Lua脚本操作Redis字节数组例子

最新推荐文章于 2024-05-30 16:30:41 发布

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最新推荐文章于 2024-05-30 16:30:41 发布

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分类专栏： JAVA高频TIPS

本文链接：https://blog.youkuaiyun.com/vmdchc/article/details/102581986

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这段Lua脚本主要用于处理Redis中的字节数组，涉及到空间索引的申请方法。通过读取和处理传入的参数，如数据长度、块生成时间和更新时间等，计算并更新字节数组的索引。脚本中包含了计算新索引、更新文件长度、处理多块数据等多种情况，最终将处理后的索引存储回Redis。

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/**
   * 空间索引申请方法(value存储为Byte类型)
   * 索引结构：
   * 块开始索引,4字节，最大1.9G :2147483647/1024/1024/1024=1.9G (没有用块编号乘2048作开始索引，然后用两个字节存块编号，是因为两字节太小)
   * 索引偏移量4字节，最大1.9G :2147483647/1024/1024/1024=1.9G
   * 块生成时间与更新时间每个占4字节共8字节
   *
   *
   * @return
   */
   public static String getSpaceIndexByteLuaScript() {
       String luaStr = "local bigkey = KEYS[1];"
               //数据长度
               + "local dataLen = tonumber(ARGV[1]);"
               //vid
               + "local smallKey = ARGV[2];"
               //临时编号
               + "local serNum = tonumber(ARGV[3]);"
               //数据块长度
               + "local blockLen = tonumber(ARGV[4]);"
               //终端时间
               + "local devTime = tonumber(ARGV[5]);"
               //写入或更新标识,0写入，1更新
               + "local inUp = tonumber(ARGV[6]);"
               //该条数据该天打点状态
               + "local dayDotState = tonumber(ARGV[7]);"
               //日期行数据打点状态数据打点状态小Key
               + "local dayDotKey = ARGV[8];"
               //报警行数据打点状态
               + "local alarmTypeState = tonumber(ARGV[9]);"
               //报警行数据打点状态数据打点状态小Key
               + "local alarmDotKey = ARGV[10];"
               //索引集合,字节:开始索引(4)+偏移索引(4)+块开始时间(4)+块开始更新(4);如果有多块，则重复前述
               + "local asciiIndex = redis.call('HGET',bigkey,smallKey);"
               //文件长度
               + "local oldfileLen = redis.call('HGET',bigkey,\"fileLen\");"
               //旧日期打点状态
               + "local oldDayDotState = redis.call('HGET',bigkey,dayDotKey);"
               //旧报警打点状态
               + "local oldAlarmTypeState = redis.call('HGET',bigkey,alarmDotKey);"

               + "local fileLen = 0;"
               + "if(oldfileLen ~= false) then "
+ " fileLen = tonumber(oldfileLen);"
               + "end "

               //上次索引日查询打点状态
               + "local oldDotState = 0;"
               + "if(oldDayDotState ~= false) then "
               + " oldDotState = tonumber(oldDayDotState);"
               + "end "

               //上次索引报警查询打点状态
//               + "local oldAlarmDotState = 0;"
//               + "if(oldAlarmTypeState ~= false) then "
//               + " oldAlarmDotState = tonumber(oldAlarmTypeState);"
//               + "end "

//如果块大小为0,设定一个固定值
               + "if(blockLen == 0) then "
               + " blockLen = 2048;"
               + "end "

               //索引内容
               + "local beginIndex = 0;"
               + "local offSet = 0;"
               + "local blockSer = 0;"
               + "local insertTime = 0;"
               + "local updateTime = 0;"
               + "local indexTab = {};"
               //开辟标识:0不开辟,1首次文件开辟,2重新开辟
               + "local blockFlag = 0;"

               //如果没有文件内容，则是文件首次申请空间
               + "if(fileLen == 0) then "
               + " beginIndex = 0;"
               //头1个字节，每块开始包含8字节对应车辆ID
               + " offSet = dataLen+1+8;"
               + " blockSer = 1;"
               + " insertTime = devTime;"
               + " updateTime = devTime;"
               + " fileLen = fileLen+blockLen;"
               //设置索引
               + " indexTab[1] = beginIndex;"
               + " indexTab[2] = offSet;"
               + " indexTab[3] = insertTime;"
               + " indexTab[4] = updateTime;"
               + " blockFlag = 1;"
               + "else "
                       //如果是该车辆ID首次申请空间, 文件中新开辟一块区间进行写入，注意每块开始包含8字节对应车辆ID
                       + "if(asciiIndex == false or asciiIndex == nil) then "
                       + " beginIndex = fileLen;"
                       //头1个字节，每块开始包含8字节对应车辆ID
                       + " offSet = fileLen+dataLen+1+8;"
                       + " blockSer = 1;"
                       + " insertTime = devTime;"
                       + " updateTime = devTime;"
                       + " fileLen = fileLen+blockLen;"
                       //设置索引
                       + " indexTab[1] = beginIndex;"
                       + " indexTab[2] = offSet;"
                       + " indexTab[3] = insertTime;"
                       + " indexTab[4] = updateTime;"
                       + " blockFlag = 2;"
                       + "else "

