static PyObject *
struct_calcsize(PyObject *self, PyObject *args)
{
char *fmt;
const formatdef *f;
int size;
if (!PyArg_ParseTuple(args, "s:calcsize", &fmt))
return NULL;
f = whichtable(&fmt);
size = calcsize(fmt, f);
if (size < 0)
return NULL;
return PyInt_FromLong((long)size);
}
static PyObject *
struct_unpack(PyObject *self, PyObject *args)
{
const formatdef *f, *e;
char *str, *start, *fmt, *s;
char c;
int len, size, num;
PyObject *res, *v;
if (!PyArg_ParseTuple(args, "ss#:unpack", &fmt, &start, &len))
return NULL;
f = whichtable(&fmt);
size = calcsize(fmt, f);
if (size < 0)
return NULL;
if (size != len) {
PyErr_SetString(StructError,
"unpack str size does not match format");
return NULL;
}
res = PyList_New(0);
if (res == NULL)
return NULL;
str = start;
s = fmt;
while ((c = *s++) != '\0') {
if (isspace(Py_CHARMASK(c)))
continue;
if ('0' <= c && c <= '9') {
num = c - '0';
while ('0' <= (c = *s++) && c <= '9')
num = num*10 + (c - '0');
if (c == '\0')
break;
}
else
num = 1;
e = getentry(c, f);
if (e == NULL)
goto fail;
str = start + align((int)(str-start), c, e);
if (num == 0 && c != 's')
continue;
do {
if (c == 'x') {
str += num;
break;
}
if (c == 's') {
/* num is string size, not repeat count */
v = PyString_FromStringAndSize(str, num);
if (v == NULL)
goto fail;
str += num;
num = 0;
}
else if (c == 'p') {
/* num is string buffer size,
not repeat count */
int n = *(unsigned char*)str;
/* first byte (unsigned) is string size */
if (n >= num)
n = num-1;
v = PyString_FromStringAndSize(str+1, n);
if (v == NULL)
goto fail;
str += num;
num = 0;
}
else {
v = e->unpack(str, e);
if (v == NULL)
goto fail;
str += e->size;
}
if (v == NULL || PyList_Append(res, v) < 0)
goto fail;
Py_DECREF(v);
} while (--num > 0);
}
v = PyList_AsTuple(res);
Py_DECREF(res);
return v;
fail:
Py_DECREF(res);
return NULL;
}
static PyObject *
struct_pack(PyObject *self, PyObject *args)
{
const formatdef *f, *e;
PyObject *format, *result, *v;
char *fmt;
int size, num;
int i, n;
char *s, *res, *restart, *nres;
char c;
if (args == NULL || !PyTuple_Check(args) ||
(n = PyTuple_Size(args)) < 1)
{
PyErr_SetString(PyExc_TypeError,
"struct.pack requires at least one argument");
return NULL;
}
format = PyTuple_GetItem(args, 0);
fmt = PyString_AsString(format);
if (!fmt)
return NULL;
f = whichtable(&fmt);
size = calcsize(fmt, f);
if (size < 0)
return NULL;
result = PyString_FromStringAndSize((char *)NULL, size);
if (result == NULL)
return NULL;
s = fmt;
i = 1;
res = restart = PyString_AsString(result);
while ((c = *s++) != '\0') {
if (isspace(Py_CHARMASK(c)))
continue;
if ('0' <= c && c <= '9') {
num = c - '0';
while ('0' <= (c = *s++) && c <= '9')
num = num*10 + (c - '0');
if (c == '\0')
break;
}
else
num = 1;
e = getentry(c, f);
if (e == NULL)
goto fail;
nres = restart + align((int)(res-restart), c, e);
/* Fill padd bytes with zeros */
while (res < nres)
*res++ = '\0';
if (num == 0 && c != 's')
continue;
do {
if (c == 'x') {
/* doesn't consume arguments */
memset(res, '\0', num);
res += num;
break;
}
if (i >= n) {
PyErr_SetString(StructError,
"insufficient arguments to pack");
goto fail;
}
v = PyTuple_GetItem(args, i++);
if (v == NULL)
goto fail;
if (c == 's') {
/* num is string size, not repeat count */
int n;
if (!PyString_Check(v)) {
PyErr_SetString(StructError,
"argument for 's' must be a string");
goto fail;
}
n = PyString_Size(v);
if (n > num)
n = num;
if (n > 0)
memcpy(res, PyString_AsString(v), n);
if (n < num)
memset(res+n, '\0', num-n);
res += num;
break;
}
else if (c == 'p') {
/* num is string size + 1,
to fit in the count byte */
int n;
num--; /* now num is max string size */
if (!PyString_Check(v)) {
PyErr_SetString(StructError,
"argument for 'p' must be a string");
goto fail;
}
n = PyString_Size(v);
if (n > num)
n = num;
if (n > 0)
memcpy(res+1, PyString_AsString(v), n);
if (n < num)
/* no real need, just to be nice */
memset(res+1+n, '\0', num-n);
if (n > 255)
n = 255;
*res++ = n; /* store the length byte */
res += num;
break;
}
else {
if (e->pack(res, v, e) < 0)
goto fail;
res += e->size;
}
} while (--num > 0);
}
if (i < n) {
PyErr_SetString(StructError,
"too many arguments for pack format");
goto fail;
}
return result;
