sapling/eden/fs/config/ReloadableConfig.cpp
Chad Austin 4ccb60e46d config: namespace facebook::eden
Summary: Start applying C++17 to our namespace definitions.

Reviewed By: fanzeyi

Differential Revision: D28964224

fbshipit-source-id: 72ad3f93c9304b34eef91d530e4e988420bd8fdc
2021-06-08 19:29:37 -07:00

91 lines
2.8 KiB
C++

/*
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This software may be used and distributed according to the terms of the
* GNU General Public License version 2.
*/
#include "eden/fs/config/ReloadableConfig.h"
#include "eden/fs/config/EdenConfig.h"
#include "eden/fs/utils/Bug.h"
#include "eden/fs/utils/EnumValue.h"
#include <folly/logging/xlog.h>
namespace {
/// Throttle change checks to a maximum of one per
/// kEdenConfigMinimumPollDuration.
constexpr std::chrono::seconds kEdenConfigMinimumPollDuration{5};
} // namespace
namespace facebook::eden {
ReloadableConfig::ReloadableConfig(std::shared_ptr<const EdenConfig> config)
: state_{ConfigState{config}} {}
ReloadableConfig::ReloadableConfig(
std::shared_ptr<const EdenConfig> config,
ConfigReloadBehavior reloadBehavior)
: state_{ConfigState{config}}, reloadBehavior_{reloadBehavior} {}
ReloadableConfig::~ReloadableConfig() {}
std::shared_ptr<const EdenConfig> ReloadableConfig::getEdenConfig(
ConfigReloadBehavior reload) {
auto now = std::chrono::steady_clock::now();
// TODO: Update this monitoring code to use FileChangeMonitor.
bool shouldReload;
if (reloadBehavior_.has_value()) {
reload = reloadBehavior_.value();
}
switch (reload) {
case ConfigReloadBehavior::NoReload:
shouldReload = false;
break;
case ConfigReloadBehavior::ForceReload:
shouldReload = true;
break;
case ConfigReloadBehavior::AutoReload: {
auto lastCheck = std::chrono::steady_clock::time_point{
std::chrono::steady_clock::duration{
lastCheck_.load(std::memory_order_acquire)}};
shouldReload = now - lastCheck >= kEdenConfigMinimumPollDuration;
break;
}
default:
EDEN_BUG() << "Unexpected reload flag: " << enumValue(reload);
}
if (!shouldReload) {
return state_.rlock()->config;
}
auto state = state_.wlock();
// Throttle the updates when using ConfigReloadBehavior::AutoReload
lastCheck_.store(now.time_since_epoch().count(), std::memory_order_release);
auto& config = state->config;
auto userConfigChanged = config->hasUserConfigFileChanged();
auto systemConfigChanged = config->hasSystemConfigFileChanged();
if (userConfigChanged || systemConfigChanged) {
auto newConfig = std::make_shared<EdenConfig>(*config);
if (userConfigChanged) {
XLOG(DBG3) << "Reloading " << config->getUserConfigPath() << " because "
<< userConfigChanged.str();
newConfig->loadUserConfig();
}
if (systemConfigChanged) {
XLOG(DBG3) << "Reloading " << config->getSystemConfigPath() << " because "
<< systemConfigChanged.str();
newConfig->loadSystemConfig();
}
state->config = std::move(newConfig);
}
return state->config;
}
} // namespace facebook::eden