993 lines
30 KiB
C
993 lines
30 KiB
C
/* hash.c - hash table lookup strings -
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Copyright (C) 1987, 1990, 1991, 1992 Free Software Foundation, Inc.
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This file is part of GAS, the GNU Assembler.
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GAS is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GAS is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GAS; see the file COPYING. If not, write to
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the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
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/*
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* BUGS, GRIPES, APOLOGIA etc.
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*
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* A typical user doesn't need ALL this: I intend to make a library out
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* of it one day - Dean Elsner.
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* Also, I want to change the definition of a symbol to (address,length)
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* so I can put arbitrary binary in the names stored. [see hsh.c for that]
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*
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* This slime is common coupled inside the module. Com-coupling (and other
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* vandalism) was done to speed running time. The interfaces at the
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* module's edges are adequately clean.
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*
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* There is no way to (a) run a test script through this heap and (b)
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* compare results with previous scripts, to see if we have broken any
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* code. Use GNU (f)utilities to do this. A few commands assist test.
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* The testing is awkward: it tries to be both batch & interactive.
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* For now, interactive rules!
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*/
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/*
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* The idea is to implement a symbol table. A test jig is here.
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* Symbols are arbitrary strings; they can't contain '\0'.
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* [See hsh.c for a more general symbol flavour.]
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* Each symbol is associated with a char*, which can point to anything
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* you want, allowing an arbitrary property list for each symbol.
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*
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* The basic operations are:
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*
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* new creates symbol table, returns handle
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* find (symbol) returns char*
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* insert (symbol,char*) error if symbol already in table
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* delete (symbol) returns char* if symbol was in table
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* apply so you can delete all symbols before die()
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* die destroy symbol table (free up memory)
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*
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* Supplementary functions include:
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*
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* say how big? what % full?
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* replace (symbol,newval) report previous value
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* jam (symbol,value) assert symbol:=value
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*
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* You, the caller, have control over errors: this just reports them.
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*
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* This package requires malloc(), free().
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* Malloc(size) returns NULL or address of char[size].
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* Free(address) frees same.
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*/
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/*
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* The code and its structures are re-enterent.
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* Before you do anything else, you must call hash_new() which will
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* return the address of a hash-table-control-block (or NULL if there
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* is not enough memory). You then use this address as a handle of the
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* symbol table by passing it to all the other hash_...() functions.
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* The only approved way to recover the memory used by the symbol table
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* is to call hash_die() with the handle of the symbol table.
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*
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* Before you call hash_die() you normally delete anything pointed to
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* by individual symbols. After hash_die() you can't use that symbol
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* table again.
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*
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* The char* you associate with a symbol may not be NULL (0) because
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* NULL is returned whenever a symbol is not in the table. Any other
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* value is OK, except DELETED, #defined below.
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*
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* When you supply a symbol string for insertion, YOU MUST PRESERVE THE
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* STRING until that symbol is deleted from the table. The reason is that
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* only the address you supply, NOT the symbol string itself, is stored
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* in the symbol table.
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*
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* You may delete and add symbols arbitrarily.
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* Any or all symbols may have the same 'value' (char *). In fact, these
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* routines don't do anything with your symbol values.
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*
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* You have no right to know where the symbol:char* mapping is stored,
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* because it moves around in memory; also because we may change how it
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* works and we don't want to break your code do we? However the handle
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* (address of struct hash_control) is never changed in
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* the life of the symbol table.
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*
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* What you CAN find out about a symbol table is:
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* how many slots are in the hash table?
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* how many slots are filled with symbols?
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* (total hashes,collisions) for (reads,writes) (*)
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* All of the above values vary in time.
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* (*) some of these numbers will not be meaningful if we change the
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* internals.
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*/
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/*
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* I N T E R N A L
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*
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* Hash table is an array of hash_entries; each entry is a pointer to a
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* a string and a user-supplied value 1 char* wide.
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*
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* The array always has 2 ** n elements, n>0, n integer.
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* There is also a 'wall' entry after the array, which is always empty
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* and acts as a sentinel to stop running off the end of the array.
