51 lines
1.4 KiB
Lua
51 lines
1.4 KiB
Lua
-- 购物车操作Lua脚本
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-- 功能：原子性地更新购物车并检查库存
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-- 参数：KEYS[1] = 购物车key, KEYS[2] = 库存key, ARGV[1] = 商品ID, ARGV[2] = 数量, ARGV[3] = 操作类型(add/update/remove)
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-- 返回值：成功返回新数量，失败返回负数
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local cart_key = KEYS[1]
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local stock_key = KEYS[2]
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local product_id = ARGV[1]
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local quantity = tonumber(ARGV[2])
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local operation = ARGV[3]
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-- 获取当前库存
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local current_stock = redis.call('GET', stock_key)
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if current_stock == false then
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return -1 -- 商品不存在
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end
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current_stock = tonumber(current_stock)
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-- 获取购物车中当前商品数量
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local cart_quantity = redis.call('HGET', cart_key, product_id)
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cart_quantity = cart_quantity and tonumber(cart_quantity) or 0
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local new_quantity = 0
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if operation == 'add' then
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new_quantity = cart_quantity + quantity
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elseif operation == 'update' then
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new_quantity = quantity
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elseif operation == 'remove' then
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redis.call('HDEL', cart_key, product_id)
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return 0
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else
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return -2 -- 无效操作
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end
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-- 检查库存是否足够
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if new_quantity > current_stock then
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return -3 -- 库存不足
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end
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-- 更新购物车
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if new_quantity > 0 then
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redis.call('HSET', cart_key, product_id, new_quantity)
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-- 设置购物车过期时间（7天）
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redis.call('EXPIRE', cart_key, 7 * 24 * 3600)
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else
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redis.call('HDEL', cart_key, product_id)
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end
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return new_quantity
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