src/vppinfra/mhash.c - fdio/vpp - Gitiles

 /*
  * 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);

   clib_memset (h, 0, sizeof (h[0]));
   h->n_key_bytes = n_key_bytes;

   vec_validate (h->key_tmps, os_get_nthreads () - 1);

   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 ();

   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 coincide 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_fast (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_fast (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:
  */
	/*
	* 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);

	clib_memset (h, 0, sizeof (h[0]));
	h->n_key_bytes = n_key_bytes;

	vec_validate (h->key_tmps, os_get_nthreads () - 1);

	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 ();

	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 coincide 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_fast (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_fast (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:
	*/