/// <summary>
/// Registers a callback to be invoked when a new IndexSearcher is being initialized.
/// This method allows an IndexSearcher to be "warmed up" by executing one or more
/// queries before the instance becomes visible on other threads.
///
/// While callbacks are being executed, other threads will continue to use the previous
/// instance of IndexSearcher if this is not the first instance being initialized.
///
/// If this is the first instance, other threads will block until all callbacks complete.
/// </summary>
public void RegisterCacheWarmingCallback <T>(Action <IQueryable <T> > callback, ObjectLookup <T> lookup, IDocumentMapper <T> documentMapper)
{
context.SearcherLoading += (s, e) =>
{
Log.Trace(m => m("Invoking cache warming callback " + lookup));
var warmupContext = new WarmUpContext(context, e.IndexSearcher);
var queryable = CreateQueryable(lookup, warmupContext, documentMapper);
callback(queryable);
Log.Trace(m => m("Callback {0} completed.", lookup));
};
}
/// <summary>
/// Same as <see cref="RegisterCacheWarmingCallback{T}(System.Action{System.Linq.IQueryable{T}})"/>
/// but allows client to provide factory method for creating new instances of <typeparamref name="T"/>.
/// </summary>
public void RegisterCacheWarmingCallback <T>(Action <IQueryable <T> > callback, Func <T> factory)
{
context.SearcherLoading += (s, e) =>
{
Log.Trace(m => m("Invoking cache warming callback " + factory));
var warmupContext = new WarmUpContext(context, e.IndexSearcher);
var queryable = CreateQueryable(factory, warmupContext);
callback(queryable);
Log.Trace(m => m("Callback {0} completed.", factory));
};
}
public MigrationHostedService(ILogger <MigrationHostedService> logger, WarmUpContext context)
{
this._logger = logger;
this._context = context;
}
