private Page TryGetNextPageFromCache(long precedingCheckpoint, string subscriptionId, CancellationToken cancellationToken)
{
if (IsCachingEnabled && cachedTransactionsByPrecedingCheckpoint.TryGet(precedingCheckpoint, out Transaction cachedTransaction))
{
var resultPage = new List <Transaction>(maxPageSize)
{
cachedTransaction
};
while (resultPage.Count < maxPageSize)
{
long lastCheckpoint = cachedTransaction.Checkpoint;
if (cachedTransactionsByPrecedingCheckpoint.TryGet(lastCheckpoint, out cachedTransaction))
{
resultPage.Add(cachedTransaction);
}
else
{
break;
}
}
logDebug(() =>
$"Cache Hit: (subscription: {subscriptionId}, precedingCheckpoint: {precedingCheckpoint}, page size: {resultPage.Count}, range: {resultPage.First().Checkpoint}-{resultPage.Last().Checkpoint})");
return(new Page(precedingCheckpoint, resultPage));
}
logDebug(() =>
$"Cache Miss: (subscription: {subscriptionId}, precedingCheckpoint: {precedingCheckpoint}).");
return(new Page(precedingCheckpoint, new Transaction[0]));
}
private Page TryGetNextPageFromCache(long previousCheckpoint, string subscriptionId)
{
Transaction cachedNextTransaction;
if ((transactionCacheByPreviousCheckpoint != null) && transactionCacheByPreviousCheckpoint.TryGet(previousCheckpoint, out cachedNextTransaction))
{
var resultPage = new List <Transaction>(maxPageSize)
{
cachedNextTransaction
};
while (resultPage.Count < maxPageSize)
{
long lastCheckpoint = cachedNextTransaction.Checkpoint;
if (transactionCacheByPreviousCheckpoint.TryGet(lastCheckpoint, out cachedNextTransaction))
{
resultPage.Add(cachedNextTransaction);
}
else
{
StartPreloadingNextPage(lastCheckpoint, subscriptionId);
break;
}
}
#if LIQUIDPROJECTIONS_DIAGNOSTICS
logger(() =>
$"Subscription {subscriptionId} has found a page of size {resultPage.Count} " +
$"from checkpoint {resultPage.First().Checkpoint} " +
$"to checkpoint {resultPage.Last().Checkpoint} in the cache.");
#endif
return(new Page(previousCheckpoint, resultPage));
}
#if LIQUIDPROJECTIONS_DIAGNOSTICS
logger(() =>
$"Subscription {subscriptionId} has not found the next transaction in the cache.");
#endif
return(new Page(previousCheckpoint, new Transaction[0]));
}
