dict2.hpp revision 0:a61af66fc99e 
1/*
2 * Copyright 1998-2000 Sun Microsystems, Inc.  All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
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23 */
24
25#ifndef _DICT_
26#define _DICT_
27// Dictionaries - An Abstract Data Type
28
29
30class Dict;
31
32// These dictionaries define a key-value mapping.  They can be inserted to,
33// searched or deleted from.  They grow and shrink as needed.  The key is a
34// pointer to something (or anything which can be stored in a pointer).  A
35// key comparison routine determines if two keys are equal or not.  A hash
36// function can be provided; if it's not provided the key itself is used
37// instead.  A nice string hash function is included.
38typedef int  (*CmpKey)(const void *key1, const void *key2);
39typedef int  (*Hash)(const void *key);
40typedef void (*PrintKeyOrValue)(const void *key_or_value);
41typedef void (*FuncDict)(const void *key, const void *val, Dict *d);
42
43class Dict { // Dictionary structure
44 private:
45  class Arena *_arena;          // Where to draw storage from
46  class bucket *_bin;           // Hash table is array of buckets
47  int _size;                    // Size (# of slots) in hash table
48  int _cnt;                     // Number of key-value pairs in hash table
49  const Hash _hash;             // Hashing function
50  const CmpKey _cmp;            // Key comparison function
51  void doubhash( void );        // Double hash table size
52
53 public:
54  friend class DictI;            // Friendly iterator function
55
56  // cmp is a key comparision routine.  hash is a routine to hash a key.
57  Dict( CmpKey cmp, Hash hash );
58  Dict( CmpKey cmp, Hash hash, Arena *arena );
59  void init();
60  ~Dict();
61
62  Dict( const Dict & );         // Deep-copy guts
63  Dict &operator =( const Dict & );
64
65  // Zap to empty; ready for re-use
66  void Clear();
67
68  // Return # of key-value pairs in dict
69  int Size(void) const { return _cnt; }
70
71  // Insert inserts the given key-value pair into the dictionary.  The prior
72  // value of the key is returned; NULL if the key was not previously defined.
73  const void *Insert(const void *key, const void *val); // A new key-value
74  const void *Delete(void *key);                        // Delete & return old
75
76  // Find finds the value of a given key; or NULL if not found.
77  // The dictionary is NOT changed.
78  const void *operator [](const void *key) const;  // Do a lookup
79
80  // == compares two dictionaries; they must have the same keys (their keys
81  // must match using CmpKey) and they must have the same values (pointer
82  // comparison).  If so 1 is returned, if not 0 is returned.
83  int operator ==(const Dict &d) const;   // Compare dictionaries for equal
84
85  // Print out the dictionary contents as key-value pairs
86  void print();
87  void print(PrintKeyOrValue print_key, PrintKeyOrValue print_value);
88};
89
90// Hashing functions
91int hashstr(const void *s);        // Nice string hash
92// Slimey cheap hash function; no guarenteed performance.  Better than the
93// default for pointers, especially on MS-DOS machines.
94int hashptr(const void *key);
95// Slimey cheap hash function; no guarenteed performance.
96int hashkey(const void *key);
97
98// Key comparators
99int cmpstr(const void *k1, const void *k2);
100// Slimey cheap key comparator.
101int cmpkey(const void *key1, const void *key2);
102
103//------------------------------Iteration--------------------------------------
104// The class of dictionary iterators.  Fails in the presences of modifications
105// to the dictionary during iteration (including searches).
106// Usage:  for( DictI i(dict); i.test(); ++i ) { body = i.key; body = i.value;}
107class DictI {
108 private:
109  const Dict *_d;               // Dictionary being iterated over
110  int _i;                      // Counter over the bins
111  int _j;                      // Counter inside each bin
112 public:
113  const void *_key, *_value;          // Easy access to the key-value pair
114  DictI( const Dict *d ) {reset(d);}; // Create a new iterator
115  void reset( const Dict *dict );     // Reset existing iterator
116  void operator ++(void);             // Increment iterator
117  int test(void) { return _i<_d->_size;} // Test for end of iteration
118};
119
120#endif // _DICT_
121