mirror of https://github.com/acidanthera/audk.git
581 lines
20 KiB
C
581 lines
20 KiB
C
/* Random objects */
|
|
|
|
/* ------------------------------------------------------------------
|
|
The code in this module was based on a download from:
|
|
http://www.math.keio.ac.jp/~matumoto/MT2002/emt19937ar.html
|
|
|
|
It was modified in 2002 by Raymond Hettinger as follows:
|
|
|
|
* the principal computational lines untouched.
|
|
|
|
* renamed genrand_res53() to random_random() and wrapped
|
|
in python calling/return code.
|
|
|
|
* genrand_int32() and the helper functions, init_genrand()
|
|
and init_by_array(), were declared static, wrapped in
|
|
Python calling/return code. also, their global data
|
|
references were replaced with structure references.
|
|
|
|
* unused functions from the original were deleted.
|
|
new, original C python code was added to implement the
|
|
Random() interface.
|
|
|
|
The following are the verbatim comments from the original code:
|
|
|
|
A C-program for MT19937, with initialization improved 2002/1/26.
|
|
Coded by Takuji Nishimura and Makoto Matsumoto.
|
|
|
|
Before using, initialize the state by using init_genrand(seed)
|
|
or init_by_array(init_key, key_length).
|
|
|
|
Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura,
|
|
All rights reserved.
|
|
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, are permitted provided that the following conditions
|
|
are met:
|
|
|
|
1. Redistributions of source code must retain the above copyright
|
|
notice, this list of conditions and the following disclaimer.
|
|
|
|
2. Redistributions in binary form must reproduce the above copyright
|
|
notice, this list of conditions and the following disclaimer in the
|
|
documentation and/or other materials provided with the distribution.
|
|
|
|
3. The names of its contributors may not be used to endorse or promote
|
|
products derived from this software without specific prior written
|
|
permission.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
|
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
|
|
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
|
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
|
|
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
|
|
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
|
|
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
|
|
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
|
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
|
|
Any feedback is very welcome.
|
|
http://www.math.keio.ac.jp/matumoto/emt.html
|
|
email: matumoto@math.keio.ac.jp
|
|
*/
|
|
|
|
/* ---------------------------------------------------------------*/
|
|
|
|
#include "Python.h"
|
|
#include <time.h> /* for seeding to current time */
|
|
|
|
/* Period parameters -- These are all magic. Don't change. */
|
|
#define N 624
|
|
#define M 397
|
|
#define MATRIX_A 0x9908b0dfUL /* constant vector a */
|
|
#define UPPER_MASK 0x80000000UL /* most significant w-r bits */
|
|
#define LOWER_MASK 0x7fffffffUL /* least significant r bits */
|
|
|
|
typedef struct {
|
|
PyObject_HEAD
|
|
unsigned long state[N];
|
|
int index;
|
|
} RandomObject;
|
|
|
|
static PyTypeObject Random_Type;
|
|
|
|
#define RandomObject_Check(v) (Py_TYPE(v) == &Random_Type)
|
|
|
|
|
|
/* Random methods */
|
|
|
|
|
|
/* generates a random number on [0,0xffffffff]-interval */
|
|
static unsigned long
|
|
genrand_int32(RandomObject *self)
|
|
{
|
|
unsigned long y;
|
|
static unsigned long mag01[2]={0x0UL, MATRIX_A};
|
|
/* mag01[x] = x * MATRIX_A for x=0,1 */
|
|
unsigned long *mt;
|
|
|
|
mt = self->state;
|
|
if (self->index >= N) { /* generate N words at one time */
|
|
int kk;
|
|
|
|
for (kk=0;kk<N-M;kk++) {
|
|
y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK);
|
|
mt[kk] = mt[kk+M] ^ (y >> 1) ^ mag01[y & 0x1UL];
|
|
}
|
|
for (;kk<N-1;kk++) {
|
|
y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK);
|
|
mt[kk] = mt[kk+(M-N)] ^ (y >> 1) ^ mag01[y & 0x1UL];
|
|
}
|
|
y = (mt[N-1]&UPPER_MASK)|(mt[0]&LOWER_MASK);
|
|
mt[N-1] = mt[M-1] ^ (y >> 1) ^ mag01[y & 0x1UL];
|
|
|
|
self->index = 0;
|
|
}
|
|
|
|
y = mt[self->index++];
|
|
y ^= (y >> 11);
|
|
y ^= (y << 7) & 0x9d2c5680UL;
|
|
y ^= (y << 15) & 0xefc60000UL;
|
|
y ^= (y >> 18);
|
|
return y;
|
|
}
|
|
|
|
/* random_random is the function named genrand_res53 in the original code;
|
|
* generates a random number on [0,1) with 53-bit resolution; note that
|
|
* 9007199254740992 == 2**53; I assume they're spelling "/2**53" as
|
|
* multiply-by-reciprocal in the (likely vain) hope that the compiler will
|
|
* optimize the division away at compile-time. 67108864 is 2**26. In
|
|
* effect, a contains 27 random bits shifted left 26, and b fills in the
|
|
* lower 26 bits of the 53-bit numerator.
