【高级技巧】Lua一致性哈希：裁决之杖仓库分片扩容的环形桶

local function bucketOf(id, n)
    return id % n + 1                -- 桶数变化，几乎全量迁移
end

-- 裁决之杖仓库分片环：锚点值0到99
local RING = {[10] = "A", [40] = "B", [70] = "C"}
local function bucketOf(id)
    local h = id % 100
    for anchor = h, h + 99 do
        local a = anchor % 100
        if RING[a] then return RING[a], a end   -- 顺时针找锚点
    end
end
sendmsg(actor, 1, "裁决之杖id落桶 " .. bucketOf(123))