src/common/lookup.h

/* RCSid $Id: lookup.h,v 2.12 2004/03/28 20:33:12 schorsch Exp $ */
/*
 * Header file for general associative table lookup routines
 */
#ifndef _RAD_LOOKUP_H_
#define _RAD_LOOKUP_H_

#include <string.h> /* strcmp() */

#ifdef __cplusplus
extern "C" {
#endif

typedef void lut_free_t(void *p);
typedef unsigned long lut_hashf_t(void*);
typedef int lut_keycmpf_t(const void*, const void*);

typedef struct {
        char    *key;                   /* key name */
        unsigned long   hval;           /* key hash value (for efficiency) */
        char    *data;                  /* pointer to client data */
} LUENT;

typedef struct {
        lut_hashf_t *hashf;     /* key hash function */
        lut_keycmpf_t *keycmp;  /* key comparison function */
        lut_free_t *freek;              /* free a key */
        lut_free_t *freed;              /* free the data */
        int     tsiz;                   /* current table size */
        LUENT   *tabl;                  /* table, if allocated */
        int     ndel;                   /* number of deleted entries */
} LUTAB;


/*
 * The lu_init routine is called to initialize a table.  The number of
 * elements passed is not a limiting factor, as a table can grow to
 * any size permitted by memory.  However, access will be more efficient
 * if this number strikes a reasonable balance between default memory use
 * and the expected (minimum) table size.  The value returned is the
 * actual allocated table size (or zero if there was insufficient memory).
 *
 * The hashf, keycmp, freek and freed member functions must be assigned
 * separately.  If the hash value is sufficient to guarantee equality
 * between keys, then the keycmp pointer may be NULL.  Otherwise, it
 * should return 0 if the two passed keys match.  If it is not necessary
 * (or possible) to free the key and/or data values, then the freek and/or
 * freed member functions may be NULL.
 *
 * It isn't fully necessary to call lu_init to initialize the LUTAB structure.
 * If tsiz is 0, then the first call to lu_find will allocate a minimal table.
 * The LU_SINIT macro provides a convenient static declaration for character
 * string keys.
 *
 * The lu_find routine returns the entry corresponding to the given
 * key.  If the entry does not exist, the corresponding key field will
 * be NULL.  If the entry has been previously deleted but not yet freed,
 * then only the data field will be NULL.  It is the caller's
 * responsibility to (allocate and) assign the key and data fields when
 * creating a new entry.  The only case where lu_find returns NULL is when
 * the system has run out of memory.
 *
 * The lu_delete routine frees an entry's data (if any) by calling
 * the freed member function, but does not free the key field.  This
 * will be freed later during (or instead of) table reallocation.
 * It is therefore an error to reuse or do anything with the key
 * field after calling lu_delete.
 *
 * The lu_doall routine loops through every filled table entry, calling
 * the given function once on each entry.  If a NULL pointer is passed
 * for this function, then lu_doall simply returns the total number of
 * active entries.  Otherwise, it returns the sum of all the function
 * evaluations.
 *
 * The lu_done routine calls the given free function once for each
 * assigned table entry (i.e. each entry with an assigned key value).
 * The user must define these routines to free the key and the data
 * in the LU_TAB structure.  The final action of lu_done is to free the
 * allocated table itself.
 */

typedef int lut_doallf_t(LUENT *e, void *p);

extern lut_keycmpf_t lu_strcmp;
extern int      lu_init(LUTAB *tbl, int nel);
extern unsigned long    lu_shash(void *s);
extern LUENT    *lu_find(LUTAB *tbl, char *key);
extern void     lu_delete(LUTAB *tbl, char *key);
extern int      lu_doall(LUTAB *tbl, lut_doallf_t *f, void *p);
extern void     lu_done(LUTAB *tbl);

