noping: Color response times based on their percentile.

Update the histogram's "ratio" array after ever response and use that to
color the response time in the noping application.

diff --git a/src/mans/oping.pod b/src/mans/oping.pod
index 313789c..a2307fe 100644 (file)
--- a/src/mans/oping.pod
+++ b/src/mans/oping.pod
@@ -258,13 +258,10 @@ If supported by the terminal, I<noping> will highlight the round-trip times
 the "expected" range, yellow marks moderately unusual times and times that
 differ a lot from the expected value are printed in red.
 
-The information used to categorize round-trip times is the I<average>
-round-trip time and the I<standard deviation>. RTTs that differ from the
-average by less than the standard deviation are considered to be "normal" and
-are printed in green. Times that differ from the average more than the standard
-deviation but less than twice the standard deviation are considered "moderately
-unusual" and are printed in yellow. Times differing more than twice the
-standard deviation from the average are considered to be "unusual" and are
+The information used to categorize round-trip times is the I<percentile>. RTTs
+in the 80th percentile are considered to be "normal" and are printed in green.
+RTTs within the 95th percentile are considered "moderately unusual" and are
+printed in yellow. RTTs above that are considered to be "unusual" and are
 printed in red.
 
 =head1 SEE ALSO

diff --git a/src/oping.c b/src/oping.c
index 367227a..6496331 100644 (file)
--- a/src/oping.c
+++ b/src/oping.c
@@ -164,7 +164,9 @@ typedef struct ping_context
 
 /* 1000 + one "infinity" bucket. */
 #define OPING_HISTOGRAM_BUCKETS 1001
-       uint32_t *latency_histogram;
+       uint32_t *histogram_counters;
+       uint32_t *histogram_accumulated;
+       double *histogram_ratio;
        size_t latency_histogram_size;
 
 #if USE_NCURSES
@@ -217,8 +219,12 @@ static ping_context_t *context_create (void) /* {{{ */
        ret->latency_total_square = 0.0;
 
        ret->latency_histogram_size = (size_t) OPING_HISTOGRAM_BUCKETS;
-       ret->latency_histogram = calloc (ret->latency_histogram_size,
-                       sizeof (*ret->latency_histogram));
+       ret->histogram_counters = calloc (ret->latency_histogram_size,
+                       sizeof (*ret->histogram_counters));
+       ret->histogram_accumulated = calloc (ret->latency_histogram_size,
+                       sizeof (*ret->histogram_accumulated));
+       ret->histogram_ratio = calloc (ret->latency_histogram_size,
+                       sizeof (*ret->histogram_ratio));
 
 #if USE_NCURSES
        ret->window = NULL;
@@ -240,8 +246,14 @@ static void context_destroy (ping_context_t *context) /* {{{ */
        }
 #endif
 
-       free (context->latency_histogram);
-       context->latency_histogram = NULL;
+       free (context->histogram_counters);
+       context->histogram_counters = NULL;
+
+       free (context->histogram_accumulated);
+       context->histogram_accumulated = NULL;
+
+       free (context->histogram_ratio);
+       context->histogram_ratio = NULL;
 
        free (context);
 } /* }}} void context_destroy */
@@ -264,27 +276,15 @@ static double context_get_percentile (ping_context_t *ctx, /* {{{ */
                double percentile)
 {
        double threshold = percentile / 100.0;
-       uint32_t accumulated[ctx->latency_histogram_size];
-       double ratios[ctx->latency_histogram_size];
        double index_to_ms_factor;
-       uint32_t num;
        size_t i;
 
-       if (ctx->latency_histogram == NULL)
+       if (ctx->histogram_ratio == NULL)
                return (NAN);
 
-       accumulated[0] = ctx->latency_histogram[0];
-       for (i = 1; i < ctx->latency_histogram_size; i++)
-               accumulated[i] = accumulated[i - 1]
-                       + ctx->latency_histogram[i];
-       num = accumulated[ctx->latency_histogram_size - 1];
-
        for (i = 0; i < ctx->latency_histogram_size; i++)
-       {
-               ratios[i] = ((double) accumulated[i]) / ((double) num);
-               if (ratios[i] >= threshold)
+               if (ctx->histogram_ratio[i] >= threshold)
                        break;
-       }
 
        if (i >= ctx->latency_histogram_size)
                return (NAN);
@@ -802,38 +802,25 @@ static _Bool has_utf8() /* {{{ */
 
 static int update_graph_boxplot (ping_context_t *ctx) /* {{{ */
 {
-       uint32_t *accumulated;
        double *ratios;
-       uint32_t num;
        size_t i;
        size_t x_max;
        size_t x;
 
        x_max = (size_t) getmaxx (ctx->window);
-       if (x_max <= 4)
+       if (x_max <= 8)
                return (EINVAL);
        x_max -= 4;
 
-       accumulated = calloc (x_max, sizeof (*accumulated));
        ratios = calloc (x_max, sizeof (*ratios));
 
