aergoio/aergo

/*
 * @file
 * @copyright defined in aergo/LICENSE.txt
 */

package subproto

import (
    "time"

    "github.com/aergoio/aergo-lib/log"
    "github.com/aergoio/aergo/v2/internal/enc/base58"
    "github.com/aergoio/aergo/v2/internal/enc/proto"
    "github.com/aergoio/aergo/v2/p2p/p2pcommon"
    "github.com/aergoio/aergo/v2/p2p/p2putil"
    "github.com/aergoio/aergo/v2/types"
)

type blockRequestHandler struct {
    BaseMsgHandler
    asyncHelper
}

var _ p2pcommon.MessageHandler = (*blockRequestHandler)(nil)

type blockResponseHandler struct {
    BaseMsgHandler
}

var _ p2pcommon.MessageHandler = (*blockResponseHandler)(nil)

// newBlockReqHandler creates handler for GetBlockRequest
func NewBlockReqHandler(pm p2pcommon.PeerManager, peer p2pcommon.RemotePeer, logger *log.Logger, actor p2pcommon.ActorService) *blockRequestHandler {
    bh := &blockRequestHandler{BaseMsgHandler: BaseMsgHandler{protocol: p2pcommon.GetBlocksRequest, pm: pm, peer: peer, actor: actor, logger: logger}, asyncHelper: newAsyncHelper()}

    return bh
}

func (bh *blockRequestHandler) ParsePayload(rawbytes []byte) (p2pcommon.MessageBody, error) {
    return p2putil.UnmarshalAndReturn(rawbytes, &types.GetBlockRequest{})
}

const (
    EmptyGetBlockResponseSize = 12 // roughly estimated maximum size if element is full
)

func (bh *blockRequestHandler) Handle(msg p2pcommon.Message, msgBody p2pcommon.MessageBody) {
    remotePeer := bh.peer
    data := msgBody.(*types.GetBlockRequest)
    p2putil.DebugLogReceive(bh.logger, bh.protocol, msg.ID().String(), remotePeer, data)
    if bh.issue() {
        go bh.handleBlkReq(msg, data)
    } else {
        bh.logger.Info().Stringer(p2putil.LogProtoID, bh.protocol).Stringer(p2putil.LogMsgID, msg.ID()).Str(p2putil.LogPeerName, remotePeer.Name()).Msg("return error for busy")
        resp := &types.GetBlockResponse{
            Status: types.ResultStatus_RESOURCE_EXHAUSTED,
            Blocks: nil, HasNext: false}

        remotePeer.SendMessage(remotePeer.MF().NewMsgResponseOrder(msg.ID(), p2pcommon.GetBlocksResponse, resp))
    }
}

func (bh *blockRequestHandler) handleBlkReq(msg p2pcommon.Message, data *types.GetBlockRequest) {
    defer bh.release()
    remotePeer := bh.peer

    requestID := msg.ID()
    sliceCap := p2pcommon.MaxBlockResponseCount
    if len(data.Hashes) < sliceCap {
        sliceCap = len(data.Hashes)
    }

    defaultMsgTimeout := time.Second * 30
    // find block info from chainservice
    idx := 0
    msgSentCount := 0
    status := types.ResultStatus_OK
    blockInfos := make([]*types.Block, 0, sliceCap)
    payloadSize := EmptyGetBlockResponseSize
    var blockSize, fieldSize int
    for _, hash := range data.Hashes {
        foundBlock, err := bh.actor.GetChainAccessor().GetBlock(hash)
        if err != nil {
            // the block hash from request must exists. this error is fatal.
            bh.logger.Warn().Err(err).Str(p2putil.LogBlkHash, base58.Encode(hash)).Str(p2putil.LogOrgReqID, requestID.String()).Msg("failed to get block while processing getBlock")
            status = types.ResultStatus_INTERNAL
            break
        }
        if foundBlock == nil {
            // the remote peer request not existing block
            bh.logger.Debug().Str(p2putil.LogBlkHash, base58.Encode(hash)).Str(p2putil.LogOrgReqID, requestID.String()).Msg("requested block hash is missing")
            status = types.ResultStatus_NOT_FOUND
            break

