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62b83e6d MT |
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 | ||
23 | #include <loc/libloc.h> | |
24 | #include "libloc-private.h" | |
25 | #include "stringpool.h" | |
26 | ||
27 | struct loc_stringpool { | |
28 | struct loc_ctx* ctx; | |
29 | ||
30 | int refcount; | |
31 | char* data; | |
32 | char* pos; | |
33 | ||
34 | ssize_t max_length; | |
35 | }; | |
36 | ||
2601e83e MT |
37 | static int loc_stringpool_allocate(struct loc_stringpool* pool, size_t length) { |
38 | // Drop old data | |
39 | if (pool->data) | |
40 | free(pool->data); | |
41 | ||
42 | pool->max_length = length; | |
43 | DEBUG(pool->ctx, "Allocating pool of %zu bytes\n", pool->max_length); | |
44 | ||
45 | if (pool->max_length > 0) { | |
46 | pool->data = malloc(pool->max_length); | |
47 | if (!pool->data) | |
48 | return -ENOMEM; | |
49 | } | |
62b83e6d | 50 | |
2601e83e MT |
51 | pool->pos = pool->data; |
52 | ||
53 | return 0; | |
54 | } | |
55 | ||
56 | LOC_EXPORT int loc_stringpool_new(struct loc_ctx* ctx, struct loc_stringpool** pool, size_t max_length) { | |
62b83e6d MT |
57 | struct loc_stringpool* p = calloc(1, sizeof(*p)); |
58 | if (!p) | |
59 | return -ENOMEM; | |
60 | ||
61 | p->ctx = loc_ref(ctx); | |
62 | p->refcount = 1; | |
62b83e6d MT |
63 | |
64 | // Allocate the data section | |
2601e83e MT |
65 | int r = loc_stringpool_allocate(p, max_length); |
66 | if (r) { | |
67 | loc_stringpool_unref(p); | |
68 | return r; | |
69 | } | |
62b83e6d MT |
70 | |
71 | DEBUG(p->ctx, "String pool allocated at %p\n", p); | |
72 | DEBUG(p->ctx, " Maximum size: %zu bytes\n", p->max_length); | |
73 | *pool = p; | |
74 | ||
75 | return 0; | |
76 | } | |
77 | ||
78 | LOC_EXPORT struct loc_stringpool* loc_stringpool_ref(struct loc_stringpool* pool) { | |
79 | pool->refcount++; | |
80 | ||
81 | return pool; | |
82 | } | |
83 | ||
84 | static void loc_stringpool_free(struct loc_stringpool* pool) { | |
85 | DEBUG(pool->ctx, "Releasing string pool %p\n", pool); | |
86 | ||
87 | loc_unref(pool->ctx); | |
88 | ||
2601e83e MT |
89 | if (pool->data) |
90 | free(pool->data); | |
91 | ||
62b83e6d MT |
92 | free(pool); |
93 | } | |
94 | ||
95 | LOC_EXPORT struct loc_stringpool* loc_stringpool_unref(struct loc_stringpool* pool) { | |
96 | if (--pool->refcount > 0) | |
97 | return NULL; | |
98 | ||
99 | loc_stringpool_free(pool); | |
100 | ||
101 | return NULL; | |
102 | } | |
103 | ||
104 | static off_t loc_stringpool_get_offset(struct loc_stringpool* pool, const char* pos) { | |
105 | if (pos < pool->data) | |
106 | return -EFAULT; | |
107 | ||
108 | if (pos > (pool->data + pool->max_length)) | |
109 | return -EFAULT; | |
110 | ||
111 | return pos - pool->data; | |
112 | } | |
113 | ||
114 | static off_t loc_stringpool_get_next_offset(struct loc_stringpool* pool, off_t offset) { | |
115 | const char* string = loc_stringpool_get(pool, offset); | |
116 | ||
117 | return offset + strlen(string) + 1; | |
118 | } | |
119 | ||
120 | static size_t loc_stringpool_space_left(struct loc_stringpool* pool) { | |
2601e83e | 121 | return pool->max_length - loc_stringpool_get_size(pool); |
62b83e6d MT |
122 | } |
123 | ||
124 | LOC_EXPORT const char* loc_stringpool_get(struct loc_stringpool* pool, off_t offset) { | |
125 | if (offset >= (ssize_t)pool->max_length) | |
126 | return NULL; | |
127 | ||
128 | const char* string = pool->data + offset; | |
129 | ||
130 | // If the string is empty, we have reached the end | |
131 | if (!*string) | |
132 | return NULL; | |
133 | ||
134 | return string; | |
135 | } | |
136 | ||
2601e83e MT |
