static gpointer new_chunk(struct sr_datastore **ds);
+/**
+ * Create a new datastore with the specified unit size.
+ *
+ * The unit size is fixed once the datastore is created, and cannot be
+ * changed later on, neither can data be added to the datastore with
+ * different unit sizes later.
+ *
+ * It is the caller's responsibility to free the allocated memory of the
+ * datastore via the sr_datastore_destroy() function, if no longer needed.
+ *
+ * TODO: Unitsize should probably be unsigned int or uint32_t or similar.
+ * TODO: This function should have a 'chunksize' parameter, and
+ * struct sr_datastore a 'chunksize' field.
+ *
+ * @param unitsize The unit size (>= 1) to be used for this datastore.
+ * @param ds Pointer to a variable which will hold the newly created
+ * datastore structure.
+ *
+ * @return SR_OK upon success, SR_ERR_MALLOC upon memory allocation errors,
+ * or SR_ERR_ARG upon invalid arguments. If something other than SR_OK
+ * is returned, the value of 'ds' is undefined.
+ */
int sr_datastore_new(int unitsize, struct sr_datastore **ds)
{
- if (!ds)
- return SR_ERR;
+ if (!ds) {
+ sr_err("ds: %s: ds was NULL", __func__);
+ return SR_ERR_ARG;
+ }
- if (unitsize <= 0)
- return SR_ERR; /* TODO: Different error? */
+ if (unitsize <= 0) {
+ sr_err("ds: %s: unitsize was %d, but it must be >= 1",
+ __func__, unitsize);
+ return SR_ERR_ARG;
+ }
if (!(*ds = g_try_malloc(sizeof(struct sr_datastore)))) {
sr_err("ds: %s: ds malloc failed", __func__);
return SR_OK;
}
+/**
+ * Destroy the specified datastore and free the memory used by it.
+ *
+ * This will free the memory used by the data in the datastore's 'chunklist',
+ * by the chunklist data structure itself, and by the datastore struct.
+ *
+ * @param ds The datastore to destroy.
+ *
+ * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments.
+ */
int sr_datastore_destroy(struct sr_datastore *ds)
{
GSList *chunk;
- if (!ds)
- return SR_ERR;
+ if (!ds) {
+ sr_err("ds: %s: ds was NULL", __func__);
+ return SR_ERR_ARG;
+ }
for (chunk = ds->chunklist; chunk; chunk = chunk->next)
g_free(chunk->data);
g_slist_free(ds->chunklist);
g_free(ds);
+ /* TODO: Set ds = NULL? */
+
return SR_OK;
}
-void sr_datastore_put(struct sr_datastore *ds, void *data, unsigned int length,
- int in_unitsize, int *probelist)
+/**
+ * Append some data to the specified datastore.
+ *
+ * TODO: More elaborate function description.
+ *
+ * TODO: This function should use the (not yet available) 'chunksize' field
+ * of struct sr_datastore (instead of hardcoding DATASTORE_CHUNKSIZE).
+ * TODO: in_unitsize and probelist are unused?
+ * TODO: A few of the parameters can be const.
+ * TODO: Handle new_chunk() returning NULL.
+ * TODO: Ideally, 'ds' should be unmodified upon errors.
+ *
+ * @param ds Pointer to the datastore which shall receive the data.
+ * Must not be NULL.
+ * @param data Pointer to the memory buffer containing the data to add.
+ * Must not be NULL. TODO: Data format?
+ * @param length Length of the data to add (in number of bytes).
+ * TODO: Should 0 be allowed as length?
+ * @param in_unitsize The unit size (>= 1) of the input data.
+ * @param probelist Pointer to a list of integers (probe numbers). The probe
+ * numbers in this list are 1-based, i.e. the first probe
+ * is expected to be numbered 1 (not 0!). Must not be NULL.
+ *
+ * @return SR_OK upon success, SR_ERR_MALLOC upon memory allocation errors,
+ * or SR_ERR_ARG upon invalid arguments. If something other than SR_OK
+ * is returned, the value/state of 'ds' is undefined.
