添加redis function

idGenerator/store/redis_id_store.lua

@@ -0,0 +1,97 @@
+#!lua name=charlie_id_generator
+
+-- 安装命令
+-- cat redis_id_store.lua | redis-cli -x --cluster-only-masters --cluster call 192.168.123.30:6379 FUNCTION LOAD REPLACE
+
+-- 标识分配的redis函数，
+-- updateMachineCode，更新客户端机器码
+-- allocateSerial，分配序列段。在分配序列段之前更新机器码
+
+-- 默认机器码有效期秒数
+local machineExpires = 60
+
+local function _updateMachineCode(key, code, token, max)
+
+    local machineKey = key..":allocated:"..tostring(code)
+    if redis.call("GET", machineKey) == token then
+        redis.call("EXPIRE", machineKey, machineExpires)
+        return code
+    end
+
+    for i = 0, tostring(max), 1 do
+        machineKey = key..":allocated:"..tostring(i)
+
+        if redis.call("EXISTS", machineKey) == 0 then 
+            redis.call("SET", machineKey, token, "EX", machineExpires)
+            return i
+        end
+    end
+
+    return -1
+end
+
+-- 请求参数：机器码当前值，机器标识，机器码最大值
+-- 响应参数：分配的机器码。分配失败时返回-1
+-- 机器标识在客户端创建时生成，分辨不同的客户。
+-- FCALL updateMachineCode 1 "bbcc" -1 "aaaaa" 9
+local function updateMachineCode(keys, args)
+    local key = keys[1]
+    local code = tonumber(args[1])
+    local token = args[2]
+    local max = tonumber(args[3])
+
+    return _updateMachineCode(key, code, token, max)
+end
+
+-- 请求参数：机器码，机器标识，步长，序列最小值，序列最大值，机器码最大值
+-- 响应参数：分配成功的机器码，序列起始值和结束值{machineCode, begin, finish}
+local function allocateSerial(keys, args)
+    local key = keys[1]
+
+    local code = tonumber(args[1])
+    local token = args[2]
+    local step = tonumber(args[3])
+    local min = tonumber(args[4])
+    local max = tonumber(args[5])    
+    local maxCode = tonumber(args[6])
+
+    code = _updateMachineCode(key, code, token, maxCode)
+    if code == -1 then
+        -- 刷新机器码失败，响应错误信息。
+        return {code, 0, 0, 0, "machine code allocation failed"}
+    end
+    
+    if step > max then 
+        step = max
+    end
+    
+    key = key..":sequence"
+    if redis.call("HEXISTS", key, code) == 0 then
+        redis.call("HSET", key, code, step)
+        
+        return {code, min, step, 0, "success"}
+    end
+
+    local begin = tonumber(redis.call("HGET", key, code))
+    local finish = redis.call("HINCRBY", key, code, step)
+    local reback = 0
+
+    -- 计算后的起始值超过最大值，从序列段起点重新开始
+    if begin >= max then 
+        begin = min
+        finish = step
+        redis.call("HSET", key, code, step)
+        reback = 1
+    end
+
+    -- 计算后结束值超过最大值
+    if finish > max then
+        finish = max
+        redis.call("HSET", key, code, finish)
+    end
+
+    return {code, begin, finish, reback, "success"}
+end
+
+redis.register_function('updateMachineCode',updateMachineCode)
+redis.register_function('allocateSerial',allocateSerial)