF(tmp);
}
Py_DECREF(args);
Py_DECREF(pack_into);
Py_DECREF(structobj);
return ret;
}
/* Pack single element */
static int
pack_single(char *ptr, PyObject *item, const char *fmt, Py_ssize_t itemsize)
{
PyObject *structobj = NULL, *pack_into = NULL, *args = NULL;
PyObject *format = NULL, *mview = NULL, *zero = NULL;
Py_ssize_t i, nmemb;
int ret = -1;
PyObject *x;
if (fmt == NULL) fmt = "B";
format = PyUnicode_FromString(fmt);
if (format == NULL)
goto out;
structobj = PyObject_CallFunctionObjArgs(Struct, format, NULL);
if (structobj == NULL)
goto out;
nmemb = get_nmemb(structobj);
assert(nmemb >= 1);
mview = PyMemoryView_FromMemory(ptr, itemsize, PyBUF_WRITE);
if (mview == NULL)
goto out;
zero = PyLong_FromLong(0);
if (zero == NULL)
goto out;
pack_into = PyObject_GetAttrString(structobj, "pack_into");
if (pack_into == NULL)
goto out;
args = PyTuple_New(2+nmemb);
if (args == NULL)
goto out;
PyTuple_SET_ITEM(args, 0, mview);
PyTuple_SET_ITEM(args, 1, zero);
if ((PyBytes_Check(item) || PyLong_Check(item) ||
PyFloat_Check(item)) && nmemb == 1) {
PyTuple_SET_ITEM(args, 2, item);
}
else if ((PyList_Check(item) || PyTuple_Check(item)) &&
PySequence_Length(item) == nmemb) {
for (i = 0; i < nmemb; i++) {
x = PySequence_Fast_GET_ITEM(item, i);
PyTuple_SET_ITEM(args, 2+i, x);
}
}
else {
PyErr_SetString(PyExc_ValueError,
"mismatch between initializer element and format string");
goto args_out;
}
x = PyObject_CallObject(pack_into, args);
if (x != NULL) {
Py_DECREF(x);
ret = 0;
}
args_out:
for (i = 0; i < 2+nmemb; i++)
Py_XINCREF(PyTuple_GET_ITEM(args, i));
Py_XDECREF(args);
out:
Py_XDECREF(pack_into);
Py_XDECREF(zero);
Py_XDECREF(mview);
Py_XDECREF(structobj);
Py_XDECREF(format);
return ret;
}
static void
copy_rec(const Py_ssize_t *shape, Py_ssize_t ndim, Py_ssize_t itemsize,
char *dptr, const Py_ssize_t *dstrides, const Py_ssize_t *dsuboffsets,
char *sptr, const Py_ssize_t *sstrides, const Py_ssize_t *ssuboffsets,
char *mem)
{
Py_ssize_t i;
assert(ndim >= 1);
if (ndim == 1) {
if (!HAVE_PTR(dsuboffsets) && !HAVE_PTR(ssuboffsets) &&
dstrides[0] == itemsize && sstrides[0] == itemsize) {
memmove(dptr, sptr, shape[0] * itemsize);
}
else {
char *p;
assert(mem != NULL);
for (i=0, p=mem; i<shape[0]; p+=itemsize, sptr+=sstrides[0], i++) {
char *xsptr = ADJUST_PTR(sptr, ssuboffsets);
memcpy(p, xsptr, itemsize);
}
for (i=0, p=mem; i<shape[0]; p+=itemsize, dptr+=dstrides[0], i++) {
char *xdptr = ADJUST_PTR(dptr, dsuboffsets);
memcpy(xdptr, p, itemsize);
}
}
return;
}
for (i = 0; i < shape[0]; dptr+=dstrides[0], sptr+=sstrides[0], i++) {
char *xdptr = ADJUST_PTR(dptr, dsuboffsets);
char *xsptr = ADJUST_PTR(sptr, ssuboffsets);
copy_rec(shape+1, ndim-1, itemsize,
xdptr, dstrides+1, dsuboffsets ? dsuboffsets+1 : NULL,
xsptr, sstrides+1, ssuboffsets ? ssuboffsets+1 : NULL,
mem);
}
}
static int
cmp_structure(Py_buffer *dest, Py_buffer *src)
{
Py_ssize_t i;
if (strcmp(FIX_FORMAT(dest->format), FIX_FORMAT(src->format)) != 0 ||
dest->itemsize != src->itemsize ||
dest->ndim != src->ndim)
return -1;
for (i = 0; i < dest->ndim; i++) {
if (dest->shape[i] != src->shape[i])
return -1;
if (dest->shape[i] == 0)
break;
}
return 0;
}
/* Copy src to dest. Both buffers must have the same format, itemsize,
ndim and shape. Copying is atomic, the function never fails with
a partial copy. */
static int
copy_buffer(Py_buffer *dest, Py_buffer *src)
{
char *mem = NULL;
assert(dest->ndim > 0);
if (cmp_structure(dest, src) < 0) {
PyErr_SetString(PyExc_ValueError,
"ndarray assignment: lvalue and rvalue have different structures");
return -1;
}
if ((dest->suboffsets && dest->suboffsets[dest->ndim-1] >= 0) ||
(src->suboffsets && src->suboffsets[src->ndim-1] >= 0) ||
dest->strides[dest->ndim-1] != dest->itemsize ||
src->strides[src->ndim-1] != src->itemsize) {
mem = PyMem_Malloc(dest->shape[dest->ndim-1] * dest->itemsize);
if (mem == NULL) {
PyErr_NoMemory();
return -1;
}
}
copy_rec(dest->shape, dest->ndim, dest->itemsize,
dest->buf, dest->strides, dest->suboffsets,
src->buf, src->strides, src->suboffsets,
mem);
PyMem_XFree(mem);
return 0;
}
/* Unpack single element */
static PyObject *
unpack_single(char *ptr, const char *fmt, Py_ssize_t itemsize)
{
PyObject *x, *unpack_from, *mview;
if (fmt == NULL) {
fmt = "B";
itemsize = 1;
}
unpack_from = PyObject_GetAttrString(structmodule, "unpack_from");
if (unpack_from == NULL)
return NULL;
mview = PyMemoryView_FromMemory(ptr, itemsize, PyBUF_READ);
if (mview == NULL) {
Py_DECREF(unpack_from);
return NULL;
}
x = PyObject_CallFunction(unpack_from, "sO", fmt, mview);
Py_DECREF(unpack_from);
Py_DECREF(mview);
if (x == NULL)
return NULL;
if (PyTuple_GET_SIZE(x) == 1) {
PyObject *tmp = PyTuple_GET_ITEM(x, 0);
Py_INCREF(tmp);
Py_DECREF(x);
return tmp;
}
return x;
}
/* Unpack a multi-dimensional matrix into a nested list. Return a scalar
for ndim = 0. */
static PyObject *
unpack_rec(PyObject *unpack_from, char *ptr, PyObject *mview, char *item,
const Py_ssize_t *shape, const Py_ssize_t *strides,
const Py_ssize_t *suboffsets, Py_ssize_t ndim, Py_ssize_t itemsize)
{
PyObject *lst, *x;
Py_ssize_t i;
assert(ndim >= 0);
assert(shape != NULL);
assert(strides != NULL);
if (ndim == 0) {
memcpy(item, ptr, itemsize);
x = PyObject_CallFunctionObjArgs(unpack_from, mview, NULL);
if (x == NULL)
return NULL;
if (PyTuple_GET_SIZE(x) == 1) {
PyObject *tmp = PyTuple_GET_ITEM(x, 0);
Py_INCREF(tmp);
Py_DECREF(x);
return tmp;
}
return x;
}
lst = PyList_New(shape[0]);
if (lst == NULL)
return NULL;
for (i = 0; i < shape[0]; ptr+=strides[0], i++) {
char *nextptr = ADJUST_PTR(ptr, suboffsets);
x = unpack_rec(unpack_from, nextptr, mview, item,
shape+1, strides+1, suboffsets ? suboffsets+1 : NULL,
ndim-1, itemsize);
if (x == NULL) {
Py_DECREF(lst);
return NULL;
}
PyList_SET_ITEM(lst, i, x);
}
return lst;
}
static PyObject *
ndarray_as_list(NDArrayObject *nd)
{
PyObject *structobj = NULL, *unpack_from = NULL;
PyObject *lst = NULL, *mview = NULL;
Py_buffer *base = &nd->head->base;
Py_ssize_t *shape = base->shape;
Py_ssize_t *strides = base->strides;
Py_ssize_t simple_shape[1];
Py_ssize_t simple_strides[1];
char *item = NULL;
PyObject *format;
char *fmt = base->format;
base = &nd->head->base;
if (fmt == NULL) {
PyErr_SetString(PyExc_ValueError,
"ndarray: tolist() does not support format=NULL, use "
"tobytes()");
return NULL;
}
if (shape == NULL) {
assert(ND_C_CONTIGUOUS(nd->head->flags));
assert(base->strides == NULL);
assert(base->ndim <= 1);
shape = simple_shape;
shape[0] = base->len;
strides = simple_strides;
strides[0] = base->itemsize;
}
else if (strides == NULL) {
assert(ND_C_CONTIGUOUS(nd->head->flags));
strides = strides_from_shape(nd->head, 0);
if (strides == NULL)
return NULL;
}
format = PyUnicode_FromString(fmt);
if (format == NULL)
goto out;
structobj = PyObject_CallFunctionObjArgs(Struct, format, NULL);
Py_DECREF(format);
if (structobj == NULL)
goto out;
unpack_from = PyObject_GetAttrString(structobj, "unpack_from");
if (unpack_from == NULL)
goto out;
item = PyMem_Malloc(base->itemsize);
if (item == NULL) {
PyErr_NoMemory();
goto out;
}
mview = PyMemoryView_FromMemory(item, base->itemsize, PyBUF_WRITE);
if (mview == NULL)
goto out;
lst = unpack_rec(unpack_from, base->buf, mview, item,
shape, strides, base->suboffsets,
base->ndim, base->itemsize);
out:
Py_XDECREF(mview);
PyMem_XFree(item);
Py_XDECREF(unpack_from);
Py_XDECREF(structobj);
if (strides != base->strides && strides != simple_strides)
PyMem_XFree(strides);
return lst;
}
/****************************************************************************/
/* Initialize ndbuf */
/****************************************************************************/
/*
State of a new ndbuf during initialization. 'OK' means that initialization
is complete. 'PTR' means that a pointer has been initialized, but the
state of the memory is still undefined and ndbuf->offset is disregarded.