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* When the array gets too full, we create a new array twice as large
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* and re-hash the symbols into the new array, then forget the old array.
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* (Of course, we copy the values into the new array before we junk the
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* old array!)
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*
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*/
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#ifndef lint
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static char rcsid[] = "$Id$";
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#endif
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#include <stdio.h>
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#ifndef FALSE
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#define FALSE (0)
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#define TRUE (!FALSE)
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#endif /* no FALSE yet */
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#include <ctype.h>
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#define min(a, b) ((a) < (b) ? (a) : (b))
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#include "as.h"
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#define error as_fatal
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#define DELETED ((char *)1) /* guarenteed invalid address */
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#define START_POWER (11) /* power of two: size of new hash table *//* JF was 6 */
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/* JF These next two aren't used any more. */
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/* #define START_SIZE (64) / * 2 ** START_POWER */
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/* #define START_FULL (32) / * number of entries before table expands */
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#define islive(ptr) (ptr->hash_string && ptr->hash_string != DELETED)
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/* above TRUE if a symbol is in entry @ ptr */
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#define STAT_SIZE (0) /* number of slots in hash table */
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/* the wall does not count here */
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/* we expect this is always a power of 2 */
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#define STAT_ACCESS (1) /* number of hash_ask()s */
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#define STAT__READ (0) /* reading */
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#define STAT__WRITE (1) /* writing */
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#define STAT_COLLIDE (3) /* number of collisions (total) */
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/* this may exceed STAT_ACCESS if we have */
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/* lots of collisions/access */
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#define STAT_USED (5) /* slots used right now */
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#define STATLENGTH (6) /* size of statistics block */
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#if STATLENGTH != HASH_STATLENGTH
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Panic! Please make #include "stat.h" agree with previous definitions!
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#endif
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/* #define SUSPECT to do runtime checks */
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/* #define TEST to be a test jig for hash...() */
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#ifdef TEST /* TEST: use smaller hash table */
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#undef START_POWER
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#define START_POWER (3)
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#undef START_SIZE
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#define START_SIZE (8)
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#undef START_FULL
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#define START_FULL (4)
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#endif
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/*------------------ plan ---------------------------------- i = internal
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struct hash_control * c;
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struct hash_entry * e; i
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int b[z]; buffer for statistics
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z size of b
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char * s; symbol string (address) [ key ]
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char * v; value string (address) [datum]
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boolean f; TRUE if we found s in hash table i
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char * t; error string; "" means OK
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int a; access type [0...n) i
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c=hash_new () create new hash_control
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hash_die (c) destroy hash_control (and hash table)
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table should be empty.
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doesn't check if table is empty.
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c has no meaning after this.
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hash_say (c,b,z) report statistics of hash_control.
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also report number of available statistics.
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v=hash_delete (c,s) delete symbol, return old value if any.
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ask() NULL means no old value.
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f
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v=hash_replace (c,s,v) replace old value of s with v.
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ask() NULL means no old value: no table change.
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f
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t=hash_insert (c,s,v) insert (s,v) in c.
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ask() return error string.
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f it is an error to insert if s is already
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in table.
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if any error, c is unchanged.
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t=hash_jam (c,s,v) assert that new value of s will be v. i
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ask() it may decide to GROW the table. i
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f i
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grow() i
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t=hash_grow (c) grow the hash table. i
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jam() will invoke JAM. i
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?=hash_apply (c,y) apply y() to every symbol in c.
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y evtries visited in 'unspecified' order.
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v=hash_find (c,s) return value of s, or NULL if s not in c.
