DialogF.c- DialogF.h
- Makefile.common
- Makefile.dependencies
- check_lin_tif
- clearcase.c
- clearcase.h
- colorchooser.c
- colorchooser.h
- dragAndDrop.c
- dragAndDrop.h
- ec_glob.c
- ec_glob.h
- fileUtils.c
- fileUtils.h
- filedialog.c
- filedialog.h
- fontsel.c
- fontsel.h
- getfiles.c
- getfiles.h
- libxattr.c
- libxattr.h
- managedList.c
- managedList.h
- misc.c
- misc.h
- motif.c
- motif.h
- nedit_malloc.c
- nedit_malloc.h
- pathutils.c
- pathutils.h
- prefFile.c
- prefFile.h
- printUtils.c
- printUtils.h
- rbTree.c
- rbTree.h
- refString.c
- refString.h
- system.h
- textfield.c
- textfield.h
- textfieldP.h
- utils.c
- utils.h
- xdnd.c
- xdnd.h
1 /*******************************************************************************
2 * *
3 * refString.c -- Nirvana editor string handling *
4 * *
5 * Copyright (C) 200 Scott Tringali *
6 * *
7 * This is free software; you can redistribute it and/or modify it under the *
8 * terms of the GNU General Public License as published by the Free Software *
9 * Foundation; either version 2 of the License, or (at your option) any later *
10 * version. In addition, you may distribute versions of this program linked to *
11 * Motif or Open Motif. See README for details. *
12 * *
13 * This software is distributed in the hope that it will be useful, but WITHOUT *
14 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or *
15 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License *
16 * for more details. *
17 * *
18 * You should have received a copy of the GNU General Public License along with *
19 * software; if not, write to the Free Software Foundation, Inc., 59 Temple *
20 * Place, Suite 330, Boston, MA 02111-1307 USA *
21 * *
22 * Nirvana Text Editor *
23 * July, 1993 *
24 * *
25 * Written by Mark Edel *
26 * *
27 *******************************************************************************/
28
29 #include "refString.h"
30 #include "nedit_malloc.h"
31 #include <string.h>
32 #include <stdio.h>
33 #include <stdlib.h>
34
35 #define RCS_SIZE 0x10000
36
37 struct rcs;
38
39 struct rcs_stats
40 {
41 int talloc, tshar, tgiveup, tbytes, tbyteshared;
42 };
43
44 struct rcs
45 {
46 struct rcs *next;
47 char *string;
48 int usage;
49 };
50
51 static struct rcs *Rcs[RCS_SIZE];
52 static struct rcs_stats RcsStats;
53
54 static unsigned const DJB2_SEED = 5381u;
55 /* djb2s hash for null-terminated string, seeded version */
56 static unsigned djb2s(char const* key, unsigned hash)
57 {
58 char c;
59 while (!!(c = *key++))
60 hash = ((hash << 5) + hash) ^ c;
61 return hash;
62 }
63
64 /* Compute hash address from a string key */
65 unsigned StringHashAddr(const char *key)
66 {
67 return djb2s(key, DJB2_SEED);
68 }
69
70 /* Compute hash address from a null-termintated list of strings */
71 unsigned StringsHashAddr(const char** keys)
72 {
73 unsigned hash = DJB2_SEED;
74 char const* key;
75 while (!!(key = *keys++))
76 hash = djb2s(key, hash);
77 return hash;
78 }
79
80 /*
81 ** Take a normal string, create a shared string from it if need be,
82 ** and return pointer to that shared string.
83 **
84 ** Returned strings are const because they are shared. Do not modify them!
85 */
86
87 const char *RefStringDup(const char *str)
88 {
89 unsigned bucket;
90 size_t len;
91 struct rcs *rp;
92 char *newstr;
93
94 if (str == NULL)
95 return NULL;
96
97 len = strlen(str);
98
99 RcsStats.talloc++;
100
101 /* Find it in hash */
102 bucket = StringHashAddr(str) % RCS_SIZE;
103 rp = Rcs[bucket];
104 for (; rp; rp = rp->next)
105 if (!strcmp(str, rp->string)) break;
106
107 newstr = NULL;
108 if (rp) /* It exists, return it and bump ref ct */
109 {
110 rp->usage++;
111 newstr = rp->string;
112
113 RcsStats.tshar++;
114 RcsStats.tbyteshared += len;
115 }
116 else /* Doesn't exist, conjure up a new one. */
117 {
118 rp = NEditNew(struct rcs);
119 rp->usage = 1;
120 rp->next = Rcs[bucket];
121 Rcs[bucket] = rp;
122
123 rp->string = (char*) NEditMalloc(len + 1);
124 memcpy(rp->string, str, len + 1);
125
126 newstr = rp->string;
127 }
128
129 RcsStats.tbytes += len;
130 return newstr;
131 }
132
133 /*
134 ** Decrease the reference count on a shared string. When the reference
135 ** count reaches zero, free the master string.
136 */
137
138 void RefStringFree(const char *rcs_str)
139 {
140 int bucket;
141 struct rcs *rp;
142 struct rcs *prev = NULL;
143
144 if (rcs_str == NULL)
145 return;
146
147 bucket = StringHashAddr(rcs_str) % RCS_SIZE;
148
149 /* find it in hash */
150 for (rp = Rcs[bucket]; rp; rp = rp->next)
151 {
152 if (rcs_str == rp->string)
153 break;
154 prev = rp;
155 }
156
157 if (rp) /* It's a shared string, decrease ref count */
158 {
159 rp->usage--;
160
161 if (rp->usage < 0) /* D'OH! */
162 {
163 fprintf(stderr, "XNEdit: internal error deallocating shared string.");
164 return;
165 }
166
167 if (rp->usage == 0) /* Last one- free the storage */
168 {
169 NEditFree(rp->string);
170 if (prev)
171 prev->next = rp->next;
172 else
173 Rcs[bucket] = rp->next;
174 NEditFree(rp);
175 }
176 }
177 else /* Doesn't appear to be a shared string */
178 {
179 fprintf(stderr, "XNEdit: attempt to free a non-shared string.");
180 return;
181 }
182 }
183
184