reduce allocations by pre-boxing the keys and interning the literals as pre-encoded chunks

NRediSearch/Client.cs

@@ -8,9 +8,15 @@ namespace NRediSearch
 {
     public sealed class Client
     {
+        internal static readonly LiteralCache Literals = new LiteralCache();
+
         [Flags]
         public enum IndexOptions
         {
+            /// <summary>
+            /// All options disabled
+            /// </summary>
+            None = 0,
             /// <summary>
             /// Set this to tell the index not to save term offset vectors. This reduces memory consumption but does not
             /// allow performing exact matches, and reduces overall relevance of multi-term queries
@@ -35,23 +41,24 @@ private static void SerializeRedisArgs(IndexOptions flags, List<object> args)
         {
             if ((flags & IndexOptions.UseTermOffsets) == 0)
             {
-                args.Add("NOOFFSETS");
+                args.Add(Literals["NOOFFSETS"]);
             }
             if ((flags & IndexOptions.KeepFieldFlags) == 0)
             {
-                args.Add("NOFIELDS");
+                args.Add(Literals["NOFIELDS"]);
             }
             if ((flags & IndexOptions.UseScoreIndexes) == 0)
             {
-                args.Add("NOSCOREIDX");
+                args.Add(Literals["NOSCOREIDX"]);
             }
         }
         IDatabase _db;
-        public RedisKey IndexName { get; }
+        private object _boxedIndexName;
+        public RedisKey IndexName => (RedisKey)_boxedIndexName;
         public Client(RedisKey indexName, IDatabase db)
         {
             _db = db;
-            IndexName = indexName;
+            _boxedIndexName = indexName; // only box once, not per-command
         }
 
         /// <summary>
@@ -64,9 +71,9 @@ public bool CreateIndex(Schema schema, IndexOptions options)
         {
             var args = new List<object>();
 
-            args.Add(IndexName);
+            args.Add(_boxedIndexName);
             SerializeRedisArgs(options, args);
-            args.Add("SCHEMA");
+            args.Add(Literals["SCHEMA"]);
 
             foreach (var f in schema.Fields)
             {
@@ -84,7 +91,7 @@ public bool CreateIndex(Schema schema, IndexOptions options)
         public SearchResult Search(Query q)
         {
             var args = new List<object>();
-            args.Add(IndexName);
+            args.Add(_boxedIndexName);
             q.SerializeRedisArgs(args);
 
             var resp = (RedisResult[])_db.Execute("FT.SEARCH", args.ToArray());
@@ -102,23 +109,23 @@ public SearchResult Search(Query q)
         /// <param name="payload">if set, we can save a payload in the index to be retrieved or evaluated by scoring functions on the server</param>
         public bool AddDocument(string docId, double score, Dictionary<string, RedisValue> fields, bool noSave, bool replace, byte[] payload)
         {
-            var args = new List<object> { IndexName, docId, score };
+            var args = new List<object> { _boxedIndexName, docId, score };
             if (noSave)
             {
-                args.Add("NOSAVE");
+                args.Add(Literals["NOSAVE"]);
             }
             if (replace)
             {
-                args.Add("REPLACE");
+                args.Add(Literals["REPLACE"]);
             }
             if (payload != null)
             {
-                args.Add("PAYLOAD");
+                args.Add(Literals["PAYLOAD"]);
                 // TODO: Fix this
                 args.Add(payload);
             }
 
-            args.Add("FIELDS");
+            args.Add(Literals["FIELDS"]);
             foreach (var ent in fields)
             {
                 args.Add(ent.Key);
@@ -150,11 +157,11 @@ public bool AddDocument(string docId, Dictionary<string, RedisValue> fields)
         /// <returns>true on success</returns>
         public bool AddHash(string docId, double score, bool replace)
         {
-            var args = new List<object> { IndexName, docId, score };
+            var args = new List<object> { _boxedIndexName, docId, score };
 
             if (replace)
             {
-                args.Add("REPLACE");
+                args.Add(Literals["REPLACE"]);
             }
 
             return (string)_db.Execute("FT.ADDHASH", args.ToArray()) == "OK";
@@ -168,7 +175,7 @@ public bool AddHash(string docId, double score, bool replace)
         public Dictionary<string, RedisValue> GetInfo()
         {
 
-            var res = (RedisValue[])_db.Execute("FT.INFO", IndexName);
+            var res = (RedisValue[])_db.Execute("FT.INFO", _boxedIndexName);
             var info = new Dictionary<string, RedisValue>();
             for (int i = 0; i < res.Length; i += 2)
             {
@@ -186,7 +193,7 @@ public bool AddHash(string docId, double score, bool replace)
         /// <returns>true if it has been deleted, false if it did not exist</returns>
         public bool DeleteDocument(string docId)
         {
-            long r = (long)_db.Execute("FT.DEL", IndexName, docId);
+            long r = (long)_db.Execute("FT.DEL", _boxedIndexName, docId);
             return r == 1;
         }
 
@@ -196,7 +203,7 @@ public bool DeleteDocument(string docId)
         /// <returns>true on success</returns>
         public bool DropIndex()
         {
-            return (string)_db.Execute("FT.DROP", IndexName) == "OK";
+            return (string)_db.Execute("FT.DROP", _boxedIndexName) == "OK";
         }
 
