Redis学习笔记1——黑马点评秒杀优化

(注：代码大部分来自黑马点评资料，稍加修改)

lua：

local voucherId=ARGV[1]

local userId=ARGV[2]

local stockKey='seckill:stock:'..voucherId

local orderKey='seckill:order:'..voucherId

if(tonumber(redis.call('get',stockKey))<=0) then
    return 1
end

if(redis.call('sismember',orderKey,userId)==1) then
    return 2
end

redis.call('incrby',stockKey,-1)

redis.call('sadd',orderKey,userId)

return 0

VoucherOrderServiceImpl：

public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;

    @Resource
    private RedisIdWorker redisIdWorker;

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    IVoucherOrderService proxy_plus;

    private static final DefaultRedisScript<Long> SECKILL_Script;
    static{
        SECKILL_Script=new DefaultRedisScript<>();
        SECKILL_Script.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_Script.setResultType(Long.class);
    }

    private BlockingQueue<VoucherOrder> orderTasks =new  ArrayBlockingQueue<>(1024 * 1024);


    private static final ExecutorService SECKILL_ORDER_EXECUTOR=Executors.newSingleThreadExecutor();

    @PostConstruct
    private void init(){
        SECKILL_ORDER_EXECUTOR.submit(new VoucherHandler());
    }

    private class VoucherHandler implements Runnable{
        @Override
        public void run() {
            while(true){
                try {
                    //从阻塞队列获取预备订单
                    VoucherOrder voucherOrder = orderTasks.take();
                    //处理预备订单
                    proxy_plus.createVoucherOrder_plus(voucherOrder);
                } catch (Exception e) {
                    log.error("处理订单异常...");
                }
            }
        }
    }

    @Transactional
    public void createVoucherOrder_plus(VoucherOrder voucherOrder){
        seckillVoucherService.update()
                .setSql("stock=stock-1")
                .eq("voucher_id", voucherOrder.getVoucherId()).gt("stock",0)
                .update();
        save(voucherOrder);
    }

    @Override
    public Result seckillVoucher(Long voucherId) {
        //执行lua
        Long userId = UserHolder.getUser().getId();
        Long result = stringRedisTemplate.execute(
                SECKILL_Script,
                Collections.emptyList(),
                voucherId.toString(), userId.toString()
        );
        int r=result.intValue();

        //不能购买
        if(r==1){
            return Result.fail("库存不足！");
        }
        if(r==2){
            return Result.fail("不能重复购买！");
        }

        //能购买
        VoucherOrder voucherOrder=new VoucherOrder();
        
        long orderId = redisIdWorker.nextId("order");
        voucherOrder.setId(orderId);
        voucherOrder.setUserId(UserHolder.getUser().getId());
        voucherOrder.setVoucherId(voucherId);

        orderTasks.add(voucherOrder);

        proxy_plus=(IVoucherOrderService) AopContext.currentProxy();

        return Result.ok(orderId);
    }
}

IVoucherOrderService：

void createVoucherOrder_plus(VoucherOrder voucherOrder);