                       //******解析ascii类型的索引:切割字符，获取最后4个索引int数值对应的个字符，再利用字符转ASCII方法string.byte()转换出数字
                       //ascii字符串长度
                       + "local asciiStrlen = #asciiIndex; "
                       //上次存储的索引
+ " local oldbeginIndex = 0;"
               + " local oldoffSet = 0;"
               + " local oldinsertTime = 0;"
               + " local oldupdateTime = 0;"
                       //获取后面16个,因为每4个num对应一块索引值
                       +"for i=1,4 do "
                       +"local num1,num2,num3,num4 = string.byte(asciiIndex,asciiStrlen-4*i+1,asciiStrlen-4*i+4); "
                       //二进制转int,这里的二进制=ascii
                       + "local num = 0; "
                       //左移动3
                       + "num = num + math.floor(num1 * (2 ^ 24)); "
                       //左移动2
                       + "num = num + math.floor(num2 * (2 ^ 16)); "
                       //左移动1
                       + "num = num + math.floor(num3 * (2 ^ 8)); "
                       //左移动0
                       + "num = num + num4; "

                       //块更新时间
                       + "if(i == 1) then "
                       + " oldupdateTime = num;"
               + "end "
               //块写入时间
               + "if(i == 2) then "
               + " oldinsertTime = num;"
               + "end "
               //偏移索引
               + "if(i == 3) then "
               + " oldoffSet = num;"
               + "end "
               //块开始索引
               + "if(i == 4) then "
               + " oldbeginIndex = num;"
               + "end "

                       + "end "
                       //上次块结束索引
                       + " local oldendIndex = oldbeginIndex+blockLen-1;"
//分块数目
+ " local blocknum = math.modf(asciiStrlen/16);"

//原来的块中(尽可能保证同一车同一个业务写入和更新在同一个块中)
                               + "if(((inUp == 1) and (oldoffSet + dataLen)<= oldendIndex) or ((inUp == 0) and (oldoffSet + dataLen*2)<= oldendIndex)) then "
                               + " beginIndex = oldbeginIndex;"
                               + " offSet = oldoffSet+dataLen;"
                               + " blockSer = blocknum;"
                               //保证块中的“写入时间”是该块数据最小时间,而非该块创建写入的第一条时间
                               + " if(devTime < oldinsertTime and devTime ~= 0) then "
                               + " insertTime = devTime;"
                               + " else "
                               + " insertTime = oldinsertTime;"
                               + " end "

                               //只有这次时间大于块更新时间才替换，要不然会有数据查不了
                               + " if(devTime > oldupdateTime) then "
                               + " updateTime = devTime;"
                               + " else "
                               + " updateTime = oldupdateTime;"
                               + " end "
                               //设置索引
                               + " indexTab[1] = beginIndex;"
                               + " indexTab[2] = offSet;"
                               + " indexTab[3] = insertTime;"
                               + " indexTab[4] = updateTime;"
                               + "else "
                           //重新开辟空间
                               + " beginIndex = fileLen;"
                               //头1个字节，每块开始包含8字节对应车辆ID
                               + " offSet = fileLen+dataLen+1+8;"
                               + " blockSer =blocknum+1;"
                               + " insertTime = devTime;"
                               + " updateTime = devTime;"
                               + " fileLen = fileLen+blockLen;"
                               //设置索引
                               + " indexTab[1] = beginIndex;"
                               + " indexTab[2] = offSet;"
                               + " indexTab[3] = insertTime;"
                               + " indexTab[4] = updateTime;"
                               + " blockFlag = 2;"
                               + "end "
                       + "end "
               + "end "

               //*******缓存新索引,indexTab转成Ascii:注意indexTab每个元素都是4个字节：开始索引(4)+偏移索引(4)+块开始时间(4)+块开始更新(4);如果有多块，则重复前述
               //本条数据所在块的索引Ascii字符
               +"local str = \"\";"
               +"local indexLen = table.getn(indexTab); "
               +"for i=1,indexLen do "
               +" local num = indexTab[i];"
               //右移动3
               +" local rightShift = math.floor(num / (2 ^ 24));"
               //转成Ascii
               +" rightShift = rightShift % 256;"
               //ASCII转字符用string.char()
               +" str = str .. string.char(rightShift);"
               //右移动2
               +" rightShift = math.floor(num / (2 ^ 16));"
               //转成Ascii
               +" rightShift = rightShift % 256;"
               +" str = str .. string.char(rightShift);"
               //右移动1
               +" rightShift = math.floor(num / (2 ^ 8));"
               //转成Ascii
               +" rightShift = rightShift % 256;"
               +" str = str .. string.char(rightShift);"
               //右移0
               //转成Ascii
               + " num = num % 256;"
               + " str = str .. string.char(num);"
               + " end "