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ask()
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f
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f,e=hash_ask() (c,s,a) return slot where s SHOULD live. i
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code() maintain collision stats in c. i
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.=hash_code (c,s) compute hash-code for s, i
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from parameters of c. i
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*/
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static char hash_found; /* returned by hash_ask() to stop extra */
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/* testing. hash_ask() wants to return both */
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/* a slot and a status. This is the status. */
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/* TRUE: found symbol */
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/* FALSE: absent: empty or deleted slot */
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/* Also returned by hash_jam(). */
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/* TRUE: we replaced a value */
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/* FALSE: we inserted a value */
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static struct hash_entry * hash_ask();
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static int hash_code ();
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static char * hash_grow();
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/*
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* h a s h _ n e w ( )
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*
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*/
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struct hash_control *
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hash_new() /* create a new hash table */
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/* return NULL if failed */
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/* return handle (address of struct hash) */
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{
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register struct hash_control * retval;
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register struct hash_entry * room; /* points to hash table */
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register struct hash_entry * wall;
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register struct hash_entry * entry;
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register int * ip; /* scan stats block of struct hash_control */
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register int * nd; /* limit of stats block */
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if (( room = (struct hash_entry *) malloc( sizeof(struct
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hash_entry)*((1<<START_POWER) + 1) ) ) != NULL)
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/* +1 for the wall entry */
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{
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if (( retval = (struct hash_control *) malloc(sizeof(struct
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hash_control)) ) != NULL)
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{
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nd = retval->hash_stat + STATLENGTH;
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for (ip=retval->hash_stat; ip<nd; ip++)
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{
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*ip = 0;
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}
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retval->hash_stat[STAT_SIZE] = 1<<START_POWER;
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retval->hash_mask = (1<<START_POWER) - 1;
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retval->hash_sizelog = START_POWER;
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/* works for 1's compl ok */
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retval->hash_where = room;
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retval->hash_wall =
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wall = room + (1<<START_POWER);
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retval->hash_full = (1<<START_POWER)/2;
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for (entry=room; entry <= wall; entry++)
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{
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entry->hash_string = NULL;
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}
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}
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}
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else
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{
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retval = NULL; /* no room for table: fake a failure */
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}
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return(retval); /* return NULL or set-up structs */
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}
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/*
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* h a s h _ d i e ( )
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*
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* Table should be empty, but this is not checked.
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* To empty the table, try hash_apply()ing a symbol deleter.
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* Return to free memory both the hash table and it's control
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* block.
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* 'handle' has no meaning after this function.
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* No errors are recoverable.
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*/
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void
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hash_die(handle)
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struct hash_control * handle;
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{
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free((char *)handle->hash_where);
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free((char *)handle);
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}
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/*
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* h a s h _ s a y ( )
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*
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* Return the size of the statistics table, and as many statistics as
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* we can until either (a) we have run out of statistics or (b) caller
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* has run out of buffer.
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* NOTE: hash_say treats all statistics alike.
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* These numbers may change with time, due to insertions, deletions
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* and expansions of the table.
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* The first "statistic" returned is the length of hash_stat[].
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* Then contents of hash_stat[] are read out (in ascending order)
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* until your buffer or hash_stat[] is exausted.
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*/
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void
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hash_say(handle,buffer,bufsiz)
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register struct hash_control * handle;
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register int buffer[/*bufsiz*/];
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register int bufsiz;
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{
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register int * nd; /* limit of statistics block */
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register int * ip; /* scan statistics */
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ip = handle->hash_stat;
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nd = ip + min(bufsiz-1,STATLENGTH);
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if (bufsiz>0) /* trust nothing! bufsiz <= 0 is dangerous */
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{
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*buffer++ = STATLENGTH;
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for (; ip<nd; ip++,buffer++)
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{
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*buffer = *ip;
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}
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}
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}
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/*
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* h a s h _ d e l e t e ( )
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*
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* Try to delete a symbol from the table.
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* If it was there, return its value (and adjust STAT_USED).
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* Otherwise, return NULL.
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* Anyway, the symbol is not present after this function.