+-----------------+-----------+-------------+----------------+
| | ndbuf_new | init_simple | init_structure |
+-----------------+-----------+-------------+----------------+
| next | OK (NULL) | OK | OK |
+-----------------+-----------+-------------+----------------+
| prev | OK (NULL) | OK | OK |
+-----------------+-----------+-------------+----------------+
| len | OK | OK | OK |
+-----------------+-----------+-------------+----------------+
| offset | OK | OK | OK |
+-----------------+-----------+-------------+----------------+
| data | PTR | OK | OK |
+-----------------+-----------+-------------+----------------+
| flags | user | user | OK |
+-----------------+-----------+-------------+----------------+
| exports | OK (0) | OK | OK |
+-----------------+-----------+-------------+----------------+
| base.obj | OK (NULL) | OK | OK |
+-----------------+-----------+-------------+----------------+
| base.buf | PTR | PTR | OK |
+-----------------+-----------+-------------+----------------+
| base.len | len(data) | len(data) | OK |
+-----------------+-----------+-------------+----------------+
| base.itemsize | 1 | OK | OK |
+-----------------+-----------+-------------+----------------+
| base.readonly | 0 | OK | OK |
+-----------------+-----------+-------------+----------------+
| base.format | NULL | OK | OK |
+-----------------+-----------+-------------+----------------+
| base.ndim | 1 | 1 | OK |
+-----------------+-----------+-------------+----------------+
| base.shape | NULL | NULL | OK |
+-----------------+-----------+-------------+----------------+
| base.strides | NULL | NULL | OK |
+-----------------+-----------+-------------+----------------+
| base.suboffsets | NULL | NULL | OK |
+-----------------+-----------+-------------+----------------+
| base.internal | OK | OK | OK |
+-----------------+-----------+-------------+----------------+
*/
static Py_ssize_t
get_itemsize(PyObject *format)
{
PyObject *tmp;
Py_ssize_t itemsize;
tmp = PyObject_CallFunctionObjArgs(calcsize, format, NULL);
if (tmp == NULL)
return -1;
itemsize = PyLong_AsSsize_t(tmp);
Py_DECREF(tmp);
return itemsize;
}
static char *
get_format(PyObject *format)
{
PyObject *tmp;
char *fmt;
tmp = PyUnicode_AsASCIIString(format);
if (tmp == NULL)
return NULL;
fmt = PyMem_Malloc(PyBytes_GET_SIZE(tmp)+1);
if (fmt == NULL) {
PyErr_NoMemory();
Py_DECREF(tmp);
return NULL;
}
strcpy(fmt, PyBytes_AS_STRING(tmp));
Py_DECREF(tmp);
return fmt;
}
static int
init_simple(ndbuf_t *ndbuf, PyObject *items, PyObject *format,
Py_ssize_t itemsize)
{
PyObject *mview;
Py_buffer *base = &ndbuf->base;
int ret;
mview = PyMemoryView_FromBuffer(base);
if (mview == NULL)
return -1;
ret = pack_from_list(mview, items, format, itemsize);
Py_DECREF(mview);
if (ret < 0)
return -1;
base->readonly = !(ndbuf->flags & ND_WRITABLE);
base->itemsize = itemsize;
base->format = get_format(format);
if (base->format == NULL)
return -1;
return 0;
}
static Py_ssize_t *
seq_as_ssize_array(PyObject *seq, Py_ssize_t len, int is_shape)
{
Py_ssize_t *dest;
Py_ssize_t x, i;
/* ndim = len <= ND_MAX_NDIM, so PyMem_New() is actually not needed. */
dest = PyMem_New(Py_ssize_t, len);
if (dest == NULL) {
PyErr_NoMemory();
return NULL;
}
for (i = 0; i < len; i++) {
PyObject *tmp = PySequence_Fast_GET_ITEM(seq, i);
if (!PyLong_Check(tmp)) {
PyErr_Format(PyExc_ValueError,
"elements of %s must be integers",
is_shape ? "shape" : "strides");
PyMem_Free(dest);
return NULL;
}
x = PyLong_AsSsize_t(tmp);
if (PyErr_Occurred()) {
PyMem_Free(dest);
return NULL;
}
if (is_shape && x < 0) {
PyErr_Format(PyExc_ValueError,
"elements of shape must be integers >= 0");
PyMem_Free(dest);
return NULL;
}
dest[i] = x;
}
return dest;
}
static Py_ssize_t *
strides_from_shape(const ndbuf_t *ndbuf, int flags)
{
const Py_buffer *base = &ndbuf->base;
Py_ssize_t *s, i;
s = PyMem_Malloc(base->ndim * (sizeof *s));
if (s == NULL) {
PyErr_NoMemory();
return NULL;
}
if (flags & ND_FORTRAN) {
s[0] = base->itemsize;
for (i = 1; i < base->ndim; i++)
s[i] = s[i-1] * base->shape[i-1];
}
else {
s[base->ndim-1] = base->itemsize;
for (i = base->ndim-2; i >= 0; i--)
s[i] = s[i+1] * base->shape[i+1];
}
return s;
}
/* Bounds check:
len := complete length of allocated memory
offset := start of the array
A single array element is indexed by:
i = indices[0] * strides[0] + indices[1] * strides[1] + ...
imin is reached when all indices[n] combined with positive strides are 0
and all indices combined with negative strides are shape[n]-1, which is
the maximum index for the nth dimension.
imax is reached when all indices[n] combined with negative strides are 0
and all indices combined with positive strides are shape[n]-1.
*/
static int
verify_structure(Py_ssize_t len, Py_ssize_t itemsize, Py_ssize_t offset,
const Py_ssize_t *shape, const Py_ssize_t *strides,
Py_ssize_t ndim)
{
Py_ssize_t imin, imax;
Py_ssize_t n;
assert(ndim >= 0);
if (ndim == 0 && (offset < 0 || offset+itemsize > len))
goto invalid_combination;
for (n = 0; n < ndim; n++)
if (strides[n] % itemsize) {
PyErr_SetString(PyExc_ValueError,
"strides must be a multiple of itemsize");
return -1;
}
for (n = 0; n < ndim; n++)
if (shape[n] == 0)
return 0;
imin = imax = 0;
for (n = 0; n < ndim; n++)
if (strides[n] <= 0)
imin += (shape[n]-1) * strides[n];
else
imax += (shape[n]-1) * strides[n];
if (imin + offset < 0 || imax + offset + itemsize > len)
goto invalid_combination;
return 0;
invalid_combination:
PyErr_SetString(PyExc_ValueError,
"invalid combination of buffer, shape and strides");
return -1;
}
/*
Convert a NumPy-style array to an array using suboffsets to stride in
the first dimension. Requirements: ndim > 0.
Contiguous example
==================
Input:
------
shape = {2, 2, 3};
strides = {6, 3, 1};
suboffsets = NULL;
data = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11};
buf = &data[0]
Output:
-------
shape = {2, 2, 3};
strides = {sizeof(char *), 3, 1};
suboffsets = {0, -1, -1};
data = {p1, p2, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11};
| | ^ ^
`---'---' |
| |
`---------------------'
buf = &data[0]
So, in the example the input resembles the three-dimensional array
char v[2][2][3], while the output resembles an array of two pointers
to two-dimensional arrays: char (*v[2])[2][3].
Non-contiguous example:
=======================
Input (with offset and negative strides):
-----------------------------------------
shape = {2, 2, 3};
strides = {-6, 3, -1};
offset = 8
suboffsets = NULL;
data = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11};
Output:
-------
shape = {2, 2, 3};
strides = {-sizeof(char *), 3, -1};
suboffsets = {2, -1, -1};
newdata = {p1, p2, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11};
| | ^ ^ ^ ^
`---'---' | | `- p2+suboffsets[0]
| `-----------|--- p1+suboffsets[0]
`---------------------'
buf = &newdata[1] # striding backwards over the pointers.
suboffsets[0] is the same as the offset that one would specify if
the two {2, 3} subarrays were created directly, hence the name.