|
|
* The orginal code credited Isaku Wada for this algorithm, 2002/01/09.
|
|
*/
|
|
static PyObject *
|
|
random_random(RandomObject *self)
|
|
{
|
|
unsigned long a=genrand_int32(self)>>5, b=genrand_int32(self)>>6;
|
|
return PyFloat_FromDouble((a*67108864.0+b)*(1.0/9007199254740992.0));
|
|
}
|
|
|
|
/* initializes mt[N] with a seed */
|
|
static void
|
|
init_genrand(RandomObject *self, unsigned long s)
|
|
{
|
|
int mti;
|
|
unsigned long *mt;
|
|
|
|
mt = self->state;
|
|
mt[0]= s & 0xffffffffUL;
|
|
for (mti=1; mti<N; mti++) {
|
|
mt[mti] =
|
|
(1812433253UL * (mt[mti-1] ^ (mt[mti-1] >> 30)) + mti);
|
|
/* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */
|
|
/* In the previous versions, MSBs of the seed affect */
|
|
/* only MSBs of the array mt[]. */
|
|
/* 2002/01/09 modified by Makoto Matsumoto */
|
|
mt[mti] &= 0xffffffffUL;
|
|
/* for >32 bit machines */
|
|
}
|
|
self->index = mti;
|
|
return;
|
|
}
|
|
|
|
/* initialize by an array with array-length */
|
|
/* init_key is the array for initializing keys */
|
|
/* key_length is its length */
|
|
static PyObject *
|
|
init_by_array(RandomObject *self, unsigned long init_key[], unsigned long key_length)
|
|
{
|
|
unsigned int i, j, k; /* was signed in the original code. RDH 12/16/2002 */
|
|
unsigned long *mt;
|
|
|
|
mt = self->state;
|
|
init_genrand(self, 19650218UL);
|
|
i=1; j=0;
|
|
k = (N>key_length ? N : key_length);
|
|
for (; k; k--) {
|
|
mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1664525UL))
|
|
+ init_key[j] + j; /* non linear */
|
|
mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */
|
|
i++; j++;
|
|
if (i>=N) { mt[0] = mt[N-1]; i=1; }
|
|
if (j>=key_length) j=0;
|
|
}
|
|
for (k=N-1; k; k--) {
|
|
mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1566083941UL))
|
|
- i; /* non linear */
|
|
mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */
|
|
i++;
|
|
if (i>=N) { mt[0] = mt[N-1]; i=1; }
|
|
}
|
|
|
|
mt[0] = 0x80000000UL; /* MSB is 1; assuring non-zero initial array */
|
|
Py_INCREF(Py_None);
|
|
return Py_None;
|
|
}
|
|
|
|
/*
|
|
* The rest is Python-specific code, neither part of, nor derived from, the
|
|
* Twister download.
|
|
*/
|
|
|
|
static PyObject *
|
|
random_seed(RandomObject *self, PyObject *args)
|
|
{
|
|
PyObject *result = NULL; /* guilty until proved innocent */
|
|
PyObject *masklower = NULL;
|
|
PyObject *thirtytwo = NULL;
|
|
PyObject *n = NULL;
|
|
unsigned long *key = NULL;
|
|
unsigned long keymax; /* # of allocated slots in key */
|
|
unsigned long keyused; /* # of used slots in key */
|
|
int err;
|
|
|
|
PyObject *arg = NULL;
|
|
|
|
if (!PyArg_UnpackTuple(args, "seed", 0, 1, &arg))
|
|
return NULL;
|
|
|
|
if (arg == NULL || arg == Py_None) {
|
|
time_t now;
|
|
|
|
time(&now);
|
|
init_genrand(self, (unsigned long)now);
|
|
Py_INCREF(Py_None);
|
|
return Py_None;
|
|
}
|
|
/* If the arg is an int or long, use its absolute value; else use
|
|
* the absolute value of its hash code.
