1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
|
/**
* @file llsimplehash.h
*
* Copyright (c) 2003-2007, Linden Research, Inc.
*
* Second Life Viewer Source Code
* The source code in this file ("Source Code") is provided by Linden Lab
* to you under the terms of the GNU General Public License, version 2.0
* ("GPL"), unless you have obtained a separate licensing agreement
* ("Other License"), formally executed by you and Linden Lab. Terms of
* the GPL can be found in doc/GPL-license.txt in this distribution, or
* online at http://secondlife.com/developers/opensource/gplv2
*
* There are special exceptions to the terms and conditions of the GPL as
* it is applied to this Source Code. View the full text of the exception
* in the file doc/FLOSS-exception.txt in this software distribution, or
* online at http://secondlife.com/developers/opensource/flossexception
*
* By copying, modifying or distributing this software, you acknowledge
* that you have read and understood your obligations described above,
* and agree to abide by those obligations.
*
* ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
* WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
* COMPLETENESS OR PERFORMANCE.
*/
#ifndef LL_LLSIMPLEHASH_H
#define LL_LLSIMPLEHASH_H
#include "llstl.h"
template <typename HASH_KEY_TYPE>
class LLSimpleHashEntry
{
protected:
HASH_KEY_TYPE mHashKey;
LLSimpleHashEntry<HASH_KEY_TYPE>* mNextEntry;
public:
LLSimpleHashEntry(HASH_KEY_TYPE key) :
mHashKey(key),
mNextEntry(0)
{
}
virtual ~LLSimpleHashEntry()
{
}
HASH_KEY_TYPE getHashKey() const
{
return mHashKey;
}
LLSimpleHashEntry<HASH_KEY_TYPE>* getNextEntry() const
{
return mNextEntry;
}
void setNextEntry(LLSimpleHashEntry<HASH_KEY_TYPE>* next)
{
mNextEntry = next;
}
};
template <typename HASH_KEY_TYPE, int TABLE_SIZE>
class LLSimpleHash
{
public:
LLSimpleHash()
{
llassert(TABLE_SIZE);
llassert((TABLE_SIZE ^ (TABLE_SIZE-1)) == (TABLE_SIZE | (TABLE_SIZE-1))); // power of 2
memset(mEntryTable, 0, sizeof(mEntryTable));
}
virtual ~LLSimpleHash()
{
}
virtual int getIndex(HASH_KEY_TYPE key)
{
return key & (TABLE_SIZE-1);
}
bool insert(LLSimpleHashEntry<HASH_KEY_TYPE>* entry)
{
llassert(entry->getNextEntry() == 0);
int index = getIndex(entry->getHashKey());
entry->setNextEntry(mEntryTable[index]);
mEntryTable[index] = entry;
return true;
}
LLSimpleHashEntry<HASH_KEY_TYPE>* find(HASH_KEY_TYPE key)
{
int index = getIndex(key);
LLSimpleHashEntry<HASH_KEY_TYPE>* res = mEntryTable[index];
while(res && (res->getHashKey() != key))
{
res = res->getNextEntry();
}
return res;
}
bool erase(LLSimpleHashEntry<HASH_KEY_TYPE>* entry)
{
return erase(entry->getHashKey());
}
bool erase(HASH_KEY_TYPE key)
{
int index = getIndex(key);
LLSimpleHashEntry<HASH_KEY_TYPE>* prev = 0;
LLSimpleHashEntry<HASH_KEY_TYPE>* res = mEntryTable[index];
while(res && (res->getHashKey() != key))
{
prev = res;
res = res->getNextEntry();
}
if (res)
{
LLSimpleHashEntry<HASH_KEY_TYPE>* next = res->getNextEntry();
if (prev)
{
prev->setNextEntry(next);
}
else
{
mEntryTable[index] = next;
}
return true;
}
else
{
return false;
}
}
// Removes and returns an arbitrary ("first") element from the table
// Used for deleting the entire table.
LLSimpleHashEntry<HASH_KEY_TYPE>* pop_element()
{
for (int i=0; i<TABLE_SIZE; i++)
{
LLSimpleHashEntry<HASH_KEY_TYPE>* entry = mEntryTable[i];
if (entry)
{
mEntryTable[i] = entry->getNextEntry();
return entry;
}
}
return 0;
}
// debugging
LLSimpleHashEntry<HASH_KEY_TYPE>* get_element_at_index(S32 index) const
{
return mEntryTable[index];
}
private:
LLSimpleHashEntry<HASH_KEY_TYPE>* mEntryTable[TABLE_SIZE];
};
#endif // LL_LLSIMPLEHASH_H
|
