beremiz

use pregenerated CRC32 lookup tables for retain on Win32 and GNU/Linux

2019-01-06, Andrey Skvortsov
68f4f2d4516b
use pregenerated CRC32 lookup tables for retain on Win32 and GNU/Linux

This code could be possible reused on low-end targets with limited RAM.

code to generate lookup table:
[---------------------------------------------------------------------]

/* CRC lookup table and initial state. */
uint32_t crc32_table[256];

/* Generate CRC32 lookup table. */
void GenerateCRC32Table(void)
{
unsigned int i, j;
/* Use CRC-32-IEEE 802.3 polynomial 0x04C11DB7 (bit reflected). */
uint32_t poly = 0xEDB88320;

for (i = 0; i <= 0xFF; i++)
{
uint32_t c = i;
for (j = 0 ; j < 8 ; j++)
c = (c & 1) ? (c >> 1 ) ^ poly : (c >> 1);
crc32_table[i] = c;
}
}

void main(void)
{
GenerateCRC32Table();
int j=0;
for(int i=0; i<256; i++) {
printf("0x%08X, ", crc32_table[i]);
if (++j >= 8) {
j = 0;
printf("\n");
}
}
}
[---------------------------------------------------------------------]
from __future__ import absolute_import
import sys
import gluon.contrib.simplejson as simplejson
class JSONRPCServiceBase(object):
def __init__(self):
self.methods = {}
def response(self, id, result):
return simplejson.dumps({'version': '1.1', 'id': id,
'result': result, 'error': None})
def error(self, id, code, message):
return simplejson.dumps({
'id': id,
'version': '1.1',
'error': {'name': 'JSONRPCError',
'code': code,
'message': message}
})
def add_method(self, name, method):
self.methods[name] = method
def process(self, data):
data = simplejson.loads(data)
id, method, params = data["id"], data["method"], data["params"]
if method in self.methods:
try:
result = self.methods[method](*params)
return self.response(id, result)
except Exception:
etype, eval, _etb = sys.exc_info()
return self.error(id, 100, 'Exception %s: %s' % (etype, eval))
except BaseException:
etype, eval, _etb = sys.exc_info()
return self.error(id, 100, '%s: %s' % (etype.__name__, eval))
else:
return self.error(id, 100, 'method "%s" does not exist' % method)
def listmethods(self):
return self.methods.keys()