From ceeeb70dcb12c06b5770d2c7c416663d72585b97 Mon Sep 17 00:00:00 2001
From: Aaron Raddon <aaron@lytics.io>
Date: Fri, 5 Dec 2014 15:20:57 -0800
Subject: [PATCH] Benchmark tests for DateParse

---
 README.md     |   6 ++-
 bench_test.go | 118 ++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 123 insertions(+), 1 deletion(-)
 create mode 100644 bench_test.go

diff --git a/README.md b/README.md
index 02ba288..710ab33 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,11 @@
 Go Date Parser 
 ---------------------------
 
-Parse Any date format without knowing format in advance.   
+Parse Any date format without knowing format in advance.  Uses
+a Scan/Lex based approach to minimize shotgun based parse attempts.
+See bench_test.go for performance comparison.
+
+
 
 
 ```go
diff --git a/bench_test.go b/bench_test.go
new file mode 100644
index 0000000..0b87270
--- /dev/null
+++ b/bench_test.go
@@ -0,0 +1,118 @@
+package dateparse
+
+import (
+	"fmt"
+	//"github.com/bmizerany/assert"
+	"testing"
+	"time"
+)
+
+/*
+
+go test -bench Parse
+
+BenchmarkShotgunParse			50000	     37588 ns/op	   13258 B/op	     167 allocs/op
+BenchmarkDateparseParseAny		500000	      5752 ns/op	       0 B/op	       0 allocs/op
+
+*/
+func BenchmarkShotgunParse(b *testing.B) {
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		for _, dateStr := range testDates {
+			parseShotgun(dateStr)
+		}
+	}
+}
+
+func BenchmarkDateparseParseAny(b *testing.B) {
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		for _, dateStr := range testDates {
+			ParseAny(dateStr)
+		}
+	}
+}
+
+var (
+	testDates = []string{
+		"2012/03/19 10:11:59",
+		"2012/03/19 10:11:59.3186369",
+		"2009-08-12T22:15:09-07:00",
+		"2014-04-26 17:24:37.3186369",
+		"2012-08-03 18:31:59.257000000",
+		"2013-04-01 22:43:22",
+		"2014-04-26 17:24:37.123",
+		"2014-12-16 06:20:00 UTC",
+		"1384216367189",
+		"1332151919",
+		"2014-05-11 08:20:13,787",
+		"2014-04-26 05:24:37 PM",
+		"2014-04-26",
+	}
+
+	DateFormatError = fmt.Errorf("Invalid Date Format")
+
+	timeFormats = []string{
+		// ISO 8601ish formats
+		time.RFC3339Nano,
+		time.RFC3339,
+
+		// Unusual formats, prefer formats with timezones
+		time.RFC1123Z,
+		time.RFC1123,
+		time.RFC822Z,
+		time.RFC822,
+		time.UnixDate,
+		time.RubyDate,
+		time.ANSIC,
+
+		// Hilariously, Go doesn't have a const for it's own time layout.
+		// See: https://code.google.com/p/go/issues/detail?id=6587
+		"2006-01-02 15:04:05.999999999 -0700 MST",
+
+		// No timezone information
+		"2006-01-02T15:04:05.999999999",
+		"2006-01-02T15:04:05",
+		"2006-01-02 15:04:05.999999999",
+		"2006-01-02 15:04:05",
+	}
+)
+
+/*
+
+	ts, err = ParseAny("May 8, 2009 5:57:51 PM")
+	ts, err = ParseAny("Mon Jan  2 15:04:05 2006")
+	ts, err = ParseAny("Mon Jan  2 15:04:05 MST 2006")
+	ts, err = ParseAny("Mon Jan 02 15:04:05 -0700 2006")
+	ts, err = ParseAny("Monday, 02-Jan-06 15:04:05 MST")
+	ts, err = ParseAny("3/31/2014")
+	ts, err = ParseAny("03/31/2014")
+	ts, err = ParseAny("4/8/2014 22:05")
+	ts, err = ParseAny("04/08/2014 22:05")
+	ts, err = ParseAny("04/2/2014 03:00:51")
+	ts, err = ParseAny("4/02/2014 03:00:51")
+	ts, err = ParseAny("03/19/2012 10:11:59")
+	ts, err = ParseAny("03/19/2012 10:11:59.3186369")
+	ts, err = ParseAny("2014/3/31")
+	ts, err = ParseAny("2014/03/31")
+	ts, err = ParseAny("2014/4/8 22:05")
+	ts, err = ParseAny("2014/04/08 22:05")
+	ts, err = ParseAny("2014/04/2 03:00:51")
+	ts, err = ParseAny("2014/4/02 03:00:51")
+	ts, err = ParseAny()
+*/
+
+// Normalizes a variety of string representations to a time.Time in UTC.
+func parseShotgun(raw string) (time.Time, error) {
+
+	// We shouldn't need these, dupes of above
+	// Well it's not a UNIX timestamp, try ISO standards
+	for _, format := range timeFormats {
+		t, err := time.Parse(format, raw)
+		if err == nil {
+			// Parsed successfully
+			return t, nil
+		}
+	}
+	return time.Time{}, DateFormatError
+}