gnuplot: Eliminate fixed-size header buffer based on max probes.

diff --git a/output/gnuplot.c b/output/gnuplot.c
index 4157323af57f2f555dc09c7b37689bf43c7bce39..7c033a91c3136f9016c7355605b5c129121c6a1d 100644 (file)
--- a/output/gnuplot.c
+++ b/output/gnuplot.c
@@ -41,9 +41,6 @@ struct context {
        uint8_t *old_sample;
 };
 
-#define MAX_HEADER_LEN \
-       (1024 + (SR_MAX_NUM_PROBES * (SR_MAX_PROBENAME_LEN + 10)))
-
 static const char *gnuplot_header = "\
 # Sample data in space-separated columns format usable by gnuplot\n\
 #\n\
@@ -66,7 +63,7 @@ static int init(struct sr_output *o)
        GVariant *gvar;
        uint64_t samplerate;
        unsigned int i;
-       int b, num_probes;
+       int num_probes;
        char *c, *frequency_s;
        char wbuf[1000], comment[128];
        time_t t;
@@ -91,12 +88,6 @@ static int init(struct sr_output *o)
                return SR_ERR_MALLOC;
        }
 
-       if (!(ctx->header = g_try_malloc0(MAX_HEADER_LEN + 1))) {
-               sr_err("%s: ctx->header malloc failed", __func__);
-               g_free(ctx);
-               return SR_ERR_MALLOC;
-       }
-
        o->internal = ctx;
        ctx->num_enabled_probes = 0;
        for (l = o->sdi->probes; l; l = l->next) {
@@ -114,7 +105,6 @@ static int init(struct sr_output *o)
                samplerate = g_variant_get_uint64(gvar);
                if (!(frequency_s = sr_samplerate_string(samplerate))) {
                        sr_err("%s: sr_samplerate_string failed", __func__);
-                       g_free(ctx->header);
                        g_free(ctx);
                        g_variant_unref(gvar);
                        return SR_ERR;
@@ -137,24 +127,15 @@ static int init(struct sr_output *o)
 
        if (!(frequency_s = sr_period_string(samplerate))) {
                sr_err("%s: sr_period_string failed", __func__);
-               g_free(ctx->header);
                g_free(ctx);
                return SR_ERR;
        }
 
        t = time(NULL);
-       b = snprintf(ctx->header, MAX_HEADER_LEN, gnuplot_header,
-                    PACKAGE_STRING, ctime(&t), comment, frequency_s,
-                    (char *)&wbuf);
+       ctx->header = g_strdup_printf(gnuplot_header, PACKAGE_STRING,
+                       ctime(&t), comment, frequency_s, (char *)&wbuf);
        g_free(frequency_s);
 
-       if (b < 0) {
-               sr_err("%s: sprintf failed", __func__);
-               g_free(ctx->header);
-               g_free(ctx);
-               return SR_ERR;
-       }
-
        if (!(ctx->old_sample = g_try_malloc0(ctx->unitsize))) {
                sr_err("%s: ctx->old_sample malloc failed", __func__);
                g_free(ctx->header);