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*
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*/
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char * /* NULL if string not in table, else */
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/* returns value of deleted symbol */
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hash_delete(handle,string)
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register struct hash_control * handle;
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register char * string;
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{
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register char * retval; /* NULL if string not in table */
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register struct hash_entry * entry; /* NULL or entry of this symbol */
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entry = hash_ask(handle,string,STAT__WRITE);
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if (hash_found)
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{
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retval = entry->hash_value;
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entry->hash_string = DELETED; /* mark as deleted */
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handle->hash_stat[STAT_USED] -= 1; /* slots-in-use count */
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#ifdef SUSPECT
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if (handle->hash_stat[STAT_USED]<0)
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{
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error("hash_delete");
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}
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#endif /* def SUSPECT */
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}
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else
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{
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retval = NULL;
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}
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return(retval);
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}
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/*
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* h a s h _ r e p l a c e ( )
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*
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* Try to replace the old value of a symbol with a new value.
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* Normally return the old value.
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* Return NULL and don't change the table if the symbol is not already
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* in the table.
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*/
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char *
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hash_replace(handle,string,value)
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register struct hash_control * handle;
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register char * string;
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register char * value;
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{
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register struct hash_entry * entry;
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register char * retval;
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entry = hash_ask(handle,string,STAT__WRITE);
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if (hash_found)
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{
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retval = entry->hash_value;
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entry->hash_value = value;
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}
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else
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{
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retval = NULL;
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}
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;
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return (retval);
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}
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/*
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* h a s h _ i n s e r t ( )
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*
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* Insert a (symbol-string, value) into the hash table.
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* Return an error string, "" means OK.
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* It is an 'error' to insert an existing symbol.
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*/
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char * /* return error string */
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hash_insert(handle,string,value)
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register struct hash_control * handle;
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register char * string;
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register char * value;
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{
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register struct hash_entry * entry;
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register char * retval;
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retval = "";
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if (handle->hash_stat[STAT_USED] > handle->hash_full)
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{
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retval = hash_grow(handle);
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}
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if ( ! * retval)
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{
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entry = hash_ask(handle,string,STAT__WRITE);
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if (hash_found)
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{
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retval = "exists";
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}
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else
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{
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entry->hash_value = value;
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entry->hash_string = string;
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handle->hash_stat[STAT_USED] += 1;
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}
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}
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return(retval);
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}
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/*
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* h a s h _ j a m ( )
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*
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* Regardless of what was in the symbol table before, after hash_jam()
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* the named symbol has the given value. The symbol is either inserted or
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* (its value is) relpaced.
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* An error message string is returned, "" means OK.
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*
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* WARNING: this may decide to grow the hashed symbol table.
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* To do this, we call hash_grow(), WHICH WILL recursively CALL US.
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*
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* We report status internally: hash_found is TRUE if we replaced, but
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* false if we inserted.
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*/
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char *
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hash_jam(handle,string,value)
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register struct hash_control * handle;
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register char * string;
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register char * value;
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{
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register char * retval;
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register struct hash_entry * entry;
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retval = "";
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if (handle->hash_stat[STAT_USED] > handle->hash_full)
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{
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retval = hash_grow(handle);
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}
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if (! * retval)
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{
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entry = hash_ask(handle,string,STAT__WRITE);
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if ( ! hash_found)
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{
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entry->hash_string = string;
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handle->hash_stat[STAT_USED] += 1;
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}
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entry->hash_value = value;
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}
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return(retval);
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}
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/*
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* h a s h _ g r o w ( )
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*
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* Grow a new (bigger) hash table from the old one.
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* We choose to double the hash table's size.
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* Return a human-scrutible error string: "" if OK.
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* Warning! This uses hash_jam(), which had better not recurse
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* back here! Hash_jam() conditionally calls us, but we ALWAYS
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* call hash_jam()!
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* Internal.