fail:
Py_DECREF(result);
return NULL;
}
static int
prepare_s(PyStructObject *self)
{
const formatdef *f;
const formatdef *e;
formatcode *codes;
const char *s;
const char *fmt;
char c;
Py_ssize_t size, len, num, itemsize, x;
fmt = PyBytes_AS_STRING(self->s_format);
f = whichtable((char **)&fmt);
s = fmt;
size = 0;
len = 0;
while ((c = *s++) != '\0') {
if (isspace(Py_CHARMASK(c)))
continue;
if ('0' <= c && c <= '9') {
num = c - '0';
while ('0' <= (c = *s++) && c <= '9') {
x = num*10 + (c - '0');
if (x/10 != num) {
PyErr_SetString(
StructError,
"overflow in item count");
return -1;
}
num = x;
}
if (c == '\0')
break;
}
else
num = 1;
e = getentry(c, f);
if (e == NULL)
return -1;
switch (c) {
case 's': /* fall through */
case 'p': len++; break;
case 'x': break;
default: len += num; break;
}
itemsize = e->size;
size = align(size, c, e);
x = num * itemsize;
size += x;
if (x/itemsize != num || size < 0) {
PyErr_SetString(StructError,
"total struct size too long");
return -1;
}
}
/* check for overflow */
if ((len + 1) > (PY_SSIZE_T_MAX / sizeof(formatcode))) {
PyErr_NoMemory();
return -1;
}
self->s_size = size;
self->s_len = len;
codes = PyMem_MALLOC((len + 1) * sizeof(formatcode));
if (codes == NULL) {
PyErr_NoMemory();
return -1;
}
self->s_codes = codes;
s = fmt;
size = 0;
while ((c = *s++) != '\0') {
if (isspace(Py_CHARMASK(c)))
continue;
if ('0' <= c && c <= '9') {
num = c - '0';
while ('0' <= (c = *s++) && c <= '9')
num = num*10 + (c - '0');
if (c == '\0')
break;
}
else
num = 1;
e = getentry(c, f);
size = align(size, c, e);
if (c == 's' || c == 'p') {
codes->offset = size;
codes->size = num;
codes->fmtdef = e;
codes++;
size += num;
} else if (c == 'x') {
size += num;
} else {
while (--num >= 0) {
codes->offset = size;
codes->size = e->size;
codes->fmtdef = e;
codes++;
size += e->size;
}
}
}
codes->fmtdef = NULL;
codes->offset = size;
codes->size = 0;
return 0;
}
static int
prepare_s(PyStructObject *self)
{
const formatdef *f;
const formatdef *e;
formatcode *codes;
const char *s;
const char *fmt;
char c;
Py_ssize_t size, len, num, itemsize;
fmt = PyBytes_AS_STRING(self->s_format);
f = whichtable((char **)&fmt);
s = fmt;
size = 0;
len = 0;
while ((c = *s++) != '\0') {
if (isspace(Py_CHARMASK(c)))
continue;
if ('0' <= c && c <= '9') {
num = c - '0';
while ('0' <= (c = *s++) && c <= '9') {
/* overflow-safe version of
if (num*10 + (c - '0') > PY_SSIZE_T_MAX) { ... } */
if (num >= PY_SSIZE_T_MAX / 10 && (
num > PY_SSIZE_T_MAX / 10 ||
(c - '0') > PY_SSIZE_T_MAX % 10))
goto overflow;
num = num*10 + (c - '0');
}
if (c == '\0') {
PyErr_SetString(StructError,
"repeat count given without format specifier");
return -1;
}
}
else
num = 1;
e = getentry(c, f);
if (e == NULL)
return -1;
switch (c) {
case 's': /* fall through */
case 'p': len++; break;
case 'x': break;
default: len += num; break;
}
itemsize = e->size;
size = align(size, c, e);
if (size == -1)
goto overflow;
/* if (size + num * itemsize > PY_SSIZE_T_MAX) { ... } */
if (num > (PY_SSIZE_T_MAX - size) / itemsize)
goto overflow;
size += num * itemsize;
}
/* check for overflow */
if ((len + 1) > (PY_SSIZE_T_MAX / sizeof(formatcode))) {
PyErr_NoMemory();
return -1;
}
self->s_size = size;
self->s_len = len;
codes = (formatcode *) PyMem_MALLOC((len + 1) * sizeof(formatcode));
if (codes == NULL) {
PyErr_NoMemory();
return -1;
}
/* Free any s_codes value left over from a previous initialization. */
if (self->s_codes != NULL)
PyMem_FREE(self->s_codes);
self->s_codes = codes;
s = fmt;
size = 0;
while ((c = *s++) != '\0') {
if (isspace(Py_CHARMASK(c)))
continue;
if ('0' <= c && c <= '9') {
num = c - '0';
while ('0' <= (c = *s++) && c <= '9')
num = num*10 + (c - '0');
if (c == '\0')
break;
}
else
num = 1;
e = getentry(c, f);
size = align(size, c, e);
if (c == 's' || c == 'p') {
codes->offset = size;
codes->size = num;
codes->fmtdef = e;
codes++;
size += num;
} else if (c == 'x') {
size += num;
} else {
while (--num >= 0) {
codes->offset = size;
codes->size = e->size;
codes->fmtdef = e;
codes++;
size += e->size;
}
}
}
codes->fmtdef = NULL;
codes->offset = size;
codes->size = 0;
return 0;
overflow:
PyErr_SetString(StructError,
"total struct size too long");
return -1;
}
