golang-用于上传大文件的功能

Question

In go there are different ways to read a file sent with a multipart form

r.FormFile("file")

r.MultipartReader()

r.ParseMultipartForm(size)

and I partially understand the difference between them, however which is it the best for handling large files (~1GB)?

And, which is the one that uses less memory?

Answer 1

https://golang.org/pkg/net/http/#Request.ParseMultipartForm

ParseMultipartForm parses a request body as multipart/form-data. The whole request body is parsed and up to a total of maxMemory bytes of its file parts are stored in memory, with the remainder stored on disk in temporary files. ParseMultipartForm calls ParseForm if necessary. After one call to ParseMultipartForm, subsequent calls have no effect.

You can therefore control the maximum memory usage by calling r.ParseMultipartForm(max), and you can control the total amount read from the request by using http.MaxBytesReader.

Also see this answer: https://stackoverflow.com/a/28292505/556573