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*/
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static char *
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hash_grow(handle) /* make a hash table grow */
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struct hash_control * handle;
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{
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register struct hash_entry * newwall;
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register struct hash_entry * newwhere;
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struct hash_entry * newtrack;
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register struct hash_entry * oldtrack;
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register struct hash_entry * oldwhere;
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register struct hash_entry * oldwall;
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register int temp;
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int newsize;
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char * string;
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char * retval;
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#ifdef SUSPECT
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int oldused;
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#endif
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|
||
/*
|
||
* capture info about old hash table
|
||
*/
|
||
oldwhere = handle->hash_where;
|
||
oldwall = handle->hash_wall;
|
||
#ifdef SUSPECT
|
||
oldused = handle->hash_stat[STAT_USED];
|
||
#endif
|
||
/*
|
||
* attempt to get enough room for a hash table twice as big
|
||
*/
|
||
temp = handle->hash_stat[STAT_SIZE];
|
||
if (( newwhere = (struct hash_entry *)
|
||
xmalloc((long)((temp+temp+1)*sizeof(struct hash_entry)))) != NULL)
|
||
/* +1 for wall slot */
|
||
{
|
||
retval = ""; /* assume success until proven otherwise */
|
||
/*
|
||
* have enough room: now we do all the work.
|
||
* double the size of everything in handle,
|
||
* note: hash_mask frob works for 1's & for 2's complement machines
|
||
*/
|
||
handle->hash_mask = handle->hash_mask + handle->hash_mask + 1;
|
||
handle->hash_stat[STAT_SIZE] <<= 1;
|
||
newsize = handle->hash_stat[STAT_SIZE];
|
||
handle->hash_where = newwhere;
|
||
handle->hash_full <<= 1;
|
||
handle->hash_sizelog += 1;
|
||
handle->hash_stat[STAT_USED] = 0;
|
||
handle->hash_wall =
|
||
newwall = newwhere + newsize;
|
||
/*
|
||
* set all those pesky new slots to vacant.
|
||
*/
|
||
for (newtrack=newwhere; newtrack <= newwall; newtrack++)
|
||
{
|
||
newtrack->hash_string = NULL;
|
||
}
|
||
/*
|
||
* we will do a scan of the old table, the hard way, using the
|
||
* new control block to re-insert the data into new hash table.
|
||
*/
|
||
handle->hash_stat[STAT_USED] = 0; /* inserts will bump it up to correct */
|
||
for (oldtrack=oldwhere; oldtrack < oldwall; oldtrack++)
|
||
{
|
||
if (((string = oldtrack->hash_string) != NULL) && string != DELETED)
|
||
{
|
||
if ( * (retval = hash_jam(handle,string,oldtrack->hash_value) ) )
|
||
{
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
#ifdef SUSPECT
|
||
if ( !*retval && handle->hash_stat[STAT_USED] != oldused)
|
||
{
|
||
retval = "hash_used";
|
||
}
|
||
#endif
|
||
if (!*retval)
|
||
{
|
||
/*
|
||
* we have a completely faked up control block.
|
||
* return the old hash table.
|
||
*/
|
||
free((char *)oldwhere);
|
||
/*
|
||
* Here with success. retval is already "".
|
||
*/
|
||
}
|
||
}
|
||
else
|
||
{
|
||
retval = "no room";
|
||
}
|
||
return(retval);
|
||
}
|
||
|
||
/*
|
||
* h a s h _ a p p l y ( )
|
||
*
|
||
* Use this to scan each entry in symbol table.
|
||
* For each symbol, this calls (applys) a nominated function supplying the
|
||
* symbol's value (and the symbol's name).
|
||
* The idea is you use this to destroy whatever is associted with
|
||
* any values in the table BEFORE you destroy the table with hash_die.
|
||
* Of course, you can use it for other jobs; whenever you need to
|
||
* visit all extant symbols in the table.
|
||
*
|
||
* We choose to have a call-you-back idea for two reasons:
|
||
* asthetic: it is a neater idea to use apply than an explicit loop
|
||
* sensible: if we ever had to grow the symbol table (due to insertions)
|
||
* then we would lose our place in the table when we re-hashed
|
||
* symbols into the new table in a different order.
|
||
*
|
||
* The order symbols are visited depends entirely on the hashing function.
|
||
* Whenever you insert a (symbol, value) you risk expanding the table. If
|
||
* you do expand the table, then the hashing function WILL change, so you
|
||
* MIGHT get a different order of symbols visited. In other words, if you
|
||
* want the same order of visiting symbols as the last time you used
|
||
* hash_apply() then you better not have done any hash_insert()s or
|
||
* hash_jam()s since the last time you used hash_apply().
