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