*/
static int
init_suboffsets(ndbuf_t *ndbuf)
{
Py_buffer *base = &ndbuf->base;
Py_ssize_t start, step;
Py_ssize_t imin, suboffset0;
Py_ssize_t addsize;
Py_ssize_t n;
char *data;
assert(base->ndim > 0);
assert(base->suboffsets == NULL);
/* Allocate new data with additional space for shape[0] pointers. */
addsize = base->shape[0] * (sizeof (char *));
/* Align array start to a multiple of 8. */
addsize = 8 * ((addsize + 7) / 8);
data = PyMem_Malloc(ndbuf->len + addsize);
if (data == NULL) {
PyErr_NoMemory();
return -1;
}
memcpy(data + addsize, ndbuf->data, ndbuf->len);
PyMem_Free(ndbuf->data);
ndbuf->data = data;
ndbuf->len += addsize;
base->buf = ndbuf->data;
/* imin: minimum index of the input array relative to ndbuf->offset.
suboffset0: offset for each sub-array of the output. This is the
same as calculating -imin' for a sub-array of ndim-1. */
imin = suboffset0 = 0;
for (n = 0; n < base->ndim; n++) {
if (base->shape[n] == 0)
break;
if (base->strides[n] <= 0) {
Py_ssize_t x = (base->shape[n]-1) * base->strides[n];
imin += x;
suboffset0 += (n >= 1) ? -x : 0;
}
}
/* Initialize the array of pointers to the sub-arrays. */
start = addsize + ndbuf->offset + imin;
step = base->strides[0] < 0 ? -base->strides[0] : base->strides[0];
for (n = 0; n < base->shape[0]; n++)
((char **)base->buf)[n] = (char *)base->buf + start + n*step;
/* Initialize suboffsets. */
base->suboffsets = PyMem_Malloc(base->ndim * (sizeof *base->suboffsets));
if (base->suboffsets == NULL) {
PyErr_NoMemory();
return -1;
}
base->suboffsets[0] = suboffset0;
for (n = 1; n < base->ndim; n++)
base->suboffsets[n] = -1;
/* Adjust strides for the first (zeroth) dimension. */
if (base->strides[0] >= 0) {
base->strides[0] = sizeof(char *);
}
else {
/* Striding backwards. */
base->strides[0] = -(Py_ssize_t)sizeof(char *);
if (base->shape[0] > 0)
base->buf = (char *)base->buf + (base->shape[0]-1) * sizeof(char *);
}
ndbuf->flags &= ~(ND_C|ND_FORTRAN);
ndbuf->offset = 0;
return 0;
}
static void
init_len(Py_buffer *base)
{
Py_ssize_t i;
base->len = 1;
for (i = 0; i < base->ndim; i++)
base->len *= base->shape[i];
base->len *= base->itemsize;
}
static int
init_structure(ndbuf_t *ndbuf, PyObject *shape, PyObject *strides,
Py_ssize_t ndim)
{
Py_buffer *base = &ndbuf->base;
base->ndim = (int)ndim;
if (ndim == 0) {
if (ndbuf->flags & ND_PIL) {
PyErr_SetString(PyExc_TypeError,
"ndim = 0 cannot be used in conjunction with ND_PIL");
return -1;
}
ndbuf->flags |= (ND_SCALAR|ND_C|ND_FORTRAN);
return 0;
}
/* shape */
base->shape = seq_as_ssize_array(shape, ndim, 1);
if (base->shape == NULL)
return -1;
/* strides */
if (strides) {
base->strides = seq_as_ssize_array(strides, ndim, 0);
}
else {
base->strides = strides_from_shape(ndbuf, ndbuf->flags);
}
if (base->strides == NULL)
return -1;
if (verify_structure(base->len, base->itemsize, ndbuf->offset,
base->shape, base->strides, ndim) < 0)
return -1;
/* buf */
base->buf = ndbuf->data + ndbuf->offset;
/* len */
init_len(base);
/* ndbuf->flags */
if (PyBuffer_IsContiguous(base, 'C'))
ndbuf->flags |= ND_C;
if (PyBuffer_IsContiguous(base, 'F'))
ndbuf->flags |= ND_FORTRAN;
/* convert numpy array to suboffset representation */
if (ndbuf->flags & ND_PIL) {
/* modifies base->buf, base->strides and base->suboffsets **/
return init_suboffsets(ndbuf);
}
return 0;
}
static ndbuf_t *
init_ndbuf(PyObject *items, PyObject *shape, PyObject *strides,
Py_ssize_t offset, PyObject *format, int flags)
{
ndbuf_t *ndbuf;
Py_ssize_t ndim;
Py_ssize_t nitems;
Py_ssize_t itemsize;
/* ndim = len(shape) */
CHECK_LIST_OR_TUPLE(shape)
ndim = PySequence_Fast_GET_SIZE(shape);
if (ndim > ND_MAX_NDIM) {
PyErr_Format(PyExc_ValueError,
"ndim must not exceed %d", ND_MAX_NDIM);
return NULL;
}
/* len(strides) = len(shape) */
if (strides) {
CHECK_LIST_OR_TUPLE(strides)
if (PySequence_Fast_GET_SIZE(strides) == 0)
strides = NULL;
else if (flags & ND_FORTRAN) {
PyErr_SetString(PyExc_TypeError,
"ND_FORTRAN cannot be used together with strides");
return NULL;
}
else if (PySequence_Fast_GET_SIZE(strides) != ndim) {
PyErr_SetString(PyExc_ValueError,
"len(shape) != len(strides)");
return NULL;
}
}
/* itemsize */
itemsize = get_itemsize(format);
if (itemsize <= 0) {
if (itemsize == 0) {
PyErr_SetString(PyExc_ValueError,
"itemsize must not be zero");
}
return NULL;
}
/* convert scalar to list */
if (ndim == 0) {
items = PyTuple_Pack(1, items);
if (items == NULL)
return NULL;
}
else {
CHECK_LIST_OR_TUPLE(items)
Py_INCREF(items);
}
/* number of items */
nitems = PySequence_Fast_GET_SIZE(items);
if (nitems == 0) {
PyErr_SetString(PyExc_ValueError,
"initializer list or tuple must not be empty");
Py_DECREF(items);
return NULL;
}
ndbuf = ndbuf_new(nitems, itemsize, offset, flags);
if (ndbuf == NULL) {
Py_DECREF(items);
return NULL;
}
if (init_simple(ndbuf, items, format, itemsize) < 0)
goto error;
if (init_structure(ndbuf, shape, strides, ndim) < 0)
goto error;
Py_DECREF(items);
return ndbuf;
error:
Py_DECREF(items);
ndbuf_free(ndbuf);
return NULL;
}
/* initialize and push a new base onto the linked list */
static int
ndarray_push_base(NDArrayObject *nd, PyObject *items,
PyObject *shape, PyObject *strides,
Py_ssize_t offset, PyObject *format, int flags)
{
ndbuf_t *ndbuf;
ndbuf = init_ndbuf(items, shape, strides, offset, format, flags);
if (ndbuf == NULL)
return -1;
ndbuf_push(nd, ndbuf);
return 0;
}
#define PyBUF_UNUSED 0x10000
static int
ndarray_init(PyObject *self, PyObject *args, PyObject *kwds)
{
NDArrayObject *nd = (NDArrayObject *)self;
static char *kwlist[] = {
"obj", "shape", "strides", "offset", "format", "flags", "getbuf", NULL
};
PyObject *v = NULL; /* initializer: scalar, list, tuple or base object */
PyObject *shape = NULL; /* size of each dimension */
PyObject *strides = NULL; /* number of bytes to the next elt in each dim */
Py_ssize_t offset = 0; /* buffer offset */
PyObject *format = simple_format; /* struct module specifier: "B" */
int flags = ND_DEFAULT; /* base buffer and ndarray flags */
int getbuf = PyBUF_UNUSED; /* re-exporter: getbuffer request flags */
if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|OOnOii", kwlist,
&v, &shape, &strides, &offset, &format, &flags, &getbuf))
return -1;
/* NDArrayObject is re-exporter */
if (PyObject_CheckBuffer(v) && shape == NULL) {
if (strides || offset || format != simple_format ||
!(flags == ND_DEFAULT || flags == ND_REDIRECT)) {
PyErr_SetString(PyExc_TypeError,
"construction from exporter object only takes 'obj', 'getbuf' "
"and 'flags' arguments");
return -1;
}
getbuf = (getbuf == PyBUF_UNUSED) ? PyBUF_FULL_RO : getbuf;
if (ndarray_init_staticbuf(v, nd, getbuf) < 0)
return -1;
init_flags(nd->head);
nd->head->flags |= flags;
return 0;
}
/* NDArrayObject is the original base object. */
if (getbuf != PyBUF_UNUSED) {
PyErr_SetString(PyExc_TypeError,
"getbuf argument only valid for construction from exporter "
"object");
return -1;
}
if (shape == NULL) {
PyErr_SetString(PyExc_TypeError,
"shape is a required argument when constructing from "
"list, tuple or scalar");
return -1;
}
if (flags & ND_VAREXPORT) {
nd->flags |= ND_VAREXPORT;
flags &= ~ND_VAREXPORT;
}
/* Initialize and push the first base buffer onto the linked list. */
return ndarray_push_base(nd, v, shape, strides, offset, format, flags);
}
/* Push an additional base onto the linked list. */
static PyObject *
ndarray_push(PyObject *self, PyObject *args, PyObject *kwds)
{
NDArrayObject *nd = (NDArrayObject *)self;
static char *kwlist[] = {
"items", "shape", "strides", "offset", "format", "flags", NULL
};
PyObject *items = NULL; /* initializer: scalar, list or tuple */
PyObject *shape = NULL; /* size of each dimension */