137 | LOC_EXPORT size_t loc_stringpool_get_size(struct loc_stringpool* pool) { |
138 | return loc_stringpool_get_offset(pool, pool->pos); | |
139 | } | |
140 | ||
62b83e6d MT |
141 | static off_t loc_stringpool_find(struct loc_stringpool* pool, const char* s) { |
142 | if (!s || !*s) | |
143 | return -EINVAL; | |
144 | ||
145 | off_t offset = 0; | |
146 | while (offset < pool->max_length) { | |
147 | const char* string = loc_stringpool_get(pool, offset); | |
148 | if (!string) | |
149 | break; | |
150 | ||
151 | int r = strcmp(s, string); | |
152 | if (r == 0) | |
153 | return offset; | |
154 | ||
155 | offset = loc_stringpool_get_next_offset(pool, offset); | |
156 | } | |
157 | ||
158 | return -ENOENT; | |
159 | } | |
160 | ||
161 | static off_t loc_stringpool_append(struct loc_stringpool* pool, const char* string) { | |
162 | if (!string || !*string) | |
163 | return -EINVAL; | |
164 | ||
165 | DEBUG(pool->ctx, "Appending '%s' to string pool at %p\n", string, pool); | |
166 | ||
167 | // Check if we have enough space left | |
168 | size_t l = strlen(string) + 1; | |
169 | if (l > loc_stringpool_space_left(pool)) { | |
170 | DEBUG(pool->ctx, "Not enough space to append '%s'\n", string); | |
171 | DEBUG(pool->ctx, " Need %zu bytes but only have %zu\n", l, loc_stringpool_space_left(pool)); | |
172 | return -ENOSPC; | |
173 | } | |
174 | ||
175 | off_t offset = loc_stringpool_get_offset(pool, pool->pos); | |
176 | ||
177 | // Copy string byte by byte | |
178 | while (*string && loc_stringpool_space_left(pool) > 1) { | |
179 | *pool->pos++ = *string++; | |
180 | } | |
181 | ||
182 | // Terminate the string | |
183 | *pool->pos++ = '\0'; | |
184 | ||
185 | return offset; | |
186 | } | |
187 | ||
188 | LOC_EXPORT off_t loc_stringpool_add(struct loc_stringpool* pool, const char* string) { | |
189 | off_t offset = loc_stringpool_find(pool, string); | |
190 | if (offset >= 0) { | |
191 | DEBUG(pool->ctx, "Found '%s' at position %jd\n", string, offset); | |
192 | return offset; | |
193 | } | |
194 | ||
195 | return loc_stringpool_append(pool, string); | |
196 | } | |
197 | ||
198 | LOC_EXPORT void loc_stringpool_dump(struct loc_stringpool* pool) { | |
199 | off_t offset = 0; | |
200 | ||
201 | while (offset < pool->max_length) { | |
202 | const char* string = loc_stringpool_get(pool, offset); | |
203 | if (!string) | |
204 | break; | |
205 | ||
206 | printf("%jd (%zu): %s\n", offset, strlen(string), string); | |
207 | ||
208 | offset = loc_stringpool_get_next_offset(pool, offset); | |
209 | } | |
210 | } | |
2601e83e MT |
211 | |
212 | LOC_EXPORT int loc_stringpool_read(struct loc_stringpool* pool, FILE* f, off_t offset, size_t length) { | |
213 | // Allocate enough space | |
214 | int r = loc_stringpool_allocate(pool, length); | |
215 | if (r) | |
216 | return r; | |
217 | ||
3f35869a MT |
218 | DEBUG(pool->ctx, "Reading string pool from %zu\n", offset); |
219 | ||
2601e83e MT |
220 | // Seek to the right offset |
221 | r = fseek(f, offset, SEEK_SET); | |
222 | if (r) | |
223 | return r; | |
224 | ||
225 | size_t bytes_read = fread(pool->data, sizeof(*pool->data), length, f); | |
226 | if (bytes_read < length) { | |
227 | ERROR(pool->ctx, "Could not read pool. Only read %zu bytes\n", bytes_read); | |
228 | return 1; | |
229 | } | |
230 | ||
231 | DEBUG(pool->ctx, "Read pool of %zu bytes\n", length); | |
232 | ||
233 | return 0; | |
234 | } | |
235 | ||
236 | LOC_EXPORT size_t loc_stringpool_write(struct loc_stringpool* pool, FILE* f) { | |
237 | size_t size = loc_stringpool_get_size(pool); | |
238 | ||
239 | return fwrite(pool->data, sizeof(*pool->data), size, f); | |
240 | } |