我可以增加Golang的http流块大小吗？

I'm trying to send data (files or whatever) through HTTP from the client to a server and read them as stream in the server.

But I noticed the chunk size or buffer size when the request's body is read it is fixed to 32kb. I tried doing it with TCP before using HTTP and the buffer size was the expected assigned size.

The data received from the request is being written to a file

Questions:

• Is it possible to increase the chunk / buffer size?
• if it is possible, by having a bigger buffer size will it increase performance due to less write calls to to the file being created?
• If it is not possible, should I worry about performance loss by doing more write calls to the file being created?
• Would it be better to use TCP? I really need the headers and http response

Here is some code for illustration:

client.go:

package main

import (
    "fmt"
    "io"
    "log"
    "net/http"
    "os"
)

func main() {
    addr := "http://localhost:8080"
    path := "path/to/file"

    sendHTTP(addr, path)
}

func sendHTTP(addr, path string) {
    f, err := os.Open(path)

    if err != nil {
        log.Fatal("Error opening file:", err)
    }

    client := &http.Client{}
    req, err := http.NewRequest("POST", addr, f)

    if err != nil {
        f.Close()
        log.Fatal("Error creating request:", err)
    }

    _, err = client.Do(req)

    if err != nil {
        f.Close()
        log.Fatal("Error doing request:", err)
    }
}

server.go:

package main

import (
    "fmt"
    "io"
    "log"
    "net/http"
)

func main() {
    addr := ":8080"

    http.HandleFunc("/", handler)

    http.ListenAndServe(addr, nil)
}

func handler(_ http.ResponseWriter, r *http.Request) {
    buf := make([]byte, 512*1024) // 512kb

    for {
        br, err := r.Body.Read(buf)

        if err == io.EOF {
            break
        } else if err != nil {
            log.Println("Error reading request:", err)
            break
        }

        fmt.Println(br) // is always 32kb
    }

}