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-rw-r--r--src/vppinfra/mhash.c408
1 files changed, 408 insertions, 0 deletions
diff --git a/src/vppinfra/mhash.c b/src/vppinfra/mhash.c
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+/*
+ * Copyright (c) 2015 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/*
+ Copyright (c) 2010 Eliot Dresselhaus
+
+ Permission is hereby granted, free of charge, to any person obtaining
+ a copy of this software and associated documentation files (the
+ "Software"), to deal in the Software without restriction, including
+ without limitation the rights to use, copy, modify, merge, publish,
+ distribute, sublicense, and/or sell copies of the Software, and to
+ permit persons to whom the Software is furnished to do so, subject to
+ the following conditions:
+
+ The above copyright notice and this permission notice shall be
+ included in all copies or substantial portions of the Software.
+
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+
+#include <vppinfra/mhash.h>
+
+always_inline u32
+load_partial_u32 (void *d, uword n)
+{
+ if (n == 4)
+ return ((u32 *) d)[0];
+ if (n == 3)
+ return ((u16 *) d)[0] | (((u8 *) d)[2] << 16);
+ if (n == 2)
+ return ((u16 *) d)[0];
+ if (n == 1)
+ return ((u8 *) d)[0];
+ ASSERT (0);
+ return 0;
+}
+
+always_inline u32
+mhash_key_sum_inline (void *data, uword n_data_bytes, u32 seed)
+{
+ u32 *d32 = data;
+ u32 a, b, c, n_left;
+
+ a = b = c = seed;
+ n_left = n_data_bytes;
+ a ^= n_data_bytes;
+
+ while (n_left > 12)
+ {
+ a += d32[0];
+ b += d32[1];
+ c += d32[2];
+ hash_v3_mix32 (a, b, c);
+ n_left -= 12;
+ d32 += 3;
+ }
+
+ if (n_left > 8)
+ {
+ c += load_partial_u32 (d32 + 2, n_left - 8);
+ n_left = 8;
+ }
+ if (n_left > 4)
+ {
+ b += load_partial_u32 (d32 + 1, n_left - 4);
+ n_left = 4;
+ }
+ if (n_left > 0)
+ a += load_partial_u32 (d32 + 0, n_left - 0);
+
+ hash_v3_finalize32 (a, b, c);
+
+ return c;
+}
+
+#define foreach_mhash_key_size \
+ _ (2) _ (3) _ (4) _ (5) _ (6) _ (7) \
+ _ (8) _ (12) _ (16) _ (20) \
+ _ (24) _ (28) _ (32) _ (36) \
+ _ (40) _ (44) _ (48) _ (52) \
+ _ (56) _ (60) _ (64)
+
+#define _(N_KEY_BYTES) \
+ static uword \
+ mhash_key_sum_##N_KEY_BYTES (hash_t * h, uword key) \
+ { \
+ mhash_t * hv = uword_to_pointer (h->user, mhash_t *); \
+ return mhash_key_sum_inline (mhash_key_to_mem (hv, key), \
+ (N_KEY_BYTES), \
+ hv->hash_seed); \
+ } \
+ \
+ static uword \
+ mhash_key_equal_##N_KEY_BYTES (hash_t * h, uword key1, uword key2) \
+ { \
+ mhash_t * hv = uword_to_pointer (h->user, mhash_t *); \
+ void * k1 = mhash_key_to_mem (hv, key1); \
+ void * k2 = mhash_key_to_mem (hv, key2); \
+ return ! memcmp (k1, k2, (N_KEY_BYTES)); \
+ }
+
+foreach_mhash_key_size
+#undef _
+static uword
+mhash_key_sum_c_string (hash_t * h, uword key)
+{
+ mhash_t *hv = uword_to_pointer (h->user, mhash_t *);
+ void *k = mhash_key_to_mem (hv, key);
+ return mhash_key_sum_inline (k, strlen (k), hv->hash_seed);
+}
+
+static uword
+mhash_key_equal_c_string (hash_t * h, uword key1, uword key2)
+{
+ mhash_t *hv = uword_to_pointer (h->user, mhash_t *);
+ void *k1 = mhash_key_to_mem (hv, key1);
+ void *k2 = mhash_key_to_mem (hv, key2);
+ return strcmp (k1, k2) == 0;
+}
+
+static uword
+mhash_key_sum_vec_string (hash_t * h, uword key)
+{
+ mhash_t *hv = uword_to_pointer (h->user, mhash_t *);
+ void *k = mhash_key_to_mem (hv, key);
+ return mhash_key_sum_inline (k, vec_len (k), hv->hash_seed);
+}
+
+static uword
+mhash_key_equal_vec_string (hash_t * h, uword key1, uword key2)
+{
+ mhash_t *hv = uword_to_pointer (h->user, mhash_t *);
+ void *k1 = mhash_key_to_mem (hv, key1);
+ void *k2 = mhash_key_to_mem (hv, key2);
+ return vec_len (k1) == vec_len (k2) && memcmp (k1, k2, vec_len (k1)) == 0;
+}
+
+/* The CLIB hash user pointer must always point to a valid mhash_t.
