Rename SetScript variants. (#38928)

src/Caching/StackExchangeRedis/src/RedisCache.cs

@@ -18,10 +18,11 @@ public class RedisCache : IDistributedCache, IDisposable
 {
     // -- Explanation of why two kinds of SetScript are used --
     // * Redis 2.0 had HSET key field value for setting individual hash fields,
-    // and HMSET key field value [field value ...] for setting multiple hash fields (against the same key)
-    // * Redis 4.0 observes this redundancy, and adds HSET key field value [field value ...],
-    // and also marks HMSET as deprecated, although it still works fine.
-    // But HSET doesn't allows multiple field/value pairs for Redis prior 4.0.
+    // and HMSET key field value [field value ...] for setting multiple hash fields (against the same key).
+    // * Redis 4.0 added HSET key field value [field value ...] and deprecated HMSET.
+    //
+    // On Redis versions that don't have the newer HSET variant, we use SetScriptPreExtendedSetCommand
+    // which uses the (now deprecated) HMSET.
 
     // KEYS[1] = = key
     // ARGV[1] = absolute-expiration - ticks as long (-1 for none)
@@ -29,13 +30,13 @@ public class RedisCache : IDistributedCache, IDisposable
     // ARGV[3] = relative-expiration (long, in seconds, -1 for none) - Min(absolute-expiration - Now, sliding-expiration)
     // ARGV[4] = data - byte[]
     // this order should not change LUA script depends on it
-    private const string SetScriptPerExtendedSetCommand = (@"
+    private const string SetScript = (@"
                 redis.call('HSET', KEYS[1], 'absexp', ARGV[1], 'sldexp', ARGV[2], 'data', ARGV[4])
                 if ARGV[3] ~= '-1' then
                   redis.call('EXPIRE', KEYS[1], ARGV[3])
                 end
                 return 1");
-    private const string DeprecatedSetScript = (@"
+    private const string SetScriptPreExtendedSetCommand = (@"
                 redis.call('HMSET', KEYS[1], 'absexp', ARGV[1], 'sldexp', ARGV[2], 'data', ARGV[4])
                 if ARGV[3] ~= '-1' then
                   redis.call('EXPIRE', KEYS[1], ARGV[3])
@@ -51,7 +52,7 @@ public class RedisCache : IDistributedCache, IDisposable
     private volatile IConnectionMultiplexer _connection;
     private IDatabase _cache;
     private bool _disposed;
-    private string _setScript = SetScriptPerExtendedSetCommand;
+    private string _setScript = SetScript;
 
     private readonly RedisCacheOptions _options;
     private readonly string _instance;
@@ -287,7 +288,7 @@ public class RedisCache : IDistributedCache, IDisposable
         {
             if (_connection.GetServer(endPoint).Version < ServerVersionWithExtendedSetCommand)
             {
-                _setScript = DeprecatedSetScript;
+                _setScript = SetScriptPreExtendedSetCommand;
                 return;
             }
         }