【运维发布】服务熔断：异常服务的自动熔断与恢复

-- 熔断器：判定与切断
local player = class(actor)
local breaker = {state = "closed", failCnt = 0, threshold = 5}
local function callService(player, func, fallback)
    if breaker.state == "open" then
        return fallback()
    end
    local ok, result = pcall(func)
    if ok then
        breaker.failCnt = math.max(0, breaker.failCnt - 1)
        return result
    end
    breaker.failCnt = breaker.failCnt + 1
    if breaker.failCnt >= breaker.threshold then
        breaker.state = "open"
        setplayvar(player, "HUMAN", "BreakerOpen", os.time(), true)
        sendmsg(player, 1, 0, "服务暂时不可用，已启用降级方案。")
    end
    return fallback()
end

-- 自动恢复：半开与合闸
local player = class(actor)
local function tryRecover(player)
    if breaker.state ~= "open" then return end
    local openTs = tonumber(getplayvar(player, "HUMAN", "BreakerOpen") or 0)
    if os.time() - openTs > 30 then
        breaker.state = "half-open"
        local ok = pcall(healthCheck)
        if ok then
            breaker.state = "closed"
            breaker.failCnt = 0
            sendmsg(player, 1, 0, "服务已恢复正常。")
        else
            breaker.state = "open"
            setplayvar(player, "HUMAN", "BreakerOpen", os.time(), true)
        end
    end
end