/// <summary>
/// Pre-fetch UTXOs for a block and some blocks with higher height.
/// <para>
/// This task runs in the background.
/// </para>
/// </summary>
/// <param name="header">Header of a block that is about to be partially validated and that requires pre-fetching.</param>
private Task OnHeaderEnqueued(ChainedHeader header, CancellationToken cancellation)
{
ChainedHeader currentHeader = header;
// Go Lookahead blocks ahead of current header and get block for pre-fetching.
// There might be several blocks at height of header.Height + Lookahead but
// only first one will be pre-fetched since pre-fetching is in place mostly to
// speed up IBD.
for (int i = 0; i < Lookahead; i++)
{
if (currentHeader.Next.Count == 0)
{
this.logger.LogTrace("(-)[NO_HEADERS]");
return(Task.CompletedTask);
}
currentHeader = currentHeader.Next.FirstOrDefault();
if (currentHeader == null)
{
this.logger.LogTrace("(-)[NO_NEXT_HEADER]");
return(Task.CompletedTask);
}
}
Block block = currentHeader.Block;
if (block == null)
{
this.logger.LogTrace("(-)[NO_BLOCK_DATA]");
return(Task.CompletedTask);
}
bool farFromTip = currentHeader.Height > this.chainIndexer.Tip.Height + (Lookahead / 2);
if (!farFromTip)
{
this.logger.LogDebug("Skipping pre-fetch, the block selected is too close to the tip.");
this.logger.LogTrace("(-)[TOO_CLOSE_TO_PREFETCH_HEIGHT]");
return(Task.CompletedTask);
}
bool enforceBIP30 = false;
if (currentHeader.Height > this.checkpoints.GetLastCheckpointHeight())
{
enforceBIP30 = DeploymentFlags.EnforceBIP30ForBlock(currentHeader);
}
OutPoint[] idsToCache = this.coinviewHelper.GetIdsToFetch(block, enforceBIP30);
if (idsToCache.Length != 0)
{
this.coinview.CacheCoins(idsToCache);
this.logger.LogDebug("Block '{0}' had {1} ids pre-fetched.", currentHeader.Height, idsToCache.Length);
}
return(Task.CompletedTask);
}
/// <summary>
/// Pre-fetches UTXOs for a block and some blocks with higher height.
/// pre-fetching is done on the background.
/// </summary>
/// <param name="header">Header of a block that is about to be partially validated and requires pre-fetching.</param>
private async Task OnHeaderEnqueuedAsync(ChainedHeader header, CancellationToken cancellation)
{
ChainedHeader currentHeader = header;
// Go Lookahead blocks ahead of current header and get block for pre-fetching.
// There might be several blocks at height of header.Height + Lookahead but
// only first one will be pre-fetched since pre-fetching is in place mostly to
// speed up IBD.
for (int i = 0; i < Lookahead; i++)
{
if (currentHeader.Next.Count == 0)
{
this.logger.LogTrace("(-)[NO_HEADERS]");
return;
}
currentHeader = currentHeader.Next.FirstOrDefault();
if (currentHeader == null)
{
this.logger.LogTrace("(-)[NO_NEXT_HEADER]");
return;
}
}
Block block = currentHeader.Block;
if (block == null)
{
this.logger.LogTrace("(-)[NO_BLOCK_DATA]");
return;
}
bool farFromTip = currentHeader.Height > this.chainIndexer.Tip.Height + (Lookahead / 2);
if (!farFromTip)
{
this.logger.LogDebug("Block selected for pre-fetching is too close to the tip! Skipping pre-fetching.");
this.logger.LogTrace("(-)[TOO_CLOSE_TO_PREFETCH]");
return;
}
bool enforceBIP30 = DeploymentFlags.EnforceBIP30ForBlock(currentHeader);
uint256[] idsToFetch = this.coinviewHelper.GetIdsToFetch(block, enforceBIP30);
if (idsToFetch.Length != 0)
{
this.coinview.FetchCoins(idsToFetch, cancellation);
this.logger.LogTrace("{0} ids were pre-fetched.", idsToFetch.Length);
}
}
