/// <summary>
/// Loads all state set definitions for the specified historian.
/// </summary>
/// <param name="historian">The historian to load the state sets from.</param>
/// <param name="callback">A callback function that is invoked every time a state set is loaded from Redis.</param>
/// <param name="cancellationToken">The cancellation token for the request.</param>
/// <returns>
/// A task that will load all state sets into the historian.
/// </returns>
internal static async Task LoadAll(RedisHistorian historian, Action <StateSet> callback, CancellationToken cancellationToken)
{
var key = historian.GetKeyForStateSetNamesList();
const int pageSize = 100;
var page = 0;
bool @continue;
// Load state sets 100 at a time.
do
{
@continue = false;
++page;
long start = (page - 1) * pageSize;
long end = start + pageSize - 1; // -1 because right-most item is included when getting the list range.
var names = await historian.Connection.GetDatabase().ListRangeAsync(key, start, end).ConfigureAwait(false);
@continue = names.Length == pageSize;
if (names.Length == 0)
{
continue;
}
var tasks = names.Select(x => Task.Run(async() => {
var tag = await Load(historian, x, cancellationToken).ConfigureAwait(false);
callback(tag);
})).ToArray();
await Task.WhenAny(Task.WhenAll(tasks), Task.Delay(-1, cancellationToken)).ConfigureAwait(false);
cancellationToken.ThrowIfCancellationRequested();
} while (@continue);
}
/// <summary>
/// Saves a state set definition to the Redis database.
/// </summary>
/// <param name="historian">The historian to load the state set from.</param>
/// <param name="stateSet">The state set to save.</param>
/// <param name="addToMasterList">
/// Specify <see langword="true"/> when the state set is being created and <see langword="false"/>
/// when it is being updated.
/// </param>
/// <param name="cancellationToken">The cancellation token for the request.</param>
/// <returns>
/// A task that will save the tag definition to the Redis database.
/// </returns>
internal static async Task Save(RedisHistorian historian, StateSet stateSet, bool addToMasterList, CancellationToken cancellationToken)
{
var key = historian.GetKeyForStateSetDefinition(stateSet.Name);
var tasks = new List <Task>();
var db = historian.Connection.GetDatabase();
var hashes = new List <HashEntry>()
{
new HashEntry("DESC", stateSet.Description)
};
hashes.AddRange(stateSet.Select(x => new HashEntry($"S_{x.Name}", x.Value)));
tasks.Add(db.HashSetAsync(key, hashes.ToArray()));
if (addToMasterList)
{
var listKey = historian.GetKeyForStateSetNamesList();
tasks.Add(db.ListRightPushAsync(listKey, stateSet.Name));
}
await Task.WhenAny(Task.WhenAll(tasks), Task.Delay(-1, cancellationToken)).ConfigureAwait(false);
cancellationToken.ThrowIfCancellationRequested();
}
/// <summary>
/// Deletes a state set definition.
/// </summary>
/// <param name="historian">The historian to delete the state set from.</param>
/// <param name="name">The name of the state set to delete.</param>
/// <param name="cancellationToken">The cancellation token for the request.</param>
/// <returns>
/// A task that will delete the tag.
/// </returns>
internal static async Task Delete(RedisHistorian historian, string name, CancellationToken cancellationToken)
{
var tasks = new List <Task>();
// Delete the state set definition.
tasks.Add(historian.Connection.GetDatabase().KeyDeleteAsync(historian.GetKeyForStateSetDefinition(name)));
// Remove the name from the list of state set names.
var nameListKey = historian.GetKeyForStateSetNamesList();
tasks.Add(historian.Connection.GetDatabase().ListRemoveAsync(nameListKey, name));
await Task.WhenAny(Task.WhenAll(tasks), Task.Delay(-1, cancellationToken)).ConfigureAwait(false);
cancellationToken.ThrowIfCancellationRequested();
}
