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api: add simple hashtable api

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merge form OpenGroup
https://pubs.opengroup.org/onlinepubs/009696899/functions/hcreate.html

Signed-off-by: guohao15 <guohao15@xiaomi.com>
This commit is contained in:
guohao15 2023-10-08 11:38:07 +08:00 committed by Alan Carvalho de Assis
parent d2d93ba58c
commit 4fd175fd5c
8 changed files with 815 additions and 0 deletions

69
LICENSE

@ -8564,3 +8564,72 @@ 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/search.h
======================
$NetBSD: search.h,v 1.12 1999/02/22 10:34:28 christos Exp $
$FreeBSD: src/include/search.h,v 1.4 2002/03/23 17:24:53 imp Exp $
Written by J.T. Conklin <jtc@netbsd.org>
Public domain.
libs/libc/search/hcreate.c
libs/libc/search/hcreate_r.c
======================
$NetBSD: hcreate.c,v 1.2 2001/02/19 21:26:04 ross Exp $
Copyright (c) 2001 Christopher G. Demetriou
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. The name of the author may not be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
libs/libc/search/hash_func.c
======================
Copyright (c) 1990, 1993
The Regents of the University of California. All rights reserved.
This code is derived from software contributed to Berkeley by
Margo Seltzer.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. Neither the name of the University nor the names of its contributors
may be used to endorse or promote products derived from this software
without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.

162
include/search.h Normal file

@ -0,0 +1,162 @@
/****************************************************************************
* include/search.h
*
* $NetBSD: search.h,v 1.12 1999/02/22 10:34:28 christos Exp $
* $FreeBSD: src/include/search.h,v 1.4 2002/03/23 17:24:53 imp Exp $
*
* Written by J.T. Conklin <jtc@netbsd.org>
* Public domain.
*
****************************************************************************/
#ifndef __INCLUDE_SEARCH_H
#define __INCLUDE_SEARCH_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <sys/types.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Public Type Definitions
****************************************************************************/
typedef struct entry
{
FAR char *key;
FAR void *data;
} ENTRY;
typedef enum
{
FIND,
ENTER
} ACTION;
struct hsearch_data
{
FAR struct internal_head *htable;
size_t htablesize;
};
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
/****************************************************************************
* Name: hcreate
*
* Description:
* The hcreate() function creates a new hashing table with nel elements.
* The hashing table will be used by subsequent calls to hsearch() with
* the same htab argument. The hashing table is initialized with nel
* hashing buckets.
*
* The hcreate_r() function is the reentrant version of hcreate().
*
* Returned Value:
* If successful, hcreate() and hcreate_r() return 1; otherwise, they
* return 0.
*
****************************************************************************/
int hcreate(size_t);
/****************************************************************************
* Name: hdestroy
*
* Description:
* The hdestroy() function destroys the hashing table specified by htab.
* The hashing table is destroyed only if there are no entries in the
* table. The hashing table cannot be used again until hcreate() or
* hcreate_r() is called.
*
* The hdestroy_r() function is the reentrant version of hdestroy().
*
* Returned Value:
* None
*
****************************************************************************/
void hdestroy(void);
/****************************************************************************
* Name: hsearch
*
* Description:
* The hsearch() function searches the hashing table specified by htab
* for an entry with a key matching that of item. If such an entry is
* found, hsearch() returns a pointer to the entry's data object. If
* such an entry is not found, hsearch() creates a new entry using the
* key and data objects specified by item and returns a pointer to the
* new entry's data object.
*
* The hsearch_r() function is the reentrant version of hsearch().
*
* Returned Value:
* If successful, hsearch() and hsearch_r() return a pointer to the data
* object of the matching or newly created entry. Otherwise, they return
* NULL.
*
****************************************************************************/
FAR ENTRY *hsearch(ENTRY, ACTION);
/****************************************************************************
* Name: hcreate_r
*
* Description:
* Create a new hash table.
*
* Input Parameters:
* nel - The number of elements in the hash table.
* htab - The location to return the hash table reference.
*
* Returned Value:
* 1 on success; 0 on failure with errno set appropriately.
*
****************************************************************************/
int hcreate_r(size_t, FAR struct hsearch_data *);
/****************************************************************************
* Name: hdestroy_r
*
* Description:
* Destroy a hash table.
*
* Input Parameters:
* htab - The hash table to be destroyed.
*
* Returned Value:
* None
*
****************************************************************************/
void hdestroy_r(FAR struct hsearch_data *);
/****************************************************************************
* Name: hsearch_r
*
* Description:
* Search a hash table.
*
* Input Parameters:
* item - The search key.
* action - The action to take.
* result - The location to return the search result.
* htab - The hash table to be searched.
*
* Returned Value:
* 1 on success; 0 on failure with errno set appropriately.
*
****************************************************************************/
int hsearch_r(ENTRY, ACTION, FAR ENTRY **, FAR struct hsearch_data *);
#endif /* __INCLUDE_SEARCH_H */

