#define LOG_PREFIX "output/wavedrom"
-struct context
-{
+struct context {
uint32_t channel_count;
- // TODO: remove this, channels are available with each call
struct sr_channel **channels;
-
- // output strings
- GString **channel_outputs;
+ GString **channel_outputs; /* output strings */
};
-// takes all data collected in context and
-// renders it all to a JSON string.
+/* Converts accumulated output data to a JSON string. */
static GString *wavedrom_render(const struct context *ctx)
{
- // open
- GString *output = g_string_new("{ \"signal\": [");
- uint32_t ch, i;
- char lastChar, currentChar;
+ GString *output;
+ size_t ch, i;
+ char last_char, curr_char;
+ output = g_string_new("{ \"signal\": [");
for (ch = 0; ch < ctx->channel_count; ch++) {
if (!ctx->channel_outputs[ch])
continue;
- // channel strip
+ /* Channel strip. */
g_string_append_printf(output,
"{ \"name\": \"%s\", \"wave\": \"", ctx->channels[ch]->name);
- lastChar = 0;
+ last_char = 0;
for (i = 0; i < ctx->channel_outputs[ch]->len; i++) {
- currentChar = ctx->channel_outputs[ch]->str[i];
- // data point
- if (currentChar == lastChar) {
+ curr_char = ctx->channel_outputs[ch]->str[i];
+ /* Data point. */
+ if (curr_char == last_char) {
g_string_append_c(output, '.');
} else {
- g_string_append_c(output, currentChar);
- lastChar = currentChar;
+ g_string_append_c(output, curr_char);
+ last_char = curr_char;
}
}
if (ch < ctx->channel_count - 1) {
g_string_append(output, "\" },");
} else {
- // last channel - no comma
+ /* Last channel, no comma. */
g_string_append(output, "\" }");
}
}
-
- // close
g_string_append(output, "], \"config\": { \"skin\": \"narrow\" }}");
+
return output;
}
+static void process_logic(const struct context *ctx,
+ const struct sr_datafeed_logic *logic)
+{
+ size_t sample_count, ch, i;
+ uint8_t *sample, bit;
+ GString *accu;
+
+ if (!ctx->channel_count)
+ return;
+
+ /*
+ * Extract the logic bits for each channel and store them
+ * as wavedrom letters (1/0) in each channel's text string.
+ * This transforms the input which consists of sample sets
+ * that span multiple channels into output stripes per logic
+ * channel which consist of bits for that individual channel.
+ *
+ * TODO Reduce memory consumption during accumulation of
+ * output data.
+ *
+ * Ideally we'd accumulate binary chunks, and defer conversion
+ * to the text format. Analog data already won't get here, only
+ * logic data does. When the per-channel transformation also
+ * gets deferred until later, then the only overhead would be
+ * for disabled logic channels. Which may be acceptable or even
+ * negligable.
+ *
+ * An optional addition to the above mentioned accumulation of
+ * binary data is RLE compression. Mark both the position in the
+ * accumulated data as well as a repetition counter, instead of
+ * repeatedly storing the same sample set. The efficiency of
+ * this approach of course depends on the change rate of input
+ * data. But the approach perfectly matches the WaveDrom syntax
+ * for repeated bit patterns, and thus is easily handled in the
+ * text rendering stage of the output module.
