refactor(http): implement shared transport and clients (#1288)

* fix(http): flip to a shared transport and clients

* nice threads

* that is terrible

* fake uri for magnet

* lazy locking

* why bother with r's

* flip magic params to struct

* refactor(http-clients): use separate clients with shared transport

* refactor(http-clients): add missing license header

* refactor(http-clients): defer and fix errors

---------

Co-authored-by: ze0s <ze0s@riseup.net>

pkg/sharedhttp/http.go

@@ -0,0 +1,84 @@
+// Copyright (c) 2021 - 2023, Ludvig Lundgren and the autobrr contributors.
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+package sharedhttp
+
+import (
+	"crypto/tls"
+	"io"
+	"net"
+	"net/http"
+	"strings"
+	"time"
+)
+
+var Transport = &http.Transport{
+	Proxy: http.ProxyFromEnvironment,
+	DialContext: (&net.Dialer{
+		Timeout:   30 * time.Second, // default transport value
+		KeepAlive: 30 * time.Second, // default transport value
+	}).DialContext,
+	ForceAttemptHTTP2:     true,             // default is true; since HTTP/2 multiplexes a single TCP connection. we'd want to use HTTP/1, which would use multiple TCP connections.
+	MaxIdleConns:          100,              // default transport value
+	MaxIdleConnsPerHost:   10,               // default is 2, so we want to increase the number to use establish more connections.
+	IdleConnTimeout:       90 * time.Second, // default transport value
+	TLSHandshakeTimeout:   10 * time.Second, // default transport value
+	ExpectContinueTimeout: 1 * time.Second,  // default transport value
+	ReadBufferSize:        65536,
+	WriteBufferSize:       65536,
+	TLSClientConfig: &tls.Config{
+		MinVersion: tls.VersionTLS12,
+	},
+}
+
+var TransportTLSInsecure = &http.Transport{
+	Proxy: http.ProxyFromEnvironment,
+	DialContext: (&net.Dialer{
+		Timeout:   30 * time.Second, // default transport value
+		KeepAlive: 30 * time.Second, // default transport value
+	}).DialContext,
+	ForceAttemptHTTP2:     true,             // default is true; since HTTP/2 multiplexes a single TCP connection. we'd want to use HTTP/1, which would use multiple TCP connections.
+	MaxIdleConns:          100,              // default transport value
+	MaxIdleConnsPerHost:   10,               // default is 2, so we want to increase the number to use establish more connections.
+	IdleConnTimeout:       90 * time.Second, // default transport value
+	TLSHandshakeTimeout:   10 * time.Second, // default transport value
+	ExpectContinueTimeout: 1 * time.Second,  // default transport value
+	ReadBufferSize:        65536,
+	WriteBufferSize:       65536,
+	TLSClientConfig: &tls.Config{
+		InsecureSkipVerify: true,
+	},
+}
+
+var Client = &http.Client{
+	Timeout:   60 * time.Second,
+	Transport: Transport,
+}
+
+type MagnetRoundTripper struct{}
+
+func (rt *MagnetRoundTripper) RoundTrip(r *http.Request) (*http.Response, error) {
+	if r.URL.Scheme == "magnet" {
+		responseBody := r.URL.String()
+		respReader := io.NopCloser(strings.NewReader(responseBody))
+
+		resp := &http.Response{
+			Status:        http.StatusText(http.StatusOK),
+			StatusCode:    http.StatusOK,
+			Body:          respReader,
+			ContentLength: int64(len(responseBody)),
+			Header: map[string][]string{
+				"Content-Type": {"text/plain"},
+				"Location":     {responseBody},
+			},
+			Proto:      "HTTP/2.0",
+			ProtoMajor: 2,
+		}
+
+		return resp, nil
+	}
+
+	return Transport.RoundTrip(r)
+}
+
+var MagnetTransport = &MagnetRoundTripper{}