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1 | /* | |
2 | libloc - A library to determine the location of someone on the Internet | |
3 | ||
4 | Copyright (C) 2017 IPFire Development Team <info@ipfire.org> | |
5 | ||
6 | This library is free software; you can redistribute it and/or | |
7 | modify it under the terms of the GNU Lesser General Public | |
8 | License as published by the Free Software Foundation; either | |
9 | version 2.1 of the License, or (at your option) any later version. | |
10 | ||
11 | This library is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | Lesser General Public License for more details. | |
15 | */ | |
16 | ||
17 | #include <errno.h> | |
18 | #include <stddef.h> | |
19 | #include <stdio.h> | |
20 | #include <stdlib.h> | |
21 | #include <string.h> | |
22 | #include <sys/mman.h> | |
23 | #include <unistd.h> | |
24 | ||
25 | #include <libloc/libloc.h> | |
26 | #include <libloc/format.h> | |
27 | #include <libloc/private.h> | |
28 | #include <libloc/stringpool.h> | |
29 | ||
30 | #define LOC_STRINGPOOL_BLOCK_SIZE (512 * 1024) | |
31 | ||
32 | struct loc_stringpool { | |
33 | struct loc_ctx* ctx; | |
34 | int refcount; | |
35 | ||
36 | // Reference to any mapped data | |
37 | const char* data; | |
38 | ssize_t length; | |
39 | ||
40 | // Reference to own storage | |
41 | char* blocks; | |
42 | size_t size; | |
43 | }; | |
44 | ||
45 | static int loc_stringpool_grow(struct loc_stringpool* pool, const size_t size) { | |
46 | DEBUG(pool->ctx, "Growing string pool by %zu byte(s)\n", size); | |
47 | ||
48 | // Increment size | |
49 | pool->size += size; | |
50 | ||
51 | // Reallocate blocks | |
52 | pool->blocks = realloc(pool->blocks, pool->size); | |
53 | if (!pool->blocks) { | |
54 | ERROR(pool->ctx, "Could not grow string pool: %m\n"); | |
55 | return 1; | |
56 | } | |
57 | ||
58 | // Update data pointer | |
59 | pool->data = pool->blocks; | |
60 | ||
61 | return 0; | |
62 | } | |
63 | ||
64 | static off_t loc_stringpool_append(struct loc_stringpool* pool, const char* string) { | |
65 | if (!string) { | |
66 | errno = EINVAL; | |
67 | return -1; | |
68 | } | |
69 | ||
70 | DEBUG(pool->ctx, "Appending '%s' to string pool at %p\n", string, pool); | |
71 | ||
72 | // How much space to we need? | |
73 | const size_t length = strlen(string) + 1; | |
74 | ||
75 | // Make sure we have enough space | |
76 | if (pool->length + length > pool->size) { | |
77 | int r = loc_stringpool_grow(pool, LOC_STRINGPOOL_BLOCK_SIZE); | |
78 | if (r) | |
79 | return r; | |
80 | } | |
81 | ||
82 | off_t offset = pool->length; | |
83 | ||
84 | // Copy the string | |
85 | memcpy(pool->blocks + offset, string, length); | |
86 | ||
87 | // Update the length of the pool | |
88 | pool->length += length; | |
89 | ||
90 | return offset; | |
91 | } | |
92 | ||
93 | static void loc_stringpool_free(struct loc_stringpool* pool) { | |
94 | DEBUG(pool->ctx, "Releasing string pool %p\n", pool); | |
95 | ||
96 | // Free any data | |
97 | if (pool->blocks) | |
98 | free(pool->blocks); | |
99 | ||
100 | loc_unref(pool->ctx); | |
101 | free(pool); | |
102 | } | |
103 | ||
104 | int loc_stringpool_new(struct loc_ctx* ctx, struct loc_stringpool** pool) { | |
105 | struct loc_stringpool* p = calloc(1, sizeof(*p)); | |
106 | if (!p) | |
107 | return 1; | |
108 | ||
109 | p->ctx = loc_ref(ctx); | |
110 | p->refcount = 1; | |
