mercurial/base85.c
author Angel Ezquerra <angel.ezquerra@gmail.com>
Sun, 01 Apr 2012 14:12:14 +0200
changeset 16402 1fb2f1400ea8
parent 13302 a4e0908ce35b
child 16522 a8065323c003
permissions -rw-r--r--
revset: add "matching" keyword This keyword can be used to find revisions that "match" one or more fields of a given set of revisions. A revision matches another if all the selected fields (description, author, branch, date, files, phase, parents, substate, user, summary and/or metadata) match the corresponding values of those fields on the source revision. By default this keyword looks for revisions that whose metadata match (description, author and date) making it ideal to look for duplicate revisions. matching takes 2 arguments (the second being optional): 1.- rev: a revset represeting a _single_ revision (e.g. tip, ., p1(.), etc) 2.- [field(s) to match]: an optional string containing the field or fields (separated by spaces) to match. Valid fields are most regular context fields and some special fields: * regular fields: - description, author, branch, date, files, phase, parents, substate, user. Note that author and user are synonyms. * special fields: summary, metadata. - summary: matches the first line of the description. - metatadata: It is equivalent to matching 'description user date' (i.e. it matches the main metadata fields). Examples: 1.- Look for revisions with the same metadata (author, description and date) as the 11th revision: hg log -r "matching(11)" 2.- Look for revisions with the same description as the 11th revision: hg log -r "matching(11, description)" 3.- Look for revisions with the same 'summary' (i.e. same first line on their description) as the 11th revision: hg log -r "matching(11, summary)" 4.- Look for revisions with the same author as the current revision: hg log -r "matching(., author)" You could use 'user' rather than 'author' to get the same result. 5.- Look for revisions with the same description _AND_ author as the tip of the repository: hg log -r "matching(tip, 'author description')" 6.- Look for revisions touching the same files as the parent of the tip of the repository hg log -r "matching(p1(tip), files)" 7.- Look for revisions whose subrepos are on the same state as the tip of the repository or its parent hg log -r "matching(p1(tip):tip, substate)" 8.- Look for revisions whose author and subrepo states both match those of any of the revisions on the stable branch: hg log -r "matching(branch(stable), 'author substate')"

/*
 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