[MDAPI-313][.NET] Implement ORCS API

src/DxFeed.Graal.Net/Native/Orcs/PriceLevelServiceHandle.cs

@@ -0,0 +1,77 @@
+// <copyright file="PriceLevelServiceHandle.cs" company="Devexperts LLC">
+// Copyright © 2025 Devexperts LLC. All rights reserved.
+// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
+// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
+// </copyright>
+
+using System;
+using System.Runtime.InteropServices;
+using DxFeed.Graal.Net.Native.ErrorHandling;
+using DxFeed.Graal.Net.Native.Interop;
+using DxFeed.Graal.Net.Native.SymbolMappers;
+
+namespace DxFeed.Graal.Net.Native.Orcs;
+
+internal sealed class PriceLevelServiceHandle : JavaHandle
+{
+    public static PriceLevelServiceHandle Create(string address)
+    {
+        ErrorCheck.SafeCall(NativeCreate(CurrentThread, address, out var service));
+
+        return service;
+    }
+
+    [DllImport(
+        ImportInfo.DllName,
+        CallingConvention = CallingConvention.Cdecl,
+        CharSet = CharSet.Ansi,
+        ExactSpelling = true,
+        BestFitMapping = false,
+        ThrowOnUnmappableChar = true,
+        EntryPoint = "dxfg_PriceLevelService_new")]
+    private static extern int NativeCreate(
+        nint thread,
+        [MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(StringMarshaler))]
+        string address,
+        out PriceLevelServiceHandle service);
+
+    [DllImport(
+        ImportInfo.DllName,
+        CallingConvention = CallingConvention.Cdecl,
+        CharSet = CharSet.Ansi,
+        ExactSpelling = true,
+        BestFitMapping = false,
+        ThrowOnUnmappableChar = true,
+        EntryPoint = "dxfg_PriceLevelService_getOrders")]
+    private static extern unsafe int NativeGetOrders(
+        nint thread,
+        PriceLevelServiceHandle service,
+        [MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(SymbolMarshaler))]
+        object candleSymbol,
+        SymbolMarshaler.IndexedEventSourceNative* orderSource,
+        long from,
+        long to,
+        [MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(StringMarshaler))]
+        string caller,
+        out IntPtr /* ListNative<EventTypeNative>* */ orders);
+
+    [DllImport(
+        ImportInfo.DllName,
+        CallingConvention = CallingConvention.Cdecl,
+        CharSet = CharSet.Ansi,
+        ExactSpelling = true,
+        BestFitMapping = false,
+        ThrowOnUnmappableChar = true,
+        EntryPoint = "dxfg_PriceLevelService_getOrders2")]
+    private static extern unsafe int NativeGetOrders(
+        nint thread,
+        PriceLevelServiceHandle service,
+        [MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(SymbolMarshaler))]
+        object candleSymbol,
+        SymbolMarshaler.IndexedEventSourceNative* orderSource,
+        long from,
+        long to,
+        out IntPtr /* ListNative<EventTypeNative>* */ orders);
+
+    // ToDo: add dxfg_PriceLevelService_getAuthOrderSource
+}

src/DxFeed.Graal.Net/Native/SymbolMappers/SymbolMarshaler.cs

@@ -20,7 +20,7 @@ internal sealed class SymbolMarshaler : AbstractMarshaler
 {
     private static readonly Lazy<SymbolMarshaler> Instance = new();
 
-    private enum IndexedSourceTypeNative
+    public enum IndexedSourceTypeNative
     {
         /// <summary>
         /// Represent <see cref="Net.Events.IndexedEventSource"/> type.
@@ -232,7 +232,7 @@ private static unsafe void ReleaseNativeIndexedEventSource(IndexedEventSourceNat
     }
 
     [StructLayout(LayoutKind.Sequential)]
-    private struct IndexedEventSourceNative
+    public struct IndexedEventSourceNative
     {
         public IndexedSourceTypeNative Type;
         public int Id;