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Use NativeMemory in System.Data.Odbc #85966

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Use NativeMemory in System.Data.Odbc #85966

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a99952d
Use `NativeMemory` in `System.Data.Odbc`
xtqqczze May 9, 2023
68c1005
Workaround lack of `NativeMemory.Clear` on .NET 6
xtqqczze May 9, 2023
b593c9b
Use `Unsafe.InitBlock`
xtqqczze May 9, 2023
08e2ed0
Merge branch 'main' into NativeMemory.Odbc
xtqqczze Sep 11, 2023
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28 changes: 0 additions & 28 deletions src/libraries/System.Data.Odbc/src/Common/System/Data/Common/SafeNativeMethods.cs
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This file was deleted.

26 changes: 8 additions & 18 deletions src/libraries/System.Data.Odbc/src/Common/System/Data/ProviderBase/DbBuffer.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -14,21 +14,14 @@ internal abstract class DbBuffer : SafeHandle
{
private readonly int _bufferLength;

protected DbBuffer(int initialSize) : base(IntPtr.Zero, true)
protected unsafe DbBuffer(int initialSize) : base(IntPtr.Zero, true)
{
Debug.Assert(initialSize % IntPtr.Size == 0, $"Expected aligned {nameof(initialSize)}.");
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What guarantees this?

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DbBuffer is is only instantiated from the derived class CNativeBuffer.

The buffer size is either 4096 bytes, or a larger value calculated in CalcParameterBufferSize.

runtime/src/libraries/System.Data.Odbc/src/System/Data/Odbc/OdbcParameterCollection.cs

Lines 112 to 128 in b593c9b

internal int CalcParameterBufferSize(OdbcCommand command)
{
// Calculate the size of the buffer we need
int parameterBufferSize = 0;
for (int i = 0; i < Count; ++i)
{
if (_rebindCollection)
{
this[i].HasChanged = true;
}
this[i].PrepareForBind(command, (short)(i + 1), ref parameterBufferSize);
parameterBufferSize = (parameterBufferSize + (IntPtr.Size - 1)) & ~(IntPtr.Size - 1); // align buffer;
}
return parameterBufferSize;
}

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Perhaps it makes sense to calculate aligned buffer size in the ctor instead.


if (0 < initialSize)
{
_bufferLength = initialSize;

try { }
finally
{
base.handle = SafeNativeMethods.LocalAlloc((IntPtr)initialSize);
}
if (IntPtr.Zero == base.handle)
{
throw new OutOfMemoryException();
}
base.handle = (IntPtr)NativeMemory.AllocZeroed((uint)initialSize);
}
}

Expand Down Expand Up @@ -368,15 +361,12 @@ internal unsafe float ReadSingle(int offset)
return BitConverter.Int32BitsToSingle(value);
}

protected override bool ReleaseHandle()
protected override unsafe bool ReleaseHandle()
{
// NOTE: The SafeHandle class guarantees this will be called exactly once.
IntPtr ptr = base.handle;
base.handle = IntPtr.Zero;
if (IntPtr.Zero != ptr)
{
SafeNativeMethods.LocalFree(ptr);
}
NativeMemory.Free((void*)ptr);
return true;
}

Expand Down Expand Up @@ -639,7 +629,7 @@ internal unsafe void WriteSingle(int offset, float value)
WriteInt32(offset, BitConverter.SingleToInt32Bits(value));
}

internal void ZeroMemory()
internal unsafe void ZeroMemory()
{
bool mustRelease = false;

Expand All @@ -648,7 +638,7 @@ internal void ZeroMemory()
DangerousAddRef(ref mustRelease);

IntPtr ptr = DangerousGetHandle();
SafeNativeMethods.ZeroMemory(ptr, Length);
Unsafe.InitBlock((void*)ptr, 0, (uint)Length);
}
finally
{
Expand Down
1 change: 0 additions & 1 deletion src/libraries/System.Data.Odbc/src/System.Data.Odbc.csproj
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Expand Up @@ -42,7 +42,6 @@ System.Data.Odbc.OdbcTransaction</PackageDescription>
<Compile Include="Common\System\Data\Common\DbConnectionStringCommon.cs" />
<Compile Include="$(CommonPath)System\Data\Common\NameValuePair.cs"
Link="Common\System\Data\Common\NameValuePair.cs" />
<Compile Include="Common\System\Data\Common\SafeNativeMethods.cs" />
<Compile Include="Common\System\Data\DataStorage.cs" />
<Compile Include="Common\System\Data\ProviderBase\DbBuffer.cs" />
<Compile Include="$(CommonPath)System\Data\Common\FieldNameLookup.cs"
Expand Down