|
||
*
|
||
* In future we may use the value returned by your nominated function.
|
||
* One idea is to abort the scan if, after applying the function to a
|
||
* certain node, the function returns a certain code.
|
||
* To be safe, please make your functions of type char *. If you always
|
||
* return NULL, then the scan will complete, visiting every symbol in
|
||
* the table exactly once. ALL OTHER RETURNED VALUES have no meaning yet!
|
||
* Caveat Actor!
|
||
*
|
||
* The function you supply should be of the form:
|
||
* char * myfunct(string,value)
|
||
* char * string; |* the symbol's name *|
|
||
* char * value; |* the symbol's value *|
|
||
* {
|
||
* |* ... *|
|
||
* return(NULL);
|
||
* }
|
||
*
|
||
* The returned value of hash_apply() is (char*)NULL. In future it may return
|
||
* other values. NULL means "completed scan OK". Other values have no meaning
|
||
* yet. (The function has no graceful failures.)
|
||
*/
|
||
char *
|
||
hash_apply(handle,function)
|
||
struct hash_control * handle;
|
||
char* (*function)();
|
||
{
|
||
register struct hash_entry * entry;
|
||
register struct hash_entry * wall;
|
||
|
||
wall = handle->hash_wall;
|
||
for (entry = handle->hash_where; entry < wall; entry++)
|
||
{
|
||
if (islive(entry)) /* silly code: tests entry->string twice! */
|
||
{
|
||
(*function)(entry->hash_string,entry->hash_value);
|
||
}
|
||
}
|
||
return (NULL);
|
||
}
|
||
|
||
/*
|
||
* h a s h _ f i n d ( )
|
||
*
|
||
* Given symbol string, find value (if any).
|
||
* Return found value or NULL.
|
||
*/
|
||
char *
|
||
hash_find(handle,string) /* return char* or NULL */
|
||
struct hash_control * handle;
|
||
char * string;
|
||
{
|
||
register struct hash_entry * entry;
|
||
register char * retval;
|
||
|
||
entry = hash_ask(handle,string,STAT__READ);
|
||
if (hash_found)
|
||
{
|
||
retval = entry->hash_value;
|
||
}
|
||
else
|
||
{
|
||
retval = NULL;
|
||
}
|
||
return(retval);
|
||
}
|
||
|
||
/*
|
||
* h a s h _ a s k ( )
|
||
*
|
||
* Searches for given symbol string.
|
||
* Return the slot where it OUGHT to live. It may be there.
|
||
* Return hash_found: TRUE only if symbol is in that slot.
|
||
* Access argument is to help keep statistics in control block.
|
||
* Internal.
|
||
*/
|
||
static struct hash_entry * /* string slot, may be empty or deleted */
|
||
hash_ask(handle,string,access)
|
||
struct hash_control * handle;
|
||
char * string;
|
||
int access; /* access type */
|
||
{
|
||
register char *string1; /* JF avoid strcmp calls */
|
||
register char * s;
|
||
register int c;
|
||
register struct hash_entry * slot;
|
||
register int collision; /* count collisions */
|
||
|
||
slot = handle->hash_where + hash_code(handle,string); /* start looking here */
|
||
handle->hash_stat[STAT_ACCESS+access] += 1;
|
||
collision = 0;
|
||
hash_found = FALSE;
|
||
while (((s = slot->hash_string) != NULL) && s != DELETED)
|
||
{
|
||
for (string1=string;;) {
|
||
if ((c= *s++) == 0) {
|
||
if (!*string1)
|
||
hash_found = TRUE;
|
||
break;
|
||
}
|
||
if (*string1++ != c)
|
||
break;
|
||
}
|
||
if (hash_found)
|
||
break;
|
||
collision++;
|
||
slot++;
|
||
}
|
||
/*
|
||
* slot: return:
|
||
* in use: we found string slot
|
||
* at empty:
|
||
* at wall: we fell off: wrap round ????