               //***检查是否开辟新块：如果开辟新块，则块索引在原来索引上追加;如只有一块，直接采用;如不只一块而且不开辟，则替换原来的最后一块索引的asciiStr
               //总索引asciiStr
               +"local allStr = \"\";"
               //只有一块数据,大多数情况下进入这个分支
               + "if(blockSer == 1) then "
               + " allStr = str; "
               + "else "
               //开辟标识:0不开辟,1首次文件开辟,2重新开辟
                       + "if(blockFlag == 2) then "
                       //开辟新块，则直接追加
                       + " allStr = asciiIndex .. str;"
                       + "else "
                       //原来的字符总长度
                       + " local asciiStrlen = #asciiIndex; "
                       //截取第一个到去掉后面的16个，再追加:即替换掉最后(1块索引)16个
                       + " local res = string.sub(asciiIndex,1,asciiStrlen-16);"
                       + " allStr = res .. str;"
           + "end "
               + "end "

               //存储索引总集合
               + " redis.call('HSET',bigkey,smallKey,allStr);"
               //缓存文件新长度
               + " redis.call('HSET',bigkey,\"fileLen\",fileLen);"

               //清空,减少传输数据量
               + "indexTab = {};"
               //返回写文件对应索引以及文件对应临时编号,在 Lua 索引值是以 1 为起始，但你也可以指定 0 开始。把块编号赋值给0编号
               + "indexTab[0] = serNum;"
               + "indexTab[-1] = blockFlag;"//块开辟标识
               //这一步类似于JAVA中:HexStr.toStr(data)
               //+ "local s=string.gsub(str,\"(.)\",function (x) return string.format(\"%02X \",string.byte(x)) end);"
               //当条写入数据索引集合序列化结果,其实这里可以在外围转换为字节效率更高，但要方法待验证
               //+ "indexTab[1] = str;"
               + "local hexStr=string.gsub(str,\"(.)\",function (x) return string.format(\"%02X \",string.byte(x)) end);"
               + "indexTab[1] = hexStr;"
               //返回块编号:当条数据所在块编号
               + "indexTab[2] = blockSer;"
               //返回该条数据的块索引天打点大Key
               + "indexTab[3] = bigkey;"
               //返回该条数据的块索引天打点小Key
               + "indexTab[4] = dayDotKey;"
               //返回该条数据的块索引天打点上次状态
               + "indexTab[5] = oldDotState;"
               //返回该条数据的块索引天打点本次状态
               + "indexTab[6] = dayDotState;"
               //返回该条数据的写入更新标识
               + "indexTab[7] = inUp;"
               //返回该条数据的块索引报警打点小Key
               + "indexTab[8] = alarmDotKey;"
               //返回该条数据的块索引报警打点上次状态，是一个JSON的Map
               + "indexTab[9] = oldAlarmTypeState;"
               //返回该条数据的块索引报警打点本次状态
               + "indexTab[10] = alarmTypeState;"
               //测试用返回上次打点状态
//               + "indexTab[11] = oldDayDotState;"

//               //****调试检查开始*****
//               + "indexTab[3] = offSet;"
//               + "local as=string.gsub(allStr,\"(.)\",function (x) return string.format(\"%02X \",string.byte(x)) end);"
//               + "indexTab[4] = as;"
//               + "local as2=string.gsub(str,\"(.)\",function (x) return string.format(\"%02X \",string.byte(x)) end);"
//               + "indexTab[5] = as2;"
//               + "local as3=string.gsub(str,\"(.)\",function (x) return string.format(\"%02X \",string.byte(x)) end);"
//               + "indexTab[6] = as3;"
//               //ascii字符的总长度
//               + "local asciiStrlen = #str; "
//               + "indexTab[-2] = asciiStrlen;"//索引集合序列化结果
//               + "local as=string.gsub(str,\"(.)\",function (x) return string.format(\"%02X \",string.byte(x)) end);"
//               + "indexTab[-3] = as;"//索引集合序列化结果
//               //获取后面16个,因为每4个num对应一块索引值
//               +"for i=1,4 do "
//               +"local num1,num2,num3,num4 = string.byte(str,asciiStrlen-4*i+1,asciiStrlen-4*i+4); "
//               //二进制转int,这里的二进制=ascii
//               + "local num = 0; "
//               //左移动3
//               + "num = num + math.floor(num1 * (2 ^ 24)); "
//               //左移动2
//               + "num = num + math.floor(num2 * (2 ^ 16)); "
//               //左移动1
//               + "num = num + math.floor(num3 * (2 ^ 8)); "
//               //左移动0
//               + "num = num + num4; "
//
//                       //块更新时间
//                       + "if(i == 1) then "
//                       + "indexTab[-4] = num;"
//               + "end "
//               //块写入时间
//               + "if(i == 2) then "
//               + "indexTab[-5] = num;"
//               + "end "
//               //偏移索引
//               + "if(i == 3) then "
//               + "indexTab[-6] = num;"
//               + "end "
//               //块开始索引
//               + "if(i == 4) then "
//               + "indexTab[-7] = num;"
//               + "end "
//               + "end "
//               //****测试检查结束*****

               + "return cjson.encode(indexTab);";

       return luaStr;
   }