annotate mercurial/cext/util.h @ 48250:1730b2fceaa1

dirstate-v2: adds a flag to mark a file as modified

Right now, a files with a file system state that requires a lookup (same size,
different mtime) will requires a lookup. If the result of that lookup is a
modified files, it will remains ambiguous, requiring a lookup on the next status
run too.

To fix this, we introduce a dedicated flag in the new format. Such flag will
allow to record such file as "known modified" avoiding an extra lookup later.

As None of the associate code currently exist in the status code, we do the
minimal implementation: if we read a dirstate entry with this flag set, we make
it as "ambiguous" so that the next status code has to look it up. The same as it
would have to without this flag existing anyway.

Differential Revision: https://phab.mercurial-scm.org/D11681

/*
 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

/* helper to switch things like string literal depending on Python version */
#ifdef IS_PY3K
#define PY23(py2, py3) py3
#else
#define PY23(py2, py3) py2
#endif

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

static const int dirstate_flag_wc_tracked = 1;
static const int dirstate_flag_p1_tracked = 1 << 1;
static const int dirstate_flag_p2_info = 1 << 2;
static const int dirstate_flag_has_meaningful_data = 1 << 3;
static const int dirstate_flag_has_file_mtime = 1 << 4;
static const int dirstate_flag_has_directory_mtime = 1 << 5;
static const int dirstate_flag_mode_exec_perm = 1 << 6;
static const int dirstate_flag_mode_is_symlink = 1 << 7;
static const int dirstate_flag_expected_state_is_modified = 1 << 8;

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_ */