PyObject *strides = NULL; /* number of bytes to the next elt in each dim */
PyObject *format = simple_format; /* struct module specifier: "B" */
Py_ssize_t offset = 0; /* buffer offset */
int flags = ND_DEFAULT; /* base buffer flags */
if (!PyArg_ParseTupleAndKeywords(args, kwds, "OO|OnOi", kwlist,
&items, &shape, &strides, &offset, &format, &flags))
return NULL;
if (flags & ND_VAREXPORT) {
PyErr_SetString(PyExc_ValueError,
"ND_VAREXPORT flag can only be used during object creation");
return NULL;
}
if (ND_IS_CONSUMER(nd)) {
PyErr_SetString(PyExc_BufferError,
"structure of re-exporting object is immutable");
return NULL;
}
if (!(nd->flags&ND_VAREXPORT) && nd->head->exports > 0) {
PyErr_Format(PyExc_BufferError,
"cannot change structure: %zd exported buffer%s",
nd->head->exports, nd->head->exports==1 ? "" : "s");
return NULL;
}
if (ndarray_push_base(nd, items, shape, strides,
offset, format, flags) < 0)
return NULL;
Py_RETURN_NONE;
}
/* Pop a base from the linked list (if possible). */
static PyObject *
ndarray_pop(PyObject *self, PyObject *dummy)
{
NDArrayObject *nd = (NDArrayObject *)self;
if (ND_IS_CONSUMER(nd)) {
PyErr_SetString(PyExc_BufferError,
"structure of re-exporting object is immutable");
return NULL;
}
if (nd->head->exports > 0) {
PyErr_Format(PyExc_BufferError,
"cannot change structure: %zd exported buffer%s",
nd->head->exports, nd->head->exports==1 ? "" : "s");
return NULL;
}
if (nd->head->next == NULL) {
PyErr_SetString(PyExc_BufferError,
"list only has a single base");
return NULL;
}
ndbuf_pop(nd);
Py_RETURN_NONE;
}
/**************************************************************************/
/* getbuffer */
/**************************************************************************/
static int
ndarray_getbuf(NDArrayObject *self, Py_buffer *view, int flags)
{
ndbuf_t *ndbuf = self->head;
Py_buffer *base = &ndbuf->base;
int baseflags = ndbuf->flags;
/* redirect mode */
if (base->obj != NULL && (baseflags&ND_REDIRECT)) {
return PyObject_GetBuffer(base->obj, view, flags);
}
/* start with complete information */
*view = *base;
view->obj = NULL;
/* reconstruct format */
if (view->format == NULL)
view->format = "B";
if (base->ndim != 0 &&
((REQ_SHAPE(flags) && base->shape == NULL) ||
(REQ_STRIDES(flags) && base->strides == NULL))) {
/* The ndarray is a re-exporter that has been created without full
information for testing purposes. In this particular case the
ndarray is not a PEP-3118 compliant buffer provider. */
PyErr_SetString(PyExc_BufferError,
"re-exporter does not provide format, shape or strides");
return -1;
}
if (baseflags & ND_GETBUF_FAIL) {
PyErr_SetString(PyExc_BufferError,
"ND_GETBUF_FAIL: forced test exception");
if (baseflags & ND_GETBUF_UNDEFINED)
view->obj = (PyObject *)0x1; /* wrong but permitted in <= 3.2 */
return -1;
}
if (REQ_WRITABLE(flags) && base->readonly) {
PyErr_SetString(PyExc_BufferError,
"ndarray is not writable");
return -1;
}
if (!REQ_FORMAT(flags)) {
/* NULL indicates that the buffer's data type has been cast to 'B'.
view->itemsize is the _previous_ itemsize. If shape is present,
the equality product(shape) * itemsize = len still holds at this
point. The equality calcsize(format) = itemsize does _not_ hold
from here on! */
view->format = NULL;
}
if (REQ_C_CONTIGUOUS(flags) && !ND_C_CONTIGUOUS(baseflags)) {
PyErr_SetString(PyExc_BufferError,
"ndarray is not C-contiguous");
return -1;
}
if (REQ_F_CONTIGUOUS(flags) && !ND_FORTRAN_CONTIGUOUS(baseflags)) {
PyErr_SetString(PyExc_BufferError,
"ndarray is not Fortran contiguous");
return -1;
}
if (REQ_ANY_CONTIGUOUS(flags) && !ND_ANY_CONTIGUOUS(baseflags)) {
PyErr_SetString(PyExc_BufferError,
"ndarray is not contiguous");
return -1;
}
if (!REQ_INDIRECT(flags) && (baseflags & ND_PIL)) {
PyErr_SetString(PyExc_BufferError,
"ndarray cannot be represented without suboffsets");
return -1;
}
if (!REQ_STRIDES(flags)) {
if (!ND_C_CONTIGUOUS(baseflags)) {
PyErr_SetString(PyExc_BufferError,
"ndarray is not C-contiguous");
return -1;
}
view->strides = NULL;
}
if (!REQ_SHAPE(flags)) {
/* PyBUF_SIMPLE or PyBUF_WRITABLE: at this point buf is C-contiguous,
so base->buf = ndbuf->data. */
if (view->format != NULL) {
/* PyBUF_SIMPLE|PyBUF_FORMAT and PyBUF_WRITABLE|PyBUF_FORMAT do
not make sense. */
PyErr_Format(PyExc_BufferError,
"ndarray: cannot cast to unsigned bytes if the format flag "
"is present");
return -1;
}
/* product(shape) * itemsize = len and calcsize(format) = itemsize
do _not_ hold from here on! */
view->ndim = 1;
view->shape = NULL;
}
/* Ascertain that the new buffer has the same contiguity as the exporter */
if (ND_C_CONTIGUOUS(baseflags) != PyBuffer_IsContiguous(view, 'C') ||
/* skip cast to 1-d */
(view->format != NULL && view->shape != NULL &&
ND_FORTRAN_CONTIGUOUS(baseflags) != PyBuffer_IsContiguous(view, 'F')) ||
/* cast to 1-d */
(view->format == NULL && view->shape == NULL &&
!PyBuffer_IsContiguous(view, 'F'))) {
PyErr_SetString(PyExc_BufferError,
"ndarray: contiguity mismatch in getbuf()");
return -1;
}
view->obj = Py_NewRef(self);
self->head->exports++;
return 0;
}
static void
ndarray_releasebuf(NDArrayObject *self, Py_buffer *view)
{
if (!ND_IS_CONSUMER(self)) {
ndbuf_t *ndbuf = view->internal;
if (--ndbuf->exports == 0 && ndbuf != self->head)
ndbuf_delete(self, ndbuf);
}
}
static PyBufferProcs ndarray_as_buffer = {
(getbufferproc)ndarray_getbuf, /* bf_getbuffer */
(releasebufferproc)ndarray_releasebuf /* bf_releasebuffer */
};
/**************************************************************************/
/* indexing/slicing */
/**************************************************************************/
static char *
ptr_from_index(Py_buffer *base, Py_ssize_t index)
{
char *ptr;
Py_ssize_t nitems; /* items in the first dimension */
if (base->shape)
nitems = base->shape[0];
else {
assert(base->ndim == 1 && SIMPLE_FORMAT(base->format));
nitems = base->len;
}
if (index < 0) {
index += nitems;
}
if (index < 0 || index >= nitems) {
PyErr_SetString(PyExc_IndexError, "index out of bounds");
return NULL;
}
ptr = (char *)base->buf;
if (base->strides == NULL)
ptr += base->itemsize * index;
else
ptr += base->strides[0] * index;
ptr = ADJUST_PTR(ptr, base->suboffsets);
return ptr;
}
static PyObject *
ndarray_item(NDArrayObject *self, Py_ssize_t index)
{
ndbuf_t *ndbuf = self->head;
Py_buffer *base = &ndbuf->base;
char *ptr;
if (base->ndim == 0) {
PyErr_SetString(PyExc_TypeError, "invalid indexing of scalar");
return NULL;
}
ptr = ptr_from_index(base, index);
if (ptr == NULL)
return NULL;
if (base->ndim == 1) {
return unpack_single(ptr, base->format, base->itemsize);
}
else {
NDArrayObject *nd;
Py_buffer *subview;
nd = (NDArrayObject *)ndarray_new(&NDArray_Type, NULL, NULL);
if (nd == NULL)
return NULL;
if (ndarray_init_staticbuf((PyObject *)self, nd, PyBUF_FULL_RO) < 0) {
Py_DECREF(nd);
return NULL;
}
subview = &nd->staticbuf.base;
subview->buf = ptr;
subview->len /= subview->shape[0];
subview->ndim--;
subview->shape++;
if (subview->strides) subview->strides++;
if (subview->suboffsets) subview->suboffsets++;
init_flags(&nd->staticbuf);
return (PyObject *)nd;
}
}
/*
For each dimension, we get valid (start, stop, step, slicelength) quadruples
from PySlice_GetIndicesEx().
Slicing NumPy arrays
====================
A pointer to an element in a NumPy array is defined by:
ptr = (char *)buf + indices[0] * strides[0] +
... +
indices[ndim-1] * strides[ndim-1]
Adjust buf:
-----------
Adding start[n] for each dimension effectively adds the constant:
c = start[0] * strides[0] + ... + start[ndim-1] * strides[ndim-1]
Therefore init_slice() adds all start[n] directly to buf.