|
||
* in table: dig here slot
|
||
* at DELETED: dig here slot
|
||
*/
|
||
if (slot == handle->hash_wall)
|
||
{
|
||
slot = handle->hash_where; /* now look again */
|
||
while (((s = slot->hash_string) != NULL) && s != DELETED)
|
||
{
|
||
for (string1=string;*s;string1++,s++) {
|
||
if (*string1 != *s)
|
||
break;
|
||
}
|
||
if (*s == *string1) {
|
||
hash_found = TRUE;
|
||
break;
|
||
}
|
||
collision++;
|
||
slot++;
|
||
}
|
||
/*
|
||
* slot: return:
|
||
* in use: we found it slot
|
||
* empty: wall: ERROR IMPOSSIBLE !!!!
|
||
* in table: dig here slot
|
||
* DELETED:dig here slot
|
||
*/
|
||
}
|
||
/* fprintf(stderr,"hash_ask(%s)->%d(%d)\n",string,hash_code(handle,string),collision); */
|
||
handle->hash_stat[STAT_COLLIDE+access] += collision;
|
||
return(slot); /* also return hash_found */
|
||
}
|
||
|
||
/*
|
||
* h a s h _ c o d e
|
||
*
|
||
* Does hashing of symbol string to hash number.
|
||
* Internal.
|
||
*/
|
||
static int
|
||
hash_code(handle,string)
|
||
struct hash_control * handle;
|
||
register char * string;
|
||
{
|
||
register long h; /* hash code built here */
|
||
register long c; /* each character lands here */
|
||
register int n; /* Amount to shift h by */
|
||
|
||
n = (handle->hash_sizelog - 3);
|
||
h = 0;
|
||
while ((c = *string++) != 0)
|
||
{
|
||
h += c;
|
||
h = (h<<3) + (h>>n) + c;
|
||
}
|
||
return (h & handle->hash_mask);
|
||
}
|
||
|
||
/*
|
||
* Here is a test program to exercise above.
|
||
*/
|
||
#ifdef TEST
|
||
|
||
#define TABLES (6) /* number of hash tables to maintain */
|
||
/* (at once) in any testing */
|
||
#define STATBUFSIZE (12) /* we can have 12 statistics */
|
||
|
||
int statbuf[STATBUFSIZE]; /* display statistics here */
|
||
char answer[100]; /* human farts here */
|
||
char * hashtable[TABLES]; /* we test many hash tables at once */
|
||
char * h; /* points to curent hash_control */
|
||
char ** pp;
|
||
char * p;
|
||
char * name;
|
||
char * value;
|
||
int size;
|
||
int used;
|
||
char command;
|
||
int number; /* number 0:TABLES-1 of current hashed */
|
||
/* symbol table */
|
||
|
||
main()
|
||
{
|
||
char (*applicatee());
|
||
char * hash_find();
|
||
char * destroy();
|
||
char * what();
|
||
struct hash_control * hash_new();
|
||
char * hash_replace();
|
||
int * ip;
|
||
|
||
number = 0;
|
||
h = 0;
|
||
printf("type h <RETURN> for help\n");
|
||
for (;;)
|
||
{
|
||
printf("hash_test command: ");
|
||
fgets(answer, 100, stdin);
|
||
command = answer[0];
|
||
if (isupper(command)) command = tolower(command); /* ecch! */
|
||
switch (command)
|
||
{
|
||
case '#':
|
||
printf("old hash table #=%d.\n",number);
|
||
whattable();
|
||
break;
|
||
case '?':
|
||
for (pp=hashtable; pp<hashtable+TABLES; pp++)
|
||
{
|
||
printf("address of hash table #%d control block is %xx\n"
|
||
,pp-hashtable,*pp);
|
||
}
|
||
break;
|
||
case 'a':
|
||
hash_apply(h,applicatee);
|
||
break;
|
||
case 'd':
|
||
hash_apply(h,destroy);
|
||
hash_die(h);
|
||
break;
|
||
case 'f':
|
||
p = hash_find(h,name=what("symbol"));
|
||
printf("value of \"%s\" is \"%s\"\n",name,p?p:"NOT-PRESENT");
