mirror of
https://gitlab.freedesktop.org/NetworkManager/NetworkManager.git
synced 2025-12-26 13:30:08 +01:00
0e9e35e309
The privious NM_HASH_* macros directly operated on a guint value and were thus close to the actual implementation. Replace them by adding a NMHashState struct and accessors to update the hash state. This hides the implementation better and would allow us to carry more state. For example, we could switch to siphash24() transparently. For now, we still do a form basically djb2 hashing, albeit with differing start seed. Also add nm_hash_str() and nm_str_hash(): - nm_hash_str() is our own string hashing implementation - nm_str_hash() is our own string implementation, but with a GHashFunc signature, suitable to pass it to g_hash_table_new(). Also, it has this name in order to remind you of g_str_hash(), which it is replacing.
128 lines
3.1 KiB
C
128 lines
3.1 KiB
C
/* -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*- */
|
|
/* NetworkManager -- Network link manager
|
|
*
|
|
* This library is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2 of the License, or (at your option) any later version.
|
|
*
|
|
* This library is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with this library; if not, write to the
|
|
* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
|
|
* Boston, MA 02110-1301 USA.
|
|
*
|
|
* (C) Copyright 2017 Red Hat, Inc.
|
|
*/
|
|
|
|
#ifndef __NM_HASH_UTILS_H__
|
|
#define __NM_HASH_UTILS_H__
|
|
|
|
#include <stdint.h>
|
|
|
|
typedef struct {
|
|
guint hash;
|
|
} NMHashState;
|
|
|
|
void nm_hash_init (NMHashState *state, guint static_seed);
|
|
|
|
static inline guint
|
|
nm_hash_complete (NMHashState *state)
|
|
{
|
|
nm_assert (state);
|
|
/* we don't ever want to return a zero hash.
|
|
*
|
|
* NMPObject requires that in _idx_obj_part(), and it's just a good idea. */
|
|
return state->hash ?: 1396707757u;
|
|
}
|
|
|
|
static inline void
|
|
nm_hash_update_uint (NMHashState *state, guint val)
|
|
{
|
|
guint h;
|
|
|
|
nm_assert (state);
|
|
|
|
h = state->hash;
|
|
h = (h << 5) + h + val;
|
|
state->hash = h;
|
|
}
|
|
|
|
static inline void
|
|
nm_hash_update_uint64 (NMHashState *state, guint64 val)
|
|
{
|
|
guint h;
|
|
|
|
nm_assert (state);
|
|
|
|
h = state->hash;
|
|
h = (h << 5) + h + ((guint) val);
|
|
h = (h << 5) + h + ((guint) (val >> 32));
|
|
state->hash = h;
|
|
}
|
|
|
|
static inline void
|
|
nm_hash_update_ptr (NMHashState *state, gconstpointer ptr)
|
|
{
|
|
if (sizeof (ptr) <= sizeof (guint))
|
|
nm_hash_update_uint (state, ((guint) ((uintptr_t) ptr)));
|
|
else
|
|
nm_hash_update_uint64 (state, (guint64) ((uintptr_t) ptr));
|
|
}
|
|
|
|
static inline void
|
|
nm_hash_update_mem (NMHashState *state, const void *ptr, gsize n)
|
|
{
|
|
gsize i;
|
|
guint h;
|
|
|
|
nm_assert (state);
|
|
|
|
/* use the same hash seed as nm_hash_update_str().
|
|
* That way, nm_hash_update_str(&h, s) is identical to
|
|
* nm_hash_update_mem(&h, s, strlen(s)). */
|
|
h = state->hash;
|
|
for (i = 0; i < n; i++)
|
|
h = (h << 5) + h + ((guint) ((const guint8 *) ptr)[i]);
|
|
h = (h << 5) + h + 1774132687u;
|
|
state->hash = h;
|
|
}
|
|
|
|
static inline void
|
|
nm_hash_update_str (NMHashState *state, const char *str)
|
|
{
|
|
const guint8 *p = (const guint8 *) str;
|
|
guint8 c;
|
|
guint h;
|
|
|
|
nm_assert (state);
|
|
|
|
/* Note that NULL hashes differently from "". */
|
|
h = state->hash;
|
|
if (str) {
|
|
while ((c = *p++))
|
|
h = (h << 5) + h + ((guint) c);
|
|
h = (h << 5) + h + 1774132687u;
|
|
} else
|
|
h = (h << 5) + h + 2967906233u;
|
|
state->hash = h;
|
|
}
|
|
|
|
static inline guint
|
|
nm_hash_ptr (gconstpointer ptr)
|
|
{
|
|
if (sizeof (ptr) <= sizeof (guint))
|
|
return (guint) ((uintptr_t) ptr);
|
|
else
|
|
return ((guint) (((uintptr_t) ptr) >> 32)) ^ ((guint) ((uintptr_t) ptr));
|
|
}
|
|
guint nm_direct_hash (gconstpointer str);
|
|
|
|
guint nm_hash_str (const char *str);
|
|
guint nm_str_hash (gconstpointer str);
|
|
|
|
#endif /* __NM_HASH_UTILS_H__ */
|