From b1270b3ae501c136d1999fa0bacc87617ffe7c40 Mon Sep 17 00:00:00 2001
From: Kirill <g4s8.public@gmail.com>
Date: Mon, 17 May 2021 12:00:10 +0300
Subject: [PATCH 1/2] Preload method with benchmarks

Fixes #13 - added preload method to initialize database without
performing any license check. Added two benchmarks to compare
the difference between calls with and without preload.
---
 licensedb/internal/investigation.go |  5 ++++
 licensedb/licensedb.go              |  5 ++++
 licensedb/licensedb_test.go         | 45 +++++++++++++++++++++++++++++
 3 files changed, 55 insertions(+)
 create mode 100644 licensedb/licensedb_test.go

diff --git a/licensedb/internal/investigation.go b/licensedb/internal/investigation.go
index bd3c924..f2c9307 100644
--- a/licensedb/internal/investigation.go
+++ b/licensedb/internal/investigation.go
@@ -161,3 +161,8 @@ func InvestigateReadmeText(text []byte, fs filer.Filer) map[string]float32 {
 func IsLicenseDirectory(fileName string) bool {
 	return licenseDirectoryRe.MatchString(strings.ToLower(fileName))
 }
+
+// Preload license database
+func Preload() {
+	_ = globalLicenseDatabase()
+}
diff --git a/licensedb/licensedb.go b/licensedb/licensedb.go
index 55670ce..520a305 100644
--- a/licensedb/licensedb.go
+++ b/licensedb/licensedb.go
@@ -53,3 +53,8 @@ func Detect(fs filer.Filer) (map[string]api.Match, error) {
 	}
 	return licenses, nil
 }
+
+// Preload database with licenses
+func Preload() {
+	internal.Preload()
+}
diff --git a/licensedb/licensedb_test.go b/licensedb/licensedb_test.go
new file mode 100644
index 0000000..a8a8295
--- /dev/null
+++ b/licensedb/licensedb_test.go
@@ -0,0 +1,45 @@
+package licensedb
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/go-enry/go-license-detector/v4/licensedb/filer"
+)
+
+func BenchmarkDetect(b *testing.B) {
+	f := pwdFiler()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_, err := Detect(f)
+		if err != nil {
+			panic(err)
+		}
+	}
+}
+
+func BenchmarkDetectWithPreload(b *testing.B) {
+	f := pwdFiler()
+	Preload()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_, err := Detect(f)
+		if err != nil {
+			panic(err)
+		}
+	}
+}
+
+func pwdFiler() filer.Filer {
+	pwd, err := os.Getwd()
+	if err != nil {
+		panic(err)
+	}
+	root := filepath.Dir(pwd)
+	f, err := filer.FromDirectory(root)
+	if err != nil {
+		panic(err)
+	}
+	return f
+}

From 6403a23e656acb8434697c4bdcd4720ec2e209a1 Mon Sep 17 00:00:00 2001
From: Kirill <g4s8.public@gmail.com>
Date: Tue, 6 Jul 2021 16:38:09 +0300
Subject: [PATCH 2/2] Described preload API doc

---
 licensedb/licensedb.go | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/licensedb/licensedb.go b/licensedb/licensedb.go
index 520a305..27fc3f8 100644
--- a/licensedb/licensedb.go
+++ b/licensedb/licensedb.go
@@ -54,7 +54,12 @@ func Detect(fs filer.Filer) (map[string]api.Match, error) {
 	return licenses, nil
 }
 
-// Preload database with licenses
+// Preload database with licenses - load internal database from assets into memory.
+// This method is an optimization for cases when the `Detect` method should return fast,
+// e.g. in HTTP web servers where connection timeout can occur during detect
+// `Preload` method could be called before server startup.
+// This method os optional and it's not required to be called, other APIs loads license database
+// lazily on first invocation.
 func Preload() {
 	internal.Preload()
 }