        /* Downsample */
        for (i = 0; i < ctx->latency_histogram_size; i++)
        {
                x = i * x_max / ctx->latency_histogram_size;
-               accumulated[x] += ctx->latency_histogram[i];
+               ratios[x] = ctx->histogram_ratio[i];
        }
 
-       /* Sum */
-       for (x = 1; x < x_max; x++)
-               accumulated[x] += accumulated[x - 1];
-
-       num = accumulated[x_max - 1];
-
-       /* Calculate ratios */
-       for (x = 0; x < x_max; x++)
-               ratios[x] = ((double) accumulated[x]) / ((double) num);
-
        for (x = 0; x < x_max; x++)
        {
                int symbol = ' ';
@@ -893,7 +880,6 @@ static int update_graph_boxplot (ping_context_t *ctx) /* {{{ */
        }
 
        free (ratios);
-       free (accumulated);
        return (0);
 } /* }}} int update_graph_boxplot */
 
@@ -1004,7 +990,7 @@ static int update_graph_histogram (ping_context_t *ctx) /* {{{ */
        for (i = 0; i < ctx->latency_histogram_size; i++)
        {
                x = i * x_max / ctx->latency_histogram_size;
-               counters[x] += ctx->latency_histogram[i];
+               counters[x] += ctx->histogram_counters[i];
                accumulated[x] = counters[x];
 
                if (max < counters[x])
@@ -1313,9 +1299,24 @@ static int post_sleep_hook (__attribute__((unused)) pingobj_t *ping) /* {{{ */
 } /* }}} int post_sleep_hook */
 #endif
 
+static size_t latency_to_bucket (ping_context_t *ctx, double latency) /* {{{ */
+{
+       size_t bucket;
+
+       /* latency is in ms, opt_interval is in s. */
+       bucket = (size_t) ((latency * (ctx->latency_histogram_size - 1))
+                       / (1000.0 * opt_interval));
+       if (bucket >= ctx->latency_histogram_size)
+               bucket = ctx->latency_histogram_size - 1;
+
+       return (bucket);
+} /* }}} size_t latency_to_bucket */
+
 static void update_context (ping_context_t *context, double latency) /* {{{ */
 {
        size_t bucket;
+       size_t i;
+       double num;
 
        context->req_rcvd++;
        context->latency_total += latency;
@@ -1326,15 +1327,19 @@ static void update_context (ping_context_t *context, double latency) /* {{{ */
        if ((context->latency_min < 0.0) || (context->latency_min > latency))
                context->latency_min = latency;
 
-       if (context->latency_histogram == NULL)
-               return;
+       bucket = latency_to_bucket (context, latency);
+       num = (double) context->req_rcvd;
 
-       /* latency is in ms, opt_interval is in s. */
-       bucket = (size_t) ((latency * (context->latency_histogram_size - 1))
-                       / (1000.0 * opt_interval));
-       if (bucket >= context->latency_histogram_size)
-               bucket = context->latency_histogram_size - 1;
-       context->latency_histogram[bucket]++;
+       context->histogram_counters[bucket]++;
+
+       context->histogram_accumulated[0] = context->histogram_counters[0];
+       context->histogram_ratio[0] = ((double) context->histogram_accumulated[0]) / num;
+       for (i = 1; i < context->latency_histogram_size; i++)
+       {
+               context->histogram_accumulated[i] = context->histogram_accumulated[i - 1]
+                       + context->histogram_counters[i];
+               context->histogram_ratio[i] = ((double) context->histogram_accumulated[i]) / num;
+       }
 } /* }}} void update_context */
 
 static void update_host_hook (pingobj_iter_t *iter, /* {{{ */
@@ -1389,16 +1394,26 @@ static void update_host_hook (pingobj_iter_t *iter, /* {{{ */
 #if USE_NCURSES
                if (has_colors () == TRUE)
                {
+                       size_t bucket;
+                       double ratio_this;
+                       double ratio_prev;
                        int color = OPING_GREEN;
-                       double average = context_get_average (context);
-                       double stddev = context_get_stddev (context);
 
-                       if ((latency < (average - (2 * stddev)))
-                                       || (latency > (average + (2 * stddev))))
-                               color = OPING_RED;
-                       else if ((latency < (average - stddev))
-                                       || (latency > (average + stddev)))
+                       bucket = latency_to_bucket (context, latency);
+                       ratio_this = context->histogram_ratio[bucket];
+                       if (bucket > 0)
+                               ratio_prev = context->histogram_ratio[bucket - 1];
+                       else
+                               ratio_prev = 0.0;
+
+                       if ((ratio_this <= 0.5) ||
+                                       ((ratio_prev < 0.5) && (ratio_this > 0.5)))
+                               color = OPING_GREEN;
+                       else if ((ratio_this <= 0.95) ||
+                                       ((ratio_prev < 0.95) && (ratio_this > 0.95)))
                                color = OPING_YELLOW;
+                       else
+                               color = OPING_RED;
 
                        HOST_PRINTF ("%zu bytes from %s (%s): icmp_seq=%u ttl=%i ",
                                        data_len, context->host, context->addr,