libsam/pkg/shreder/client.go

package shreder

import (
	"context"
	"fmt"
	"runtime"
	"time"

	"github.com/gagliardetto/solana-go/rpc"
	"github.com/panjf2000/ants/v2"
	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials/insecure"
)

type Client struct {
	EnableClientStats bool
	conn              *grpc.ClientConn
	client            ShrederServiceClient
	tableLoader       *AddressTables
	subscription      map[string]*SubscribeRequestFilterTransactions

	pool *ants.Pool

	lastSlot     uint64
	lastSlotTime time.Time
}

func NewShrederClient(
	url string,
	rpcClient *rpc.Client,
	subscription map[string]*SubscribeRequestFilterTransactions,
) (*Client, func(), error) {
	if rpcClient == nil {
		return nil, func() {}, fmt.Errorf("rpc client is nil")
	}

	conn, err := grpc.NewClient(url, grpc.WithTransportCredentials(insecure.NewCredentials()))
	if err != nil {
		return nil, func() {}, err
	}

	poolSize := runtime.NumCPU()*2 + 2
	logger.Info("creating shreder client", "url", url, "pool_size", poolSize)
	pool, err := ants.NewPool(poolSize, ants.WithNonblocking(false))
	if err != nil {
		return nil, func() {}, err
	}

	s := &Client{
		conn:         conn,
		client:       NewShrederServiceClient(conn),
		subscription: subscription,
		tableLoader:  NewAddressTables(rpcClient),
		pool:         pool,
	}

	return s, func() {
		s.Wait()
	}, nil
}

func (c *Client) Wait() {
	logger.Debug("waiting for shreder client to stop")

	if c.pool != nil {
		c.pool.Release()
	}

	err := c.conn.Close()
	if err != nil {
		logger.Error("failed to close connection: ", "err", err)
	}

	logger.Debug("shreder client stopped")
}

func (c *Client) ReadSync(ctx context.Context, txCh chan<- TxSignalBatch) error {
	stream, err := c.client.SubscribeTransactions(ctx)
	if err != nil {
		return err
	}

	logger.Debug("subscribing to transactions")

	err = stream.Send(&SubscribeTransactionsRequest{
		Transactions: c.subscription,
	})
	if err != nil {
		return err
	}

	for {
		response, err := stream.Recv()
		if err != nil {
			return err
		}

		if c.EnableClientStats {
			slot := response.Transaction.Slot
			now := time.Now()
			if c.lastSlotTime.IsZero() || slot > c.lastSlot {
				if !c.lastSlotTime.IsZero() {
					logger.Info("block processed", "running", c.pool.Running(), "slot", slot, "prev_slot", c.lastSlot, "delta_ms", now.Sub(c.lastSlotTime).Milliseconds())
				}
				c.lastSlot = slot
				c.lastSlotTime = now
			}
		}

		txData := response.Transaction

		err = c.pool.Submit(func() {
			txBatch := ParseTransaction(txData, c.tableLoader, c.EnableClientStats)
			if len(txBatch) == 0 {
				return
			}

			for _, tx := range txBatch {
				tx.Source = "shreder"
			}

			select {
			case <-ctx.Done():
				return
			case txCh <- txBatch:
			}
		})
		if err != nil {
			return err
		}
	}
}