Adjust shape:
-------------
Obviously shape[n] = slicelength[n]
Adjust strides:
---------------
In the original array, the next element in a dimension is reached
by adding strides[n] to the pointer. In the sliced array, elements
may be skipped, so the next element is reached by adding:
strides[n] * step[n]
Slicing PIL arrays
==================
Layout:
-------
In the first (zeroth) dimension, PIL arrays have an array of pointers
to sub-arrays of ndim-1. Striding in the first dimension is done by
getting the index of the nth pointer, dereference it and then add a
suboffset to it. The arrays pointed to can best be seen a regular
NumPy arrays.
Adjust buf:
-----------
In the original array, buf points to a location (usually the start)
in the array of pointers. For the sliced array, start[0] can be
added to buf in the same manner as for NumPy arrays.
Adjust suboffsets:
------------------
Due to the dereferencing step in the addressing scheme, it is not
possible to adjust buf for higher dimensions. Recall that the
sub-arrays pointed to are regular NumPy arrays, so for each of
those arrays adding start[n] effectively adds the constant:
c = start[1] * strides[1] + ... + start[ndim-1] * strides[ndim-1]
This constant is added to suboffsets[0]. suboffsets[0] in turn is
added to each pointer right after dereferencing.
Adjust shape and strides:
-------------------------
Shape and strides are not influenced by the dereferencing step, so
they are adjusted in the same manner as for NumPy arrays.
Multiple levels of suboffsets
=============================
For a construct like an array of pointers to array of pointers to
sub-arrays of ndim-2:
suboffsets[0] = start[1] * strides[1]
suboffsets[1] = start[2] * strides[2] + ...
*/
static int
init_slice(Py_buffer *base, PyObject *key, int dim)
{
Py_ssize_t start, stop, step, slicelength;
if (PySlice_Unpack(key, &start, &stop, &step) < 0) {
return -1;
}
slicelength = PySlice_AdjustIndices(base->shape[dim], &start, &stop, step);
if (base->suboffsets == NULL || dim == 0) {
adjust_buf:
base->buf = (char *)base->buf + base->strides[dim] * start;
}
else {
Py_ssize_t n = dim-1;
while (n >= 0 && base->suboffsets[n] < 0)
n--;
if (n < 0)
goto adjust_buf; /* all suboffsets are negative */
base->suboffsets[n] = base->suboffsets[n] + base->strides[dim] * start;
}
base->shape[dim] = slicelength;
base->strides[dim] = base->strides[dim] * step;
return 0;
}
static int
copy_structure(Py_buffer *base)
{
Py_ssize_t *shape = NULL, *strides = NULL, *suboffsets = NULL;
Py_ssize_t i;
shape = PyMem_Malloc(base->ndim * (sizeof *shape));
strides = PyMem_Malloc(base->ndim * (sizeof *strides));
if (shape == NULL || strides == NULL)
goto err_nomem;
suboffsets = NULL;
if (base->suboffsets) {
suboffsets = PyMem_Malloc(base->ndim * (sizeof *suboffsets));
if (suboffsets == NULL)
goto err_nomem;
}
for (i = 0; i < base->ndim; i++) {
shape[i] = base->shape[i];
strides[i] = base->strides[i];
if (suboffsets)
suboffsets[i] = base->suboffsets[i];
}
base->shape = shape;
base->strides = strides;
base->suboffsets = suboffsets;
return 0;
err_nomem:
PyErr_NoMemory();
PyMem_XFree(shape);
PyMem_XFree(strides);
PyMem_XFree(suboffsets);
return -1;
}
static PyObject *
ndarray_subscript(NDArrayObject *self, PyObject *key)
{
NDArrayObject *nd;
ndbuf_t *ndbuf;
Py_buffer *base = &self->head->base;
if (base->ndim == 0) {
if (PyTuple_Check(key) && PyTuple_GET_SIZE(key) == 0) {
return unpack_single(base->buf, base->format, base->itemsize);
}
else if (key == Py_Ellipsis) {
return Py_NewRef(self);
}
else {
PyErr_SetString(PyExc_TypeError, "invalid indexing of scalar");
return NULL;
}
}
if (PyIndex_Check(key)) {
Py_ssize_t index = PyLong_AsSsize_t(key);
if (index == -1 && PyErr_Occurred())
return NULL;
return ndarray_item(self, index);
}
nd = (NDArrayObject *)ndarray_new(&NDArray_Type, NULL, NULL);
if (nd == NULL)
return NULL;
/* new ndarray is a consumer */
if (ndarray_init_staticbuf((PyObject *)self, nd, PyBUF_FULL_RO) < 0) {
Py_DECREF(nd);
return NULL;
}
/* copy shape, strides and suboffsets */
ndbuf = nd->head;
base = &ndbuf->base;
if (copy_structure(base) < 0) {
Py_DECREF(nd);
return NULL;
}
ndbuf->flags |= ND_OWN_ARRAYS;
if (PySlice_Check(key)) {
/* one-dimensional slice */
if (init_slice(base, key, 0) < 0)
goto err_occurred;
}
else if (PyTuple_Check(key)) {
/* multi-dimensional slice */
PyObject *tuple = key;
Py_ssize_t i, n;
n = PyTuple_GET_SIZE(tuple);
for (i = 0; i < n; i++) {
key = PyTuple_GET_ITEM(tuple, i);
if (!PySlice_Check(key))
goto type_error;
if (init_slice(base, key, (int)i) < 0)
goto err_occurred;
}
}
else {
goto type_error;
}
init_len(base);
init_flags(ndbuf);
return (PyObject *)nd;
type_error:
PyErr_Format(PyExc_TypeError,
"cannot index memory using \"%.200s\"",
Py_TYPE(key)->tp_name);
err_occurred:
Py_DECREF(nd);
return NULL;
}
static int
ndarray_ass_subscript(NDArrayObject *self, PyObject *key, PyObject *value)
{
NDArrayObject *nd;
Py_buffer *dest = &self->head->base;
Py_buffer src;
char *ptr;
Py_ssize_t index;
int ret = -1;
if (dest->readonly) {
PyErr_SetString(PyExc_TypeError, "ndarray is not writable");
return -1;
}
if (value == NULL) {
PyErr_SetString(PyExc_TypeError, "ndarray data cannot be deleted");
return -1;
}
if (dest->ndim == 0) {
if (key == Py_Ellipsis ||
(PyTuple_Check(key) && PyTuple_GET_SIZE(key) == 0)) {
ptr = (char *)dest->buf;
return pack_single(ptr, value, dest->format, dest->itemsize);
}
else {
PyErr_SetString(PyExc_TypeError, "invalid indexing of scalar");
return -1;
}
}
if (dest->ndim == 1 && PyIndex_Check(key)) {
/* rvalue must be a single item */
index = PyLong_AsSsize_t(key);
if (index == -1 && PyErr_Occurred())
return -1;
else {
ptr = ptr_from_index(dest, index);
if (ptr == NULL)
return -1;
}
return pack_single(ptr, value, dest->format, dest->itemsize);
}
/* rvalue must be an exporter */
if (PyObject_GetBuffer(value, &src, PyBUF_FULL_RO) == -1)
return -1;
nd = (NDArrayObject *)ndarray_subscript(self, key);
if (nd != NULL) {
dest = &nd->head->base;
ret = copy_buffer(dest, &src);
Py_DECREF(nd);
}
PyBuffer_Release(&src);
return ret;
}
static PyObject *
slice_indices(PyObject *self, PyObject *args)
{
PyObject *ret, *key, *tmp;
Py_ssize_t s[4]; /* start, stop, step, slicelength */
Py_ssize_t i, len;
if (!PyArg_ParseTuple(args, "On", &key, &len)) {
return NULL;
}
if (!PySlice_Check(key)) {
PyErr_SetString(PyExc_TypeError,
"first argument must be a slice object");
return NULL;
}
if (PySlice_Unpack(key, &s[0], &s[1], &s[2]) < 0) {
return NULL;
}
s[3] = PySlice_AdjustIndices(len, &s[0], &s[1], s[2]);
ret = PyTuple_New(4);
if (ret == NULL)
return NULL;
for (i = 0; i < 4; i++) {
tmp = PyLong_FromSsize_t(s[i]);
if (tmp == NULL)
goto error;
PyTuple_SET_ITEM(ret, i, tmp);
}
return ret;
error:
Py_DECREF(ret);
return NULL;
}
static PyMappingMethods ndarray_as_mapping = {
NULL, /* mp_length */
(binaryfunc)ndarray_subscript, /* mp_subscript */
(objobjargproc)ndarray_ass_subscript /* mp_ass_subscript */
};
static PySequenceMethods ndarray_as_sequence = {
0, /* sq_length */
0, /* sq_concat */
0, /* sq_repeat */
(ssizeargfunc)ndarray_item, /* sq_item */
};
/**************************************************************************/
/* getters */
/**************************************************************************/
static PyObject *
ssize_array_as_tuple(Py_ssize_t *array, Py_ssize_t len)
{
PyObject *tuple, *x;
Py_ssize_t i;
if (array == NULL)
return PyTuple_New(0);
tuple = PyTuple_New(len);
if (tuple == NULL)
return NULL;
for (i = 0; i < len; i++) {
x = PyLong_FromSsize_t(array[i]);
if (x == NULL) {
Py_DECREF(tuple);
return NULL;