1
libs/libc/Makefile

@ -49,6 +49,7 @@ include pwd/Make.defs
include queue/Make.defs
include regex/Make.defs
include sched/Make.defs
include search/Make.defs
include semaphore/Make.defs
include signal/Make.defs
include spawn/Make.defs

23
libs/libc/search/CMakeLists.txt Normal file

@ -0,0 +1,23 @@
# ##############################################################################
# libs/libc/search/CMakeLists.txt
#
# Licensed to the Apache Software Foundation (ASF) under one or more contributor
# license agreements. See the NOTICE file distributed with this work for
# additional information regarding copyright ownership. The ASF licenses this
# file to you 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.
#
# ##############################################################################
set(SRCS hash_func.c hcreate.c hcreate_r.c)
target_sources(c PRIVATE ${SRCS})

28
libs/libc/search/Make.defs Normal file

@ -0,0 +1,28 @@
############################################################################
# libs/libc/search/Make.defs
#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements. See the NOTICE file distributed with
# this work for additional information regarding copyright ownership. The
# ASF licenses this file to you 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.
#
############################################################################
# Add the search C files to the build
CSRCS += hcreate_r.c hcreate.c hash_func.c
# Add the search directory to the build
DEPPATH += --dep-path search
VPATH += :search

126
libs/libc/search/hash_func.c Normal file

@ -0,0 +1,126 @@
/****************************************************************************
* libs/libc/search/hash_func.c
*
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Margo Seltzer.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <sys/types.h>
#include <stdint.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define HASH4 h = (h << 5) + h + *key++;
/****************************************************************************
* Private Types
****************************************************************************/
static uint32_t hash4(FAR const void *, size_t);
/****************************************************************************
* Public Data
****************************************************************************/
/* Global default hash function */
uint32_t (*g_default_hash)(FAR const void *, size_t) = hash4;
/****************************************************************************
* Public Functions
****************************************************************************/
/* Hash function from Chris Torek. */
static uint32_t hash4(FAR const void *keyarg, size_t len)
{
FAR const u_char *key = keyarg;
uint32_t h = 0;
size_t loop;
if (len > 0)
{
loop = (len + 8 - 1) >> 3;
switch (len & (8 - 1))
{
case 0:
do
{
HASH4;
/* FALLTHROUGH */
case 7:
HASH4;
/* FALLTHROUGH */
case 6:
HASH4;
/* FALLTHROUGH */
case 5:
HASH4;
/* FALLTHROUGH */
case 4:
HASH4;
/* FALLTHROUGH */
case 3:
HASH4;
/* FALLTHROUGH */
case 2:
HASH4;
/* FALLTHROUGH */
case 1:
HASH4;
}
while (--loop);
}
}
return h;
}

