private async Task LoadKeyValuesRegisteredForRefresh(IDictionary <string, ConfigurationSetting> data)
{
_watchedSettings.Clear();
foreach (KeyValueWatcher changeWatcher in _options.ChangeWatchers)
{
string watchedKey = changeWatcher.Key;
string watchedLabel = changeWatcher.Label;
KeyValueIdentifier watchedKeyLabel = new KeyValueIdentifier(watchedKey, watchedLabel);
// Skip the loading for the key-value in case it has already been loaded
if (data.TryGetValue(watchedKey, out ConfigurationSetting loadedKv) &&
watchedKeyLabel.Equals(new KeyValueIdentifier(loadedKv.Key, loadedKv.Label)))
{
_watchedSettings[watchedKeyLabel] = loadedKv;
continue;
}
// Send a request to retrieve key-value since it may be either not loaded or loaded with a different label or different casing
ConfigurationSetting watchedKv = null;
try
{
await CallWithRequestTracing(async() => watchedKv = await _client.GetConfigurationSettingAsync(watchedKey, watchedLabel, CancellationToken.None)).ConfigureAwait(false);
}
catch (RequestFailedException e) when(e.Status == (int)HttpStatusCode.NotFound)
{
watchedKv = null;
}
// If the key-value was found, store it for updating the settings
if (watchedKv != null)
{
data[watchedKey] = watchedKv;
_watchedSettings[watchedKeyLabel] = watchedKv;
}
}
}
private async Task RefreshIndividualKeyValues()
{
bool shouldRefreshAll = false;
foreach (KeyValueWatcher changeWatcher in _options.ChangeWatchers)
{
string watchedKey = changeWatcher.Key;
string watchedLabel = changeWatcher.Label;
// Skip the refresh for this key if the cached value has not expired or a refresh operation is in progress
if (DateTimeOffset.UtcNow < changeWatcher.CacheExpires || !changeWatcher.Semaphore.Wait(0))
{
continue;
}
try
{
bool hasChanged = false;
KeyValueIdentifier watchedKeyLabel = new KeyValueIdentifier(watchedKey, watchedLabel);
if (_watchedSettings.TryGetValue(watchedKeyLabel, out ConfigurationSetting watchedKv))
{
KeyValueChange keyValueChange = default;
await TracingUtils.CallWithRequestTracing(_requestTracingEnabled, RequestType.Watch, _hostType,
async() => keyValueChange = await _client.GetKeyValueChange(watchedKv, CancellationToken.None).ConfigureAwait(false)).ConfigureAwait(false);
changeWatcher.CacheExpires = DateTimeOffset.UtcNow.Add(changeWatcher.CacheExpirationInterval);
// Check if a change has been detected in the key-value registered for refresh
if (keyValueChange.ChangeType != KeyValueChangeType.None)
{
if (changeWatcher.RefreshAll)
{
shouldRefreshAll = true;
break;
}
if (keyValueChange.ChangeType == KeyValueChangeType.Deleted)
{
_watchedSettings.TryRemove(watchedKeyLabel, out ConfigurationSetting _);
}
else if (keyValueChange.ChangeType == KeyValueChangeType.Modified)
{
_watchedSettings[watchedKeyLabel] = keyValueChange.Current;
}
hasChanged = true;
ProcessChanges(Enumerable.Repeat(keyValueChange, 1));
}
}
else
{
// Load the key-value in case the previous load attempts had failed
var options = new SettingSelector {
LabelFilter = watchedLabel
};
try
{
await CallWithRequestTracing(async() => watchedKv = await _client.GetConfigurationSettingAsync(watchedKey, watchedLabel, CancellationToken.None).ConfigureAwait(false)).ConfigureAwait(false);
}
catch (RequestFailedException e) when(e.Status == (int)HttpStatusCode.NotFound)
{
watchedKv = null;
}
changeWatcher.CacheExpires = DateTimeOffset.UtcNow.Add(changeWatcher.CacheExpirationInterval);
if (watchedKv != null)
{
if (changeWatcher.RefreshAll)
{
shouldRefreshAll = true;
break;
}
hasChanged = true;
// Add the key-value if it is not loaded, or update it if it was loaded with a different label
_applicationSettings[watchedKey] = watchedKv;
_watchedSettings[watchedKeyLabel] = watchedKv;
}
}
if (hasChanged)
{
await SetData(_applicationSettings).ConfigureAwait(false);
}
}
finally
{
changeWatcher.Semaphore.Release();
}
}
// Trigger a single refresh-all operation if a change was detected in one or more key-values with refreshAll: true
if (shouldRefreshAll)
{
await LoadAll(ignoreFailures : false).ConfigureAwait(false);
}
}
