Added option for lin/log scale (not yet accessible)

Added ability to specify fixed maximum for bandwidth scale.

iftop.h

@@ -8,7 +8,7 @@
 
 #include "config.h"
 
-/* 60 / 3  */
+/* 40 / 2  */
 #define HISTORY_LENGTH  20
 #define RESOLUTION 2
 

options.c

@@ -28,7 +28,7 @@
 
 options_t options;
 
-char optstr[] = "+i:f:nN:hpbBP";
+char optstr[] = "+i:f:nN:hpbBPm:";
 
 /* Global options. */
 
@@ -112,6 +112,8 @@ static void set_defaults() {
     options.linedisplay = OPTION_LINEDISPLAY_TWO_LINE;
     options.screen_offset = 0;
     options.show_totals = 0;
+    options.max_bandwidth = 0; /* auto */
+    options.log_scale = 1; /* auto */
 }
 
 static void die(char *msg) {
@@ -119,6 +121,32 @@ static void die(char *msg) {
     exit(1);
 }
 
+static void set_max_bandwidth(char* arg) {
+    char* units;
+    long long mult = 1;
+    long long value;
+    units = arg + strspn(arg, "0123456789");
+    if(strlen(units) > 1) {
+        die("Invalid units\n");
+    }
+    if(strlen(units) == 1) {
+        if(*units == 'k' || *units == 'K') {
+            mult = 1024;
+        }
+        else if(*units == 'm' || *units == 'M') {
+            mult = 1024 * 1024;
+        }
+        else if(*units == 'g' || *units == 'G') {
+            mult = 1024 * 1024 * 1024;
+        }
+    }
+    *units = '\0';
+    if(sscanf(arg, "%lld", &value) != 1) {
+        die("Error reading max bandwidth\n");
+    }
+    options.max_bandwidth = value * mult;
+}
+
 static void set_net_filter(char* arg) {
     char* mask;
 
@@ -180,6 +208,7 @@ static void usage(FILE *fp) {
 "                       (default: none, but only IP packets are counted)\n"
 "   -N net/mask         show traffic flows in/out of network\n"
 "   -P                  show ports as well as hosts\n"
+"   -m limit            sets the upper limit for the bandwidth scale\n"
 "\n"
 "iftop, version " IFTOP_VERSION "\n"
 "copyright (c) 2002 Paul Warren <pdw@ex-parrot.com> and contributors\n"
@@ -223,6 +252,11 @@ void options_read(int argc, char **argv) {
                 set_net_filter(optarg);
                 break;
             
+            case 'm':
+                set_max_bandwidth(optarg);
+                break;
+
+
             case 'b':
                 options.showbars = 0;
                 break;

options.h

@@ -66,6 +66,9 @@ typedef struct {
 
     int show_totals;
 
+    long long max_bandwidth;
+    int log_scale;
+
 } options_t;
 
 #endif /* __OPTIONS_H_ */

ui.c

@@ -202,6 +202,25 @@ static struct {
     };
 static int rateidx = 0, wantbiggerrate;
 
+static int get_bar_interval(float bandwidth) {
+    int i = 10;
+    if(bandwidth > 100000000) {
+        i = 100;
+    }
+    return i;
+}
+
+static float get_max_bandwidth() {
+    float max;
+    if(options.max_bandwidth > 0) {
+        max = options.max_bandwidth;
+    }
+    else {
+        max = scale[rateidx].max;
+    }
+    return max;
+}
+
 /* rate in bits */
 static int get_bar_length(const int rate) {
     float l;
@@ -209,28 +228,56 @@ static int get_bar_length(const int rate) {
         return 0;
     if (rate > scale[rateidx].max)
         wantbiggerrate = 1;
-    l = log(rate) / log(scale[rateidx].max);
+    if(options.log_scale) {
+        l = log(rate) / log(get_max_bandwidth());
+    }
+    else {
+        l = rate / get_max_bandwidth();
+    }
     return (l * COLS);
 }
 
 static void draw_bar_scale(int* y) {
     float i;
+    float max,interval;
+    max = get_max_bandwidth();
+    interval = get_bar_interval(max);
     if(options.showbars) {
+        float stop;
         /* Draw bar graph scale on top of the window. */
         move(*y, 0);
         clrtoeol();
         mvhline(*y + 1, 0, 0, COLS);
         /* i in bytes */
-        for (i = 1.25; i * 8 <= scale[rateidx].max; i *= scale[rateidx].interval) {
+
+        if(options.log_scale) {
+            i = 1.25;
+            stop = max / 8;
+        }
+        else {
+            i = max / (5 * 8);
+            stop = max / 8;
+        }
+
+        /* for (i = 1.25; i * 8 <= max; i *= interval) { */
+        while(i <= stop) {
             char s[40], *p;
             int x;
-            readable_size(i, s, sizeof s, 1000, 0);
+            /* This 1024 vs 1000 stuff is just plain evil */
+            readable_size(i, s, sizeof s, options.log_scale ? 1000 : 1024, 0);
             p = s + strspn(s, " ");
             x = get_bar_length(i * 8);
             mvaddch(*y + 1, x, ACS_BTEE);
             if (x + strlen(p) >= COLS)
                 x = COLS - strlen(p);
             mvaddstr(*y, x, p);
+
+            if(options.log_scale) {
+                i *= interval;
+            }
+            else {
+                i += max / (5 * 8);
+            }
         }
         mvaddch(*y + 1, 0, ACS_LLCORNER);
         *y += 2;
@@ -677,7 +724,7 @@ void ui_print() {
     refresh();
 
     /* Bar chart auto scale */
-    if (wantbiggerrate) {
+    if (wantbiggerrate && options.max_bandwidth == 0) {
         ++rateidx;
         wantbiggerrate = 0;
     }