--- ray/src/cv/mgflib/lookup.h	1994/06/25 09:47:57	1.3
+++ ray/src/cv/mgflib/lookup.h	2003/11/15 17:54:06	1.12
@@ -1,25 +1,37 @@
-/* Copyright (c) 1994 Regents of the University of California */
-
-/* SCCSid "$SunId$ LBL" */
-
+/* RCSid $Id: lookup.h,v 1.12 2003/11/15 17:54:06 schorsch Exp $ */
 /*
- * Header file for table lookup routines
+ * 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*);
+
 typedef struct {
-	char	*key;		/* key name (dynamically allocated) */
-	char	*data;		/* pointer to client data */
+	char	*key;			/* key name */
+	unsigned long	hval;		/* key hash value (for efficiency) */
+	char	*data;			/* pointer to client data */
 } LUENT;
 
 typedef struct {
-	void	(*freek)();	/* free entry key */
-	void	(*freed)();	/* free entry data */
-	int	tsiz;		/* current table size */
-	LUENT	*tabl;		/* table, if allocated */
-	int	ndel;		/* number of deleted entries */
+	unsigned long (*hashf)(char*);	/* key hash function */
+	int (*keycmp)(const char*, const char*);	/* 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;
 
-#define LU_SINIT(fk,fd)		{(void (*)())(fk),(void (*)())(fd),0,NULL,0}
+#undef strcmp
+#define LU_SINIT(fk,fd)		{lu_shash,strcmp,fk,\
+				fd,0,NULL,0}
 
 /*
  * The lu_init routine is called to initialize a table.  The number of
@@ -29,24 +41,38 @@ typedef struct {
  * and the expected (minimum) table size.  The value returned is the
  * actual allocated table size (or zero if there was insufficient memory).
  *
- * It isn't fully necessary to initialize the LUTAB structure.  If it
- * is cleared (tsiz = 0, tabl = NULL), then the first call to lu_find
- * will allocate a minimal table.  If key and data free functions are
- * to be used, the LU_SINIT macro provides a convenient declaration.
+ * 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 (any nul-terminated string).  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.
+ * 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
@@ -54,16 +80,16 @@ typedef struct {
  * allocated table itself.
  */
 
-#ifdef NOPROTO
-extern int	lu_init();
-extern LUENT	*lu_find();
-extern void	lu_delete();
-extern void	lu_done();
-extern int	lu_hash();
-#else
-extern int	lu_init(LUTAB *, int);
-extern LUENT	*lu_find(LUTAB *, char *);
-extern void	lu_delete(LUTAB *, char *);
-extern void	lu_done(LUTAB *);
-extern int	lu_hash(char *);
+extern int	lu_init(LUTAB *tbl, int nel);
+extern unsigned long	lu_shash(char *s);
+extern LUENT	*lu_find(LUTAB *tbl, char *key);
+extern void	lu_delete(LUTAB *tbl, char *key);
+extern int	lu_doall(LUTAB *tbl, int (*f)(LUENT*));
+extern void	lu_done(LUTAB *tbl);
+
+
+#ifdef __cplusplus
+}
 #endif
+#endif /* _RAD_LOOKUP_H_ */
+