|
|
*/
|
|
if (PyInt_Check(arg) || PyLong_Check(arg))
|
|
n = PyNumber_Absolute(arg);
|
|
else {
|
|
long hash = PyObject_Hash(arg);
|
|
if (hash == -1)
|
|
goto Done;
|
|
n = PyLong_FromUnsignedLong((unsigned long)hash);
|
|
}
|
|
if (n == NULL)
|
|
goto Done;
|
|
|
|
/* Now split n into 32-bit chunks, from the right. Each piece is
|
|
* stored into key, which has a capacity of keymax chunks, of which
|
|
* keyused are filled. Alas, the repeated shifting makes this a
|
|
* quadratic-time algorithm; we'd really like to use
|
|
* _PyLong_AsByteArray here, but then we'd have to break into the
|
|
* long representation to figure out how big an array was needed
|
|
* in advance.
|
|
*/
|
|
keymax = 8; /* arbitrary; grows later if needed */
|
|
keyused = 0;
|
|
key = (unsigned long *)PyMem_Malloc(keymax * sizeof(*key));
|
|
if (key == NULL)
|
|
goto Done;
|
|
|
|
masklower = PyLong_FromUnsignedLong(0xffffffffU);
|
|
if (masklower == NULL)
|
|
goto Done;
|
|
thirtytwo = PyInt_FromLong(32L);
|
|
if (thirtytwo == NULL)
|
|
goto Done;
|
|
while ((err=PyObject_IsTrue(n))) {
|
|
PyObject *newn;
|
|
PyObject *pychunk;
|
|
unsigned long chunk;
|
|
|
|
if (err == -1)
|
|
goto Done;
|
|
pychunk = PyNumber_And(n, masklower);
|
|
if (pychunk == NULL)
|
|
goto Done;
|
|
chunk = PyLong_AsUnsignedLong(pychunk);
|
|
Py_DECREF(pychunk);
|
|
if (chunk == (unsigned long)-1 && PyErr_Occurred())
|
|
goto Done;
|
|
newn = PyNumber_Rshift(n, thirtytwo);
|
|
if (newn == NULL)
|
|
goto Done;
|
|
Py_DECREF(n);
|
|
n = newn;
|
|
if (keyused >= keymax) {
|
|
unsigned long bigger = keymax << 1;
|
|
if ((bigger >> 1) != keymax) {
|
|
PyErr_NoMemory();
|
|
goto Done;
|
|
}
|
|
key = (unsigned long *)PyMem_Realloc(key,
|
|
bigger * sizeof(*key));
|
|
if (key == NULL)
|
|
goto Done;
|
|
keymax = bigger;
|
|
}
|
|
assert(keyused < keymax);
|
|
key[keyused++] = chunk;
|
|
}
|
|
|
|
if (keyused == 0)
|
|
key[keyused++] = 0UL;
|
|
result = init_by_array(self, key, keyused);
|
|
Done:
|
|
Py_XDECREF(masklower);
|
|
Py_XDECREF(thirtytwo);
|
|
Py_XDECREF(n);
|
|
PyMem_Free(key);
|
|
return result;
|
|
}
|
|
|
|
static PyObject *
|
|
random_getstate(RandomObject *self)
|
|
{
|
|
PyObject *state;
|
|
PyObject *element;
|
|
int i;
|
|
|
|
state = PyTuple_New(N+1);
|
|
if (state == NULL)
|
|
return NULL;
|
|
for (i=0; i<N ; i++) {
|
|
element = PyLong_FromUnsignedLong(self->state[i]);
|
|
if (element == NULL)
|
|
goto Fail;
|
|
PyTuple_SET_ITEM(state, i, element);
|
|
}
|
|
element = PyLong_FromLong((long)(self->index));
|
|
if (element == NULL)
|
|
goto Fail;
|
|
PyTuple_SET_ITEM(state, i, element);
|
|
return state;
|
|
|
|
Fail:
|
|
Py_DECREF(state);
|
|
return NULL;
|
|
}
|
|
|
|
static PyObject *
|
|
random_setstate(RandomObject *self, PyObject *state)
|
|
{
|
|
int i;
|
|
unsigned long element;
|
|
long index;
|
|
|
|
if (!PyTuple_Check(state)) {
|
|
PyErr_SetString(PyExc_TypeError,
|
|
"state vector must be a tuple");
|
|
return NULL;
|
|
}
|
|
if (PyTuple_Size(state) != N+1) {
|
|
PyErr_SetString(PyExc_ValueError,
|
|
"state vector is the wrong size");
|
|
return NULL;
|
|
}
|
|
|
|
for (i=0; i<N ; i++) {
|
|
element = PyLong_AsUnsignedLong(PyTuple_GET_ITEM(state, i));
|
|
if (element == (unsigned long)-1 && PyErr_Occurred())
|
|
return NULL;
|
|
self->state[i] = element & 0xffffffffUL; /* Make sure we get sane state */
|
|
}
|
|
|
|
index = PyLong_AsLong(PyTuple_GET_ITEM(state, i));
|
|
if (index == -1 && PyErr_Occurred())
|
|
return NULL;
|
|
self->index = (int)index;
|
|
|
|
Py_INCREF(Py_None);
|
|
return Py_None;
|
|
}
|
|
|
|
/*
|
|
Jumpahead should be a fast way advance the generator n-steps ahead, but
|
|
lacking a formula for that, the next best is to use n and the existing
|
|
state to create a new state far away from the original.
