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vmuriartvmuriart
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Merge pull request #407 from vmuriart/custom_marshal
Refactor Managed-Native conversion - ICustomMarshaler
2 parents 7dba617 + 78939c5 commit 01a35cb

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5 files changed

+238
-184
lines changed

5 files changed

+238
-184
lines changed

‎src/runtime/CustomMarshaler.cs

Lines changed: 171 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,171 @@
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using System;
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using System.Linq;
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using System.Runtime.InteropServices;
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using System.Text;
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namespace Python.Runtime
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{
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/// <summary>
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/// Abstract class defining boiler plate methods that
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/// Custom Marshalers will use.
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/// </summary>
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public abstract class MarshalerBase : ICustomMarshaler
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{
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public object MarshalNativeToManaged(IntPtr pNativeData)
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{
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throw new NotImplementedException();
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}
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public abstract IntPtr MarshalManagedToNative(object managedObj);
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public void CleanUpNativeData(IntPtr pNativeData)
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{
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Marshal.FreeHGlobal(pNativeData);
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}
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public void CleanUpManagedData(object managedObj)
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{
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// Let GC deal with it
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}
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public int GetNativeDataSize()
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{
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return IntPtr.Size;
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}
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}
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/// <summary>
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/// Custom Marshaler to deal with Managed String to Native
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/// conversion differences on UCS2/UCS4.
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/// </summary>
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public class StrMarshaler : MarshalerBase
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{
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private static readonly MarshalerBase Instance = new StrMarshaler();
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private static readonly Encoding PyEncoding = Runtime.PyEncoding;
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public override IntPtr MarshalManagedToNative(object managedObj)
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{
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var s = managedObj as string;
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if (s == null)
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{
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return IntPtr.Zero;
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}
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byte[] bStr = PyEncoding.GetBytes(s + "\0");
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IntPtr mem = Marshal.AllocHGlobal(bStr.Length);
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try
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{
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Marshal.Copy(bStr, 0, mem, bStr.Length);
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}
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catch (Exception)
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{
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Marshal.FreeHGlobal(mem);
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throw;
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}
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return mem;
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}
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public static ICustomMarshaler GetInstance(string cookie)
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{
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return Instance;
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}
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}
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/// <summary>
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/// Custom Marshaler to deal with Managed String Arrays to Native
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/// conversion differences on UCS2/UCS4.
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/// </summary>
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public class StrArrayMarshaler : MarshalerBase
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{
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private static readonly MarshalerBase Instance = new StrArrayMarshaler();
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private static readonly Encoding PyEncoding = Runtime.PyEncoding;
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public override IntPtr MarshalManagedToNative(object managedObj)
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{
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var argv = managedObj as string[];
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if (argv == null)
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{
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return IntPtr.Zero;
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}
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int totalStrLength = argv.Sum(arg => arg.Length + 1);
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int memSize = argv.Length * IntPtr.Size + totalStrLength * Runtime.UCS;
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IntPtr mem = Marshal.AllocHGlobal(memSize);
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try
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{
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// Preparing array of pointers to strings
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IntPtr curStrPtr = mem + argv.Length * IntPtr.Size;
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for (var i = 0; i < argv.Length; i++)
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{
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byte[] bStr = PyEncoding.GetBytes(argv[i] + "\0");
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Marshal.Copy(bStr, 0, curStrPtr, bStr.Length);
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Marshal.WriteIntPtr(mem + i * IntPtr.Size, curStrPtr);
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curStrPtr += bStr.Length;
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}
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}
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catch (Exception)
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{
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Marshal.FreeHGlobal(mem);
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throw;
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}
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return mem;
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}
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public static ICustomMarshaler GetInstance(string cookie)
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{
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return Instance;
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}
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}
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/// <summary>
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/// Custom Marshaler to deal with Managed String to Native
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/// conversion on UTF-8. Use on functions that expect UTF-8 encoded
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/// strings like `PyUnicode_FromStringAndSize`
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/// </summary>
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/// <remarks>
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/// If instead we used `MarshalAs(UnmanagedType.LPWStr)` the output to
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/// `foo` would be `f\x00o\x00o\x00`.
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/// </remarks>
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public class Utf8Marshaler : MarshalerBase
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{
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private static readonly MarshalerBase Instance = new Utf8Marshaler();
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private static readonly Encoding PyEncoding = Encoding.UTF8;
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public override IntPtr MarshalManagedToNative(object managedObj)
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{
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var s = managedObj as string;
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if (s == null)
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{
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return IntPtr.Zero;
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}
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byte[] bStr = PyEncoding.GetBytes(s + "\0");
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IntPtr mem = Marshal.AllocHGlobal(bStr.Length);
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try
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{
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Marshal.Copy(bStr, 0, mem, bStr.Length);
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}
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catch (Exception)
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{
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Marshal.FreeHGlobal(mem);
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throw;
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}
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return mem;
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}
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public static ICustomMarshaler GetInstance(string cookie)
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{
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return Instance;
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}
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}
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}

‎src/runtime/Python.Runtime.csproj

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -89,6 +89,7 @@
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<Compile Include="constructorbinder.cs" />
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<Compile Include="constructorbinding.cs" />
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<Compile Include="converter.cs" />
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<Compile Include="CustomMarshaler.cs" />
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<Compile Include="debughelper.cs" />
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<Compile Include="delegatemanager.cs" />
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<Compile Include="delegateobject.cs" />

‎src/runtime/converter.cs

Lines changed: 4 additions & 15 deletions
Original file line numberDiff line numberDiff line change
@@ -599,21 +599,10 @@ private static bool ToPrimitive(IntPtr value, Type obType, out object result, bo
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{
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if (Runtime.PyUnicode_GetSize(value) == 1)
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{
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op = Runtime.PyUnicode_AS_UNICODE(value);
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if (Runtime.UCS == 2) // Don't trust linter, statement not always true.
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{
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// 2011-01-02: Marshal as character array because the cast
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// result = (char)Marshal.ReadInt16(op); throws an OverflowException
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// on negative numbers with Check Overflow option set on the project
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Char[] buff = new Char[1];
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Marshal.Copy(op, buff, 0, 1);
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result = buff[0];
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}
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else // UCS4
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{
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// XXX this is probably NOT correct?
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result = (char)Marshal.ReadInt32(op);
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}
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op = Runtime.PyUnicode_AsUnicode(value);
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Char[] buff = new Char[1];
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Marshal.Copy(op, buff, 0, 1);
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result = buff[0];
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return true;
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}
619608
goto type_error;

‎src/runtime/debughelper.cs

Lines changed: 22 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -115,5 +115,27 @@ internal static void debug(string msg)
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Console.WriteLine("thread {0} : {1}", tid, caller);
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Console.WriteLine(" {0}", msg);
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}
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/// <summary>
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/// Helper function to inspect/compare managed to native conversions.
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/// Especially useful when debugging CustomMarshaler.
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/// </summary>
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/// <param name="bytes"></param>
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[Conditional("DEBUG")]
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public static void PrintHexBytes(byte[] bytes)
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{
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if ((bytes == null) || (bytes.Length == 0))
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{
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Console.WriteLine("<none>");
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}
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else
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{
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foreach (byte t in bytes)
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{
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Console.Write("{0:X2} ", t);
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}
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Console.WriteLine();
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}
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}
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}
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}

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