Question

PayoutsProcessor定义

type PayoutsProcessor struct {
    config   *PayoutsConfig
    backend  *storage.RedisClient
    rpc      *rpc.RPCClient
    halt     bool
    lastFail error
}

payouts流程图

GetPendingPayments原理

func (r *RedisClient) GetPendingPayments() []*PendingPayment {
    //ZREVRANGE eth:payments:pending 0 -1 WITHSCORES
    raw := r.client.ZRevRangeWithScores(r.formatKey("payments", "pending"), 0, -1)
    var result []*PendingPayment
    for _, v := range raw.Val() {
        // timestamp -> "address:amount"
        payment := PendingPayment{}
        payment.Timestamp = int64(v.Score)
        fields := strings.Split(v.Member.(string), ":")
        payment.Address = fields[0]
        payment.Amount, _ = strconv.ParseInt(fields[1], 10, 64)
        result = append(result, &payment)
    }
    return result
}

GetPayees原理

func (r *RedisClient) GetPayees() ([]string, error) {
    payees := make(map[string]struct{})
    var result []string
    var c int64

    for {
        var keys []string
        var err error
        c, keys, err = r.client.Scan(c, r.formatKey("miners", "*"), 100).Result()
        if err != nil {
            return nil, err
        }
        for _, row := range keys {
            login := strings.Split(row, ":")[2]
            payees[login] = struct{}{}
        }
        if c == 0 {
            break
        }
    }
    for login, _ := range payees {
        result = append(result, login)
    }
    return result, nil
}

LockPayouts原理

func (r *RedisClient) LockPayouts(login string, amount int64) error {
    //eth:payments:lock
    key := r.formatKey("payments", "lock")

    //SETNX eth:payments:lock login:amount 0
    //Setnx（SET if Not eXists） 命令在指定的 key 不存在时，为 key 设置指定的值
    result := r.client.SetNX(key, join(login, amount), 0).Val()
    if !result {
        return fmt.Errorf("Unable to acquire lock '%s'", key)
    }
    return nil
}

UpdateBalance原理

func (r *RedisClient) UpdateBalance(login string, amount int64) error {
        tx := r.client.Multi()
        defer tx.Close()

        ts := util.MakeTimestamp() / 1000

        _, err := tx.Exec(func() error {
                //Hincrby 命令用于为哈希表中的字段值加上指定增量值
                //HINCRBY eth:miners:login balance -amount
                tx.HIncrBy(r.formatKey("miners", login), "balance", (amount * -1))

                //HINCRBY eth:miners:login pending amount
                tx.HIncrBy(r.formatKey("miners", login), "pending", amount)

                //HINCRBY eth:finances balance -amount
                tx.HIncrBy(r.formatKey("finances"), "balance", (amount * -1))

                //HINCRBY eth:finances pending amount
                tx.HIncrBy(r.formatKey("finances"), "pending", amount)

                //ZADD eth:payments:pending ts login:amount
                //Zadd 命令用于将一个或多个成员元素及其分数值加入到有序集当中
                tx.ZAdd(r.formatKey("payments", "pending"), redis.Z{Score: float64(ts), Member: join(login, amount)})
                return nil
        })
        return err
}

RollbackBalance原理

func (r *RedisClient) RollbackBalance(login string, amount int64) error {
    tx := r.client.Multi()
    defer tx.Close()

    _, err := tx.Exec(func() error {
        tx.HIncrBy(r.formatKey("miners", login), "balance", amount)
        tx.HIncrBy(r.formatKey("miners", login), "pending", (amount * -1))
        tx.HIncrBy(r.formatKey("finances"), "balance", amount)
        tx.HIncrBy(r.formatKey("finances"), "pending", (amount * -1))
        tx.ZRem(r.formatKey("payments", "pending"), join(login, amount))
        return nil
    })
    return err
}

WritePayment原理

func (r *RedisClient) WritePayment(login, txHash string, amount int64) error {
    tx := r.client.Multi()
    defer tx.Close()

    ts := util.MakeTimestamp() / 1000

    _, err := tx.Exec(func() error {
        //HINCRBY eth:miners:login pending -amount
        tx.HIncrBy(r.formatKey("miners", login), "pending", (amount * -1))

        //HINCRBY eth:miners:login paid amount
        tx.HIncrBy(r.formatKey("miners", login), "paid", amount)

        //HINCRBY eth:finances pending -amount
        tx.HIncrBy(r.formatKey("finances"), "pending", (amount * -1))

        //HINCRBY eth:finances paid amount
        tx.HIncrBy(r.formatKey("finances"), "paid", amount)

        //ZADD eth:payments:all ts txHash:login:amount
        tx.ZAdd(r.formatKey("payments", "all"), redis.Z{Score: float64(ts), Member: join(txHash, login, amount)})

        //ZADD eth:payments:login ts txHash:amount
        tx.ZAdd(r.formatKey("payments", login), redis.Z{Score: float64(ts), Member: join(txHash, amount)})

        //ZREM eth:payments:pending login:amount
        //Zrem 命令 Redis 有序集合(sorted set) Redis Zrem 命令用于移除有序集中的一个或多个成员
        tx.ZRem(r.formatKey("payments", "pending"), join(login, amount))

        //DEL 命令用于删除已存在的键
        //DEL eth:payments:lock
        tx.Del(r.formatKey("payments", "lock"))
        return nil
    })
    return err
}