+ */
+int sr_datastore_put(struct sr_datastore *ds, void *data, unsigned int length,
+ int in_unitsize, int *probelist)
{
unsigned int stored;
int capacity, size, num_chunks, chunk_bytes_free, chunk_offset;
(void)in_unitsize;
(void)probelist;
+ if (!ds) {
+ sr_err("ds: %s: ds was NULL", __func__);
+ return SR_ERR_ARG;
+ }
+
+ /* Unitsize must not be 0, we'll divide by 0 otherwise. */
+ if (ds->ds_unitsize == 0) {
+ sr_err("ds: %s: ds->ds_unitsize was 0", __func__);
+ return SR_ERR_ARG;
+ }
+
+ if (!data) {
+ sr_err("ds: %s: data was NULL", __func__);
+ return SR_ERR_ARG;
+ }
+
+ if (in_unitsize < 1) {
+ sr_err("ds: %s: in_unitsize was %d, but it must be >= 1",
+ __func__, in_unitsize);
+ return SR_ERR_ARG;
+ }
+
+ if (!probelist) {
+ sr_err("ds: %s: probelist was NULL", __func__);
+ return SR_ERR_ARG;
+ }
+
+ /* Get the last chunk in the list, or create a new one if needed. */
if (ds->chunklist == NULL)
chunk = new_chunk(&ds);
else
chunk = g_slist_last(ds->chunklist)->data;
+ /* Get/calculate number of chunks, free space, etc. */
num_chunks = g_slist_length(ds->chunklist);
capacity = (num_chunks * DATASTORE_CHUNKSIZE);
chunk_bytes_free = capacity - (ds->ds_unitsize * ds->num_units);
chunk_offset = capacity - (DATASTORE_CHUNKSIZE * (num_chunks - 1))
- chunk_bytes_free;
+
stored = 0;
while (stored < length) {
+ /* No more free space left, allocate a new chunk. */
if (chunk_bytes_free == 0) {
chunk = new_chunk(&ds);
chunk_bytes_free = DATASTORE_CHUNKSIZE;
chunk_bytes_free -= size;
stored += size;
}
+
ds->num_units += stored / ds->ds_unitsize;
+
+ return SR_OK;
}
+/**
+ * Allocate a new memory chunk, append it to the datastore's chunklist.
+ *
+ * The newly allocated chunk is added to the datastore's chunklist by this
+ * function, and the return value additionally points to the new chunk.
+ *
+ * The allocated memory is guaranteed to be cleared.
+ *
+ * TODO: This function should use the datastore's 'chunksize' field instead
+ * of hardcoding DATASTORE_CHUNKSIZE.
+ * TODO: Return int, so we can return SR_OK / SR_ERR_ARG / SR_ERR_MALLOC?
+ *
+ * @param ds Pointer to a variable which holds the datastore structure.
+ * Must not be NULL. The contents of 'ds' are modified in-place.
+ *
+ * @return Pointer to the newly allocated chunk, or NULL upon failure.
+ */
static gpointer new_chunk(struct sr_datastore **ds)
{
gpointer chunk;
- if (!(chunk = malloc(DATASTORE_CHUNKSIZE * (*ds)->ds_unitsize)))
- return NULL;
+ if (!ds) {
+ sr_err("ds: %s: ds was NULL", __func__);
+ return NULL; /* TODO: SR_ERR_ARG later? */
+ }
+
+ chunk = g_try_malloc0(DATASTORE_CHUNKSIZE * (*ds)->ds_unitsize);
+ if (!chunk) {
+ sr_err("ds: %s: chunk malloc failed", __func__);
+ return NULL; /* TODO: SR_ERR_MALLOC later? */
+ }
(*ds)->chunklist = g_slist_append((*ds)->chunklist, chunk);
- return chunk;
+ return chunk; /* TODO: SR_OK later? */
}
projects / libsigrok.git / commitdiff