view mercurial/cext/util.h @ 52167:7346f93be7a4

revlog: add the glue to use the Rust `InnerRevlog` from Python

The performance of this has been looked at for quite some time, and some
workflows are actually quite a bit faster than with the Python + C code.

However, we are still (up to 20%) slower in some crucial places like cloning
certain repos, log, cat, which makes this an incomplete rewrite. This is
mostly due to the high amount of overhead in Python <-> Rust FFI, especially
around the VFS code. A future patch series will rewrite the VFS code in
pure Rust, which should hopefully get us up to par with current perfomance,
if not better in all important cases.

This is a "save state" of sorts, as this is a ton of code, and I don't want
to pile up even more things in a single review.

Continuing to try to match the current performance will take an extremely
long time, if it's not impossible, without the aforementioned VFS work.

/*
 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"

/* clang-format off */
typedef struct {
	PyObject_HEAD
	int flags;
	int mode;
	int size;
	int mtime_s;
	int mtime_ns;
} dirstateItemObject;
/* clang-format on */

static const int dirstate_flag_wc_tracked = 1 << 0;
static const int dirstate_flag_p1_tracked = 1 << 1;
static const int dirstate_flag_p2_info = 1 << 2;
static const int dirstate_flag_mode_exec_perm = 1 << 3;
static const int dirstate_flag_mode_is_symlink = 1 << 4;
static const int dirstate_flag_has_fallback_exec = 1 << 5;
static const int dirstate_flag_fallback_exec = 1 << 6;
static const int dirstate_flag_has_fallback_symlink = 1 << 7;
static const int dirstate_flag_fallback_symlink = 1 << 8;
static const int dirstate_flag_expected_state_is_modified = 1 << 9;
static const int dirstate_flag_has_meaningful_data = 1 << 10;
static const int dirstate_flag_has_mtime = 1 << 11;
static const int dirstate_flag_mtime_second_ambiguous = 1 << 12;
static const int dirstate_flag_directory = 1 << 13;
static const int dirstate_flag_all_unknown_recorded = 1 << 14;
static const int dirstate_flag_all_ignored_recorded = 1 << 15;

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

#ifndef MIN
#define MIN(a, b) (((a) < (b)) ? (a) : (b))
#endif
/* 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 inline PyObject *_dict_new_presized(Py_ssize_t expected_size)
{
	/* _PyDict_NewPresized expects a minused parameter, but it actually
	   creates a dictionary that's the nearest power of two bigger than the
	   parameter. For example, with the initial minused = 1000, the
	   dictionary created has size 1024. Of course in a lot of cases that
	   can be greater than the maximum load factor Python's dict object
	   expects (= 2/3), so as soon as we cross the threshold we'll resize
	   anyway. So create a dictionary that's at least 3/2 the size. */
	return _PyDict_NewPresized(((1 + expected_size) / 2) * 3);
}

/* Convert a PyInt or PyLong to a long. Returns false if there is an
   error, in which case an exception will already have been set. */
static inline bool pylong_to_long(PyObject *pylong, long *out)
{
	*out = PyLong_AsLong(pylong);
	/* Fast path to avoid hitting PyErr_Occurred if the value was obviously
	 * not an error. */
	if (*out != -1) {
		return true;
	}
	return PyErr_Occurred() == NULL;
}

#endif /* _HG_UTIL_H_ */