lua

Author: wang-jun-coder

Storage/Redis/project/lua/script.lua

@@ -1,23 +1,40 @@
-
 -- ******************************************** lua 基本语法 ********************************************
 
 -- 变量声明
-local key = {KEYS[1],KEYS[2]};
-local value = {ARGV[1],ARGV[2]};
+local retTable = {};
+
+-- 取参数
+local k1 = KEYS[1];
+local k2 = KEYS[2];
+local v1 = ARGV[1];
+local v2 = ARGV[2];
+table.insert(retTable, {k1, k2, v1, v2}); -- ["key1","key2","1","2.3"]
 
-local table = {'this', 'is', 'table'};
+-- 变量声明
+local tableIns = {'this', 'is', 'table'};
 local luaNil = nil;
 local boolean = true
 local number = 3.2;
 local str = 'this is string';
-
-
+-- 注意 nil 的位置
+table.insert(retTable, {tableIns, boolean, number, str, luaNil}); -- [["this","is","table"],1,3,"this is string"]
 
 -- 类型判断
 local tk1 = type(KEYS[1]);
 local tk2 = type(KEYS[2]);
 local tv1 = type(ARGV[1]);
 local tv2 = type(ARGV[2]);
+table.insert(retTable, {tk1, tk2, tv1, tv2}); -- ["string","string","string","string"]
+
+-- 类型转换
+local numV1 = tonumber(v1);
+local numV2 = tonumber(v2);
+local str1 = tostring(1.1);
+local str2 = 'this'..' is'..' str' -- 字符串拼接
+local str2Len = #str2;
+
+table.insert(retTable, {numV1, type(numV1), numV2, type(numV2), str1, type(str1), str2, type(str2), str2Len, type(str2Len)});
+-- [1,"number",2,"number","1.1","string","this is str","string",11,"number"]
 
 -- 函数定义
 local function factorial(num)
@@ -27,30 +44,64 @@ local function factorial(num)
         return num * factorial(num-1);
     end
 end
-
-
-
+table.insert(retTable, factorial(3)); -- 6
+
+-- 多返回值, 返回最大值和其索引
+local function max(a) -- 不确定参数个数, 可用 ... 表示变长参数, 类似 js 中的 ...rest
+    local index = 1;
+    local m = a[index];
+
+    for i, val in ipairs(a) do
+        if val > m then
+            index = i;
+            m = val;
+        end
+    end
+    return m, index
+end
+local m, index = max({1, 9, 5, 3,7});
+table.insert(retTable, {m, index}); -- [9,2]
 
 -- ******************************************** 与redis 交互 ********************************************
+local redisTable = {};
+table.insert(retTable, redisTable);
 -- redis.call(), 执行命令出错, 将导致脚本退出
 redis.call('set', 'lua-key1', 'lua-value1');
-local v1 = redis.call('get', 'lua-key1');
+local rv1 = redis.call('get', 'lua-key1');
+table.insert(redisTable, rv1); -- "lua-value1"
+
+-- 一次添加多个数据, 如: zadd set-name 0 a 1 b 等等
+local function mAdd(cmd, key, values)
+    local args = {cmd, key};
+    for i, v in ipairs(values) do
+        table.insert(args, v);
+    end
+    return redis.call(unpack(args));
+end
 
+local function randomScoreAndVal(len)
+    local random = {}
+    for i = 1, len do
+        local score = math.random(0, 100);
+        local key = 'value'..i;
+        table.insert(random, score);
+        table.insert(random, key);
+    end
+    return random;
+end
 
+mAdd('zadd', 'zset', randomScoreAndVal(10));
+table.insert(redisTable, redis.call('zrange', 'zset', 0, 5, 'WITHSCORES'));
+-- ["value3","9","value1","17","value8","37","value5","58","value7","69","value10","75"], zset 随机添加, 所以输出值可能不同
 
 --[[
     redis.pcall(), 执行命令出错, 会返回一个带 err 域的 lua table
+    lua 脚本返回值只能是数组, 如果是 带域的 table 会被忽略
+    脚本执行时,会被 redis 封装成一个 lua 函数进行执行
+    redis 对 lua 有一定限制, 比如不能声明全局变量??
+--]]
 
-    {
-        err:
-    }
+table.insert(redisTable, redis.pcall('zrange')['err']);
+-- "@user_script: 109: Wrong number of args calling Redis command From Lua script"
 
---]]
-return {
-    key,
-    value,
-    {table,  boolean, number, str, luaNil}, -- nil 位置需注意
-    {tk1, tk2, tv1, tv2},
-    v1,
-    factorial(10)
-};
+return retTable;