111 | ||
112 | *pool = p; | |
113 | ||
114 | return 0; | |
115 | } | |
116 | ||
117 | int loc_stringpool_open(struct loc_ctx* ctx, struct loc_stringpool** pool, | |
118 | const char* data, const size_t length) { | |
119 | struct loc_stringpool* p = NULL; | |
120 | ||
121 | // Allocate a new stringpool | |
122 | int r = loc_stringpool_new(ctx, &p); | |
123 | if (r) | |
124 | goto ERROR; | |
125 | ||
126 | // Store data and length | |
127 | p->data = data; | |
128 | p->length = length; | |
129 | ||
130 | DEBUG(p->ctx, "Opened string pool at %p (%zu bytes)\n", p->data, p->length); | |
131 | ||
132 | *pool = p; | |
133 | return 0; | |
134 | ||
135 | ERROR: | |
136 | if (p) | |
137 | loc_stringpool_free(p); | |
138 | ||
139 | return r; | |
140 | } | |
141 | ||
142 | struct loc_stringpool* loc_stringpool_ref(struct loc_stringpool* pool) { | |
143 | pool->refcount++; | |
144 | ||
145 | return pool; | |
146 | } | |
147 | ||
148 | struct loc_stringpool* loc_stringpool_unref(struct loc_stringpool* pool) { | |
149 | if (--pool->refcount > 0) | |
150 | return NULL; | |
151 | ||
152 | loc_stringpool_free(pool); | |
153 | ||
154 | return NULL; | |
155 | } | |
156 | ||
157 | const char* loc_stringpool_get(struct loc_stringpool* pool, off_t offset) { | |
158 | // Check boundaries | |
159 | if (offset < 0 || offset >= pool->length) { | |
160 | errno = ERANGE; | |
161 | return NULL; | |
162 | } | |
163 | ||
164 | // Return any data that we have in memory | |
165 | return pool->data + offset; | |
166 | } | |
167 | ||
168 | size_t loc_stringpool_get_size(struct loc_stringpool* pool) { | |
169 | return pool->length; | |
170 | } | |
171 | ||
172 | static off_t loc_stringpool_find(struct loc_stringpool* pool, const char* s) { | |
173 | if (!s || !*s) { | |
174 | errno = EINVAL; | |
175 | return -1; | |
176 | } | |
177 | ||
178 | off_t offset = 0; | |
179 | while (offset < pool->length) { | |
180 | const char* string = loc_stringpool_get(pool, offset); | |
181 | ||
182 | // Error! | |
183 | if (!string) | |
184 | return 1; | |
185 | ||
186 | // Is this a match? | |
187 | if (strcmp(s, string) == 0) | |
188 | return offset; | |
189 | ||
190 | // Shift offset | |
191 | offset += strlen(string) + 1; | |
192 | } | |
193 | ||
194 | // Nothing found | |
195 | errno = ENOENT; | |
196 | return -1; | |
197 | } | |
198 | ||
199 | off_t loc_stringpool_add(struct loc_stringpool* pool, const char* string) { | |
200 | off_t offset = loc_stringpool_find(pool, string); | |
201 | if (offset >= 0) { | |
202 | DEBUG(pool->ctx, "Found '%s' at position %jd\n", string, (intmax_t)offset); | |
203 | return offset; | |
204 | } | |
205 | ||
206 | return loc_stringpool_append(pool, string); | |
207 | } | |
208 | ||
209 | void loc_stringpool_dump(struct loc_stringpool* pool) { | |
210 | off_t offset = 0; | |
211 | ||
212 | while (offset < pool->length) { | |
213 | const char* string = loc_stringpool_get(pool, offset); | |
214 | if (!string) | |
215 | return; | |
216 | ||
217 | printf("%jd (%zu): %s\n", (intmax_t)offset, strlen(string), string); | |
218 | ||
219 | // Shift offset | |
220 | offset += strlen(string) + 1; | |
221 | } | |
222 | } | |
223 | ||
224 | size_t loc_stringpool_write(struct loc_stringpool* pool, FILE* f) { | |
225 | size_t size = loc_stringpool_get_size(pool); | |
226 | ||
227 | return fwrite(pool->data, sizeof(*pool->data), size, f); | |
228 | } |