2 * This file is part of the sigrok project.
4 * Copyright (C) 2010-2012 Bert Vermeulen <bert@biot.com>
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.
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.
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/>.
24 #include "libsigrok.h"
25 #include "libsigrok-internal.h"
28 * @defgroup grp_datastore Datastore
30 * Creating, using, or destroying libsigrok datastores.
35 static gpointer new_chunk(struct sr_datastore **ds);
38 * Create a new datastore with the specified unit size.
40 * The unit size is fixed once the datastore is created, and cannot be
41 * changed later on, neither can data be added to the datastore with
42 * different unit sizes later.
44 * It is the caller's responsibility to free the allocated memory of the
45 * datastore via the sr_datastore_destroy() function, if no longer needed.
47 * @todo Unitsize should probably be unsigned int or uint32_t or similar.
48 * @todo This function should have a 'chunksize' parameter, and
49 * struct sr_datastore a 'chunksize' field.
51 * @param unitsize The unit size (>= 1) to be used for this datastore.
52 * @param ds Pointer to a variable which will hold the newly created
53 * datastore structure.
55 * @return SR_OK upon success, SR_ERR_MALLOC upon memory allocation errors,
56 * or SR_ERR_ARG upon invalid arguments. If something other than SR_OK
57 * is returned, the value of 'ds' is undefined.
59 SR_API int sr_datastore_new(int unitsize, struct sr_datastore **ds)
62 sr_err("ds: %s: ds was NULL", __func__);
67 sr_err("ds: %s: unitsize was %d, but it must be >= 1",
72 if (!(*ds = g_try_malloc(sizeof(struct sr_datastore)))) {
73 sr_err("ds: %s: ds malloc failed", __func__);
77 (*ds)->ds_unitsize = unitsize;
79 (*ds)->chunklist = NULL;
85 * Destroy the specified datastore and free the memory used by it.
87 * This will free the memory used by the data in the datastore's 'chunklist',
88 * by the chunklist data structure itself, and by the datastore struct.
90 * @param ds The datastore to destroy.
92 * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments.
94 SR_API int sr_datastore_destroy(struct sr_datastore *ds)
99 sr_err("ds: %s: ds was NULL", __func__);
103 for (chunk = ds->chunklist; chunk; chunk = chunk->next)
105 g_slist_free(ds->chunklist);
113 * Append some data to the specified datastore.
115 * @todo More elaborate function description.
116 * @todo This function should use the (not yet available) 'chunksize' field
117 * of struct sr_datastore (instead of hardcoding DATASTORE_CHUNKSIZE).
118 * @todo in_unitsize and probelist are unused?
119 * @todo A few of the parameters can be const.
120 * @todo Ideally, 'ds' should be unmodified upon errors.
121 * @todo Should 0 be allowed as length?
122 * @todo Specify/document the data format of the 'data' parameter.
124 * @param ds Pointer to the datastore which shall receive the data.
126 * @param data Pointer to the memory buffer containing the data to add.
128 * @param length Length of the data to add (in number of bytes).
129 * @param in_unitsize The unit size (>= 1) of the input data.
130 * @param probelist Pointer to a list of integers (probe numbers). The probe
131 * numbers in this list are 1-based, i.e. the first probe
132 * is expected to be numbered 1 (not 0!). Must not be NULL.
134 * @return SR_OK upon success, SR_ERR_MALLOC upon memory allocation errors,
135 * or SR_ERR_ARG upon invalid arguments. If something other than SR_OK
136 * is returned, the value/state of 'ds' is undefined.
138 SR_API int sr_datastore_put(struct sr_datastore *ds, void *data,
139 unsigned int length, int in_unitsize, const int *probelist)
142 int capacity, size, num_chunks, chunk_bytes_free, chunk_offset;
146 sr_err("ds: %s: ds was NULL", __func__);
150 /* Unitsize must not be 0, we'll divide by 0 otherwise. */
151 if (ds->ds_unitsize == 0) {
152 sr_err("ds: %s: ds->ds_unitsize was 0", __func__);
157 sr_err("ds: %s: data was NULL", __func__);
161 if (in_unitsize < 1) {
162 sr_err("ds: %s: in_unitsize was %d, but it must be >= 1",
163 __func__, in_unitsize);
168 sr_err("ds: %s: probelist was NULL", __func__);
172 /* Get the last chunk in the list, or create a new one if needed. */
173 if (ds->chunklist == NULL) {
174 if (!(chunk = new_chunk(&ds))) {
175 sr_err("ds: %s: couldn't allocate new chunk", __func__);
176 return SR_ERR_MALLOC;
179 chunk = g_slist_last(ds->chunklist)->data;
182 /* Get/calculate number of chunks, free space, etc. */
183 num_chunks = g_slist_length(ds->chunklist);
184 capacity = (num_chunks * DATASTORE_CHUNKSIZE);
185 chunk_bytes_free = capacity - (ds->ds_unitsize * ds->num_units);
186 chunk_offset = capacity - (DATASTORE_CHUNKSIZE * (num_chunks - 1))
190 while (stored < length) {
191 /* No more free space left, allocate a new chunk. */
192 if (chunk_bytes_free == 0) {
193 if (!(chunk = new_chunk(&ds))) {
194 sr_err("ds: %s: couldn't allocate new chunk",
196 return SR_ERR_MALLOC;
198 chunk_bytes_free = DATASTORE_CHUNKSIZE;
202 if (length - stored > (unsigned int)chunk_bytes_free)
203 size = chunk_bytes_free;
205 /* Last part, won't fill up this chunk. */
206 size = length - stored;
208 memcpy(chunk + chunk_offset, data + stored, size);
209 chunk_bytes_free -= size;
213 ds->num_units += stored / ds->ds_unitsize;
219 * Allocate a new memory chunk, append it to the datastore's chunklist.
221 * The newly allocated chunk is added to the datastore's chunklist by this
222 * function, and the return value additionally points to the new chunk.
224 * The allocated memory is guaranteed to be cleared.
226 * @todo This function should use the datastore's 'chunksize' field instead
227 * of hardcoding DATASTORE_CHUNKSIZE.
228 * @todo Return int, so we can return SR_OK / SR_ERR_ARG / SR_ERR_MALLOC?
230 * @param ds Pointer to a variable which holds the datastore structure.
231 * Must not be NULL. The contents of 'ds' are modified in-place.
233 * @return Pointer to the newly allocated chunk, or NULL upon failure.
235 static gpointer new_chunk(struct sr_datastore **ds)
239 /* Note: Caller checked that ds != NULL. */
241 chunk = g_try_malloc0(DATASTORE_CHUNKSIZE * (*ds)->ds_unitsize);
243 sr_err("ds: %s: chunk malloc failed (ds_unitsize was %u)",
244 __func__, (*ds)->ds_unitsize);
245 return NULL; /* TODO: SR_ERR_MALLOC later? */
248 (*ds)->chunklist = g_slist_append((*ds)->chunklist, chunk);
250 return chunk; /* TODO: SR_OK later? */