}
PyTuple_SET_ITEM(tuple, i, x);
}
return tuple;
}
static PyObject *
ndarray_get_flags(NDArrayObject *self, void *closure)
{
return PyLong_FromLong(self->head->flags);
}
static PyObject *
ndarray_get_offset(NDArrayObject *self, void *closure)
{
ndbuf_t *ndbuf = self->head;
return PyLong_FromSsize_t(ndbuf->offset);
}
static PyObject *
ndarray_get_obj(NDArrayObject *self, void *closure)
{
Py_buffer *base = &self->head->base;
if (base->obj == NULL) {
Py_RETURN_NONE;
}
return Py_NewRef(base->obj);
}
static PyObject *
ndarray_get_nbytes(NDArrayObject *self, void *closure)
{
Py_buffer *base = &self->head->base;
return PyLong_FromSsize_t(base->len);
}
static PyObject *
ndarray_get_readonly(NDArrayObject *self, void *closure)
{
Py_buffer *base = &self->head->base;
return PyBool_FromLong(base->readonly);
}
static PyObject *
ndarray_get_itemsize(NDArrayObject *self, void *closure)
{
Py_buffer *base = &self->head->base;
return PyLong_FromSsize_t(base->itemsize);
}
static PyObject *
ndarray_get_format(NDArrayObject *self, void *closure)
{
Py_buffer *base = &self->head->base;
const char *fmt = base->format ? base->format : "";
return PyUnicode_FromString(fmt);
}
static PyObject *
ndarray_get_ndim(NDArrayObject *self, void *closure)
{
Py_buffer *base = &self->head->base;
return PyLong_FromSsize_t(base->ndim);
}
static PyObject *
ndarray_get_shape(NDArrayObject *self, void *closure)
{
Py_buffer *base = &self->head->base;
return ssize_array_as_tuple(base->shape, base->ndim);
}
static PyObject *
ndarray_get_strides(NDArrayObject *self, void *closure)
{
Py_buffer *base = &self->head->base;
return ssize_array_as_tuple(base->strides, base->ndim);
}
static PyObject *
ndarray_get_suboffsets(NDArrayObject *self, void *closure)
{
Py_buffer *base = &self->head->base;
return ssize_array_as_tuple(base->suboffsets, base->ndim);
}
static PyObject *
ndarray_c_contig(PyObject *self, PyObject *dummy)
{
NDArrayObject *nd = (NDArrayObject *)self;
int ret = PyBuffer_IsContiguous(&nd->head->base, 'C');
if (ret != ND_C_CONTIGUOUS(nd->head->flags)) {
PyErr_SetString(PyExc_RuntimeError,
"results from PyBuffer_IsContiguous() and flags differ");
return NULL;
}
return PyBool_FromLong(ret);
}
static PyObject *
ndarray_fortran_contig(PyObject *self, PyObject *dummy)
{
NDArrayObject *nd = (NDArrayObject *)self;
int ret = PyBuffer_IsContiguous(&nd->head->base, 'F');
if (ret != ND_FORTRAN_CONTIGUOUS(nd->head->flags)) {
PyErr_SetString(PyExc_RuntimeError,
"results from PyBuffer_IsContiguous() and flags differ");
return NULL;
}
return PyBool_FromLong(ret);
}
static PyObject *
ndarray_contig(PyObject *self, PyObject *dummy)
{
NDArrayObject *nd = (NDArrayObject *)self;
int ret = PyBuffer_IsContiguous(&nd->head->base, 'A');
if (ret != ND_ANY_CONTIGUOUS(nd->head->flags)) {
PyErr_SetString(PyExc_RuntimeError,
"results from PyBuffer_IsContiguous() and flags differ");
return NULL;
}
return PyBool_FromLong(ret);
}
static PyGetSetDef ndarray_getset [] =
{
/* ndbuf */
{ "flags", (getter)ndarray_get_flags, NULL, NULL, NULL},
{ "offset", (getter)ndarray_get_offset, NULL, NULL, NULL},
/* ndbuf.base */
{ "obj", (getter)ndarray_get_obj, NULL, NULL, NULL},
{ "nbytes", (getter)ndarray_get_nbytes, NULL, NULL, NULL},
{ "readonly", (getter)ndarray_get_readonly, NULL, NULL, NULL},
{ "itemsize", (getter)ndarray_get_itemsize, NULL, NULL, NULL},
{ "format", (getter)ndarray_get_format, NULL, NULL, NULL},
{ "ndim", (getter)ndarray_get_ndim, NULL, NULL, NULL},
{ "shape", (getter)ndarray_get_shape, NULL, NULL, NULL},
{ "strides", (getter)ndarray_get_strides, NULL, NULL, NULL},
{ "suboffsets", (getter)ndarray_get_suboffsets, NULL, NULL, NULL},
{ "c_contiguous", (getter)ndarray_c_contig, NULL, NULL, NULL},
{ "f_contiguous", (getter)ndarray_fortran_contig, NULL, NULL, NULL},
{ "contiguous", (getter)ndarray_contig, NULL, NULL, NULL},
{NULL}
};
static PyObject *
ndarray_tolist(PyObject *self, PyObject *dummy)
{
return ndarray_as_list((NDArrayObject *)self);
}
static PyObject *
ndarray_tobytes(PyObject *self, PyObject *dummy)
{
ndbuf_t *ndbuf = ((NDArrayObject *)self)->head;
Py_buffer *src = &ndbuf->base;
Py_buffer dest;
PyObject *ret = NULL;
char *mem;
if (ND_C_CONTIGUOUS(ndbuf->flags))
return PyBytes_FromStringAndSize(src->buf, src->len);
assert(src->shape != NULL);
assert(src->strides != NULL);
assert(src->ndim > 0);
mem = PyMem_Malloc(src->len);
if (mem == NULL) {
PyErr_NoMemory();
return NULL;
}
dest = *src;
dest.buf = mem;
dest.suboffsets = NULL;
dest.strides = strides_from_shape(ndbuf, 0);
if (dest.strides == NULL)
goto out;
if (copy_buffer(&dest, src) < 0)
goto out;
ret = PyBytes_FromStringAndSize(mem, src->len);
out:
PyMem_XFree(dest.strides);
PyMem_Free(mem);
return ret;
}
/* add redundant (negative) suboffsets for testing */
static PyObject *
ndarray_add_suboffsets(PyObject *self, PyObject *dummy)
{
NDArrayObject *nd = (NDArrayObject *)self;
Py_buffer *base = &nd->head->base;
Py_ssize_t i;
if (base->suboffsets != NULL) {
PyErr_SetString(PyExc_TypeError,
"cannot add suboffsets to PIL-style array");
return NULL;
}
if (base->strides == NULL) {
PyErr_SetString(PyExc_TypeError,
"cannot add suboffsets to array without strides");
return NULL;
}
base->suboffsets = PyMem_Malloc(base->ndim * (sizeof *base->suboffsets));
if (base->suboffsets == NULL) {
PyErr_NoMemory();
return NULL;
}
for (i = 0; i < base->ndim; i++)
base->suboffsets[i] = -1;
nd->head->flags &= ~(ND_C|ND_FORTRAN);
Py_RETURN_NONE;
}
/* Test PyMemoryView_FromBuffer(): return a memoryview from a static buffer.
Obviously this is fragile and only one such view may be active at any
time. Never use anything like this in real code! */
static char *infobuf = NULL;
static PyObject *
ndarray_memoryview_from_buffer(PyObject *self, PyObject *dummy)
{
const NDArrayObject *nd = (NDArrayObject *)self;
const Py_buffer *view = &nd->head->base;
const ndbuf_t *ndbuf;
static char format[ND_MAX_NDIM+1];
static Py_ssize_t shape[ND_MAX_NDIM];
static Py_ssize_t strides[ND_MAX_NDIM];
static Py_ssize_t suboffsets[ND_MAX_NDIM];
static Py_buffer info;
char *p;
if (!ND_IS_CONSUMER(nd))
ndbuf = nd->head; /* self is ndarray/original exporter */
else if (NDArray_Check(view->obj) && !ND_IS_CONSUMER(view->obj))
/* self is ndarray and consumer from ndarray/original exporter */
ndbuf = ((NDArrayObject *)view->obj)->head;
else {
PyErr_SetString(PyExc_TypeError,
"memoryview_from_buffer(): ndarray must be original exporter or "
"consumer from ndarray/original exporter");
return NULL;
}
info = *view;
p = PyMem_Realloc(infobuf, ndbuf->len);
if (p == NULL) {
PyMem_Free(infobuf);
PyErr_NoMemory();
infobuf = NULL;
return NULL;
}
else {
infobuf = p;
}
/* copy the complete raw data */
memcpy(infobuf, ndbuf->data, ndbuf->len);
info.buf = infobuf + ((char *)view->buf - ndbuf->data);
if (view->format) {
if (strlen(view->format) > ND_MAX_NDIM) {
PyErr_Format(PyExc_TypeError,
"memoryview_from_buffer: format is limited to %d characters",
ND_MAX_NDIM);
return NULL;
}
strcpy(format, view->format);
info.format = format;
}
if (view->ndim > ND_MAX_NDIM) {
PyErr_Format(PyExc_TypeError,
"memoryview_from_buffer: ndim is limited to %d", ND_MAX_NDIM);
return NULL;
}
if (view->shape) {
memcpy(shape, view->shape, view->ndim * sizeof(Py_ssize_t));
info.shape = shape;
}
if (view->strides) {
memcpy(strides, view->strides, view->ndim * sizeof(Py_ssize_t));
info.strides = strides;
}
if (view->suboffsets) {
memcpy(suboffsets, view->suboffsets, view->ndim * sizeof(Py_ssize_t));
info.suboffsets = suboffsets;
}
return PyMemoryView_FromBuffer(&info);
}
/* Get a single item from bufobj at the location specified by seq.
