human-readable: use dynamic precision length

Let's lower precision for huge numbers.

The output used to be:

  3.45M -> 46.73M -> 523.11M -> 1.24G -> ...

With this change the code always gives the three most significant digits:

  3.45M -> 46.7M -> 523M -> 1.24G -> ...

Author: eworm-de

lib/compat.c

@@ -185,6 +185,7 @@ char *do_big_num(int64 num, int human_flag, const char *fract)
 		if (num >= mult || num <= -mult) {
 			const char* units = " KMGTPEZY";
 			int64 powi = 1;
+			int powj = 1, precision = 2;
 
 			for (;;) {
 				if (labs(num / mult) < powi)
@@ -197,8 +198,14 @@ char *do_big_num(int64 num, int human_flag, const char *fract)
 				++units;
 			}
 
-			snprintf(bufs[n], sizeof bufs[0], "%.2f%c",
-				(double) num / powi, *units);
+			for (; precision > 0; precision--) {
+				powj *= 10;
+				if (labs(num / powi) < powj)
+					break;
+			}
+
+			snprintf(bufs[n], sizeof bufs[0], "%.*f%c",
+				precision, (double) num / powi, *units);
 			return bufs[n];
 		}
 	}