From c9b344118f6426e9211c2e4530ac983a541f437a Mon Sep 17 00:00:00 2001
From: "Daniel M. Lambea" <dmlambea@gmail.com>
Date: Thu, 7 Sep 2017 04:45:16 +0100
Subject: [PATCH] Moved const 'defaultMemory' to attrib.
 Engine.MaxMultipartMemory instead. (#1100)

---
 README.md                             |  4 ++++
 context.go                            |  7 +++----
 examples/upload-file/multiple/main.go |  2 ++
 examples/upload-file/single/main.go   |  2 ++
 gin.go                                | 10 +++++++++-
 5 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index 07357be4..d16a8682 100644
--- a/README.md
+++ b/README.md
@@ -277,6 +277,8 @@ References issue [#774](https://github.com/gin-gonic/gin/issues/774) and detail
 ```go
 func main() {
 	router := gin.Default()
+	// Set a lower memory limit for multipart forms (default is 32 MiB)
+	// router.MaxMultipartMemory = 8 << 20  // 8 MiB
 	router.POST("/upload", func(c *gin.Context) {
 		// single file
 		file, _ := c.FormFile("file")
@@ -306,6 +308,8 @@ See the detail [example code](examples/upload-file/multiple).
 ```go
 func main() {
 	router := gin.Default()
+	// Set a lower memory limit for multipart forms (default is 32 MiB)
+	// router.MaxMultipartMemory = 8 << 20  // 8 MiB
 	router.POST("/upload", func(c *gin.Context) {
 		// Multipart form
 		form, _ := c.MultipartForm()
diff --git a/context.go b/context.go
index d7b6c61d..74995e68 100644
--- a/context.go
+++ b/context.go
@@ -34,8 +34,7 @@ const (
 )
 
 const (
-	defaultMemory      = 32 << 20 // 32 MB
-	abortIndex    int8 = math.MaxInt8 / 2
+	abortIndex int8 = math.MaxInt8 / 2
 )
 
 // Context is the most important part of gin. It allows us to pass variables between middleware,
@@ -407,7 +406,7 @@ func (c *Context) PostFormArray(key string) []string {
 func (c *Context) GetPostFormArray(key string) ([]string, bool) {
 	req := c.Request
 	req.ParseForm()
-	req.ParseMultipartForm(defaultMemory)
+	req.ParseMultipartForm(c.engine.MaxMultipartMemory)
 	if values := req.PostForm[key]; len(values) > 0 {
 		return values, true
 	}
@@ -427,7 +426,7 @@ func (c *Context) FormFile(name string) (*multipart.FileHeader, error) {
 
 // MultipartForm is the parsed multipart form, including file uploads.
 func (c *Context) MultipartForm() (*multipart.Form, error) {
-	err := c.Request.ParseMultipartForm(defaultMemory)
+	err := c.Request.ParseMultipartForm(c.engine.MaxMultipartMemory)
 	return c.Request.MultipartForm, err
 }
 
diff --git a/examples/upload-file/multiple/main.go b/examples/upload-file/multiple/main.go
index 4bb4cdcb..a55325ed 100644
--- a/examples/upload-file/multiple/main.go
+++ b/examples/upload-file/multiple/main.go
@@ -9,6 +9,8 @@ import (
 
 func main() {
 	router := gin.Default()
+	// Set a lower memory limit for multipart forms (default is 32 MiB)
+	router.MaxMultipartMemory = 8 << 20 // 8 MiB
 	router.Static("/", "./public")
 	router.POST("/upload", func(c *gin.Context) {
 		name := c.PostForm("name")
diff --git a/examples/upload-file/single/main.go b/examples/upload-file/single/main.go
index 372a2994..5d438651 100644
--- a/examples/upload-file/single/main.go
+++ b/examples/upload-file/single/main.go
@@ -9,6 +9,8 @@ import (
 
 func main() {
 	router := gin.Default()
+	// Set a lower memory limit for multipart forms (default is 32 MiB)
+	router.MaxMultipartMemory = 8 << 20 // 8 MiB
 	router.Static("/", "./public")
 	router.POST("/upload", func(c *gin.Context) {
 		name := c.PostForm("name")
diff --git a/gin.go b/gin.go
index ee39c9aa..24c4dd8d 100644
--- a/gin.go
+++ b/gin.go
@@ -15,7 +15,10 @@ import (
 )
 
 // Version is Framework's version.
-const Version = "v1.2"
+const (
+	Version                = "v1.2"
+	defaultMultipartMemory = 32 << 20 // 32 MB
+)
 
 var default404Body = []byte("404 page not found")
 var default405Body = []byte("405 method not allowed")
@@ -92,6 +95,10 @@ type Engine struct {
 	// If UseRawPath is false (by default), the UnescapePathValues effectively is true,
 	// as url.Path gonna be used, which is already unescaped.
 	UnescapePathValues bool
+
+	// Value of 'maxMemory' param that is given to http.Request's ParseMultipartForm
+	// method call.
+	MaxMultipartMemory int64
 }
 
 var _ IRouter = &Engine{}
@@ -120,6 +127,7 @@ func New() *Engine {
 		AppEngine:              defaultAppEngine,
 		UseRawPath:             false,
 		UnescapePathValues:     true,
+		MaxMultipartMemory:     defaultMultipartMemory,
 		trees:                  make(methodTrees, 0, 9),
 		delims:                 render.Delims{Left: "{{", Right: "}}"},
 		secureJsonPrefix:       "while(1);",