+ */
+ sample_count = logic->length / logic->unitsize;
+ for (i = 0; i < sample_count; i++) {
+ sample = logic->data + i * logic->unitsize;
+ for (ch = 0; ch < ctx->channel_count; ch++) {
+ accu = ctx->channel_outputs[ch];
+ if (!accu)
+ continue;
+ bit = sample[ch / 8] & (1 << (ch % 8));
+ g_string_append_c(accu, bit ? '1' : '0');
+ }
+ }
+}
+
+static int receive(const struct sr_output *o,
+ const struct sr_datafeed_packet *packet, GString **out)
+{
+ struct context *ctx;
+
+ *out = NULL;
+
+ if (!o || !o->sdi || !o->priv)
+ return SR_ERR_ARG;
+
+ ctx = o->priv;
+
+ switch (packet->type) {
+ case SR_DF_LOGIC:
+ process_logic(ctx, packet->payload);
+ break;
+ case SR_DF_END:
+ *out = wavedrom_render(ctx);
+ break;
+ }
+
+ return SR_OK;
+}
+
static int init(struct sr_output *o, GHashTable *options)
{
struct context *ctx;
struct sr_channel *channel;
GSList *l;
- uint32_t i;
+ size_t i;
(void)options;
if (!o || !o->sdi)
return SR_ERR_ARG;
- o->priv = ctx = g_malloc(sizeof(struct context));
+ o->priv = ctx = g_malloc0(sizeof(*ctx));
ctx->channel_count = g_slist_length(o->sdi->channels);
- ctx->channels = g_malloc(
- sizeof(struct sr_channel) * ctx->channel_count);
- ctx->channel_outputs = g_malloc(
- sizeof(GString *) * ctx->channel_count);
+ ctx->channels = g_malloc0(
+ sizeof(ctx->channels[0]) * ctx->channel_count);
+ ctx->channel_outputs = g_malloc0(
+ sizeof(ctx->channel_outputs[0]) * ctx->channel_count);
for (i = 0, l = o->sdi->channels; l; l = l->next, i++) {
channel = l->data;
- if (channel->enabled &&
- channel->type == SR_CHANNEL_LOGIC) {
+ if (channel->enabled && channel->type == SR_CHANNEL_LOGIC) {
ctx->channels[i] = channel;
ctx->channel_outputs[i] = g_string_new(NULL);
- } else {
- ctx->channels[i] = NULL;
- ctx->channel_outputs[i] = NULL;
}
}
static int cleanup(struct sr_output *o)
{
struct context *ctx;
- uint32_t i;
+ GString *s;
if (!o)
return SR_ERR_ARG;
o->priv = NULL;
if (ctx) {
- for (i = 0; i < ctx->channel_count; i++) {
- if (ctx->channel_outputs[i])
- g_string_free(ctx->channel_outputs[i], TRUE);
+ while (--ctx->channel_count) {
+ s = ctx->channel_outputs[ctx->channel_count];
+ if (s)
+ g_string_free(s, TRUE);
}
g_free(ctx->channel_outputs);
g_free(ctx->channels);
return SR_OK;
}
-static void process_logic(const struct context *ctx,
- const struct sr_datafeed_logic *logic)
-{
- unsigned int sample_count, ch, i;
- uint8_t *sample;
-
- sample_count = logic->length / logic->unitsize;
-
- // extract the logic bits for each channel and
- // store them as wavedrom letters (1/0) in each channel's string
- for (ch = 0; ch < ctx->channel_count; ch++) {
- if (ctx->channels[ch]) {
- for (i = 0; i < sample_count; i++) {
- sample = logic->data + i * logic->unitsize;
-
- if (ctx->channel_outputs[ch]) {
- g_string_append_c(ctx->channel_outputs[ch],
- sample[ch / 8] & (1 << (ch % 8)) ? '1' : '0');
- }
- }
- }
- }
-}
-
-static int receive(const struct sr_output *o,
- const struct sr_datafeed_packet *packet, GString **out)
-{
- struct context *ctx;
-
- *out = NULL;
-
- if (!o || !o->sdi || !o->priv)
- return SR_ERR_ARG;
-
- ctx = o->priv;
-
- switch (packet->type) {
- case SR_DF_LOGIC:
- process_logic(ctx, packet->payload);
- break;
- case SR_DF_END:
- *out = wavedrom_render(ctx);
- break;
- }
-
- return SR_OK;
-}
-
SR_PRIV struct sr_output_module output_wavedrom = {
.id = "wavedrom",
- .name = "WAVEDROM",
+ .name = "WaveDrom",
.desc = "WaveDrom.com file format",
.exts = (const char *[]){"wavedrom", "json", NULL},
.flags = 0,
projects / libsigrok.git / blobdiff