Optimization using SymbolLoaderFactory

[dfreiberger]

In using this library for reading/writing a very large nested structure, I found that significant improvements in read/write time (up to 92% speedup on writes to a structure of 21kb, from 68 seconds down to 5 seconds) can be made by utilizing SymbolLoaderFactory to pre-load the datatypes for the PLC prior to executing read and write operations. This looks like:

private async Task InitializeClient(AmsNetId amsNetId, int adsPort, string CallerSource)
{
    // Initialize the ADS client
    client = new AdsClient();
    client.Connect(amsNetId, adsPort);
    
    // Load datatypes
    var loader = SymbolLoaderFactory.Create(client, SymbolLoaderSettings.DefaultDynamic);
    var symbolsResult = await loader.GetSymbolsAsync(cancel);
    
    _symbols = symbolsResult.Symbols;
...

Elsewhere I wrote custom functions to read the object as json and to "merge" a JObject back into the DynamicValue prior to writing to the PLC.

public async Task<string> ReadObject(string objectPath)
{
    var symbol = (DynamicSymbol)_symbols[objectPath];
    
    var readResult = await symbol.ReadValueAsync(cancel);
    
    // try to convert to json
    var jsonObject = JObject.FromObject(readResult.Value).ToString(Formatting.Indented);
...

private async Task WriteJson(string objectPath, JObject writeObject)
{
        var symbol = (DynamicSymbol)_symbols[objectPath];

        var readResult = await symbol.ReadValueAsync(cancel);

        var dynamicValue = (DynamicValue)readResult.Value;
        dynamicValue.UpdateMode = ValueUpdateMode.Triggered; // necessary so that setting values internally does not trigger ADS writes

        // Merge the JSON objects recursively
        MergeJObjectIntoDynamicValue(dynamicValue, writeObject);

        // Write the JSON object to the PLC
        await symbol.WriteValueAsync(managedResult, cancel);
...

This basically replaces most of the functions in the TcJsonSettings library, except for TryConvertToPlcOpenType and logic to merge a JObject with a DynamicValue.

Does it make sense to try to bring this optimization into this library? If so, I am not sure on first glance how to handle this since there needs to be a persistent reference to the symbol maintained somewhere that these methods could reference. Do you have suggestions on this?