|
|
|
|
The generator uses constant spaced additive feedback, so shuffling the
|
|
state elements ought to produce a state which would not be encountered
|
|
(in the near term) by calls to random(). Shuffling is normally
|
|
implemented by swapping the ith element with another element ranging
|
|
from 0 to i inclusive. That allows the element to have the possibility
|
|
of not being moved. Since the goal is to produce a new, different
|
|
state, the swap element is ranged from 0 to i-1 inclusive. This assures
|
|
that each element gets moved at least once.
|
|
|
|
To make sure that consecutive calls to jumpahead(n) produce different
|
|
states (even in the rare case of involutory shuffles), i+1 is added to
|
|
each element at position i. Successive calls are then guaranteed to
|
|
have changing (growing) values as well as shuffled positions.
|
|
|
|
Finally, the self->index value is set to N so that the generator itself
|
|
kicks in on the next call to random(). This assures that all results
|
|
have been through the generator and do not just reflect alterations to
|
|
the underlying state.
|
|
*/
|
|
|
|
static PyObject *
|
|
random_jumpahead(RandomObject *self, PyObject *n)
|
|
{
|
|
long i, j;
|
|
PyObject *iobj;
|
|
PyObject *remobj;
|
|
unsigned long *mt, tmp;
|
|
|
|
if (!PyInt_Check(n) && !PyLong_Check(n)) {
|
|
PyErr_Format(PyExc_TypeError, "jumpahead requires an "
|
|
"integer, not '%s'",
|
|
Py_TYPE(n)->tp_name);
|
|
return NULL;
|
|
}
|
|
|
|
mt = self->state;
|
|
for (i = N-1; i > 1; i--) {
|
|
iobj = PyInt_FromLong(i);
|
|
if (iobj == NULL)
|
|
return NULL;
|
|
remobj = PyNumber_Remainder(n, iobj);
|
|
Py_DECREF(iobj);
|
|
if (remobj == NULL)
|
|
return NULL;
|
|
j = PyInt_AsLong(remobj);
|
|
Py_DECREF(remobj);
|
|
if (j == -1L && PyErr_Occurred())
|
|
return NULL;
|
|
tmp = mt[i];
|
|
mt[i] = mt[j];
|
|
mt[j] = tmp;
|
|
}
|
|
|
|
for (i = 0; i < N; i++)
|
|
mt[i] += i+1;
|
|
|
|
self->index = N;
|
|
Py_INCREF(Py_None);
|
|
return Py_None;
|
|
}
|
|
|
|
static PyObject *
|
|
random_getrandbits(RandomObject *self, PyObject *args)
|
|
{
|
|
int k, i, bytes;
|
|
unsigned long r;
|
|
unsigned char *bytearray;
|
|
PyObject *result;
|
|
|
|
if (!PyArg_ParseTuple(args, "i:getrandbits", &k))
|
|
return NULL;
|
|
|
|
if (k <= 0) {
|
|
PyErr_SetString(PyExc_ValueError,
|
|
"number of bits must be greater than zero");
|
|
return NULL;
|
|
}
|
|
|
|
bytes = ((k - 1) / 32 + 1) * 4;
|
|
bytearray = (unsigned char *)PyMem_Malloc(bytes);
|
|
if (bytearray == NULL) {
|
|
PyErr_NoMemory();
|
|
return NULL;
|
|
}
|
|
|
|
/* Fill-out whole words, byte-by-byte to avoid endianness issues */
|
|
for (i=0 ; i<bytes ; i+=4, k-=32) {
|
|
r = genrand_int32(self);
|
|
if (k < 32)
|
|
r >>= (32 - k);
|
|
bytearray[i+0] = (unsigned char)r;
|
|
bytearray[i+1] = (unsigned char)(r >> 8);
|
|
bytearray[i+2] = (unsigned char)(r >> 16);
|
|
bytearray[i+3] = (unsigned char)(r >> 24);
|
|
}
|
|
|
|
/* little endian order to match bytearray assignment order */
