ef52122469
shared/nm-utils/nm-hash-utils.c:110:3: error: right shift count >= width of type [-Werror]
h = h ^ ((guint) (((uintptr_t) ptr) >> 32)) ^ ((guint) ((uintptr_t) ptr));
^
Even if the branch is not reached on 32-bit architectures, the
compiler still emits a warning for the 32-bit right shift.
Fixes: ee76b0979f
120 lines
2.8 KiB
C
120 lines
2.8 KiB
C
/* -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*- */
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/* NetworkManager -- Network link manager
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
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* Boston, MA 02110-1301 USA.
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*
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* (C) Copyright 2017 Red Hat, Inc.
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*/
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#include "nm-default.h"
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#include "nm-hash-utils.h"
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#include <stdint.h>
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#include "nm-shared-utils.h"
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#include "nm-random-utils.h"
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/*****************************************************************************/
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#define HASH_KEY_SIZE 16u
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#define HASH_KEY_SIZE_GUINT ((HASH_KEY_SIZE + sizeof (guint) - 1) / sizeof (guint))
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G_STATIC_ASSERT (sizeof (guint) * HASH_KEY_SIZE_GUINT >= HASH_KEY_SIZE);
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static const guint8 *
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_get_hash_key (void)
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{
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static const guint8 *volatile global_seed = NULL;
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const guint8 *g;
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g = global_seed;
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if (G_UNLIKELY (g == NULL)) {
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/* the returned hash is aligned to guin64, hence, it is save
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* to use it as guint* or guint64* pointer. */
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static union {
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guint8 v8[HASH_KEY_SIZE];
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} g_arr _nm_alignas (guint64);
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static gsize g_lock;
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if (g_once_init_enter (&g_lock)) {
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nm_utils_random_bytes (g_arr.v8, sizeof (g_arr.v8));
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g_atomic_pointer_compare_and_exchange (&global_seed, NULL, g_arr.v8);
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g = g_arr.v8;
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g_once_init_leave (&g_lock, 1);
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} else {
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g = global_seed;
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nm_assert (g);
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}
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}
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return g;
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}
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void
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nm_hash_init (NMHashState *state, guint static_seed)
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{
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const guint8 *g;
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guint seed[HASH_KEY_SIZE_GUINT];
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nm_assert (state);
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g = _get_hash_key ();
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memcpy (seed, g, HASH_KEY_SIZE);
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seed[0] ^= static_seed;
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siphash24_init (&state->_state, (const guint8 *) seed);
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}
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guint
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nm_hash_str (const char *str)
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{
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NMHashState h;
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if (str) {
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nm_hash_init (&h, 1867854211u);
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nm_hash_update_str (&h, str);
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} else
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nm_hash_init (&h, 842995561u);
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return nm_hash_complete (&h);
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}
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guint
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nm_str_hash (gconstpointer str)
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{
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return nm_hash_str (str);
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}
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guint
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nm_hash_ptr (gconstpointer ptr)
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{
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guint h;
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h = ((const guint *) _get_hash_key ())[0];
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if (sizeof (ptr) <= sizeof (guint))
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h = h ^ ((guint) ((uintptr_t) ptr));
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else
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h = h ^ ((guint) (((guint64) (uintptr_t) ptr) >> 32)) ^ ((guint) ((uintptr_t) ptr));
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return h ?: 2907677551u;
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}
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guint
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nm_direct_hash (gconstpointer ptr)
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{
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return nm_hash_ptr (ptr);
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}
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