140
libs/libc/search/hcreate.c Normal file

@ -0,0 +1,140 @@
/****************************************************************************
* libs/libc/search/hcreate.c
*
* $NetBSD: hcreate.c,v 1.2 2001/02/19 21:26:04 ross Exp $
*
* Copyright (c) 2001 Christopher G. Demetriou
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* <<Id: LICENSE_GC,v 1.1 2001/10/01 23:24:05 cgd Exp>>
*
*
* hcreate() / hsearch() / hdestroy()
*
* SysV/XPG4 hash table functions.
*
* Implementation done based on NetBSD manual page and Solaris manual page,
* plus my own personal experience about how they're supposed to work.
*
* I tried to look at Knuth (as cited by the Solaris manual page), but
* nobody had a copy in the office, so...
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <search.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
static struct hsearch_data g_htab;
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: hcreate
*
* Description:
* The hcreate() function creates a new hashing table with nel elements.
* The hashing table will be used by subsequent calls to hsearch() with
* the same htab argument. The hashing table is initialized with nel
* hashing buckets.
*
* The hcreate_r() function is the reentrant version of hcreate().
*
* Returned Value:
* If successful, hcreate() and hcreate_r() return 1; otherwise, they
* return 0.
*
****************************************************************************/
int hcreate(size_t nel)
{
return hcreate_r(nel, &g_htab);
}
/****************************************************************************
* Name: hdestroy
*
* Description:
* The hdestroy() function destroys the hashing table specified by htab.
* The hashing table is destroyed only if there are no entries in the
* table. The hashing table cannot be used again until hcreate() or
* hcreate_r() is called.
*
* The hdestroy_r() function is the reentrant version of hdestroy().
*
* Returned Value:
* None
*
****************************************************************************/
void hdestroy(void)
{
hdestroy_r(&g_htab);
}
/****************************************************************************
* Name: hsearch
*
* Description:
* The hsearch() function searches the hashing table specified by htab
* for an entry with a key matching that of item. If such an entry is
* found, hsearch() returns a pointer to the entry's data object. If
* such an entry is not found, hsearch() creates a new entry using the
* key and data objects specified by item and returns a pointer to the
* new entry's data object.
*
* The hsearch_r() function is the reentrant version of hsearch().
*
* Returned Value:
* If successful, hsearch() and hsearch_r() return a pointer to the data
* object of the matching or newly created entry. Otherwise, they return
* NULL.
*
****************************************************************************/
FAR ENTRY *hsearch(ENTRY item, ACTION action)
{
FAR ENTRY *retval;
hsearch_r(item, action, &retval, &g_htab);
return retval;
}

