Class: LIBUSB::Bos

Inherits:
FFI::Struct
  • Object
show all
Defined in:
lib/libusb/bos.rb

Overview

A structure representing the Binary Device Object Store (BOS) descriptor. This descriptor is documented in section 9.6.2 of the USB 3.0 specification. All multiple-byte fields are represented in host-endian format.

Defined Under Namespace

Modules: GenericMethods Classes: ContainerId, DeviceCapability, PlatformDescriptor, SsUsbDeviceCapability, Usb20Extension

Instance Method Summary collapse

Constructor Details

#initialize(ctx, *args) ⇒ Bos

Returns a new instance of Bos.



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# File 'lib/libusb/bos.rb', line 276

def initialize(ctx, *args)
  @ctx = ctx
  super(*args)

  register_context(ctx, :libusb_free_bos_descriptor)
end

Instance Method Details

#bDescriptorType ⇒ Integer

in this context.

Returns:

  • (Integer) —

    Descriptor type. Will have value LIBUSB::DT_BOS LIBUSB_DT_BOS



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# File 'lib/libusb/bos.rb', line 296

def bDescriptorType
  self[:bDescriptorType]
end

#bLength ⇒ Integer

Returns Size of this descriptor (in bytes).

Returns:

  • (Integer) —

    Size of this descriptor (in bytes)



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# File 'lib/libusb/bos.rb', line 290

def bLength
  self[:bLength]
end

#bNumDeviceCaps ⇒ Integer

the BOS

Returns:

  • (Integer) —

    The number of separate device capability descriptors in



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# File 'lib/libusb/bos.rb', line 307

def bNumDeviceCaps
  self[:bNumDeviceCaps]
end

#device_capabilities ⇒ Array<Bos::DeviceCapability, Bos::Usb20Extension, Bos::SsUsbDeviceCapability, Bos::ContainerId>

bNumDeviceCap Device Capability Descriptors

Returns:



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# File 'lib/libusb/bos.rb', line 314

def device_capabilities
  pp_ext = FFI::MemoryPointer.new :pointer
  caps = []
  # Capabilities are appended to the bos header
  ptr = pointer + offset_of(:dev_capability)
  bNumDeviceCaps.times do
    cap = DeviceCapability.new self, ptr.read_pointer
    case cap.bDevCapabilityType
      when LIBUSB::BT_WIRELESS_USB_DEVICE_CAPABILITY
        # no struct defined in libusb -> use generic DeviceCapability
      when LIBUSB::BT_USB_2_0_EXTENSION
        res = Call.libusb_get_usb_2_0_extension_descriptor(@ctx, cap.pointer, pp_ext)
        cap = Usb20Extension.new(@ctx, pp_ext.read_pointer) if res==0
      when LIBUSB::BT_SS_USB_DEVICE_CAPABILITY
        res = Call.libusb_get_ss_usb_device_capability_descriptor(@ctx, cap.pointer, pp_ext)
        cap = SsUsbDeviceCapability.new(@ctx, pp_ext.read_pointer) if res==0
      when LIBUSB::BT_CONTAINER_ID
        res = Call.libusb_get_container_id_descriptor(@ctx, cap.pointer, pp_ext)
        cap = ContainerId.new(@ctx, pp_ext.read_pointer) if res==0
      when LIBUSB::BT_PLATFORM_DESCRIPTOR
        res = Call.libusb_get_platform_descriptor(@ctx, cap.pointer, pp_ext)
        cap = PlatformDescriptor.new(@ctx, pp_ext.read_pointer) if res==0
      else
        # unknown capability -> use generic DeviceCapability
    end
    ptr += FFI.type_size(:pointer)
    caps << cap
  end
  caps
end

#device_capability_types ⇒ Array<Symbol>

Returns Types of Capabilities.

Returns:

  • (Array<Symbol>) —

    Types of Capabilities

See Also:



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# File 'lib/libusb/bos.rb', line 348

def device_capability_types
  # Capabilities are appended to the bos header
  ptr = pointer + offset_of(:dev_capability)
  bNumDeviceCaps.times.map do
    cap = DeviceCapability.new self, ptr.read_pointer
    ptr += FFI.type_size(:pointer)
    Call::BosTypes.find cap.bDevCapabilityType
  end
end

#inspect ⇒ Object 



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# File 'lib/libusb/bos.rb', line 358

def inspect
  "\#<#{self.class} #{device_capability_types.join(", ")}>"
end

#wTotalLength ⇒ Integer

Returns Length of this descriptor and all of its sub descriptors.

Returns:

  • (Integer) —

    Length of this descriptor and all of its sub descriptors



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# File 'lib/libusb/bos.rb', line 301

def wTotalLength
  self[:wTotalLength]
end