cpython/Modules/ucnhash.c

213 lines
5.0 KiB
C

/* unicode character name tables */
/* rewritten for Python 2.1 by Fredrik Lundh (fredrik@pythonware.com) */
#include "Python.h"
#include "ucnhash.h"
/* data file generated by Tools/unicode/makeunicodedata.py */
#include "unicodename_db.h"
/* -------------------------------------------------------------------- */
/* database code (cut and pasted from the unidb package) */
static unsigned long
gethash(const char *s, int len, int scale)
{
int i;
unsigned long h = 0;
unsigned long ix;
for (i = 0; i < len; i++) {
h = (h * scale) + (unsigned char) toupper(s[i]);
ix = h & 0xff000000;
if (ix)
h = (h ^ ((ix>>24) & 0xff)) & 0x00ffffff;
}
return h;
}
static int
getname(Py_UCS4 code, char* buffer, int buflen)
{
int offset;
int i;
int word;
unsigned char* w;
if (code < 0 || code >= 65536)
return 0;
/* get offset into phrasebook */
offset = phrasebook_offset1[(code>>phrasebook_shift)];
offset = phrasebook_offset2[(offset<<phrasebook_shift) +
(code&((1<<phrasebook_shift)-1))];
if (!offset)
return 0;
i = 0;
for (;;) {
/* get word index */
word = phrasebook[offset] - phrasebook_short;
if (word >= 0) {
word = (word << 8) + phrasebook[offset+1];
offset += 2;
} else
word = phrasebook[offset++];
if (i) {
if (i > buflen)
return 0; /* buffer overflow */
buffer[i++] = ' ';
}
/* copy word string from lexicon. the last character in the
word has bit 7 set. the last word in a string ends with
0x80 */
w = lexicon + lexicon_offset[word];
while (*w < 128) {
if (i >= buflen)
return 0; /* buffer overflow */
buffer[i++] = *w++;
}
if (i >= buflen)
return 0; /* buffer overflow */
buffer[i++] = *w & 127;
if (*w == 128)
break; /* end of word */
}
return 1;
}
static int
cmpname(int code, const char* name, int namelen)
{
/* check if code corresponds to the given name */
int i;
char buffer[NAME_MAXLEN];
if (!getname(code, buffer, sizeof(buffer)))
return 0;
for (i = 0; i < namelen; i++) {
if (toupper(name[i]) != buffer[i])
return 0;
}
return buffer[namelen] == '\0';
}
static int
getcode(const char* name, int namelen, Py_UCS4* code)
{
unsigned int h, v;
unsigned int mask = code_size-1;
unsigned int i, incr;
/* the following is the same as python's dictionary lookup, with
only minor changes. see the makeunicodedata script for more
details */
h = (unsigned int) gethash(name, namelen, code_magic);
i = (~h) & mask;
v = code_hash[i];
if (!v)
return 0;
if (cmpname(v, name, namelen)) {
*code = v;
return 1;
}
incr = (h ^ (h >> 3)) & mask;
if (!incr)
incr = mask;
for (;;) {
i = (i + incr) & mask;
v = code_hash[i];
if (!v)
return -1;
if (cmpname(v, name, namelen)) {
*code = v;
return 1;
}
incr = incr << 1;
if (incr > mask)
incr = incr ^ code_poly;
}
}
static const _PyUnicode_Name_CAPI hashAPI =
{
sizeof(_PyUnicode_Name_CAPI),
getname,
getcode
};
/* -------------------------------------------------------------------- */
/* Python bindings */
static PyObject *
ucnhash_getname(PyObject* self, PyObject* args)
{
char name[NAME_MAXLEN];
int code;
if (!PyArg_ParseTuple(args, "i", &code))
return NULL;
if (!getname((Py_UCS4) code, name, sizeof(name))) {
PyErr_SetString(PyExc_ValueError, "undefined character code");
return NULL;
}
return Py_BuildValue("s", name);
}
static PyObject *
ucnhash_getcode(PyObject* self, PyObject* args)
{
Py_UCS4 code;
char* name;
int namelen;
if (!PyArg_ParseTuple(args, "s#", &name, &namelen))
return NULL;
if (!getcode(name, namelen, &code)) {
PyErr_SetString(PyExc_ValueError, "undefined character name");
return NULL;
}
return Py_BuildValue("i", code);
}
static
PyMethodDef ucnhash_methods[] =
{
{"getname", ucnhash_getname, 1},
{"getcode", ucnhash_getcode, 1},
{NULL, NULL},
};
static char *ucnhash_docstring = "ucnhash hash function module";
/* Create PyMethodObjects and register them in the module's dict */
DL_EXPORT(void)
initucnhash(void)
{
PyObject *m, *d, *v;
m = Py_InitModule4(
"ucnhash", /* Module name */
ucnhash_methods, /* Method list */
ucnhash_docstring, /* Module doc-string */
(PyObject *)NULL, /* always pass this as *self */
PYTHON_API_VERSION); /* API Version */
if (!m)
return;
d = PyModule_GetDict(m);
if (!d)
return;
/* Export C API */
v = PyCObject_FromVoidPtr((void *) &hashAPI, NULL);
PyDict_SetItemString(d, "Unicode_Names_CAPI", v);
Py_XDECREF(v);
}