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1 | /* | |
2 | * This file is part of the sigrok project. | |
3 | * | |
4 | * Copyright (C) 2010-2012 Bert Vermeulen <bert@biot.com> | |
5 | * | |
6 | * This program is free software: you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation, either version 3 of the License, or | |
9 | * (at your option) any later version. | |
10 | * | |
11 | * This program 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 | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
18 | */ | |
19 | ||
20 | #include <stdlib.h> | |
21 | #include <stdint.h> | |
22 | #include <string.h> | |
23 | #include <glib.h> | |
24 | #include "libsigrok.h" | |
25 | #include "libsigrok-internal.h" | |
26 | ||
27 | /** | |
28 | * @file | |
29 | * | |
30 | * Creating, using, or destroying libsigrok datastores. | |
31 | */ | |
32 | ||
33 | /** | |
34 | * @defgroup grp_datastore Datastore | |
35 | * | |
36 | * Creating, using, or destroying libsigrok datastores. | |
37 | * | |
38 | * @{ | |
39 | */ | |
40 | ||
41 | static gpointer new_chunk(struct sr_datastore **ds); | |
42 | ||
43 | /** | |
44 | * Create a new datastore with the specified unit size. | |
45 | * | |
46 | * The unit size is fixed once the datastore is created, and cannot be | |
47 | * changed later on, neither can data be added to the datastore with | |
48 | * different unit sizes later. | |
49 | * | |
50 | * It is the caller's responsibility to free the allocated memory of the | |
51 | * datastore via the sr_datastore_destroy() function, if no longer needed. | |
52 | * | |
53 | * @todo Unitsize should probably be unsigned int or uint32_t or similar. | |
54 | * @todo This function should have a 'chunksize' parameter, and | |
55 | * struct sr_datastore a 'chunksize' field. | |
56 | * | |
57 | * @param unitsize The unit size (>= 1) to be used for this datastore. | |
58 | * @param ds Pointer to a variable which will hold the newly created | |
59 | * datastore structure. | |
60 | * | |
61 | * @return SR_OK upon success, SR_ERR_MALLOC upon memory allocation errors, | |
62 | * or SR_ERR_ARG upon invalid arguments. If something other than SR_OK | |
63 | * is returned, the value of 'ds' is undefined. | |
64 | */ | |
65 | SR_API int sr_datastore_new(int unitsize, struct sr_datastore **ds) | |
66 | { | |
67 | if (!ds) { | |
68 | sr_err("ds: %s: ds was NULL", __func__); | |
69 | return SR_ERR_ARG; | |
70 | } | |
71 | ||
72 | if (unitsize <= 0) { | |
73 | sr_err("ds: %s: unitsize was %d, but it must be >= 1", | |
74 | __func__, unitsize); | |
75 | return SR_ERR_ARG; | |
76 | } | |
77 | ||
78 | if (!(*ds = g_try_malloc(sizeof(struct sr_datastore)))) { | |
79 | sr_err("ds: %s: ds malloc failed", __func__); | |
80 | return SR_ERR_MALLOC; | |
81 | } | |
82 | ||
83 | (*ds)->ds_unitsize = unitsize; | |
84 | (*ds)->num_units = 0; | |
85 | (*ds)->chunklist = NULL; | |
86 | ||
87 | return SR_OK; | |
88 | } | |
89 | ||
90 | /** | |
91 | * Destroy the specified datastore and free the memory used by it. | |
92 | * | |
93 | * This will free the memory used by the data in the datastore's 'chunklist', | |
94 | * by the chunklist data structure itself, and by the datastore struct. | |
95 | * | |
96 | * @param ds The datastore to destroy. | |
97 | * | |
98 | * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments. | |
99 | */ | |
100 | SR_API int sr_datastore_destroy(struct sr_datastore *ds) | |
101 | { | |
102 | GSList *chunk; | |
103 | ||
104 | if (!ds) { | |
105 | sr_err("ds: %s: ds was NULL", __func__); | |
106 | return SR_ERR_ARG; | |
107 | } | |
108 | ||
109 | for (chunk = ds->chunklist; chunk; chunk = chunk->next) | |
110 | g_free(chunk->data); | |
111 | g_slist_free(ds->chunklist); | |
112 | g_free(ds); | |
113 | ds = NULL; | |
114 | ||
115 | return SR_OK; | |
116 | } | |
117 | ||
118 | /** | |
119 | * Append some data to the specified datastore. | |
120 | * | |
121 | * @todo More elaborate function description. | |
122 | * @todo This function should use the (not yet available) 'chunksize' field | |
123 | * of struct sr_datastore (instead of hardcoding DATASTORE_CHUNKSIZE). | |
124 | * @todo in_unitsize and probelist are unused? | |
125 | * @todo A few of the parameters can be const. | |
126 | * @todo Ideally, 'ds' should be unmodified upon errors. | |
127 | * @todo Should 0 be allowed as length? | |
128 | * @todo Specify/document the data format of the 'data' parameter. | |
129 | * | |
130 | * @param ds Pointer to the datastore which shall receive the data. | |
131 | * Must not be NULL. | |
132 | * @param data Pointer to the memory buffer containing the data to add. | |
133 | * Must not be NULL. | |
134 | * @param length Length of the data to add (in number of bytes). | |
