Initial project import

tools/v/vlib/net/http/h2_client.v

@@ -0,0 +1,92 @@
+// Copyright (c) 2019-2024 Alexander Medvednikov. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+module http
+
+// This file converts between net.http's Request/Response and the HTTP/2
+// client types in h2_conn.v. The actual transport wiring (ALPN negotiation on
+// the TLS socket) lives in backend.c.v; these helpers are pure and backend
+// agnostic, so they can be tested without a socket.
+
+// h2_hop_by_hop are header names that must not be forwarded on HTTP/2
+// (RFC 7540 Section 8.1.2.2), plus `host` (replaced by the :authority
+// pseudo-header) and `cookie` (handled specially below).
+const h2_hop_by_hop = ['connection', 'keep-alive', 'proxy-connection', 'transfer-encoding', 'upgrade',
+	'host', 'cookie']
+
+// h2_authority returns the :authority value for a host and port, omitting the
+// port for the default HTTPS port.
+fn h2_authority(host string, port int) string {
+	if port == 443 || port == 0 {
+		return host
+	}
+	return '${host}:${port}'
+}
+
+// to_h2_request builds an HTTP/2 request from this request. Header names are
+// lowercased, hop-by-hop headers are dropped, the Host header becomes the
+// :authority pseudo-header, and cookies are collapsed into a single field.
+fn (req &Request) to_h2_request(method Method, authority string, path string, data string, header Header) H2ClientRequest {
+	// An explicit Host header overrides the URL host, matching the HTTP/1.1
+	// path (used for virtual-host / host-override requests).
+	mut auth := authority
+	if host := header.get(.host) {
+		if host != '' {
+			auth = host
+		}
+	}
+	mut extra := []H2HeaderField{}
+	if !header.contains(.user_agent) && req.user_agent != '' {
+		extra << H2HeaderField{'user-agent', req.user_agent}
+	}
+	if data.len > 0 && !header.contains(.content_length) {
+		extra << H2HeaderField{'content-length', data.len.str()}
+	}
+	for key in header.keys() {
+		lkey := key.to_lower()
+		if lkey in h2_hop_by_hop {
+			continue
+		}
+		for val in header.custom_values(key) {
+			extra << H2HeaderField{lkey, val}
+		}
+	}
+	// Cookies: the request's own cookie map plus any Cookie header values,
+	// joined into one field (RFC 7540 Section 8.1.2.5 also allows splitting).
+	mut cookie_parts := []string{}
+	for k, v in req.cookies {
+		cookie_parts << '${k}=${v}'
+	}
+	for cv in header.values(.cookie) {
+		cookie_parts << cv
+	}
+	if cookie_parts.len > 0 {
+		extra << H2HeaderField{'cookie', cookie_parts.join('; ')}
+	}
+	return H2ClientRequest{
+		method:    method.str()
+		scheme:    'https'
+		authority: auth
+		path:      path
+		headers:   extra
+		body:      data.bytes()
+	}
+}
+
+// h2_response_to_http converts an HTTP/2 response into a net.http Response,
+// decoding any Content-Encoding the same way the HTTP/1.1 path does.
+fn h2_response_to_http(h2resp H2ClientResponse) Response {
+	mut h := new_header()
+	for f in h2resp.headers {
+		h.add_custom(f.name, f.value) or {}
+	}
+	body := decode_response_body(h2resp.body.bytestr(), h.get(.content_encoding) or { '' })
+	status := status_from_int(h2resp.status)
+	return Response{
+		http_version: '2.0'
+		status_code:  h2resp.status
+		status_msg:   status.str()
+		header:       h
+		body:         body
+	}
+}