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173 lines
5.3 KiB
C
173 lines
5.3 KiB
C
/* Format bytes as hexadecimal */
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#include "Python.h"
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#include "pycore_strhex.h" // _Py_strhex_with_sep()
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#include "pycore_unicodeobject.h" // _PyUnicode_CheckConsistency()
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static PyObject *_Py_strhex_impl(const char* argbuf, const Py_ssize_t arglen,
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PyObject* sep, int bytes_per_sep_group,
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const int return_bytes)
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{
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assert(arglen >= 0);
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Py_UCS1 sep_char = 0;
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if (sep) {
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Py_ssize_t seplen = PyObject_Length((PyObject*)sep);
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if (seplen < 0) {
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return NULL;
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}
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if (seplen != 1) {
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PyErr_SetString(PyExc_ValueError, "sep must be length 1.");
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return NULL;
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}
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if (PyUnicode_Check(sep)) {
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if (PyUnicode_KIND(sep) != PyUnicode_1BYTE_KIND) {
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PyErr_SetString(PyExc_ValueError, "sep must be ASCII.");
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return NULL;
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}
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sep_char = PyUnicode_READ_CHAR(sep, 0);
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}
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else if (PyBytes_Check(sep)) {
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sep_char = PyBytes_AS_STRING(sep)[0];
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}
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else {
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PyErr_SetString(PyExc_TypeError, "sep must be str or bytes.");
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return NULL;
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}
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if (sep_char > 127 && !return_bytes) {
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PyErr_SetString(PyExc_ValueError, "sep must be ASCII.");
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return NULL;
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}
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}
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else {
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bytes_per_sep_group = 0;
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}
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unsigned int abs_bytes_per_sep = Py_ABS(bytes_per_sep_group);
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Py_ssize_t resultlen = 0;
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if (bytes_per_sep_group && arglen > 0) {
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/* How many sep characters we'll be inserting. */
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resultlen = (arglen - 1) / abs_bytes_per_sep;
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}
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/* Bounds checking for our Py_ssize_t indices. */
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if (arglen >= PY_SSIZE_T_MAX / 2 - resultlen) {
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return PyErr_NoMemory();
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}
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resultlen += arglen * 2;
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if ((size_t)abs_bytes_per_sep >= (size_t)arglen) {
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bytes_per_sep_group = 0;
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abs_bytes_per_sep = 0;
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}
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PyObject *retval;
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Py_UCS1 *retbuf;
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if (return_bytes) {
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/* If _PyBytes_FromSize() were public we could avoid malloc+copy. */
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retval = PyBytes_FromStringAndSize(NULL, resultlen);
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if (!retval) {
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return NULL;
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}
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retbuf = (Py_UCS1 *)PyBytes_AS_STRING(retval);
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}
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else {
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retval = PyUnicode_New(resultlen, 127);
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if (!retval) {
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return NULL;
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}
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retbuf = PyUnicode_1BYTE_DATA(retval);
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}
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/* Hexlify */
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Py_ssize_t i, j;
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unsigned char c;
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if (bytes_per_sep_group == 0) {
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for (i = j = 0; i < arglen; ++i) {
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assert((j + 1) < resultlen);
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c = argbuf[i];
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retbuf[j++] = Py_hexdigits[c >> 4];
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retbuf[j++] = Py_hexdigits[c & 0x0f];
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}
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assert(j == resultlen);
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}
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else {
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/* The number of complete chunk+sep periods */
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Py_ssize_t chunks = (arglen - 1) / abs_bytes_per_sep;
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Py_ssize_t chunk;
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unsigned int k;
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if (bytes_per_sep_group < 0) {
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i = j = 0;
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for (chunk = 0; chunk < chunks; chunk++) {
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for (k = 0; k < abs_bytes_per_sep; k++) {
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c = argbuf[i++];
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retbuf[j++] = Py_hexdigits[c >> 4];
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retbuf[j++] = Py_hexdigits[c & 0x0f];
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}
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retbuf[j++] = sep_char;
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}
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while (i < arglen) {
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c = argbuf[i++];
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retbuf[j++] = Py_hexdigits[c >> 4];
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retbuf[j++] = Py_hexdigits[c & 0x0f];
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}
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assert(j == resultlen);
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}
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else {
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i = arglen - 1;
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j = resultlen - 1;
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for (chunk = 0; chunk < chunks; chunk++) {
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for (k = 0; k < abs_bytes_per_sep; k++) {
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c = argbuf[i--];
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retbuf[j--] = Py_hexdigits[c & 0x0f];
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retbuf[j--] = Py_hexdigits[c >> 4];
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}
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retbuf[j--] = sep_char;
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}
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while (i >= 0) {
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c = argbuf[i--];
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retbuf[j--] = Py_hexdigits[c & 0x0f];
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retbuf[j--] = Py_hexdigits[c >> 4];
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}
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assert(j == -1);
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}
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}
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#ifdef Py_DEBUG
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if (!return_bytes) {
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assert(_PyUnicode_CheckConsistency(retval, 1));
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}
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#endif
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return retval;
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}
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PyObject * _Py_strhex(const char* argbuf, const Py_ssize_t arglen)
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{
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return _Py_strhex_impl(argbuf, arglen, NULL, 0, 0);
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}
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/* Same as above but returns a bytes() instead of str() to avoid the
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* need to decode the str() when bytes are needed. */
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PyObject* _Py_strhex_bytes(const char* argbuf, const Py_ssize_t arglen)
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{
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return _Py_strhex_impl(argbuf, arglen, NULL, 0, 1);
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}
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/* These variants include support for a separator between every N bytes: */
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PyObject* _Py_strhex_with_sep(const char* argbuf, const Py_ssize_t arglen,
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PyObject* sep, const int bytes_per_group)
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{
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return _Py_strhex_impl(argbuf, arglen, sep, bytes_per_group, 0);
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}
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/* Same as above but returns a bytes() instead of str() to avoid the
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* need to decode the str() when bytes are needed. */
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PyObject* _Py_strhex_bytes_with_sep(const char* argbuf, const Py_ssize_t arglen,
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PyObject* sep, const int bytes_per_group)
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{
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return _Py_strhex_impl(argbuf, arglen, sep, bytes_per_group, 1);
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}
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