+ Now, the address of mhash_t can change (think vec_resize).
+ So we must always be careful that it points to the correct
+ address. */
+always_inline void
+mhash_sanitize_hash_user (mhash_t * mh)
+{
+ uword *hash = mh->hash;
+ hash_t *h = hash_header (hash);
+ h->user = pointer_to_uword (mh);
+}
+
+void
+mhash_init (mhash_t * h, uword n_value_bytes, uword n_key_bytes)
+{
+ static struct
+ {
+ hash_key_sum_function_t *key_sum;
+ hash_key_equal_function_t *key_equal;
+ } t[] =
+ {
+#define _(N_KEY_BYTES) \
+ [N_KEY_BYTES] = { \
+ .key_sum = mhash_key_sum_##N_KEY_BYTES, \
+ .key_equal = mhash_key_equal_##N_KEY_BYTES, \
+ },
+
+ foreach_mhash_key_size
+#undef _
+ [MHASH_C_STRING_KEY] =
+ {
+ .key_sum = mhash_key_sum_c_string,.key_equal = mhash_key_equal_c_string,},
+ [MHASH_VEC_STRING_KEY] =
+ {
+ .key_sum = mhash_key_sum_vec_string,.key_equal =
+ mhash_key_equal_vec_string,},};
+
+ if (mhash_key_vector_is_heap (h))
+ heap_free (h->key_vector_or_heap);
+ else
+ vec_free (h->key_vector_or_heap);
+ vec_free (h->key_vector_free_indices);
+ {
+ int i;
+ for (i = 0; i < vec_len (h->key_tmps); i++)
+ vec_free (h->key_tmps[i]);
+ }
+ vec_free (h->key_tmps);
+ hash_free (h->hash);
+
+ memset (h, 0, sizeof (h[0]));
+ h->n_key_bytes = n_key_bytes;
+
+#if 0
+ if (h->n_key_bytes > 0)
+ {
+ vec_validate (h->key_tmp, h->n_key_bytes - 1);
+ _vec_len (h->key_tmp) = 0;
+ }
+#endif
+
+ ASSERT (n_key_bytes < ARRAY_LEN (t));
+ h->hash = hash_create2 ( /* elts */ 0,
+ /* user */ pointer_to_uword (h),
+ /* value_bytes */ n_value_bytes,
+ t[n_key_bytes].key_sum, t[n_key_bytes].key_equal,
+ /* format pair/arg */
+ 0, 0);
+}
+
+static uword
+mhash_set_tmp_key (mhash_t * h, const void *key)
+{
+ u8 *key_tmp;
+ int my_cpu = os_get_thread_index ();
+
+ vec_validate (h->key_tmps, my_cpu);
+ key_tmp = h->key_tmps[my_cpu];
+
+ vec_reset_length (key_tmp);
+
+ if (mhash_key_vector_is_heap (h))
+ {
+ uword is_c_string = h->n_key_bytes == MHASH_C_STRING_KEY;
+
+ if (is_c_string)
+ vec_add (key_tmp, key, strlen (key) + 1);
+ else
+ vec_add (key_tmp, key, vec_len (key));
+ }
+ else
+ vec_add (key_tmp, key, h->n_key_bytes);
+
+ h->key_tmps[my_cpu] = key_tmp;
+
+ return ~0;
+}
+
+hash_pair_t *
+mhash_get_pair (mhash_t * h, const void *key)
+{
+ uword ikey;
+ mhash_sanitize_hash_user (h);
+ ikey = mhash_set_tmp_key (h, key);
+ return hash_get_pair (h->hash, ikey);
+}
+
+typedef struct
+{
+ u32 heap_handle;
+
+ /* Must conincide with vec_header. */
+ vec_header_t vec;
+} mhash_string_key_t;
+
+uword
+mhash_set_mem (mhash_t * h, void *key, uword * new_value, uword * old_value)
+{
+ u8 *k;
+ uword ikey, i, l = 0, n_key_bytes, old_n_elts, key_alloc_from_free_list = 0;
+
+ mhash_sanitize_hash_user (h);
+
+ if (mhash_key_vector_is_heap (h))
+ {
+ mhash_string_key_t *sk;
