async Task <bool> DownloadBlockSlices(RemoteSyncItem remote, ChainSyncItem chainSyncItem) { var chainType = chainSyncItem.ChainType; var chainId = chainSyncItem.ChainId; var chainIndex = chainSyncItem.ChainIndex; chainSyncItem.UpdateLastBlockInfo((await remote.Client.DownloadLastBlockInfo(chainType, chainId, chainIndex)).Data); var lastBlockId = chainSyncItem.BlockState.LastBlockId; if (lastBlockId <= Protocol.InvalidBlockId) { Log.Debug($"Skipping block slice download for chain {chainId}/{chainIndex}, blockid invalid.", this); return(true); } var remoteLastAvailableSlice = BlockSliceInfo.GetSliceIndex(lastBlockId) - 1; if (remoteLastAvailableSlice < 0) // -1: ignore last "hot" slice { Log.Debug($"Skipping block slice download for chain {chainId}/{chainIndex}, no available remote stored slice found.", this); return(true); } var localStartSlice = 0L; var localLast = BlockStorage.GetBlockSlices(_storage, chainType, chainId, chainIndex, true).LastOrDefault(); if (localLast.Value != null) { localStartSlice = localLast.Value.SliceIndex + 1; } if (!(chainSyncItem.LowestFoundBlockSliceId <= localStartSlice)) { Log.Error($"Download block slices for chain {chainId}/{chainIndex} failed, last local slice is {localStartSlice}, lowest remote slice found is {chainSyncItem.LowestFoundBlockSliceId}.", this); return(false); } var count = 0; for (var sliceIndex = localStartSlice; sliceIndex <= remoteLastAvailableSlice; sliceIndex++) { Log.Trace($"Downloading block slice {sliceIndex}/{remoteLastAvailableSlice} for chain {chainId}/{chainIndex}.", this); var sliceData = (await remote.Client.DownloadBlockSlice(_storage, chainType, chainId, chainIndex, sliceIndex)).Data; var error = false; if (sliceData == null || !sliceData.Move()) { Log.Trace($"Block slice {sliceIndex} download failed.", this); sliceData?.Delete(); error = true; } sliceData?.Dispose(); if (error) { return(false); } count++; } if (count > 0) { return(await DownloadBlockSlices(remote, chainSyncItem)); } return(true); }