MINOR: tools: add print_time_short() to print a condensed duration value
When reporting some values in debugging output we often need to have
some condensed, stable-length values. This function prints a duration
from nanosecond to years with at least 4 digits of accuracy using the
most suitable unit, always on 7 chars.
diff --git a/src/tools.c b/src/tools.c
index 19b6122..f2f456f 100644
--- a/src/tools.c
+++ b/src/tools.c
@@ -3817,6 +3817,44 @@
return 0;
}
+/* print the time <ns> in a short form (exactly 7 chars) at the end of buffer
+ * <out>. "-" is printed if the value is zero, "inf" if larger than 1000 years.
+ * It returns the new buffer length, or 0 if it doesn't fit. The value will be
+ * surrounded by <pfx> and <sfx> respectively if not NULL.
+ */
+int print_time_short(struct buffer *out, const char *pfx, uint64_t ns, const char *sfx)
+{
+ double val = ns; // 52 bits of mantissa keep ns accuracy over 52 days
+ const char *unit;
+
+ if (!pfx)
+ pfx = "";
+ if (!sfx)
+ sfx = "";
+
+ do {
+ unit = " - "; if (val <= 0.0) break;
+ unit = "ns"; if (val < 1000.0) break;
+ unit = "us"; val /= 1000.0; if (val < 1000.0) break;
+ unit = "ms"; val /= 1000.0; if (val < 1000.0) break;
+ unit = "s "; val /= 1000.0; if (val < 60.0) break;
+ unit = "m "; val /= 60.0; if (val < 60.0) break;
+ unit = "h "; val /= 60.0; if (val < 24.0) break;
+ unit = "d "; val /= 24.0; if (val < 365.0) break;
+ unit = "yr"; val /= 365.0; if (val < 1000.0) break;
+ unit = " inf "; val = 0.0; break;
+ } while (0);
+
+ if (val <= 0.0)
+ return chunk_appendf(out, "%s%7s%s", pfx, unit, sfx);
+ else if (val < 10.0)
+ return chunk_appendf(out, "%s%1.3f%s%s", pfx, val, unit, sfx);
+ else if (val < 100.0)
+ return chunk_appendf(out, "%s%2.2f%s%s", pfx, val, unit, sfx);
+ else
+ return chunk_appendf(out, "%s%3.1f%s%s", pfx, val, unit, sfx);
+}
+
/* Dynamically allocates a string of the proper length to hold the formatted
* output. NULL is returned on error. The caller is responsible for freeing the
* memory area using free(). The resulting string is returned in <out> if the