        }
        blockSize = proto.Size(foundBlock)
        fieldSize = blockSize + p2putil.CalculateFieldDescSize(blockSize)
        if len(blockInfos) >= sliceCap || uint32(payloadSize+fieldSize) > p2pcommon.MaxPayloadLength {
            msgSentCount++
            // send partial list
            resp := &types.GetBlockResponse{
                Status:  status,
                Blocks:  blockInfos,
                HasNext: true,
                //HasNext:msgSentCount<MaxResponseSplitCount, // always have nextItem ( see foundBlock) but msg count limit will affect
            }
            bh.logger.Debug().Uint64("first_blk_number", blockInfos[0].Header.GetBlockNo()).Int(p2putil.LogBlkCount, len(blockInfos)).Str(p2putil.LogOrgReqID, requestID.String()).Msg("Sending partial getBlock response")
            err := remotePeer.SendAndWaitMessage(remotePeer.MF().NewMsgResponseOrder(requestID, p2pcommon.GetBlocksResponse, resp), defaultMsgTimeout)
            if err != nil {
                bh.logger.Info().Uint64("first_blk_number", blockInfos[0].Header.GetBlockNo()).Err(err).Int(p2putil.LogBlkCount, len(blockInfos)).Str(p2putil.LogOrgReqID, requestID.String()).Msg("Sending failed")
                return
            }
            blockInfos = make([]*types.Block, 0, sliceCap)
            payloadSize = EmptyGetBlockResponseSize
        }
        blockInfos = append(blockInfos, foundBlock)
        payloadSize += fieldSize
        idx++
    }

    if 0 == idx {
        status = types.ResultStatus_NOT_FOUND
    }
    // Failed response does not need incomplete blocks information
    if status != types.ResultStatus_OK {
        blockInfos = blockInfos[:0]
    }
    // generate response message
    resp := &types.GetBlockResponse{
        Status: status,
        Blocks: blockInfos, HasNext: false}

    // ???: have to check arguments
    bh.logger.Debug().Int(p2putil.LogBlkCount, len(blockInfos)).Str(p2putil.LogOrgReqID, requestID.String()).Msg("Sending last part of getBlock response")
    err := remotePeer.SendAndWaitMessage(remotePeer.MF().NewMsgResponseOrder(requestID, p2pcommon.GetBlocksResponse, resp), defaultMsgTimeout)
    if err != nil {
        bh.logger.Info().Int(p2putil.LogBlkCount, len(data.Hashes)).Err(err).Str(p2putil.LogOrgReqID, requestID.String()).Msg("Sending failed")
        return
    }
}

// NewBlockRespHandler creates handler for GetBlockResponse
func NewBlockRespHandler(pm p2pcommon.PeerManager, peer p2pcommon.RemotePeer, logger *log.Logger, actor p2pcommon.ActorService, sm p2pcommon.SyncManager) *blockResponseHandler {
    bh := &blockResponseHandler{BaseMsgHandler{protocol: p2pcommon.GetBlocksResponse, pm: pm, sm: sm, peer: peer, actor: actor, logger: logger}}
    return bh
}

func (bh *blockResponseHandler) ParsePayload(rawbytes []byte) (p2pcommon.MessageBody, error) {
    return p2putil.UnmarshalAndReturn(rawbytes, &types.GetBlockResponse{})
}

func (bh *blockResponseHandler) Handle(msg p2pcommon.Message, msgBody p2pcommon.MessageBody) {
    remotePeer := bh.peer
    data := msgBody.(*types.GetBlockResponse)
    if bh.logger.IsDebugEnabled() {
        p2putil.DebugLogReceiveResponse(bh.logger, bh.protocol, msg.ID().String(), msg.OriginalID().String(), remotePeer, data)
    }

    // locate request data and remove it if found
    if !remotePeer.GetReceiver(msg.OriginalID())(msg, data) {
        remotePeer.ConsumeRequest(msg.OriginalID())
        // TODO temporary code and will be deleted after newer syncer is made.
        if data.Status != types.ResultStatus_OK || len(data.Blocks) == 0 {
            return
        }
        bh.sm.HandleGetBlockResponse(remotePeer, msg, data)
    }
}