private void GetInterfaces()
{
if (mInterfaces != null)
{
return;
}
GetConfigurationBlob();
UsbInterfaceInfo[] interfaces = new UsbInterfaceInfo[Descriptor.NumInterfaces];
int index = 0;
int first = -1;
for (int i = 0; i < mDescriptors.Length; i++)
{
UsbDescriptorBlob descriptor = mDescriptors[i];
if (descriptor.Type != UsbDescriptorType.Interface)
{
continue;
}
if (first != -1)
{
if (index >= interfaces.Length)
{
Array.Resize(ref interfaces, index + 1);
}
interfaces[index] = new UsbInterfaceInfo(this, ArrayUtil.Slice(mDescriptors, first, i - first));
index++;
}
first = i;
}
if (first != -1)
{
if (index >= interfaces.Length)
{
Array.Resize(ref interfaces, index + 1);
}
interfaces[index] = new UsbInterfaceInfo(this, ArrayUtil.Slice(mDescriptors, first, mDescriptors.Length - first));
}
mInterfaces = interfaces;
}
private void GetConfigurationBlob()
{
if (mConfigurationBlob != null)
{
return;
}
int length = Descriptor.TotalLength;
if (!mHasConfigurationDescriptor)
{
throw new Exception("Configuration descriptor is invalid");
}
Byte[] blob = new Byte[length];
length = Device.Device.GetDescriptor((Byte)UsbDescriptorType.Configuration, Index, 0, blob, 0, length);
if (length != blob.Length)
{
throw new Exception("Could not read configuration descriptor");
}
List <UsbDescriptorBlob> descriptors = new List <UsbDescriptorBlob>();
for (int offset = 0; offset < length;)
{
if (length - offset < 2)
{
throw new Exception("Descriptor has been truncated");
}
UsbDescriptorBlob descriptor = new UsbDescriptorBlob(blob, offset);
if (length - offset < descriptor.Length)
{
throw new Exception("Descriptor has been truncated");
}
descriptors.Add(descriptor);
offset += descriptor.Length;
}
mConfigurationBlob = blob;
mDescriptors = descriptors.ToArray();
}