public static unsafe byte[] GetByteArray(NativeCollectionGetter getter, int size = 0)
{
// Initially called with size = 0, we make a native call just to get the size of the buffer.
var bytes = new byte[size];
bool isNull;
NativeException nativeException;
int actualSize;
fixed(byte *buffer = bytes)
{
actualSize = (int)getter((IntPtr)buffer, (IntPtr)size, out isNull, out nativeException);
}
nativeException.ThrowIfNecessary();
if (isNull)
{
return(null);
}
if (actualSize > size)
{
return(GetByteArray(getter, actualSize));
}
return(bytes);
}
public static string GetString(NativeCollectionGetter getter)
{
// TODO: rework to use GetCollection
var bufferSize = 128;
// First alloc this thread
var stringGetBuffer = Marshal.AllocHGlobal((IntPtr)(bufferSize * sizeof(char)));
try
{
// try to read
var bytesRead = (int)getter(stringGetBuffer, (IntPtr)bufferSize, out var isNull, out var nativeException);
nativeException.ThrowIfNecessary();
if (bytesRead == -1)
{
throw new RealmInvalidDatabaseException("Corrupted string data");
}
// need a bigger buffer
if (bytesRead > bufferSize)
{
bufferSize = bytesRead;
Marshal.FreeHGlobal(stringGetBuffer);
stringGetBuffer = Marshal.AllocHGlobal((IntPtr)(bufferSize * sizeof(char)));
// try to read with big buffer
bytesRead = (int)getter(stringGetBuffer, (IntPtr)bufferSize, out isNull, out nativeException);
nativeException.ThrowIfNecessary();
// bad UTF-8 in full string
if (bytesRead == -1)
{
throw new RealmInvalidDatabaseException("Corrupted string data");
}
Debug.Assert(bytesRead <= bufferSize, "Buffer must have overflowed.");
} // needed re-read with expanded buffer
return(bytesRead != 0 ? Marshal.PtrToStringUni(stringGetBuffer, bytesRead) : (isNull ? null : string.Empty));
}
finally
{
Marshal.FreeHGlobal(stringGetBuffer);
}
}
public static T[] GetCollection <T>(NativeCollectionGetter <T> getter, int bufferSize) where T : struct
{
var buffer = new T[bufferSize];
var itemsRead = (int)getter(buffer, (IntPtr)bufferSize, out var nativeException);
nativeException.ThrowIfNecessary();
if (itemsRead > bufferSize)
{
bufferSize = itemsRead;
buffer = new T[bufferSize];
itemsRead = (int)getter(buffer, (IntPtr)bufferSize, out nativeException);
nativeException.ThrowIfNecessary();
Debug.Assert(itemsRead <= bufferSize, "Buffer must have overflowed.");
}
Array.Resize(ref buffer, itemsRead);
return(buffer);
}