|
||
break;
|
||
case 'h':
|
||
printf("# show old, select new default hash table number\n");
|
||
printf("? display all hashtable control block addresses\n");
|
||
printf("a apply a simple display-er to each symbol in table\n");
|
||
printf("d die: destroy hashtable\n");
|
||
printf("f find value of nominated symbol\n");
|
||
printf("h this help\n");
|
||
printf("i insert value into symbol\n");
|
||
printf("j jam value into symbol\n");
|
||
printf("n new hashtable\n");
|
||
printf("r replace a value with another\n");
|
||
printf("s say what %% of table is used\n");
|
||
printf("q exit this program\n");
|
||
printf("x delete a symbol from table, report its value\n");
|
||
break;
|
||
case 'i':
|
||
p = hash_insert(h,name=what("symbol"),value=what("value"));
|
||
if (*p)
|
||
{
|
||
printf("symbol=\"%s\" value=\"%s\" error=%s\n",name,value,p);
|
||
}
|
||
break;
|
||
case 'j':
|
||
p = hash_jam(h,name=what("symbol"),value=what("value"));
|
||
if (*p)
|
||
{
|
||
printf("symbol=\"%s\" value=\"%s\" error=%s\n",name,value,p);
|
||
}
|
||
break;
|
||
case 'n':
|
||
h = hashtable[number] = (char *) hash_new();
|
||
break;
|
||
case 'q':
|
||
exit();
|
||
case 'r':
|
||
p = hash_replace(h,name=what("symbol"),value=what("value"));
|
||
printf("old value was \"%s\"\n",p?p:"{}");
|
||
break;
|
||
case 's':
|
||
hash_say(h,statbuf,STATBUFSIZE);
|
||
for (ip=statbuf; ip<statbuf+STATBUFSIZE; ip++)
|
||
{
|
||
printf("%d ",*ip);
|
||
}
|
||
printf("\n");
|
||
break;
|
||
case 'x':
|
||
p = hash_delete(h,name=what("symbol"));
|
||
printf("old value was \"%s\"\n",p?p:"{}");
|
||
break;
|
||
default:
|
||
printf("I can't understand command \"%c\"\n",command);
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
|
||
char *
|
||
what(description)
|
||
char * description;
|
||
{
|
||
char * retval;
|
||
char * malloc();
|
||
|
||
printf(" %s : ",description);
|
||
fgets(answer, 100, stdin);
|
||
/* will one day clean up answer here */
|
||
retval = malloc(strlen(answer)+1);
|
||
if (!retval)
|
||
{
|
||
error("room");
|
||
}
|
||
(void)strcpy(retval,answer);
|
||
return(retval);
|
||
}
|
||
|
||
char *
|
||
destroy(string,value)
|
||
char * string;
|
||
char * value;
|
||
{
|
||
free(string);
|
||
free(value);
|
||
return(NULL);
|
||
}
|
||
|
||
|
||
char *
|
||
applicatee(string,value)
|
||
char * string;
|
||
char * value;
|
||
{
|
||
printf("%.20s-%.20s\n",string,value);
|
||
return(NULL);
|
||
}
|
||
|
||
whattable() /* determine number: what hash table to use */
|
||
/* also determine h: points to hash_control */
|
||
{
|
||
|
||
for (;;)
|
||
{
|
||
printf(" what hash table (%d:%d) ? ",0,TABLES-1);
|
||
fgets(answer, 100, stdin);
|
||
sscanf(answer,"%d",&number);
|
||
if (number >= 0 && number<TABLES)
|
||
{
|
||
h = hashtable[number];
|
||
if (!h)
|
||
{
|
||
printf("warning: current hash-table-#%d. has no hash-control\n",number);
|
||
}
|
||
return;
|
||
}
|
||
else
|
||
{
|
||
printf("invalid hash table number: %d\n",number);
|
||
}
|
||
}
|
||
}
|
||
|
||
|
||
|
||
#endif /* #ifdef TEST */
|
||
|
||
/* end of hash.c */
|