         /// <summary>
@@ -204,7 +211,7 @@ public bool DropIndex()
         /// </summary>
         public long OptimizeIndex()
         {
-            long ret = (long)_db.Execute("FT.OPTIMIZE", IndexName);
+            long ret = (long)_db.Execute("FT.OPTIMIZE", _boxedIndexName);
             return ret;
         }
     }

NRediSearch/LiteralCache.cs

+using StackExchange.Redis;
+using System.Collections;
+namespace NRediSearch
+{
+    // encode and box literals once only
+    internal sealed class LiteralCache
+    {
+        private static Hashtable _boxed = new Hashtable();
+
+        public object this[string value]
+        {
+            get
+            {
+                if (value == null) return "";
+                object boxed = _boxed[value];
+                if (boxed == null)
+                {
+                    lock (_boxed)
+                    {
+                        boxed = _boxed[value];
+                        if (boxed == null)
+                        {
+                            boxed = (RedisValue)value;
+                            _boxed.Add(value, boxed);
+                        }
+                    }
+                }
+                return boxed;
+            }
+        }
+    }
+}

NRediSearch/Query.cs

@@ -60,7 +60,7 @@ RedisValue FormatNum(double num, bool exclude)
                     // need to add leading bracket
                     return "(" + num.ToString("G17", NumberFormatInfo.InvariantInfo);
                 }
-                args.Add("FILTER");
+                args.Add(Client.Literals["FILTER"]);
                 args.Add(Property);
                 args.Add(FormatNum(min, exclusiveMin));
                 args.Add(FormatNum(max, exclusiveMax));
@@ -86,7 +86,7 @@ public GeoFilter(string property, double lon, double lat, double radius, GeoUnit
 
             internal override void SerializeRedisArgs(List<object> args)
             {
-                args.Add("GEOFILTER");
+                args.Add(Client.Literals["GEOFILTER"]);
                 args.Add(Property);
                 args.Add(lon);
                 args.Add(lat);
@@ -94,10 +94,10 @@ internal override void SerializeRedisArgs(List<object> args)
 
                 switch (unit)
                 {
-                    case GeoUnit.Feet: args.Add("ft"); break;
-                    case GeoUnit.Kilometers: args.Add("km"); break;
-                    case GeoUnit.Meters: args.Add("m"); break;
-                    case GeoUnit.Miles: args.Add("mi"); break;
+                    case GeoUnit.Feet: args.Add(Client.Literals["ft"]); break;
+                    case GeoUnit.Kilometers: args.Add(Client.Literals["km"]); break;
+                    case GeoUnit.Meters: args.Add(Client.Literals["m"]); break;
+                    case GeoUnit.Miles: args.Add(Client.Literals["mi"]); break;
                     default: throw new InvalidOperationException($"Unknown unit: {unit}");
                 }
             }
@@ -175,45 +175,45 @@ internal void SerializeRedisArgs(List<object> args)
 
             if (Verbatim)
             {
-                args.Add("VERBATIM");
+                args.Add(Client.Literals["VERBATIM"]);
             }
             if (NoContent)
             {
-                args.Add("NOCONTENT");
+                args.Add(Client.Literals["NOCONTENT"]);
             }
             if (NoStopwords)
             {
-                args.Add("NOSTOPWORDS");
+                args.Add(Client.Literals["NOSTOPWORDS"]);
             }
             if (WithScores)
             {
-                args.Add("WITHSCORES");
+                args.Add(Client.Literals["WITHSCORES"]);
             }
             if (WithPayloads)
             {
-                args.Add("WITHPAYLOADS");
+                args.Add(Client.Literals["WITHPAYLOADS"]);
             }
             if (Language != null)
             {
-                args.Add("LANGUAGE");
+                args.Add(Client.Literals["LANGUAGE"]);
                 args.Add(Language);
             }
             if (_fields != null && _fields.Length > 0)
             {
-                args.Add("INFIELDS");
+                args.Add(Client.Literals["INFIELDS"]);
                 args.Add(_fields.Length);
                 args.AddRange(_fields);
             }
 
             if (Payload != null)
             {
-                args.Add("PAYLOAD");
+                args.Add(Client.Literals["PAYLOAD"]);
                 args.Add(Payload);
             }
 
             if (_paging.Offset != 0 || _paging.Count != 10)
             {
-                args.Add("LIMIT");
+                args.Add(Client.Literals["LIMIT"]);
                 args.Add(_paging.Offset);
                 args.Add(_paging.Count);
             }

NRediSearch/Schema.cs

@@ -31,13 +31,13 @@ internal Field(string name, FieldType type)
 
             internal virtual void SerializeRedisArgs(List<object> args)
             {
-                string GetForRedis(FieldType type)
+                object GetForRedis(FieldType type)
                 {
                     switch (type)
                     {
-                        case FieldType.FullText: return "TEXT";
-                        case FieldType.Geo: return "GEO";
-                        case FieldType.Numeric: return "NUMERIC";
+                        case FieldType.FullText: return Client.Literals["TEXT"];
+                        case FieldType.Geo: return Client.Literals["GEO"];
+                        case FieldType.Numeric: return Client.Literals["NUMERIC"];
                         default: throw new ArgumentOutOfRangeException(nameof(type));
                     }
                 }
@@ -57,7 +57,7 @@ internal override void SerializeRedisArgs(List<object> args)
                 base.SerializeRedisArgs(args);
                 if (Weight != 1.0)
                 {
-                    args.Add("WEIGHT");
+                    args.Add(Client.Literals["WEIGHT"]);
                     args.Add(Weight);
                 }
             }