seq is a list or tuple of indices. The purpose of this function
is to check other functions against PyBuffer_GetPointer(). */
static PyObject *
get_pointer(PyObject *self, PyObject *args)
{
PyObject *ret = NULL, *bufobj, *seq;
Py_buffer view;
Py_ssize_t indices[ND_MAX_NDIM];
Py_ssize_t i;
void *ptr;
if (!PyArg_ParseTuple(args, "OO", &bufobj, &seq)) {
return NULL;
}
CHECK_LIST_OR_TUPLE(seq);
if (PyObject_GetBuffer(bufobj, &view, PyBUF_FULL_RO) < 0)
return NULL;
if (view.ndim > ND_MAX_NDIM) {
PyErr_Format(PyExc_ValueError,
"get_pointer(): ndim > %d", ND_MAX_NDIM);
goto out;
}
if (PySequence_Fast_GET_SIZE(seq) != view.ndim) {
PyErr_SetString(PyExc_ValueError,
"get_pointer(): len(indices) != ndim");
goto out;
}
for (i = 0; i < view.ndim; i++) {
PyObject *x = PySequence_Fast_GET_ITEM(seq, i);
indices[i] = PyLong_AsSsize_t(x);
if (PyErr_Occurred())
goto out;
if (indices[i] < 0 || indices[i] >= view.shape[i]) {
PyErr_Format(PyExc_ValueError,
"get_pointer(): invalid index %zd at position %zd",
indices[i], i);
goto out;
}
}
ptr = PyBuffer_GetPointer(&view, indices);
ret = unpack_single(ptr, view.format, view.itemsize);
out:
PyBuffer_Release(&view);
return ret;
}
static PyObject *
get_sizeof_void_p(PyObject *self, PyObject *Py_UNUSED(ignored))
{
return PyLong_FromSize_t(sizeof(void *));
}
static char
get_ascii_order(PyObject *order)
{
PyObject *ascii_order;
char ord;
if (!PyUnicode_Check(order)) {
PyErr_SetString(PyExc_TypeError,
"order must be a string");
return CHAR_MAX;
}
ascii_order = PyUnicode_AsASCIIString(order);
if (ascii_order == NULL) {
return CHAR_MAX;
}
ord = PyBytes_AS_STRING(ascii_order)[0];
Py_DECREF(ascii_order);
if (ord != 'C' && ord != 'F' && ord != 'A') {
PyErr_SetString(PyExc_ValueError,
"invalid order, must be C, F or A");
return CHAR_MAX;
}
return ord;
}
/* Get a contiguous memoryview. */
static PyObject *
get_contiguous(PyObject *self, PyObject *args)
{
PyObject *obj;
PyObject *buffertype;
PyObject *order;
long type;
char ord;
if (!PyArg_ParseTuple(args, "OOO", &obj, &buffertype, &order)) {
return NULL;
}
if (!PyLong_Check(buffertype)) {
PyErr_SetString(PyExc_TypeError,
"buffertype must be PyBUF_READ or PyBUF_WRITE");
return NULL;
}
type = PyLong_AsLong(buffertype);
if (type == -1 && PyErr_Occurred()) {
return NULL;
}
if (type != PyBUF_READ && type != PyBUF_WRITE) {
PyErr_SetString(PyExc_ValueError,
"invalid buffer type");
return NULL;
}
ord = get_ascii_order(order);
if (ord == CHAR_MAX)
return NULL;
return PyMemoryView_GetContiguous(obj, (int)type, ord);
}
/* PyBuffer_ToContiguous() */
static PyObject *
py_buffer_to_contiguous(PyObject *self, PyObject *args)
{
PyObject *obj;
PyObject *order;
PyObject *ret = NULL;
int flags;
char ord;
Py_buffer view;
char *buf = NULL;
if (!PyArg_ParseTuple(args, "OOi", &obj, &order, &flags)) {
return NULL;
}
if (PyObject_GetBuffer(obj, &view, flags) < 0) {
return NULL;
}
ord = get_ascii_order(order);
if (ord == CHAR_MAX) {
goto out;
}
buf = PyMem_Malloc(view.len);
if (buf == NULL) {
PyErr_NoMemory();
goto out;
}
if (PyBuffer_ToContiguous(buf, &view, view.len, ord) < 0) {
goto out;
}
ret = PyBytes_FromStringAndSize(buf, view.len);
out:
PyBuffer_Release(&view);
PyMem_XFree(buf);
return ret;
}
static int
fmtcmp(const char *fmt1, const char *fmt2)
{
if (fmt1 == NULL) {
return fmt2 == NULL || strcmp(fmt2, "B") == 0;
}
if (fmt2 == NULL) {
return fmt1 == NULL || strcmp(fmt1, "B") == 0;
}
return strcmp(fmt1, fmt2) == 0;
}
static int
arraycmp(const Py_ssize_t *a1, const Py_ssize_t *a2, const Py_ssize_t *shape,
Py_ssize_t ndim)
{
Py_ssize_t i;
for (i = 0; i < ndim; i++) {
if (shape && shape[i] <= 1) {
/* strides can differ if the dimension is less than 2 */
continue;
}
if (a1[i] != a2[i]) {
return 0;
}
}
return 1;
}
/* Compare two contiguous buffers for physical equality. */
static PyObject *
cmp_contig(PyObject *self, PyObject *args)
{
PyObject *b1, *b2; /* buffer objects */
Py_buffer v1, v2;
PyObject *ret;
int equal = 0;
if (!PyArg_ParseTuple(args, "OO", &b1, &b2)) {
return NULL;
}
if (PyObject_GetBuffer(b1, &v1, PyBUF_FULL_RO) < 0) {
PyErr_SetString(PyExc_TypeError,
"cmp_contig: first argument does not implement the buffer "
"protocol");
return NULL;
}
if (PyObject_GetBuffer(b2, &v2, PyBUF_FULL_RO) < 0) {
PyErr_SetString(PyExc_TypeError,
"cmp_contig: second argument does not implement the buffer "
"protocol");
PyBuffer_Release(&v1);
return NULL;
}
if (!(PyBuffer_IsContiguous(&v1, 'C')&&PyBuffer_IsContiguous(&v2, 'C')) &&
!(PyBuffer_IsContiguous(&v1, 'F')&&PyBuffer_IsContiguous(&v2, 'F'))) {
goto result;
}
/* readonly may differ if created from non-contiguous */
if (v1.len != v2.len ||
v1.itemsize != v2.itemsize ||
v1.ndim != v2.ndim ||
!fmtcmp(v1.format, v2.format) ||
!!v1.shape != !!v2.shape ||
!!v1.strides != !!v2.strides ||
!!v1.suboffsets != !!v2.suboffsets) {
goto result;
}
if ((v1.shape && !arraycmp(v1.shape, v2.shape, NULL, v1.ndim)) ||
(v1.strides && !arraycmp(v1.strides, v2.strides, v1.shape, v1.ndim)) ||
(v1.suboffsets && !arraycmp(v1.suboffsets, v2.suboffsets, NULL,
v1.ndim))) {
goto result;
}
if (memcmp((char *)v1.buf, (char *)v2.buf, v1.len) != 0) {
goto result;
}
equal = 1;
result:
PyBuffer_Release(&v1);
PyBuffer_Release(&v2);
ret = equal ? Py_True : Py_False;
return Py_NewRef(ret);
}
static PyObject *
is_contiguous(PyObject *self, PyObject *args)
{
PyObject *obj;
PyObject *order;
PyObject *ret = NULL;
Py_buffer view, *base;
char ord;
if (!PyArg_ParseTuple(args, "OO", &obj, &order)) {
return NULL;
}
ord = get_ascii_order(order);
if (ord == CHAR_MAX) {
return NULL;
}
if (NDArray_Check(obj)) {
/* Skip the buffer protocol to check simple etc. buffers directly. */
base = &((NDArrayObject *)obj)->head->base;
ret = PyBuffer_IsContiguous(base, ord) ? Py_True : Py_False;
}
else {
if (PyObject_GetBuffer(obj, &view, PyBUF_FULL_RO) < 0) {
PyErr_SetString(PyExc_TypeError,
"is_contiguous: object does not implement the buffer "
"protocol");
return NULL;
}
ret = PyBuffer_IsContiguous(&view, ord) ? Py_True : Py_False;
PyBuffer_Release(&view);
}
return Py_NewRef(ret);
}
static Py_hash_t
ndarray_hash(PyObject *self)
{
const NDArrayObject *nd = (NDArrayObject *)self;
const Py_buffer *view = &nd->head->base;
PyObject *bytes;
Py_hash_t hash;
if (!view->readonly) {
PyErr_SetString(PyExc_ValueError,
"cannot hash writable ndarray object");
return -1;
}
if (view->obj != NULL && PyObject_Hash(view->obj) == -1) {
return -1;
}
bytes = ndarray_tobytes(self, NULL);
if (bytes == NULL) {
return -1;
}
hash = PyObject_Hash(bytes);
Py_DECREF(bytes);
return hash;
}
static PyMethodDef ndarray_methods [] =
{
{ "tolist", ndarray_tolist, METH_NOARGS, NULL },
{ "tobytes", ndarray_tobytes, METH_NOARGS, NULL },
{ "push", _PyCFunction_CAST(ndarray_push), METH_VARARGS|METH_KEYWORDS, NULL },
{ "pop", ndarray_pop, METH_NOARGS, NULL },
