summaryrefslogtreecommitdiff
path: root/indra/llcommon/llstringtable.h
blob: e41701ce9cff1abc6d55f6efca625ff00c4eca59 (plain)
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
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
/**
 * @file llstringtable.h
 * @brief The LLStringTable class provides a _fast_ method for finding
 * unique copies of strings.
 *
 * $LicenseInfo:firstyear=2001&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#ifndef LL_STRING_TABLE_H
#define LL_STRING_TABLE_H

#include "lldefs.h"
#include "llformat.h"
#include "llstl.h"
#include <list>
#include <set>

#if LL_WINDOWS
# if (_MSC_VER >= 1300 && _MSC_VER < 1400)
#  define STRING_TABLE_HASH_MAP 1
# endif
#else
//# define STRING_TABLE_HASH_MAP 1
#endif

const U32 MAX_STRINGS_LENGTH = 256;

class LL_COMMON_API LLStringTableEntry
{
public:
    LLStringTableEntry(const char *str);
    ~LLStringTableEntry();

    void incCount()     { mCount++; }
    BOOL decCount()     { return --mCount; }

    char *mString;
    S32  mCount;
};

class LL_COMMON_API LLStringTable
{
public:
    LLStringTable(int tablesize);
    ~LLStringTable();

    char *checkString(const char *str);
    char *checkString(const std::string& str);
    LLStringTableEntry *checkStringEntry(const char *str);
    LLStringTableEntry *checkStringEntry(const std::string& str);

    char *addString(const char *str);
    char *addString(const std::string& str);
    LLStringTableEntry *addStringEntry(const char *str);
    LLStringTableEntry *addStringEntry(const std::string& str);
    void  removeString(const char *str);

    S32 mMaxEntries;
    S32 mUniqueEntries;

#if STRING_TABLE_HASH_MAP
#if LL_WINDOWS
    typedef std::hash_multimap<U32, LLStringTableEntry *> string_hash_t;
#else
    typedef __gnu_cxx::hash_multimap<U32, LLStringTableEntry *> string_hash_t;
#endif
    string_hash_t mStringHash;
#else
    typedef std::list<LLStringTableEntry *> string_list_t;
    typedef string_list_t * string_list_ptr_t;
    string_list_ptr_t   *mStringList;
#endif
};

extern LL_COMMON_API LLStringTable gStringTable;

//============================================================================

// This class is designed to be used locally,
// e.g. as a member of an LLXmlTree
// Strings can be inserted only, then quickly looked up

typedef const std::string* LLStdStringHandle;

class LL_COMMON_API LLStdStringTable
{
public:
    LLStdStringTable(S32 tablesize = 0)
    {
        if (tablesize == 0)
        {
            tablesize = 256; // default
        }
        // Make sure tablesize is power of 2
        for (S32 i = 31; i>0; i--)
        {
            if (tablesize & (1<<i))
            {
                if (tablesize >= (3<<(i-1)))
                    tablesize = (1<<(i+1));
                else
                    tablesize = (1<<i);
                break;
            }
        }
        mTableSize = tablesize;
        mStringList = new string_set_t[tablesize];
    }
    ~LLStdStringTable()
    {
        cleanup();
        delete[] mStringList;
    }
    void cleanup()
    {
        // remove strings
        for (S32 i = 0; i<mTableSize; i++)
        {
            string_set_t& stringset = mStringList[i];
            for (LLStdStringHandle str : stringset)
            {
                delete str;
            }
            stringset.clear();
        }
    }

    LLStdStringHandle lookup(const std::string& s)
    {
        U32 hashval = makehash(s);
        return lookup(hashval, s);
    }

    LLStdStringHandle checkString(const std::string& s)
    {
        U32 hashval = makehash(s);
        return lookup(hashval, s);
    }

    LLStdStringHandle insert(const std::string& s)
    {
        U32 hashval = makehash(s);
        LLStdStringHandle result = lookup(hashval, s);
        if (result == NULL)
        {
            result = new std::string(s);
            mStringList[hashval].insert(result);
        }
        return result;
    }
    LLStdStringHandle addString(const std::string& s)
    {
        return insert(s);
    }

private:
    U32 makehash(const std::string& s)
    {
        S32 len = (S32)s.size();
        const char* c = s.c_str();
        U32 hashval = 0;
        for (S32 i=0; i<len; i++)
        {
            hashval = ((hashval<<5) + hashval) + *c++;
        }
        return hashval & (mTableSize-1);
    }
    LLStdStringHandle lookup(U32 hashval, const std::string& s)
    {
        string_set_t& stringset = mStringList[hashval];
        LLStdStringHandle handle = &s;
        string_set_t::iterator iter = stringset.find(handle); // compares actual strings
        if (iter != stringset.end())
        {
            return *iter;
        }
        else
        {
            return NULL;
        }
    }

private:
    S32 mTableSize;
    typedef std::set<LLStdStringHandle, compare_pointer_contents<std::string> > string_set_t;
    string_set_t* mStringList; // [mTableSize]
};


#endif