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/* Copyright (c) 1994 Regents of the University of California */ |
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|
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/* SCCSid "$SunId$ LBL" */ |
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|
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/* |
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* Header file for table lookup routines |
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*/ |
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|
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typedef struct { |
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char *key; /* key name (dynamically allocated) */ |
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char *data; /* pointer to client data */ |
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} LUENT; |
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|
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typedef struct { |
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void (*freek)(); /* free entry key */ |
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void (*freed)(); /* free entry data */ |
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int tsiz; /* current table size */ |
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LUENT *tabl; /* table, if allocated */ |
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int ndel; /* number of deleted entries */ |
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} LUTAB; |
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|
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#define LU_SINIT(fk,fd) {(void (*)())(fk),(void (*)())(fd),0,NULL,0} |
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|
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/* |
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* The lu_init routine is called to initialize a table. The number of |
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* elements passed is not a limiting factor, as a table can grow to |
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* any size permitted by memory. However, access will be more efficient |
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* if this number strikes a reasonable balance between default memory use |
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* and the expected (minimum) table size. The value returned is the |
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* actual allocated table size (or zero if there was insufficient memory). |
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* |
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* It isn't fully necessary to initialize the LUTAB structure. If it |
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* is cleared (tsiz = 0, tabl = NULL), then the first call to lu_find |
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* will allocate a minimal table. If key and data free functions are |
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* to be used, the LU_SINIT macro provides a convenient declaration. |
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* |
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* The lu_find routine returns the entry corresponding to the given |
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* key (any nul-terminated string). If the entry does not exist, the |
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* corresponding key field will be NULL. If the entry has been |
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* previously deleted but not yet freed, then only the data field |
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* will be NULL. It is the caller's responsibility to (allocate and) |
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* assign the key and data fields when creating a new entry. |
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* The only case where lu_find returns NULL is when the system |
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* has run out of memory. |
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* |
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* The lu_delete routine frees an entry's data (if any) by calling |
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* the freed member function, but does not free the key field. This |
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* will be freed later during (or instead of) table reallocation. |
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* |
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* The lu_done routine calls the given free function once for each |
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* assigned table entry (i.e. each entry with an assigned key value). |
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* The user must define these routines to free the key and the data |
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* in the LU_TAB structure. The final action of lu_done is to free the |
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* allocated table itself. |
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*/ |
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|
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#ifdef NOPROTO |
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extern int lu_init(); |
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extern LUENT *lu_find(); |
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extern void lu_delete(); |
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extern void lu_done(); |
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extern int lu_hash(); |
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#else |
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extern int lu_init(LUTAB *, int); |
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extern LUENT *lu_find(LUTAB *, char *); |
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extern void lu_delete(LUTAB *, char *); |
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extern void lu_done(LUTAB *); |
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extern int lu_hash(char *); |
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#endif |
