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/include/haproxy/tools.h b/include/haproxy/tools.h
index 5be00b7fcb99f6fbf45758a48dc312bab05661db..4e3e4af9809034811c4917dbb8f4298ede5ad281 100644 (file)
--- a/include/haproxy/tools.h
+++ b/include/haproxy/tools.h
@@ -790,6 +790,7 @@ int parse_http_date(const char *date, int len, struct tm *tm);
 int parse_imf_date(const char *date, int len, struct tm *tm);
 int parse_rfc850_date(const char *date, int len, struct tm *tm);
 int parse_asctime_date(const char *date, int len, struct tm *tm);
+int print_time_short(struct buffer *out, const char *pfx, uint64_t ns, const char *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

diff --git a/src/tools.c b/src/tools.c
index 19b612250ef2e27f0fa3abdb3440158efc76ac00..f2f456fc2a97e926e9421b0ac3572610bfad6f4f 100644 (file)
--- a/src/tools.c
+++ b/src/tools.c
@@ -3817,6 +3817,44 @@ int parse_http_date(const char *date, int len, struct tm *tm)
        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