view mercurial/cext/util.h @ 33289:abd7dedbaa36

sparse: vendor Facebook-developed extension Facebook has developed an extension to enable "sparse" checkouts - a working directory with a subset of files. This feature is a critical component in enabling repositories to scale to infinite number of files while retaining reasonable performance. It's worth noting that sparse checkout is only one possible solution to this problem: another is virtual filesystems that realize files on first access. But given that virtual filesystems may not be accessible to all users, sparse checkout is necessary as a fallback. Per mailing list discussion at https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-March/095868.html we want to add sparse checkout to the Mercurial distribution via roughly the following mechanism: 1. Vendor extension as-is with minimal modifications (this patch) 2. Refactor extension so it is more clearly experimental and inline with Mercurial practices 3. Move code from extension into core where possible 4. Drop experimental labeling and/or move feature into core after sign-off from narrow clone feature owners This commit essentially copies the sparse extension and tests from revision 71e0a2aeca92a4078fe1b8c76e32c88ff1929737 of the https://bitbucket.org/facebook/hg-experimental repository. A list of modifications made as part of vendoring is as follows: * "EXPERIMENTAL" added to module docstring * Imports were changed to match Mercurial style conventions * "testedwith" value was updated to core Mercurial special value and comment boilerplate was inserted * A "clone_sparse" function was renamed to "clonesparse" to appease the style checker * Paths to the sparse extension in tests reflect built-in location * test-sparse-extensions.t was renamed to test-sparse-fsmonitor.t and references to "simplecache" were removed. The test always skips because it isn't trivial to run it given the way we currently run fsmonitor tests * A double empty line was removed from test-sparse-profiles.t There are aspects of the added code that are obviously not ideal. The goal is to make a minimal number of modifications as part of the vendoring to make it easier to track changes from the original implementation. Refactoring will occur in subsequent patches.
author Gregory Szorc <gregory.szorc@gmail.com>
date Sat, 01 Jul 2017 10:43:29 -0700
parents 7640584e697c
children 5866ba5e9c48
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/*
 util.h - utility functions for interfacing with the various python APIs.

 This software may be used and distributed according to the terms of
 the GNU General Public License, incorporated herein by reference.
*/

#ifndef _HG_UTIL_H_
#define _HG_UTIL_H_

#include "compat.h"

#if PY_MAJOR_VERSION >= 3
#define IS_PY3K
#endif

typedef struct {
	PyObject_HEAD
	char state;
	int mode;
	int size;
	int mtime;
} dirstateTupleObject;

extern PyTypeObject dirstateTupleType;
#define dirstate_tuple_check(op) (Py_TYPE(op) == &dirstateTupleType)

/* This should be kept in sync with normcasespecs in encoding.py. */
enum normcase_spec {
	NORMCASE_LOWER = -1,
	NORMCASE_UPPER = 1,
	NORMCASE_OTHER = 0
};

#define MIN(a, b) (((a)<(b))?(a):(b))
/* VC9 doesn't include bool and lacks stdbool.h based on my searching */
#if defined(_MSC_VER) || __STDC_VERSION__ < 199901L
#define true 1
#define false 0
typedef unsigned char bool;
#else
#include <stdbool.h>
#endif

static const int8_t hextable[256] = {
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, -1, -1, -1, -1, -1, -1, /* 0-9 */
	-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* A-F */
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* a-f */
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
};

static inline int hexdigit(const char *p, Py_ssize_t off)
{
	int8_t val = hextable[(unsigned char)p[off]];

	if (val >= 0) {
		return val;
	}

	PyErr_SetString(PyExc_ValueError, "input contains non-hex character");
	return 0;
}

#endif /* _HG_UTIL_H_ */