Gnuplot: Nicer output formatting.

[libsigrok.git] / output / output_gnuplot.c

diff --git a/output/output_gnuplot.c b/output/output_gnuplot.c
index 9d550a48ef4a14db76940aeb2f2443475943ce3e..2c062397db98075c3167a45ba000b86c4433eeea 100644 (file)
--- a/output/output_gnuplot.c
+++ b/output/output_gnuplot.c
@@ -34,10 +34,16 @@ struct context {
 const char *gnuplot_header = "\
 # Sample data in space-separated columns format usable by gnuplot\n\
 #\n\
-# Generated by: %s on %s\n\
-# Comment: Acquisition with %d/%d probes at %s\n\
+# Generated by: %s on %s%s\
 # Timescale: %d %s\n\
-# Column assignment:\n%s\n";
+#\n\
+# Column\tProbe\n\
+# -------------------------------------\
+----------------------------------------\n\
+# 0\t\tSample counter (for internal gnuplot purposes)\n%s\n";
+
+const char *gnuplot_header_comment = "\
+# Comment: Acquisition with %d/%d probes at %s\n";
 
 static int init(struct output *o)
 {
@@ -51,11 +57,12 @@ static int init(struct output *o)
        unsigned int i;
        int b, num_probes;
        char *c, *samplerate_s;
-       char wbuf[1000];
+       char wbuf[1000], comment[128];
+       time_t t;
 
-       ctx = malloc(sizeof(struct context));
-       if (ctx == NULL)
+       if (!(ctx = calloc(1, sizeof(struct context))))
                return SIGROK_ERR_MALLOC;
+
        o->internal = ctx;
        ctx->num_enabled_probes = 0;
        for (l = o->device->probes; l; l = l->next) {
@@ -69,31 +76,41 @@ static int init(struct output *o)
 
        /* TODO: Allow for configuration via o->param. */
 
-       ctx->header = calloc(1, MAX_HEADER_LEN + 1);
-       if (ctx->header == NULL)
+       if (!(ctx->header = calloc(1, MAX_HEADER_LEN + 1))) {
+               free(ctx);
                return SIGROK_ERR_MALLOC;
+       }
+
        num_probes = g_slist_length(o->device->probes);
        /* TODO: Handle num_probes == 0, too many probes, etc. */
-       samplerate = *((uint64_t *) o->device->plugin->get_device_info(
-                       o->device->plugin_index, DI_CUR_SAMPLERATE));
-  
-       if ((samplerate_s = sigrok_samplerate_string(samplerate)) == NULL)
-               return -1; // FIXME
+
+       comment[0] = '\0';
+       if (o->device->plugin) {
+               samplerate = *((uint64_t *) o->device->plugin->get_device_info(
+                               o->device->plugin_index, DI_CUR_SAMPLERATE));
+               if (!(samplerate_s = sigrok_samplerate_string(samplerate))) {
+                       free(ctx->header);
+                       free(ctx);
+                       return SIGROK_ERR;
+               }
+               snprintf(comment, 127, gnuplot_header_comment,
+                        ctx->num_enabled_probes, num_probes, samplerate_s);
+               free(samplerate_s);
+       }
 
        /* Columns / channels */
        wbuf[0] = '\0';
        for (i = 0; i < ctx->num_enabled_probes; i++) {
                c = (char *)&wbuf + strlen((char *)&wbuf);
-               sprintf(c, "# Column %d: channel %s\n", i, ctx->probelist[i]);
+               sprintf(c, "# %d\t\t%s\n", i + 1, ctx->probelist[i]);
        }
 
        /* TODO: date: File or signals? Make y/n configurable. */
        /* TODO: Timescale */
+       t = time(NULL);
        b = snprintf(ctx->header, MAX_HEADER_LEN, gnuplot_header,
-                    PACKAGE_STRING, "TODO", ctx->num_enabled_probes,
-                    num_probes, samplerate_s, 1, "ns", (char *)&wbuf);
-
-       free(samplerate_s);
+                    PACKAGE_STRING, ctime(&t), comment, 1, "ns",
+                    (char *)&wbuf);
 
        /* TODO: Handle snprintf errors. */
 
@@ -104,19 +121,15 @@ static int event(struct output *o, int event_type, char **data_out,
                 uint64_t *length_out)
 {
        struct context *ctx;
-       char *outbuf;
-       int outlen = 1; /* FIXME */
 
        ctx = o->internal;
-       switch(event_type) {
+       switch (event_type) {
        case DF_TRIGGER:
+               /* TODO */
                break;
        case DF_END:
-               outbuf = calloc(1, 1); // FIXME
-               if (outbuf == NULL)
-                       return SIGROK_ERR_MALLOC;
-               *data_out = outbuf;
-               *length_out = outlen;
+               *data_out = NULL;
+               *length_out = 0;
                free(o->internal);
                o->internal = NULL;
                break;
@@ -129,33 +142,35 @@ static int data(struct output *o, char *data_in, uint64_t length_in,
                char **data_out, uint64_t *length_out)
 {
        struct context *ctx;
-       unsigned int offset, outsize, p, curbit;
+       unsigned int i, outsize, p, curbit;
        uint64_t sample, count = 0;
        char *outbuf, *c;
 
        ctx = o->internal;
-       outsize = strlen(ctx->header);
-       outbuf = calloc(1, outsize + 1 + 10000); // FIXME: Use realloc().
-       if (outbuf == NULL)
-               return SIGROK_ERR_MALLOC;
+       outsize = 0;
+       if (ctx->header)
+               outsize = strlen(ctx->header);
+
+       /* FIXME: Use realloc(). */
+       if (!(outbuf = calloc(1, outsize + 1 + 1000000)))
+               return SIGROK_ERR_MALLOC; /* TODO: free()? What to free? */
+
+       outbuf[0] = '\0';
        if (ctx->header) {
                /* The header is still here, this must be the first packet. */
                strncpy(outbuf, ctx->header, outsize);
                free(ctx->header);
                ctx->header = NULL;
-       } else {
-               outbuf[0] = 0;
        }
 
        /* TODO: Are disabled probes handled correctly? */
 
-       for (offset = 0; offset <= length_in - ctx->unitsize;
-                                               offset += ctx->unitsize) {
-               memcpy(&sample, data_in + offset, ctx->unitsize);
+       for (i = 0; i <= length_in - ctx->unitsize; i += ctx->unitsize) {
+               memcpy(&sample, data_in + i, ctx->unitsize);
 
                /* The first column is a counter (needed for gnuplot). */
                c = outbuf + strlen(outbuf);
-               sprintf(c, "%"PRIu64"\t\t", count++);
+               sprintf(c, "%" PRIu64 "\t\t", count++);
 
                /* The next columns are the values of all channels. */
                for (p = 0; p < ctx->num_enabled_probes; p++) {