cpython/Python/pystrhex.c

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/* bytes to hex implementation */
#include "Python.h"
static PyObject *_Py_strhex_impl(const char* argbuf, const Py_ssize_t arglen,
int return_bytes)
{
PyObject *retval;
Py_UCS1* retbuf;
Py_ssize_t i, j;
assert(arglen >= 0);
if (arglen > PY_SSIZE_T_MAX / 2)
return PyErr_NoMemory();
if (return_bytes) {
/* If _PyBytes_FromSize() were public we could avoid malloc+copy. */
retbuf = (Py_UCS1*) PyMem_Malloc(arglen*2);
if (!retbuf)
return PyErr_NoMemory();
retval = NULL; /* silence a compiler warning, assigned later. */
} else {
retval = PyUnicode_New(arglen*2, 127);
if (!retval)
return NULL;
retbuf = PyUnicode_1BYTE_DATA(retval);
}
/* make hex version of string, taken from shamodule.c */
for (i=j=0; i < arglen; i++) {
unsigned char c;
c = (argbuf[i] >> 4) & 0xf;
retbuf[j++] = Py_hexdigits[c];
c = argbuf[i] & 0xf;
retbuf[j++] = Py_hexdigits[c];
}
if (return_bytes) {
retval = PyBytes_FromStringAndSize((const char *)retbuf, arglen*2);
PyMem_Free(retbuf);
}
#ifdef Py_DEBUG
else {
assert(_PyUnicode_CheckConsistency(retval, 1));
}
#endif
return retval;
}
PyAPI_FUNC(PyObject *) _Py_strhex(const char* argbuf, const Py_ssize_t arglen)
{
return _Py_strhex_impl(argbuf, arglen, 0);
}
/* Same as above but returns a bytes() instead of str() to avoid the
* need to decode the str() when bytes are needed. */
PyAPI_FUNC(PyObject *) _Py_strhex_bytes(const char* argbuf, const Py_ssize_t arglen)
{
return _Py_strhex_impl(argbuf, arglen, 1);
}