load_timing_info.h | Explore in Territory

// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef NET_BASE_LOAD_TIMING_INFO_H_
#define NET_BASE_LOAD_TIMING_INFO_H_

#include <stdint.h>

#include "base/time/time.h"
#include "net/base/net_export.h"

namespace net {

// Structure containing timing information for a request.
// It addresses the needs of
// http://groups.google.com/group/http-archive-specification/web/har-1-1-spec,
// http://dev.w3.org/2006/webapi/WebTiming/, and
// http://www.w3.org/TR/resource-timing/.
//
// All events that do not apply to a request have null times.  For non-HTTP
// requests, all times other than the request_start times are null.
//
// Requests with connection errors generally only have request start times as
// well, since they never received an established socket.
//
// The general order for events is:
// request_start
// service_worker_router_evaluation_start
// service_worker_cache_lookup_start
// service_worker_start_time
// proxy_start
// proxy_end
// domain_lookup_start
// domain_lookup_end
// connect_start
// ssl_start
// ssl_end
// connect_end
// send_start
// send_end
// service_worker_ready_time
// service_worker_fetch_start
// service_worker_respond_with_settled
// first_early_hints_time
// receive_headers_start
// receive_non_informational_headers_start
// receive_headers_end
//
// Times represent when a request starts/stops blocking on an event(*), not the
// time the events actually occurred. In particular, in the case of preconnects
// and socket reuse, no time may be spent blocking on establishing a connection.
// In the case of SPDY, PAC scripts are only run once for each shared session,
// so no time may be spent blocking on them.
//
// (*) Note 1: push_start and push_end are the exception to this, as they
// represent the operation which is asynchronous to normal request flow and
// hence are provided as absolute values and not converted to "blocking" time.
//
// (*) Note 2: Internally to the network stack, times are those of actual event
// occurrence. URLRequest converts them to time which the network stack was
// blocked on each state, as per resource timing specs.
//
// DNS and SSL times are both times for the host, not the proxy, so DNS times
// when using proxies are null, and only requests to HTTPS hosts (Not proxies)
// have SSL times.
struct NET_EXPORT LoadTimingInfo { … };

}  // namespace net

#endif  // NET_BASE_LOAD_TIMING_INFO_H_
chromium/net/base/load_timing_info.h
