private bool RevertQuotesAndReturnFalse(IReadOnlyCollection <T> originalQuotes, IQuoteStorageService <T> quoteStorageService)
{
if (originalQuotes == null || originalQuotes.Count == 0)
{
return(false);
}
foreach (var originalQuote in originalQuotes)
{
quoteStorageService.AddOrUpdate(originalQuote);
}
return(false);
}
public void AddOrUpdate(T quote)
{
// Index first, and if successful send to primary storage - taking this approach vs. the inverted as the indexes are simply pointers to the
// primary storage and do not require thread syncronization, so reverting those is relatively painless and side-effect free compared to the possibility
// of something existing in primary storage for a while, getting read possibly and used, then having to revert because something went wrong with
// indexing. An alternate approach here could be to lock things for the duration of the add/update, but that would be either fairly broad (i.e. a
// lock on an entire symbol), or fairly complex (locking portions of a symbol, i.e. a symbol and quote combination), which...why?
_quoteIndexService.AddOrUpdate(quote);
try
{
_quoteStorageService.AddOrUpdate(quote);
}
catch when(RemoveFromIndexAndReturnFalse(quote))
{ // Unreachable throw - the above when filter will remove from the index and return false, which allows us to ensure index removal witout
// unwinding the call stack just to throw an exception - as is, it'll just bubble out of here like an unhandled exception
throw;
}
}