266
libs/libc/search/hcreate_r.c Normal file

@ -0,0 +1,266 @@
/****************************************************************************
* libs/libc/search/hcreate_r.c
*
* $NetBSD: hcreate.c,v 1.2 2001/02/19 21:26:04 ross Exp $
*
* Copyright (c) 2001 Christopher G. Demetriou
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* <<Id: LICENSE_GC,v 1.1 2001/10/01 23:24:05 cgd Exp>>
*
* hcreate() / hsearch() / hdestroy()
*
* SysV/XPG4 hash table functions.
*
* Implementation done based on NetBSD manual page and Solaris manual page,
* plus my own personal experience about how they're supposed to work.
*
* I tried to look at Knuth (as cited by the Solaris manual page), but
* nobody had a copy in the office, so...
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <sys/types.h>
#include <sys/queue.h>
#include <errno.h>
#include <search.h>
#include <stdlib.h>
#include <string.h>
#include "libc.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define MIN_BUCKETS_LG2 4
#define MIN_BUCKETS (1 << MIN_BUCKETS_LG2)
#define MAX_BUCKETS_LG2 (sizeof (size_t) * 8 - 1 - 5)
#define MAX_BUCKETS ((size_t)1 << MAX_BUCKETS_LG2)
/****************************************************************************
* Private Types
****************************************************************************/
struct internal_entry
{
SLIST_ENTRY(internal_entry) link;
ENTRY ent;
};
/****************************************************************************
* Public Data
****************************************************************************/
SLIST_HEAD(internal_head, internal_entry);
extern uint32_t (*g_default_hash)(FAR const void *, size_t);
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: hcreate_r
*
* Description:
* Create a new hash table.
*
* Input Parameters:
* nel - The number of elements in the hash table.
* htab - The location to return the hash table reference.
*
* Returned Value:
* 1 on success; 0 on failure with errno set appropriately.
*
****************************************************************************/
int hcreate_r(size_t nel, FAR struct hsearch_data *htab)
{
size_t idx;
unsigned int p2;
/* Make sure this this isn't called when a table already exists. */
if (htab->htable != NULL)
{
_NX_SETERRNO(-EINVAL);
return 0;
}
/* If nel is too small, make it min sized. */
if (nel < MIN_BUCKETS)
{
nel = MIN_BUCKETS;
}
/* If it's too large, cap it. */
if (nel > MAX_BUCKETS)
{
nel = MAX_BUCKETS;
}
/* If it's is not a power of two in size, round up. */
if ((nel & (nel - 1)) != 0)
{
for (p2 = 0; nel != 0; p2++)
{
nel >>= 1;
}
nel = 1 << p2;
}
/* Allocate the table. */
htab->htablesize = nel;
htab->htable = lib_malloc(htab->htablesize * sizeof htab->htable[0]);
if (htab->htable == NULL)
{
_NX_SETERRNO(-ENOMEM);
return 0;
}
/* Initialize it. */
for (idx = 0; idx < htab->htablesize; idx++)
{
SLIST_INIT(&(htab->htable[idx]));
}
return 1;
}
/****************************************************************************
* Name: hdestroy_r
*
* Description:
* Destroy a hash table.
*
* Input Parameters:
* htab - The hash table to be destroyed.
*
* Returned Value:
* None
*
****************************************************************************/
void hdestroy_r(FAR struct hsearch_data *htab)
{
FAR struct internal_entry *ie;
size_t idx;
if (htab->htable == NULL)
{
return;
}
for (idx = 0; idx < htab->htablesize; idx++)
{
while (!SLIST_EMPTY(&(htab->htable[idx])))
{
ie = SLIST_FIRST(&(htab->htable[idx]));
SLIST_REMOVE_HEAD(&(htab->htable[idx]), link);
lib_free(ie->ent.key);
lib_free(ie);
}
}
lib_free(htab->htable);
htab->htable = NULL;
}
/****************************************************************************
* Name: hsearch_r
*
* Description:
* Search for an entry in a hash table.
*
* Input Parameters:
* item - The search key
* action - The action to take if the item is not found
* retval - The location to return the search result
* htab - The hash table to be searched
*
* Returned Value:
* 1 on success; 0 on failure with errno set appropriately.
*
****************************************************************************/
int hsearch_r(ENTRY item, ACTION action, FAR ENTRY **retval,
FAR struct hsearch_data *htab)
{
FAR struct internal_head *head;
FAR struct internal_entry *ie;
uint32_t hashval;
size_t len;
len = strlen(item.key);
hashval = (*g_default_hash)(item.key, len);
head = &(htab->htable[hashval & (htab->htablesize - 1)]);
ie = SLIST_FIRST(head);
while (ie != NULL)
{
if (strcmp(ie->ent.key, item.key) == 0)
{
break;
}
ie = SLIST_NEXT(ie, link);
}
if (ie != NULL)
{
*retval = &ie->ent;
return 1;
}
else if (action == FIND)
{
*retval = NULL;
return 0;
}
ie = lib_malloc(sizeof *ie);
if (ie == NULL)
{
*retval = NULL;
return 0;
}
ie->ent.key = item.key;
ie->ent.data = item.data;
SLIST_INSERT_HEAD(head, ie, link);
*retval = &ie->ent;
return 1;
}