135 | * @param in_unitsize The unit size (>= 1) of the input data. | |
136 | * @param probelist Pointer to a list of integers (probe numbers). The probe | |
137 | * numbers in this list are 1-based, i.e. the first probe | |
138 | * is expected to be numbered 1 (not 0!). Must not be NULL. | |
139 | * | |
140 | * @return SR_OK upon success, SR_ERR_MALLOC upon memory allocation errors, | |
141 | * or SR_ERR_ARG upon invalid arguments. If something other than SR_OK | |
142 | * is returned, the value/state of 'ds' is undefined. | |
143 | */ | |
144 | SR_API int sr_datastore_put(struct sr_datastore *ds, void *data, | |
145 | unsigned int length, int in_unitsize, const int *probelist) | |
146 | { | |
147 | unsigned int stored; | |
148 | int capacity, size, num_chunks, chunk_bytes_free, chunk_offset; | |
149 | gpointer chunk; | |
150 | ||
151 | if (!ds) { | |
152 | sr_err("ds: %s: ds was NULL", __func__); | |
153 | return SR_ERR_ARG; | |
154 | } | |
155 | ||
156 | /* Unitsize must not be 0, we'll divide by 0 otherwise. */ | |
157 | if (ds->ds_unitsize == 0) { | |
158 | sr_err("ds: %s: ds->ds_unitsize was 0", __func__); | |
159 | return SR_ERR_ARG; | |
160 | } | |
161 | ||
162 | if (!data) { | |
163 | sr_err("ds: %s: data was NULL", __func__); | |
164 | return SR_ERR_ARG; | |
165 | } | |
166 | ||
167 | if (in_unitsize < 1) { | |
168 | sr_err("ds: %s: in_unitsize was %d, but it must be >= 1", | |
169 | __func__, in_unitsize); | |
170 | return SR_ERR_ARG; | |
171 | } | |
172 | ||
173 | if (!probelist) { | |
174 | sr_err("ds: %s: probelist was NULL", __func__); | |
175 | return SR_ERR_ARG; | |
176 | } | |
177 | ||
178 | /* Get the last chunk in the list, or create a new one if needed. */ | |
179 | if (ds->chunklist == NULL) { | |
180 | if (!(chunk = new_chunk(&ds))) { | |
181 | sr_err("ds: %s: couldn't allocate new chunk", __func__); | |
182 | return SR_ERR_MALLOC; | |
183 | } | |
184 | } else { | |
185 | chunk = g_slist_last(ds->chunklist)->data; | |
186 | } | |
187 | ||
188 | /* Get/calculate number of chunks, free space, etc. */ | |
189 | num_chunks = g_slist_length(ds->chunklist); | |
190 | capacity = (num_chunks * DATASTORE_CHUNKSIZE); | |
191 | chunk_bytes_free = capacity - (ds->ds_unitsize * ds->num_units); | |
192 | chunk_offset = capacity - (DATASTORE_CHUNKSIZE * (num_chunks - 1)) | |
193 | - chunk_bytes_free; | |
194 | ||
195 | stored = 0; | |
196 | while (stored < length) { | |
197 | /* No more free space left, allocate a new chunk. */ | |
198 | if (chunk_bytes_free == 0) { | |
199 | if (!(chunk = new_chunk(&ds))) { | |
200 | sr_err("ds: %s: couldn't allocate new chunk", | |
201 | __func__); | |
202 | return SR_ERR_MALLOC; | |
203 | } | |
204 | chunk_bytes_free = DATASTORE_CHUNKSIZE; | |
205 | chunk_offset = 0; | |
206 | } | |
207 | ||
208 | if (length - stored > (unsigned int)chunk_bytes_free) | |
209 | size = chunk_bytes_free; | |
210 | else | |
211 | /* Last part, won't fill up this chunk. */ | |
212 | size = length - stored; | |
213 | ||
214 | memcpy(chunk + chunk_offset, data + stored, size); | |
215 | chunk_bytes_free -= size; | |
216 | stored += size; | |
217 | } | |
218 | ||
219 | ds->num_units += stored / ds->ds_unitsize; | |
220 | ||
221 | return SR_OK; | |
222 | } | |
223 | ||
224 | /** | |
225 | * Allocate a new memory chunk, append it to the datastore's chunklist. | |
226 | * | |
227 | * The newly allocated chunk is added to the datastore's chunklist by this | |
228 | * function, and the return value additionally points to the new chunk. | |
229 | * | |
230 | * The allocated memory is guaranteed to be cleared. | |
231 | * | |
232 | * @todo This function should use the datastore's 'chunksize' field instead | |
233 | * of hardcoding DATASTORE_CHUNKSIZE. | |
234 | * @todo Return int, so we can return SR_OK / SR_ERR_ARG / SR_ERR_MALLOC? | |
235 | * | |
236 | * @param ds Pointer to a variable which holds the datastore structure. | |
237 | * Must not be NULL. The contents of 'ds' are modified in-place. | |
238 | * | |
239 | * @return Pointer to the newly allocated chunk, or NULL upon failure. | |
240 | */ | |
241 | static gpointer new_chunk(struct sr_datastore **ds) | |
242 | { | |
243 | gpointer chunk; | |
244 | ||
245 | /* Note: Caller checked that ds != NULL. */ | |
246 | ||
247 | chunk = g_try_malloc0(DATASTORE_CHUNKSIZE * (*ds)->ds_unitsize); | |
248 | if (!chunk) { | |
249 | sr_err("ds: %s: chunk malloc failed (ds_unitsize was %u)", | |
250 | __func__, (*ds)->ds_unitsize); | |
251 | return NULL; /* TODO: SR_ERR_MALLOC later? */ | |
252 | } | |
253 | ||
254 | (*ds)->chunklist = g_slist_append((*ds)->chunklist, chunk); | |
255 | ||
256 | return chunk; /* TODO: SR_OK later? */ | |
257 | } | |
258 | ||
259 | /** @} */ |