|
|
result = _PyLong_FromByteArray(bytearray, bytes, 1, 0);
|
|
PyMem_Free(bytearray);
|
|
return result;
|
|
}
|
|
|
|
static PyObject *
|
|
random_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
|
|
{
|
|
RandomObject *self;
|
|
PyObject *tmp;
|
|
|
|
if (type == &Random_Type && !_PyArg_NoKeywords("Random()", kwds))
|
|
return NULL;
|
|
|
|
self = (RandomObject *)type->tp_alloc(type, 0);
|
|
if (self == NULL)
|
|
return NULL;
|
|
tmp = random_seed(self, args);
|
|
if (tmp == NULL) {
|
|
Py_DECREF(self);
|
|
return NULL;
|
|
}
|
|
Py_DECREF(tmp);
|
|
return (PyObject *)self;
|
|
}
|
|
|
|
static PyMethodDef random_methods[] = {
|
|
{"random", (PyCFunction)random_random, METH_NOARGS,
|
|
PyDoc_STR("random() -> x in the interval [0, 1).")},
|
|
{"seed", (PyCFunction)random_seed, METH_VARARGS,
|
|
PyDoc_STR("seed([n]) -> None. Defaults to current time.")},
|
|
{"getstate", (PyCFunction)random_getstate, METH_NOARGS,
|
|
PyDoc_STR("getstate() -> tuple containing the current state.")},
|
|
{"setstate", (PyCFunction)random_setstate, METH_O,
|
|
PyDoc_STR("setstate(state) -> None. Restores generator state.")},
|
|
{"jumpahead", (PyCFunction)random_jumpahead, METH_O,
|
|
PyDoc_STR("jumpahead(int) -> None. Create new state from "
|
|
"existing state and integer.")},
|
|
{"getrandbits", (PyCFunction)random_getrandbits, METH_VARARGS,
|
|
PyDoc_STR("getrandbits(k) -> x. Generates a long int with "
|
|
"k random bits.")},
|
|
{NULL, NULL} /* sentinel */
|
|
};
|
|
|
|
PyDoc_STRVAR(random_doc,
|
|
"Random() -> create a random number generator with its own internal state.");
|
|
|
|
static PyTypeObject Random_Type = {
|
|
PyVarObject_HEAD_INIT(NULL, 0)
|
|
"_random.Random", /*tp_name*/
|
|
sizeof(RandomObject), /*tp_basicsize*/
|
|
0, /*tp_itemsize*/
|
|
/* methods */
|
|
0, /*tp_dealloc*/
|
|
0, /*tp_print*/
|
|
0, /*tp_getattr*/
|
|
0, /*tp_setattr*/
|
|
0, /*tp_compare*/
|
|
0, /*tp_repr*/
|
|
0, /*tp_as_number*/
|
|
0, /*tp_as_sequence*/
|
|
0, /*tp_as_mapping*/
|
|
0, /*tp_hash*/
|
|
0, /*tp_call*/
|
|
0, /*tp_str*/
|
|
PyObject_GenericGetAttr, /*tp_getattro*/
|
|
0, /*tp_setattro*/
|
|
0, /*tp_as_buffer*/
|
|
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/
|
|
random_doc, /*tp_doc*/
|
|
0, /*tp_traverse*/
|
|
0, /*tp_clear*/
|
|
0, /*tp_richcompare*/
|
|
0, /*tp_weaklistoffset*/
|
|
0, /*tp_iter*/
|
|
0, /*tp_iternext*/
|
|
random_methods, /*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*/
|
|
0, /*tp_init*/
|
|
0, /*tp_alloc*/
|
|
random_new, /*tp_new*/
|
|
_PyObject_Del, /*tp_free*/
|
|
0, /*tp_is_gc*/
|
|
};
|
|
|
|
PyDoc_STRVAR(module_doc,
|
|
"Module implements the Mersenne Twister random number generator.");
|
|
|
|
PyMODINIT_FUNC
|
|
init_random(void)
|
|
{
|
|
PyObject *m;
|
|
|
|
if (PyType_Ready(&Random_Type) < 0)
|
|
return;
|
|
m = Py_InitModule3("_random", NULL, module_doc);
|
|
if (m == NULL)
|
|
return;
|
|
Py_INCREF(&Random_Type);
|
|
PyModule_AddObject(m, "Random", (PyObject *)&Random_Type);
|
|
}
|