{ "add_suboffsets", ndarray_add_suboffsets, METH_NOARGS, NULL },
{ "memoryview_from_buffer", ndarray_memoryview_from_buffer, METH_NOARGS, NULL },
{NULL}
};
static PyTypeObject NDArray_Type = {
PyVarObject_HEAD_INIT(NULL, 0)
"ndarray", /* Name of this type */
sizeof(NDArrayObject), /* Basic object size */
0, /* Item size for varobject */
(destructor)ndarray_dealloc, /* tp_dealloc */
0, /* tp_vectorcall_offset */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_as_async */
0, /* tp_repr */
0, /* tp_as_number */
&ndarray_as_sequence, /* tp_as_sequence */
&ndarray_as_mapping, /* tp_as_mapping */
(hashfunc)ndarray_hash, /* tp_hash */
0, /* tp_call */
0, /* tp_str */
PyObject_GenericGetAttr, /* tp_getattro */
0, /* tp_setattro */
&ndarray_as_buffer, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT, /* tp_flags */
0, /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
0, /* tp_richcompare */
0, /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
ndarray_methods, /* tp_methods */
0, /* tp_members */
ndarray_getset, /* tp_getset */
0, /* tp_base */
0, /* tp_dict */
0, /* tp_descr_get */
0, /* tp_descr_set */
0, /* tp_dictoffset */
ndarray_init, /* tp_init */
0, /* tp_alloc */
ndarray_new, /* tp_new */
};
/**************************************************************************/
/* StaticArray Object */
/**************************************************************************/
static PyTypeObject StaticArray_Type;
typedef struct {
PyObject_HEAD
int legacy_mode; /* if true, use the view.obj==NULL hack */
} StaticArrayObject;
static char static_mem[12] = {0,1,2,3,4,5,6,7,8,9,10,11};
static Py_ssize_t static_shape[1] = {12};
static Py_ssize_t static_strides[1] = {1};
static Py_buffer static_buffer = {
static_mem, /* buf */
NULL, /* obj */
12, /* len */
1, /* itemsize */
1, /* readonly */
1, /* ndim */
"B", /* format */
static_shape, /* shape */
static_strides, /* strides */
NULL, /* suboffsets */
NULL /* internal */
};
static PyObject *
staticarray_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
return (PyObject *)PyObject_New(StaticArrayObject, &StaticArray_Type);
}
static int
staticarray_init(PyObject *self, PyObject *args, PyObject *kwds)
{
StaticArrayObject *a = (StaticArrayObject *)self;
static char *kwlist[] = {
"legacy_mode", NULL
};
PyObject *legacy_mode = Py_False;
if (!PyArg_ParseTupleAndKeywords(args, kwds, "|O", kwlist, &legacy_mode))
return -1;
a->legacy_mode = (legacy_mode != Py_False);
return 0;
}
static void
staticarray_dealloc(StaticArrayObject *self)
{
PyObject_Free(self);
}
/* Return a buffer for a PyBUF_FULL_RO request. Flags are not checked,
which makes this object a non-compliant exporter! */
static int
staticarray_getbuf(StaticArrayObject *self, Py_buffer *view, int flags)
{
*view = static_buffer;
if (self->legacy_mode) {
view->obj = NULL; /* Don't use this in new code. */
}
else {
view->obj = Py_NewRef(self);
}
return 0;
}
static PyBufferProcs staticarray_as_buffer = {
(getbufferproc)staticarray_getbuf, /* bf_getbuffer */
NULL, /* bf_releasebuffer */
};
static PyTypeObject StaticArray_Type = {
PyVarObject_HEAD_INIT(NULL, 0)
"staticarray", /* Name of this type */
sizeof(StaticArrayObject), /* Basic object size */
0, /* Item size for varobject */
(destructor)staticarray_dealloc, /* tp_dealloc */
0, /* tp_vectorcall_offset */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_as_async */
0, /* tp_repr */
0, /* tp_as_number */
0, /* tp_as_sequence */
0, /* tp_as_mapping */
0, /* tp_hash */
0, /* tp_call */
0, /* tp_str */
0, /* tp_getattro */
0, /* tp_setattro */
&staticarray_as_buffer, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT, /* tp_flags */
0, /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
0, /* tp_richcompare */
0, /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
0, /* tp_methods */
0, /* tp_members */
0, /* tp_getset */
0, /* tp_base */
0, /* tp_dict */
0, /* tp_descr_get */
0, /* tp_descr_set */
0, /* tp_dictoffset */
staticarray_init, /* tp_init */
0, /* tp_alloc */
staticarray_new, /* tp_new */
};
static struct PyMethodDef _testbuffer_functions[] = {
{"slice_indices", slice_indices, METH_VARARGS, NULL},
{"get_pointer", get_pointer, METH_VARARGS, NULL},
{"get_sizeof_void_p", get_sizeof_void_p, METH_NOARGS, NULL},
{"get_contiguous", get_contiguous, METH_VARARGS, NULL},
{"py_buffer_to_contiguous", py_buffer_to_contiguous, METH_VARARGS, NULL},
{"is_contiguous", is_contiguous, METH_VARARGS, NULL},
{"cmp_contig", cmp_contig, METH_VARARGS, NULL},
{NULL, NULL}
};
static struct PyModuleDef _testbuffermodule = {
PyModuleDef_HEAD_INIT,
"_testbuffer",
NULL,
-1,
_testbuffer_functions,
NULL,
NULL,
NULL,
NULL
};
static int
_testbuffer_exec(PyObject *mod)
{
Py_SET_TYPE(&NDArray_Type, &PyType_Type);
if (PyType_Ready(&NDArray_Type)) {
return -1;
}
if (PyModule_AddType(mod, &NDArray_Type) < 0) {
return -1;
}
Py_SET_TYPE(&StaticArray_Type, &PyType_Type);
if (PyModule_AddType(mod, &StaticArray_Type) < 0) {
return -1;
}
structmodule = PyImport_ImportModule("struct");
if (structmodule == NULL) {
return -1;
}
Struct = PyObject_GetAttrString(structmodule, "Struct");
if (Struct == NULL) {
return -1;
}
calcsize = PyObject_GetAttrString(structmodule, "calcsize");
if (calcsize == NULL) {
return -1;
}
simple_format = PyUnicode_FromString(simple_fmt);
if (simple_format == NULL) {
return -1;
}
#define ADD_INT_MACRO(mod, macro) \
do { \
if (PyModule_AddIntConstant(mod, #macro, macro) < 0) { \
return -1; \
} \
} while (0)
ADD_INT_MACRO(mod, ND_MAX_NDIM);
ADD_INT_MACRO(mod, ND_VAREXPORT);
ADD_INT_MACRO(mod, ND_WRITABLE);
ADD_INT_MACRO(mod, ND_FORTRAN);
ADD_INT_MACRO(mod, ND_SCALAR);
ADD_INT_MACRO(mod, ND_PIL);
ADD_INT_MACRO(mod, ND_GETBUF_FAIL);
ADD_INT_MACRO(mod, ND_GETBUF_UNDEFINED);
ADD_INT_MACRO(mod, ND_REDIRECT);
ADD_INT_MACRO(mod, PyBUF_SIMPLE);
ADD_INT_MACRO(mod, PyBUF_WRITABLE);
ADD_INT_MACRO(mod, PyBUF_FORMAT);
ADD_INT_MACRO(mod, PyBUF_ND);
ADD_INT_MACRO(mod, PyBUF_STRIDES);
ADD_INT_MACRO(mod, PyBUF_INDIRECT);
ADD_INT_MACRO(mod, PyBUF_C_CONTIGUOUS);
ADD_INT_MACRO(mod, PyBUF_F_CONTIGUOUS);
ADD_INT_MACRO(mod, PyBUF_ANY_CONTIGUOUS);
ADD_INT_MACRO(mod, PyBUF_FULL);
ADD_INT_MACRO(mod, PyBUF_FULL_RO);
ADD_INT_MACRO(mod, PyBUF_RECORDS);
ADD_INT_MACRO(mod, PyBUF_RECORDS_RO);
ADD_INT_MACRO(mod, PyBUF_STRIDED);
ADD_INT_MACRO(mod, PyBUF_STRIDED_RO);
ADD_INT_MACRO(mod, PyBUF_CONTIG);
ADD_INT_MACRO(mod, PyBUF_CONTIG_RO);
ADD_INT_MACRO(mod, PyBUF_READ);
ADD_INT_MACRO(mod, PyBUF_WRITE);
#undef ADD_INT_MACRO
return 0;
}
PyMODINIT_FUNC
PyInit__testbuffer(void)
{
PyObject *mod = PyModule_Create(&_testbuffermodule);
if (mod == NULL) {
return NULL;
}
#ifdef Py_GIL_DISABLED
PyUnstable_Module_SetGIL(mod, Py_MOD_GIL_NOT_USED);
#endif
if (_testbuffer_exec(mod) < 0) {
Py_DECREF(mod);
return NULL;
}
return mod;
}
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