120 lines
3.3 KiB
PHP
120 lines
3.3 KiB
PHP
<?php
|
||
|
||
namespace app\common\library;
|
||
|
||
class RedpacketLua
|
||
{
|
||
/**
|
||
* 抢红包Lua脚本
|
||
* 保证原子性操作，防止超抢
|
||
*/
|
||
public static function grabRedpacketScript()
|
||
{
|
||
return <<<LUA
|
||
-- KEYS[1]: 红包key, KEYS[2]: 用户集合key, KEYS[3]: 用户ID
|
||
-- ARGV[1]: 当前时间
|
||
|
||
local redpacketKey = KEYS[1]
|
||
local userSetKey = KEYS[2]
|
||
local userId = KEYS[3]
|
||
local currentTime = tonumber(ARGV[1])
|
||
|
||
-- 检查红包是否存在
|
||
local redpacketData = redis.call('HGETALL', redpacketKey)
|
||
if not redpacketData or #redpacketData == 0 then
|
||
return {0, "红包不存在", 0}
|
||
end
|
||
|
||
-- 将哈希数据转为table
|
||
local redpacket = {}
|
||
for i = 1, #redpacketData, 2 do
|
||
redpacket[redpacketData[i]] = redpacketData[i + 1]
|
||
end
|
||
|
||
-- 检查红包状态
|
||
local status = tonumber(redpacket['status'])
|
||
local startTime = tonumber(redpacket['start_time'])
|
||
local endTime = tonumber(redpacket['end_time'])
|
||
|
||
if status == 0 then
|
||
if currentTime < startTime then
|
||
return {0, "红包还未开始", 0}
|
||
else
|
||
-- 更新状态为进行中(1)
|
||
redis.call('HSET', redpacketKey, 'status', 1)
|
||
status = 1
|
||
end
|
||
end
|
||
|
||
if status ~= 1 then
|
||
return {0, "红包已结束", 0}
|
||
end
|
||
|
||
if currentTime > endTime then
|
||
redis.call('HSET', redpacketKey, 'status', 2)
|
||
return {0, "红包已结束", 0}
|
||
end
|
||
|
||
-- 检查是否已经抢过
|
||
local hasGrabbed = redis.call('SISMEMBER', userSetKey, userId)
|
||
if hasGrabbed == 1 then
|
||
return {0, "已经抢过该红包", 0}
|
||
end
|
||
|
||
-- 检查是否还有剩余
|
||
local leftAmount = tonumber(redpacket['left_amount'])
|
||
local leftCount = tonumber(redpacket['left_count'])
|
||
|
||
if leftCount <= 0 or leftAmount <= 0 then
|
||
return {0, "红包已抢完", 0}
|
||
end
|
||
|
||
-- 计算红包金额（核心修改：适配整数金币，避免0）
|
||
local amount = 0
|
||
local isFinished = 0
|
||
|
||
if leftCount == 1 then
|
||
-- 最后一个红包，获得剩余所有金额（确保至少1）
|
||
amount = leftAmount
|
||
isFinished = 1
|
||
else
|
||
-- 随机算法：二倍均值法（适配整数，保证最低1）
|
||
-- 1. 计算二倍均值（整数处理，向下取整）
|
||
local avg = leftAmount / leftCount
|
||
local maxAmount = math.floor(avg * 2)
|
||
-- 2. 确保最大金额至少为1，且不超过剩余金额-（剩余个数-1）（避免后续红包无金额可分）
|
||
-- 剩余金额-（剩余个数-1）：保证剩下的每个红包至少能分1个金币
|
||
local safeMax = leftAmount - (leftCount - 1)
|
||
maxAmount = math.min(maxAmount, safeMax)
|
||
maxAmount = math.max(maxAmount, 1) -- 确保最小可随机值为1
|
||
|
||
-- 3. 随机生成1到maxAmount之间的整数（避免0）
|
||
amount = math.random(1, maxAmount)
|
||
|
||
-- 4. 检查是否抢完（整数判断，无需浮点数误差处理）
|
||
if leftCount - 1 == 1 or (leftAmount - amount) <= 0 then
|
||
isFinished = 1
|
||
end
|
||
end
|
||
|
||
-- 更新红包数据（整数处理，无小数）
|
||
local newLeftAmount = leftAmount - amount
|
||
local newLeftCount = leftCount - 1
|
||
|
||
redis.call('HSET', redpacketKey, 'left_amount', newLeftAmount)
|
||
redis.call('HSET', redpacketKey, 'left_count', newLeftCount)
|
||
|
||
-- 标记用户已抢
|
||
redis.call('SADD', userSetKey, userId)
|
||
|
||
-- 如果抢完了，更新状态为已结束(2)
|
||
if isFinished == 1 then
|
||
redis.call('HSET', redpacketKey, 'status', 2)
|
||
end
|
||
|
||
return {1, tostring(amount), isFinished}
|
||
LUA;
|
||
}
|
||
|
||
|
||
} |