From 59bd479ebee1c296d11908e7b3a619ee7bcdf5aa Mon Sep 17 00:00:00 2001
From: "Alexander \"Arav\" Andreev" <me@arav.top>
Date: Wed, 17 Aug 2022 21:47:27 +0400
Subject: [PATCH] Image now passed by a pointer instead of value. Hope it will
 help with memory consumption a little.

---
 internal/captcha/dwelling_captcha.go | 5 +++--
 internal/captcha/instance.go         | 2 +-
 internal/handlers/handlers.go        | 2 +-
 pkg/captcha/captcha.go               | 2 +-
 pkg/captcha/db.go                    | 2 +-
 5 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/internal/captcha/dwelling_captcha.go b/internal/captcha/dwelling_captcha.go
index 9880208..7ec1b90 100644
--- a/internal/captcha/dwelling_captcha.go
+++ b/internal/captcha/dwelling_captcha.go
@@ -24,7 +24,7 @@ func NewDwellingCaptcha(expiry time.Duration) *DwellingCaptcha {
 			ExpireIn: captcha.ExpiryDate(expiry)}}
 }
 
-func (c *DwellingCaptcha) Image(style string) image.Image {
+func (c *DwellingCaptcha) Image(style string) *image.Image {
 	isDark := style == "dark"
 	ctx := gg.NewContext(dwImageWidth, dwImageHeight)
 
@@ -67,5 +67,6 @@ func (c *DwellingCaptcha) Image(style string) image.Image {
 		ctx.Stroke()
 	}
 
-	return ctx.Image()
+	i := ctx.Image()
+	return &i
 }
diff --git a/internal/captcha/instance.go b/internal/captcha/instance.go
index fea0322..1440647 100644
--- a/internal/captcha/instance.go
+++ b/internal/captcha/instance.go
@@ -17,7 +17,7 @@ func New(data string, captcha captcha.Captcha) (captcha.Captcha, captcha.ID) {
 	return captchaDb.New(data, captcha)
 }
 
-func Image(id captcha.ID, style string) (image.Image, error) {
+func Image(id captcha.ID, style string) (*image.Image, error) {
 	return captchaDb.Image(id, style)
 }
 
diff --git a/internal/handlers/handlers.go b/internal/handlers/handlers.go
index 8ca27b9..567dd9a 100644
--- a/internal/handlers/handlers.go
+++ b/internal/handlers/handlers.go
@@ -39,7 +39,7 @@ func (h *CaptchaHandlers) Image(w http.ResponseWriter, r *http.Request) {
 
 	w.Header().Add("Content-Disposition", "inline; filename=\""+string(captchaID)+"\"")
 
-	png.Encode(w, captchaImage)
+	png.Encode(w, *captchaImage)
 }
 
 func (h *CaptchaHandlers) Solve(w http.ResponseWriter, r *http.Request) {
diff --git a/pkg/captcha/captcha.go b/pkg/captcha/captcha.go
index 2cd47cd..774df00 100644
--- a/pkg/captcha/captcha.go
+++ b/pkg/captcha/captcha.go
@@ -21,7 +21,7 @@ func NewIntAnswer() Answer {
 // Captcha interface that should be implemented by captcha.
 type Captcha interface {
 	// Image generates and returns an image of captcha.
-	Image(style string) image.Image
+	Image(style string) *image.Image
 	// GetAnswer returns a pregenerated answer.
 	GetAnswer() Answer
 	// Solve compares a stored answer with a passed one.
diff --git a/pkg/captcha/db.go b/pkg/captcha/db.go
index cfb6af8..1bca24b 100644
--- a/pkg/captcha/db.go
+++ b/pkg/captcha/db.go
@@ -87,7 +87,7 @@ func (cdb *InMemoryCaptchaDB) GetExpiry() time.Duration {
 }
 
 // Image returns image for a captcha.
-func (cdb *InMemoryCaptchaDB) Image(id ID, style string) (image.Image, error) {
+func (cdb *InMemoryCaptchaDB) Image(id ID, style string) (*image.Image, error) {
 	cdb.Lock()
 	defer cdb.Unlock()
 	if c, ok := cdb.DB[id]; ok {