Mercurial > hg
view mercurial/base85.c @ 16504:e3c7ca15cde2 stable
doc: add note about pattern rooted/unrooted cases to "hgignore" and "patterns"
each help topics describe that patterns are "not rooted" and "rooted"
in themselves, but not describe about each other.
so, this may causes misunderstanding about "rooted"-ness of patterns.
author | FUJIWARA Katsunori <foozy@lares.dti.ne.jp> |
---|---|
date | Mon, 23 Apr 2012 00:38:22 +0900 |
parents | a4e0908ce35b |
children | a8065323c003 |
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/* base85 codec Copyright 2006 Brendan Cully <brendan@kublai.com> This software may be used and distributed according to the terms of the GNU General Public License, incorporated herein by reference. Largely based on git's implementation */ #include <Python.h> #include "util.h" static const char b85chars[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ" "abcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~"; static char b85dec[256]; static void b85prep(void) { int i; memset(b85dec, 0, sizeof(b85dec)); for (i = 0; i < sizeof(b85chars); i++) b85dec[(int)(b85chars[i])] = i + 1; } static PyObject * b85encode(PyObject *self, PyObject *args) { const unsigned char *text; PyObject *out; char *dst; int len, olen, i; unsigned int acc, val, ch; int pad = 0; if (!PyArg_ParseTuple(args, "s#|i", &text, &len, &pad)) return NULL; if (pad) olen = ((len + 3) / 4 * 5) - 3; else { olen = len % 4; if (olen) olen++; olen += len / 4 * 5; } if (!(out = PyBytes_FromStringAndSize(NULL, olen + 3))) return NULL; dst = PyBytes_AsString(out); while (len) { acc = 0; for (i = 24; i >= 0; i -= 8) { ch = *text++; acc |= ch << i; if (--len == 0) break; } for (i = 4; i >= 0; i--) { val = acc % 85; acc /= 85; dst[i] = b85chars[val]; } dst += 5; } if (!pad) _PyBytes_Resize(&out, olen); return out; } static PyObject * b85decode(PyObject *self, PyObject *args) { PyObject *out; const char *text; char *dst; int len, i, j, olen, c, cap; unsigned int acc; if (!PyArg_ParseTuple(args, "s#", &text, &len)) return NULL; olen = len / 5 * 4; i = len % 5; if (i) olen += i - 1; if (!(out = PyBytes_FromStringAndSize(NULL, olen))) return NULL; dst = PyBytes_AsString(out); i = 0; while (i < len) { acc = 0; cap = len - i - 1; if (cap > 4) cap = 4; for (j = 0; j < cap; i++, j++) { c = b85dec[(int)*text++] - 1; if (c < 0) return PyErr_Format( PyExc_ValueError, "Bad base85 character at position %d", i); acc = acc * 85 + c; } if (i++ < len) { c = b85dec[(int)*text++] - 1; if (c < 0) return PyErr_Format( PyExc_ValueError, "Bad base85 character at position %d", i); /* overflow detection: 0xffffffff == "|NsC0", * "|NsC" == 0x03030303 */ if (acc > 0x03030303 || (acc *= 85) > 0xffffffff - c) return PyErr_Format( PyExc_ValueError, "Bad base85 sequence at position %d", i); acc += c; } cap = olen < 4 ? olen : 4; olen -= cap; for (j = 0; j < 4 - cap; j++) acc *= 85; if (cap && cap < 4) acc += 0xffffff >> (cap - 1) * 8; for (j = 0; j < cap; j++) { acc = (acc << 8) | (acc >> 24); *dst++ = acc; } } return out; } static char base85_doc[] = "Base85 Data Encoding"; static PyMethodDef methods[] = { {"b85encode", b85encode, METH_VARARGS, "Encode text in base85.\n\n" "If the second parameter is true, pad the result to a multiple of " "five characters.\n"}, {"b85decode", b85decode, METH_VARARGS, "Decode base85 text.\n"}, {NULL, NULL} }; #ifdef IS_PY3K static struct PyModuleDef base85_module = { PyModuleDef_HEAD_INIT, "base85", base85_doc, -1, methods }; PyMODINIT_FUNC PyInit_base85(void) { b85prep(); return PyModule_Create(&base85_module); } #else PyMODINIT_FUNC initbase85(void) { Py_InitModule3("base85", methods, base85_doc); b85prep(); } #endif