#define LU_SINIT(fk,fd) {lu_shash,lu_strcmp,fk,fd,0,NULL,0}

#ifdef __cplusplus
}
#endif
#endif /* _RAD_LOOKUP_H_ */

Revision:	2.13
Committed:	Tue May 25 06:30:46 2004 UTC (19 years, 11 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.12:	+3 -3 lines
Log Message:	Added argument for client data to lu_doall()
#	User	Rev	Content
1	greg	2.13	/* RCSid $Id: lookup.h,v 2.12 2004/03/28 20:33:12 schorsch Exp $ */
2	greg	2.1	/*
3			* Header file for general associative table lookup routines
4			*/
5	schorsch	2.8	#ifndef _RAD_LOOKUP_H_
6			#define _RAD_LOOKUP_H_
7	schorsch	2.10
8			#include <string.h> /* strcmp() */
9
10	schorsch	2.8	#ifdef __cplusplus
11			extern "C" {
12			#endif
13	greg	2.6
14	schorsch	2.12	typedef void lut_free_t(void *p);
15			typedef unsigned long lut_hashf_t(void*);
16			typedef int lut_keycmpf_t(const void, const void);
17	schorsch	2.11
18	greg	2.1	typedef struct {
19	gwlarson	2.5	char key; / key name */
20			unsigned long hval; /* key hash value (for efficiency) */
21			char data; / pointer to client data */
22	greg	2.1	} LUENT;
23
24			typedef struct {
25	schorsch	2.12	lut_hashf_t hashf; / key hash function */
26			lut_keycmpf_t keycmp; / key comparison function */
27	schorsch	2.11	lut_free_t freek; / free a key */
28			lut_free_t freed; / free the data */
29	gwlarson	2.5	int tsiz; /* current table size */
30			LUENT tabl; / table, if allocated */
31			int ndel; /* number of deleted entries */
32	greg	2.1	} LUTAB;
33
34
35			/*
36			* The lu_init routine is called to initialize a table. The number of
37			* elements passed is not a limiting factor, as a table can grow to
38			* any size permitted by memory. However, access will be more efficient
39			* if this number strikes a reasonable balance between default memory use
40			* and the expected (minimum) table size. The value returned is the
41			* actual allocated table size (or zero if there was insufficient memory).
42			*
43			* The hashf, keycmp, freek and freed member functions must be assigned
44			* separately. If the hash value is sufficient to guarantee equality
45			* between keys, then the keycmp pointer may be NULL. Otherwise, it
46			* should return 0 if the two passed keys match. If it is not necessary
47			* (or possible) to free the key and/or data values, then the freek and/or
48			* freed member functions may be NULL.
49			*
50			* It isn't fully necessary to call lu_init to initialize the LUTAB structure.
51			* If tsiz is 0, then the first call to lu_find will allocate a minimal table.
52			* The LU_SINIT macro provides a convenient static declaration for character
53			* string keys.
54			*
55			* The lu_find routine returns the entry corresponding to the given
56			* key. If the entry does not exist, the corresponding key field will
57			* be NULL. If the entry has been previously deleted but not yet freed,
58			* then only the data field will be NULL. It is the caller's
59			* responsibility to (allocate and) assign the key and data fields when
60			* creating a new entry. The only case where lu_find returns NULL is when
61			* the system has run out of memory.
62			*
63			* The lu_delete routine frees an entry's data (if any) by calling
64			* the freed member function, but does not free the key field. This
65			* will be freed later during (or instead of) table reallocation.
66	greg	2.2	* It is therefore an error to reuse or do anything with the key
67			* field after calling lu_delete.
68	greg	2.1	*
69	gwlarson	2.4	* The lu_doall routine loops through every filled table entry, calling
70			* the given function once on each entry. If a NULL pointer is passed
71			* for this function, then lu_doall simply returns the total number of
72			* active entries. Otherwise, it returns the sum of all the function
73			* evaluations.
74			*
75	greg	2.1	* The lu_done routine calls the given free function once for each
76			* assigned table entry (i.e. each entry with an assigned key value).
77			* The user must define these routines to free the key and the data
78			* in the LU_TAB structure. The final action of lu_done is to free the
79			* allocated table itself.
80			*/
81	greg	2.6
82	greg	2.13	typedef int lut_doallf_t(LUENT e, void p);
83	schorsch	2.12
84			extern lut_keycmpf_t lu_strcmp;
85	greg	2.6	extern int lu_init(LUTAB *tbl, int nel);
86	schorsch	2.12	extern unsigned long lu_shash(void *s);
87	greg	2.6	extern LUENT lu_find(LUTAB tbl, char *key);
88			extern void lu_delete(LUTAB tbl, char key);
89	greg	2.13	extern int lu_doall(LUTAB tbl, lut_doallf_t f, void *p);
90	greg	2.6	extern void lu_done(LUTAB *tbl);
91
92	schorsch	2.12	#define LU_SINIT(fk,fd) {lu_shash,lu_strcmp,fk,fd,0,NULL,0}
93	schorsch	2.8
94			#ifdef __cplusplus
95			}
96	greg	2.6	#endif
97	schorsch	2.8	#endif /* _RAD_LOOKUP_H_ */
98