mercurial/base85.c
author Pierre-Yves David <pierre-yves.david@ens-lyon.org>
Tue, 02 May 2017 20:01:54 +0200
branchstable
changeset 32102 9a85ea1daf49
parent 27060 4613a89bea42
child 32356 7948adb53e28
permissions -rw-r--r--
color: turn 'ui.color' into a boolean (auto or off) Previously, 'ui.color=yes' meant "always show color", While "ui.color=auto" meant "use color automatically when it appears sensible". This feels problematic to some people because if an administrator has disabled color with "ui.color=off", and a user turn it back on using "color=on", it will get surprised (because it breaks their output when redirected to a file.) This patch changes ui.color=true to only move the default value of --color from "never" to "auto". I'm not really in favor of this changes as I suspect the above case will be pretty rare and I would rather keep the logic simpler. However, I'm providing this patch to help the 4.2 release in the case were others decide to make this changes. Users that want to force colors without specifying --color on the command line can use the 'ui.formatted' config knob, which had to be enabled in a handful of tests for this patch. Nice summary table (credit: Augie Fackler) That is, before this patch: +--------------------+--------------------+--------------------+ | | not a tty | a tty | | | --color not set | --color not set | | | | | +--------------------+--------------------+--------------------+ | [ui] | | | | color (not set) | no color | no color | | | | | +--------------------+--------------------+--------------------+ | [ui] | | | | color = auto | no color | color | | | | | +--------------------+--------------------+--------------------+ | [ui] | | | | color = yes | *color* | color | | | | | +--------------------+--------------------+--------------------+ | [ui] | | | | color = no | no color | no color | | | | | +--------------------+--------------------+--------------------+ (if --color is specified, it always clobbers the setting in [ui]) and after this patch: +--------------------+--------------------+--------------------+ | | not a tty | a tty | | | --color not set | --color not set | | | | | +--------------------+--------------------+--------------------+ | [ui] | | | | color (not set) | no color | no color | | | | | +--------------------+--------------------+--------------------+ | [ui] | | | | color = auto | no color | color | | | | | +--------------------+--------------------+--------------------+ | [ui] | | | | color = yes | *no color* | color | | | | | +--------------------+--------------------+--------------------+ | [ui] | | | | color = no | no color | no color | | | | | +--------------------+--------------------+--------------------+ (if --color is specified, it always clobbers the setting in [ui])

/*
 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
*/

#define PY_SSIZE_T_CLEAN
#include <Python.h>

#include "util.h"

static const char b85chars[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
	"abcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~";
static char b85dec[256];

static void b85prep(void)
{
	unsigned 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;
	Py_ssize_t 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;
	Py_ssize_t len, i, j, olen, cap;
	int c;
	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",
					(int)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",
					(int)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",
					(int)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