+ uword is_c_string = h->n_key_bytes == MHASH_C_STRING_KEY;
+ uword handle;
+
+ n_key_bytes = is_c_string ? (strlen (key) + 1) : vec_len (key);
+ i =
+ heap_alloc (h->key_vector_or_heap, n_key_bytes + sizeof (sk[0]),
+ handle);
+
+ sk = (void *) (h->key_vector_or_heap + i);
+ sk->heap_handle = handle;
+ sk->vec.len = n_key_bytes;
+ clib_memcpy (sk->vec.vector_data, key, n_key_bytes);
+
+ /* Advance key past vector header. */
+ i += sizeof (sk[0]);
+ }
+ else
+ {
+ key_alloc_from_free_list = (l =
+ vec_len (h->key_vector_free_indices)) > 0;
+ if (key_alloc_from_free_list)
+ {
+ i = h->key_vector_free_indices[l - 1];
+ k = vec_elt_at_index (h->key_vector_or_heap, i);
+ _vec_len (h->key_vector_free_indices) = l - 1;
+ }
+ else
+ {
+ vec_add2 (h->key_vector_or_heap, k, h->n_key_bytes);
+ i = k - h->key_vector_or_heap;
+ }
+
+ n_key_bytes = h->n_key_bytes;
+ clib_memcpy (k, key, n_key_bytes);
+ }
+ ikey = i;
+
+ old_n_elts = hash_elts (h->hash);
+ h->hash = _hash_set3 (h->hash, ikey, new_value, old_value);
+
+ /* If element already existed remove duplicate key. */
+ if (hash_elts (h->hash) == old_n_elts)
+ {
+ hash_pair_t *p;
+
+ /* Fetch old key for return value. */
+ p = hash_get_pair (h->hash, ikey);
+ ikey = p->key;
+
+ /* Remove duplicate key. */
+ if (mhash_key_vector_is_heap (h))
+ {
+ mhash_string_key_t *sk;
+ sk = (void *) (h->key_vector_or_heap + i - sizeof (sk[0]));
+ heap_dealloc (h->key_vector_or_heap, sk->heap_handle);
+ }
+ else
+ {
+ if (key_alloc_from_free_list)
+ {
+ h->key_vector_free_indices[l] = i;
+ _vec_len (h->key_vector_free_indices) = l + 1;
+ }
+ else
+ _vec_len (h->key_vector_or_heap) -= h->n_key_bytes;
+ }
+ }
+
+ return ikey;
+}
+
+uword
+mhash_unset (mhash_t * h, void *key, uword * old_value)
+{
+ hash_pair_t *p;
+ uword i;
+
+ mhash_sanitize_hash_user (h);
+ i = mhash_set_tmp_key (h, key);
+
+ p = hash_get_pair (h->hash, i);
+ if (!p)
+ return 0;
+
+ ASSERT (p->key != ~0);
+ i = p->key;
+
+ if (mhash_key_vector_is_heap (h))
+ {
+ mhash_string_key_t *sk;
+ sk = (void *) (h->key_vector_or_heap + i) - sizeof (sk[0]);
+ heap_dealloc (h->key_vector_or_heap, sk->heap_handle);
+ }
+ else
+ vec_add1 (h->key_vector_free_indices, i);
+
+ hash_unset3 (h->hash, i, old_value);
+ return 1;
+}
+
+u8 *
+format_mhash_key (u8 * s, va_list * va)
+{
+ mhash_t *h = va_arg (*va, mhash_t *);
+ u32 ki = va_arg (*va, u32);
+ void *k = mhash_key_to_mem (h, ki);
+
+ if (mhash_key_vector_is_heap (h))
+ {
+ uword is_c_string = h->n_key_bytes == MHASH_C_STRING_KEY;
+ u32 l = is_c_string ? strlen (k) : vec_len (k);
+ vec_add (s, k, l);
+ }
+ else if (h->format_key)
+ s = format (s, "%U", h->format_key, k);
+ else
+ s = format (s, "%U", format_hex_bytes, k, h->n_key_bytes);
+
+ return s;
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */