Add the bihash_vec8_8 variant

This is an all-purpose octet-vector memory hash, intended as a
thread-safe replacement for hash_create_mem / hash_create_string.  All
u8 * key vectors are memorized by the hash table.

Change-Id: I22944daea8fda07dde8ba118a6529a6d382491f9
Signed-off-by: Dave Barach <dave@barachs.net>

1 files changed, 123 insertions, 0 deletions

diff --git a/src/vppinfra/bihash_vec8_8.h b/src/vppinfra/bihash_vec8_8.h
new file mode 100644
index 00000000000..cc78f1d51d7
--- /dev/null
+++ b/src/vppinfra/bihash_vec8_8.h
@@ -0,0 +1,123 @@
+/*
+ * Copyright (c) 2017 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.
+ */
+#undef BIHASH_TYPE
+#undef BIHASH_KVP_CACHE_SIZE
+#undef BIHASH_KVP_PER_PAGE
+
+#define BIHASH_TYPE _vec8_8
+#define BIHASH_KVP_PER_PAGE 4
+#define BIHASH_KVP_CACHE_SIZE 0
+
+#ifndef __included_bihash_vec8_8_h__
+#define __included_bihash_vec8_8_h__
+
+#include <vppinfra/heap.h>
+#include <vppinfra/format.h>
+#include <vppinfra/pool.h>
+#include <vppinfra/xxhash.h>
+#include <vppinfra/crc32.h>
+
+/** 8 octet key, 8 octet key value pair */
+typedef struct
+{
+  u64 key;			/**< the key */
+  u64 value;			/**< the value */
+} clib_bihash_kv_vec8_8_t;
+
+/** Decide if a clib_bihash_kv_vec8_8_t instance is free
+    @param v- pointer to the (key,value) pair
+*/
+static inline int
+clib_bihash_is_free_vec8_8 (clib_bihash_kv_vec8_8_t * v)
+{
+  if (v->key == ~0ULL && v->value == ~0ULL)
+    return 1;
+  return 0;
+}
+
+/** Hash a clib_bihash_kv_vec8_8_t instance
+    @param v - pointer to the (key,value) pair, hash the key (only)
+*/
+static inline u64
+clib_bihash_hash_vec8_8 (clib_bihash_kv_vec8_8_t * v)
+{
+  u8 *keyp = (u8 *) (v->key);
+  /* Note: to torture-test linear scan, make this fn return a constant */
+#ifdef clib_crc32c_uses_intrinsics
+  return clib_crc32c (keyp, vec_len (keyp));
+#else
+  {
+    int i, j;
+    u64 sum = 0;
+
+    for (i = 0, j = 0; i < vec_len (keyp); i++)
+      {
+	sum ^= keyp[i] << (j * 8);
+	j++;
+	if (j == 4)
+	  j = 0;
+      }
+
+    return clib_xxhash (sum);
+  }
+#endif
+}
+
+/** Format a clib_bihash_kv_vec8_8_t instance
+    @param s - u8 * vector under construction
+    @param args (vararg) - the (key,value) pair to format
+    @return s - the u8 * vector under construction
+*/
+static inline u8 *
+format_bihash_kvp_vec8_8 (u8 * s, va_list * args)
+{
+  clib_bihash_kv_vec8_8_t *v = va_arg (*args, clib_bihash_kv_vec8_8_t *);
+
+  s = format (s, "key %U value %llu",
+	      format_hex_bytes, v->key, vec_len ((u8 *) (v->key)), v->value);
+  return s;
+}
+
+/** Compare two clib_bihash_kv_vec8_8_t instances
+    @param a - first key
+    @param b - second key
+*/
+static inline int
+clib_bihash_key_compare_vec8_8 (u64 a_arg, u64 b_arg)
+{
+  u8 *a = (u8 *) a_arg;
+  u8 *b = (u8 *) b_arg;
+
+  if (a_arg == ~0ULL || b_arg == ~0ULL)
+    return 0;
+
+  if (vec_len (a) != vec_len (b))
+    return 0;
+
+  return memcmp (a, b, vec_len (a)) == 0;
+}
+
+#undef __included_bihash_template_h__
+#include <vppinfra/bihash_template.h>
+
+#endif /* __included_bihash_vec8_8_h__ */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */