add PRETTY_TIME_HMS pretty printer

Summary:
`PRETTY_TIME_HMS` extends `PRETTY_TIME` by adding additional minutes
and hours units which are more useful for human-reporting of time intervals.

Reviewed By: yfeldblum

Differential Revision: D7762524

fbshipit-source-id: 881936916db182c163a3df14196f4f11fb649527

folly/String.cpp

@@ -283,6 +283,18 @@ const PrettySuffix kPrettyTimeSuffixes[] = {
   { nullptr, 0 },
 };
 
+const PrettySuffix kPrettyTimeHmsSuffixes[] = {
+  { "h ", 60L * 60L },
+  { "m ", 60L },
+  { "s ", 1e0L },
+  { "ms", 1e-3L },
+  { "us", 1e-6L },
+  { "ns", 1e-9L },
+  { "ps", 1e-12L },
+  { "s ", 0 },
+  { nullptr, 0 },
+};
+
 const PrettySuffix kPrettyBytesMetricSuffixes[] = {
   { "EB", 1e18L },
   { "PB", 1e15L },
@@ -376,6 +388,7 @@ const PrettySuffix kPrettySISuffixes[] = {
 
 const PrettySuffix* const kPrettySuffixes[PRETTY_NUM_TYPES] = {
   kPrettyTimeSuffixes,
+  kPrettyTimeHmsSuffixes,
   kPrettyBytesMetricSuffixes,
   kPrettyBytesBinarySuffixes,
   kPrettyBytesBinaryIECSuffixes,

folly/String.h

@@ -287,7 +287,7 @@ OutputString unhexlify(StringPiece input) {
   return output;
 }
 
-/*
+/**
  * A pretty-printer for numbers that appends suffixes of units of the
  * given type.  It prints 4 sig-figs of value with the most
  * appropriate unit.
@@ -297,6 +297,7 @@ OutputString unhexlify(StringPiece input) {
  *
  * Current types are:
  *   PRETTY_TIME         - s, ms, us, ns, etc.
+ *   PRETTY_TIME_HMS     - h, m, s, ms, us, ns, etc.
  *   PRETTY_BYTES_METRIC - kB, MB, GB, etc (goes up by 10^3 = 1000 each time)
  *   PRETTY_BYTES        - kB, MB, GB, etc (goes up by 2^10 = 1024 each time)
  *   PRETTY_BYTES_IEC    - KiB, MiB, GiB, etc
@@ -305,10 +306,12 @@ OutputString unhexlify(StringPiece input) {
  *   PRETTY_UNITS_BINARY_IEC - Ki, Mi, Gi, etc
  *   PRETTY_SI           - full SI metric prefixes from yocto to Yotta
  *                         http://en.wikipedia.org/wiki/Metric_prefix
+ *
  * @author Mark Rabkin <mrabkin@fb.com>
  */
 enum PrettyType {
   PRETTY_TIME,
+  PRETTY_TIME_HMS,
 
   PRETTY_BYTES_METRIC,
   PRETTY_BYTES_BINARY,
@@ -345,7 +348,7 @@ std::string prettyPrint(double val, PrettyType, bool addSpace = true);
 double prettyToDouble(folly::StringPiece *const prettyString,
                       const PrettyType type);
 
-/*
+/**
  * Same as prettyToDouble(folly::StringPiece*, PrettyType), but
  * expects whole string to be correctly parseable. Throws std::range_error
  * otherwise

folly/test/StringTest.cpp

@@ -297,6 +297,7 @@ double pow2(int exponent) {
 }
 
 } // namespace
+
 struct PrettyTestCase{
   std::string prettyString;
   double realValue;
@@ -305,6 +306,13 @@ struct PrettyTestCase{
 
 PrettyTestCase prettyTestCases[] =
 {
+  {string("853 ms"), 85.3e-2,  PRETTY_TIME_HMS},
+  {string("8.53 s "), 85.3e-1,  PRETTY_TIME_HMS},
+  {string("1.422 m "), 85.3,  PRETTY_TIME_HMS},
+  {string("14.22 m "), 85.3e1,  PRETTY_TIME_HMS},
+  {string("2.369 h "), 85.3e2,  PRETTY_TIME_HMS},
+  {string("2.369e+04 h "), 85.3e6,  PRETTY_TIME_HMS},
+
   {string("8.53e+07 s "), 85.3e6,  PRETTY_TIME},
   {string("8.53e+07 s "), 85.3e6,  PRETTY_TIME},
   {string("85.3 ms"), 85.3e-3,  PRETTY_TIME},
@@ -417,6 +425,7 @@ PrettyTestCase prettyTestCases[] =
   {string("-85.3 ms"), -85.3e-3,  PRETTY_TIME},
   {string("-85.3 us"), -85.3e-6,  PRETTY_TIME},
   {string("-85.3 ns"), -85.3e-9,  PRETTY_TIME},
+
   // end of test
   {string("endoftest"), 0, PRETTY_NUM_TYPES}
 };