+ const char *fmt;
+ char c;
+ unsigned v, u, idx = 0;
+
+ if (ul > 99999) { // do not scale if 99999 or less
+ ul *= 10;
+ do {
+ ul /= 1024;
+ idx++;
+ } while (ul >= 100000);
+ }
+ v = ul; // ullong divisions are expensive, avoid them
+
+ fmt = " 123456789";
+ u = v / 10;
+ v = v % 10;
+ if (!idx) {
+ // 99999 or less: use "12345" format
+ // u is value/10, v is last digit
+ c = buf[0] = " 123456789"[u/1000];
+ if (c != ' ') fmt = "0123456789";
+ c = buf[1] = fmt[u/100%10];
+ if (c != ' ') fmt = "0123456789";
+ c = buf[2] = fmt[u/10%10];
+ if (c != ' ') fmt = "0123456789";
+ buf[3] = fmt[u%10];
+ buf[4] = "0123456789"[v];
+ } else {
+ // value has been scaled into 0..9999.9 range
+ // u is value, v is 1/10ths (allows for 92.1M format)
+ if (u >= 100) {
+ // value is >= 100: use "1234M', " 123M" formats
+ c = buf[0] = " 123456789"[u/1000];
+ if (c != ' ') fmt = "0123456789";
+ c = buf[1] = fmt[u/100%10];
+ if (c != ' ') fmt = "0123456789";
+ v = u % 10;
+ u = u / 10;
+ buf[2] = fmt[u%10];
+ } else {
+ // value is < 100: use "92.1M" format
+ c = buf[0] = " 123456789"[u/10];
+ if (c != ' ') fmt = "0123456789";
+ buf[1] = fmt[u%10];
+ buf[2] = '.';
+ }
+ buf[3] = "0123456789"[v];
+ buf[4] = scale[idx]; /* typically scale = " kmgt..." */
+ }