Cache S7 variable names

Sharp7.Rx/CacheVariableNameParser.cs

@@ -0,0 +1,20 @@
+using System;
+using System.Collections.Concurrent;
+using Sharp7.Rx.Interfaces;
+
+namespace Sharp7.Rx
+{
+    internal class CacheVariableNameParser : IS7VariableNameParser
+    {
+        private static readonly ConcurrentDictionary<string, S7VariableAddress> addressCache = new ConcurrentDictionary<string, S7VariableAddress>(StringComparer.OrdinalIgnoreCase);
+
+        private readonly IS7VariableNameParser inner;
+
+        public CacheVariableNameParser(IS7VariableNameParser inner)
+        {
+            this.inner = inner;
+        }
+
+        public S7VariableAddress Parse(string input) => addressCache.GetOrAdd(input, inner.Parse);
+    }
+}

Sharp7.Rx/Interfaces/IS7Connector.cs

@@ -21,6 +21,6 @@ namespace Sharp7.Rx.Interfaces
         Task<bool> WriteBit(Operand operand, ushort startByteAddress, byte bitAdress, bool value, ushort dbNr, CancellationToken token);
         Task<ushort> WriteBytes(Operand operand, ushort startByteAdress, byte[] data, ushort dBNr, CancellationToken token);
 	    ILogger Logger { get; }
-        Task<Dictionary<string, byte[]>> ExecuteMultiVarRequest(IEnumerable<string> variableNames);
+        Task<Dictionary<string, byte[]>> ExecuteMultiVarRequest(IReadOnlyList<string> variableNames);
     }
 }

Sharp7.Rx/S7VariableNameParser.cs

@@ -12,7 +12,7 @@ namespace Sharp7.Rx
     {
         private static readonly Regex regex = new Regex(@"^(?<operand>db{1})(?<dbNr>\d{1,4})\.?(?<type>dbx|x|s|string|b|dbb|d|int|dbw|w|dint|dul|dulint|dulong|){1}(?<start>\d+)(\.(?<bitOrLength>\d+))?$", RegexOptions.IgnoreCase | RegexOptions.Compiled | RegexOptions.CultureInvariant);
 
-        private static readonly IReadOnlyDictionary<string, DbType> types = new Dictionary<string, DbType>(StringComparer.InvariantCultureIgnoreCase)
+        private static readonly IReadOnlyDictionary<string, DbType> types = new Dictionary<string, DbType>(StringComparer.OrdinalIgnoreCase)
         {
             {"x", DbType.Bit},
             {"dbx", DbType.Bit},

Sharp7.Rx/Sharp7Connector.cs

@@ -21,7 +21,6 @@ namespace Sharp7.Rx
     {
         private readonly IS7VariableNameParser variableNameParser;
         private readonly BehaviorSubject<ConnectionState> connectionStateSubject = new BehaviorSubject<ConnectionState>(Enums.ConnectionState.Initial);
-        private ConcurrentDictionary<string, S7VariableAddress> s7VariableAddresses = new ConcurrentDictionary<string, S7VariableAddress>();
 
         private readonly CompositeDisposable disposables = new CompositeDisposable();
         private readonly LimitedConcurrencyLevelTaskScheduler scheduler = new LimitedConcurrencyLevelTaskScheduler(maxDegreeOfParallelism:1);
@@ -34,16 +33,15 @@ namespace Sharp7.Rx
         private bool disposed;
 
 		public ILogger Logger { get; set; }
-        public async Task<Dictionary<string, byte[]>> ExecuteMultiVarRequest(IEnumerable<string> variableNames)
+        public async Task<Dictionary<string, byte[]>> ExecuteMultiVarRequest(IReadOnlyList<string> variableNames)
         {
-            var enumerable = variableNames as string[] ?? variableNames.ToArray();
+            if (variableNames.IsEmpty())
-
-            if (enumerable.IsEmpty())
                 return new Dictionary<string, byte[]>();
 
             var s7MultiVar = new S7MultiVar(sharp7);
 
-            var buffers = enumerable.Select(key => new {VariableName = key, Address = s7VariableAddresses.GetOrAdd(key, s => variableNameParser.Parse(s))})
+            var buffers = variableNames
+                .Select(key => new {VariableName = key, Address = variableNameParser.Parse(key)})
                 .Select(x =>
                 {
                     var buffer = new byte[x.Address.Length];
@@ -67,10 +65,10 @@ namespace Sharp7.Rx
         public Sharp7Connector(PlcConnectionSettings settings, IS7VariableNameParser variableNameParser)
 		{
             this.variableNameParser = variableNameParser;
-            this.ipAddress = settings.IpAddress;
+            ipAddress = settings.IpAddress;
-            this.cpuSlotNr = settings.CpuMpiAddress;
+            cpuSlotNr = settings.CpuMpiAddress;
-			this.port = settings.Port;
+			port = settings.Port;
-			this.rackNr = settings.RackNumber;
+			rackNr = settings.RackNumber;
 
 			ReconnectDelay = TimeSpan.FromSeconds(5);
         }
@@ -120,7 +118,7 @@ namespace Sharp7.Rx
             try
             {
                 sharp7 = new S7Client();
-	            sharp7.PLCPort = this.port;
+	            sharp7.PLCPort = port;
 
 				var subscription =
                     ConnectionState
@@ -223,7 +221,7 @@ namespace Sharp7.Rx
             if (result != 0)
             {
                 await EvaluateErrorCode(result);
-                var errorText = this.sharp7.ErrorText(result);
+                var errorText = sharp7.ErrorText(result);
                 throw new InvalidOperationException($"Error reading {operand}{dBNr}:{startByteAddress}->{bytesToRead} ({errorText})");
             }
 

Sharp7.Rx/Sharp7Plc.cs

@@ -20,11 +20,7 @@ namespace Sharp7.Rx
 {
     public class Sharp7Plc : IPlc
     {
-        private readonly string ipAddress;
+        private readonly IS7VariableNameParser varaibleNameParser = new CacheVariableNameParser(new S7VariableNameParser());
-        private readonly int rackNumber;
-        private readonly int cpuMpiAddress;
-        private readonly int port;
-        private readonly IS7VariableNameParser varaibleNameParser;
         private bool disposed;
         private ISubject<Unit> disposingSubject = new Subject<Unit>();
         private IS7Connector s7Connector;
@@ -37,14 +33,7 @@ namespace Sharp7.Rx
 
         public Sharp7Plc(string ipAddress, int rackNumber, int cpuMpiAddress, int port = 102)
         {
-            this.ipAddress = ipAddress;
-            this.rackNumber = rackNumber;
-            this.cpuMpiAddress = cpuMpiAddress;
-            this.port = port;
-            
             plcConnectionSettings = new PlcConnectionSettings(){IpAddress = ipAddress, RackNumber = rackNumber, CpuMpiAddress = cpuMpiAddress, Port = port};
-
-            varaibleNameParser = new S7VariableNameParser();
         }
 
         public IObservable<ConnectionState> ConnectionState { get; private set; }
@@ -403,7 +392,7 @@ namespace Sharp7.Rx
             var stopWatch = Stopwatch.StartNew();
             foreach (var partsOfMultiVarRequest in multiVariableSubscriptions.ExistingKeys.Buffer(MultiVarRequestMaxItems))
             {
-                var multiVarRequest = await connector.ExecuteMultiVarRequest(partsOfMultiVarRequest);
+                var multiVarRequest = await connector.ExecuteMultiVarRequest(partsOfMultiVarRequest as IReadOnlyList<string>??partsOfMultiVarRequest.ToList());
 
                 foreach (var pair in multiVarRequest)
                 {