nghttp2/src/shrpx_downstream_queue.cc

228 lines
6.7 KiB
C++

/*
* nghttp2 - HTTP/2 C Library
*
* Copyright (c) 2012 Tatsuhiro Tsujikawa
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include "shrpx_downstream_queue.h"
#include <cassert>
#include <limits>
#include "shrpx_downstream.h"
namespace shrpx {
DownstreamQueue::HostEntry::HostEntry() : num_active(0) {}
DownstreamQueue::DownstreamQueue(size_t conn_max_per_host, bool unified_host)
: conn_max_per_host_(conn_max_per_host == 0
? std::numeric_limits<size_t>::max()
: conn_max_per_host),
unified_host_(unified_host) {}
DownstreamQueue::~DownstreamQueue() {}
void DownstreamQueue::add_pending(std::unique_ptr<Downstream> downstream) {
auto stream_id = downstream->get_stream_id();
pending_downstreams_[stream_id] = std::move(downstream);
}
void DownstreamQueue::add_failure(std::unique_ptr<Downstream> downstream) {
auto stream_id = downstream->get_stream_id();
failure_downstreams_[stream_id] = std::move(downstream);
}
DownstreamQueue::HostEntry &
DownstreamQueue::find_host_entry(const std::string &host) {
auto itr = host_entries_.find(host);
if (itr == std::end(host_entries_)) {
#ifdef HAVE_STD_MAP_EMPLACE
std::tie(itr, std::ignore) = host_entries_.emplace(host, HostEntry());
#else // !HAVE_STD_MAP_EMPLACE
// for g++-4.7
std::tie(itr, std::ignore) = host_entries_.insert({host, HostEntry()});
#endif // !HAVE_STD_MAP_EMPLACE
}
return (*itr).second;
}
const std::string &
DownstreamQueue::make_host_key(const std::string &host) const {
static std::string empty_key;
return unified_host_ ? empty_key : host;
}
const std::string &
DownstreamQueue::make_host_key(Downstream *downstream) const {
return make_host_key(downstream->get_request_http2_authority());
}
void DownstreamQueue::add_active(std::unique_ptr<Downstream> downstream) {
auto &ent = find_host_entry(make_host_key(downstream.get()));
++ent.num_active;
auto stream_id = downstream->get_stream_id();
active_downstreams_[stream_id] = std::move(downstream);
}
void DownstreamQueue::add_blocked(std::unique_ptr<Downstream> downstream) {
auto &ent = find_host_entry(make_host_key(downstream.get()));
auto stream_id = downstream->get_stream_id();
ent.blocked.insert(stream_id);
blocked_downstreams_[stream_id] = std::move(downstream);
}
bool DownstreamQueue::can_activate(const std::string &host) const {
auto itr = host_entries_.find(make_host_key(host));
if (itr == std::end(host_entries_)) {
return true;
}
auto &ent = (*itr).second;
return ent.num_active < conn_max_per_host_;
}
namespace {
std::unique_ptr<Downstream>
pop_downstream(DownstreamQueue::DownstreamMap::iterator i,
DownstreamQueue::DownstreamMap &downstreams) {
auto downstream = std::move((*i).second);
downstreams.erase(i);
return downstream;
}
} // namespace
namespace {
bool remove_host_entry_if_empty(const DownstreamQueue::HostEntry &ent,
DownstreamQueue::HostEntryMap &host_entries,
const std::string &host) {
if (ent.blocked.empty() && ent.num_active == 0) {
host_entries.erase(host);
return true;
}
return false;
}
} // namespace
std::unique_ptr<Downstream> DownstreamQueue::pop_pending(int32_t stream_id) {
auto itr = pending_downstreams_.find(stream_id);
if (itr == std::end(pending_downstreams_)) {
return nullptr;
}
return pop_downstream(itr, pending_downstreams_);
}
std::unique_ptr<Downstream>
DownstreamQueue::remove_and_pop_blocked(int32_t stream_id) {
auto kv = active_downstreams_.find(stream_id);
if (kv != std::end(active_downstreams_)) {
auto downstream = pop_downstream(kv, active_downstreams_);
auto &host = make_host_key(downstream.get());
auto &ent = find_host_entry(host);
--ent.num_active;
if (remove_host_entry_if_empty(ent, host_entries_, host)) {
return nullptr;
}
if (ent.blocked.empty() || ent.num_active >= conn_max_per_host_) {
return nullptr;
}
auto next_stream_id = *std::begin(ent.blocked);
ent.blocked.erase(std::begin(ent.blocked));
auto itr = blocked_downstreams_.find(next_stream_id);
assert(itr != std::end(blocked_downstreams_));
auto next_downstream = pop_downstream(itr, blocked_downstreams_);
remove_host_entry_if_empty(ent, host_entries_, host);
return next_downstream;
}
kv = blocked_downstreams_.find(stream_id);
if (kv != std::end(blocked_downstreams_)) {
auto downstream = pop_downstream(kv, blocked_downstreams_);
auto &host = make_host_key(downstream.get());
auto &ent = find_host_entry(host);
ent.blocked.erase(stream_id);
remove_host_entry_if_empty(ent, host_entries_, host);
return nullptr;
}
kv = pending_downstreams_.find(stream_id);
if (kv != std::end(pending_downstreams_)) {
pop_downstream(kv, pending_downstreams_);
return nullptr;
}
kv = failure_downstreams_.find(stream_id);
if (kv != std::end(failure_downstreams_)) {
pop_downstream(kv, failure_downstreams_);
return nullptr;
}
return nullptr;
}
Downstream *DownstreamQueue::find(int32_t stream_id) {
auto kv = active_downstreams_.find(stream_id);
if (kv != std::end(active_downstreams_)) {
return (*kv).second.get();
}
kv = blocked_downstreams_.find(stream_id);
if (kv != std::end(blocked_downstreams_)) {
return (*kv).second.get();
}
kv = pending_downstreams_.find(stream_id);
if (kv != std::end(pending_downstreams_)) {
return (*kv).second.get();
}
kv = failure_downstreams_.find(stream_id);
if (kv != std::end(failure_downstreams_)) {
return (*kv).second.get();
}
return nullptr;
}
const DownstreamQueue::DownstreamMap &
DownstreamQueue::get_active_downstreams() const {
return active_downstreams_;
}
} // namespace shrpx