/// <summary>
    /// Descriptor information.
    /// </summary>
    public class Descriptor<K> {

        /// <summary>
        /// Key.
        /// </summary>
        public K Key { get; set; }

        /// <summary>
        /// Name.
        /// </summary>
        public String Name { get; set; }

        /// <summary>
        /// Description
        /// </summary>
        public String Description { get; set; }

        /// <summary>
        /// Get descriptor caption.
        /// </summary>
        public String Caption {
            get {
                if (String.IsNullOrEmpty(Description))
                    return Name;

                return String.Format("{0} - {1}", Name, Description);
            }
        }

        /// <summary>
        /// To String
        /// </summary>
        /// <returns>Default string display on binding list</returns>
        public override string ToString() {
            return Caption;
        }

        /// <summary>
        /// Equals
        /// </summary>
        /// <param name="obj">Equals object</param>
        /// <returns>When object has same key return true else return false</returns>
        public override bool Equals(object obj) {
            if (obj is Descriptor<K>) {
                return ((Descriptor<K>)obj).Key.Equals(Key);
            }

            return base.Equals(obj);
        }

        /// <summary>
        /// Get hashcode.
        /// </summary>
        /// <returns>Hashcode</returns>
        public override int GetHashCode() {
            return Key.GetHashCode();
        }
    }


        /// <summary>
        /// Get all resource descriptors.
        /// </summary>
        /// <returns>Resource descriptor list</returns>
        public static async Task<IList<Descriptor<Int32>>> GetAllDescriptors() {
            using (MesproContext db = GetContext()) {
                return await db.Resources
                               .OrderBy(m => m.Name)
                               .Select(m => new Descriptor<Int32>() { Key = m.ID, Name = m.Name, Description = m.Description })
                               .ToListAsync();
            }
        }

整個Configuration 分成4大部分 :

configuration
interface,
class or vendor specific( 如 HID， Audio）
endpoint



以一个usb audio 的设备configuration descriptor来举例：

typedef struct

{

configuration_descriptor cd;        // Configuration descriptor

interface_descriptor id0;              // Audio control interface

audio_header_descriptor ahd;        // Audio control header

input_terminal_descriptor itd;      // Audio input terminal

feature_unit_descriptor fud;        // Audio feature unit

output_terminal_descriptor otd;     // Audio output terminal

interface_descriptor id1_0;         // Audio zero-bandwidth interface

interface_descriptor id1_1;         // Audio streaming interface

stream_interface_descriptor sid;    // Audio stream descriptor

typeI_format_descriptor tfd;        // Audio format descriptor

stream_endpoint_descriptor sed;     // Streaming endpoint descriptor

audio_endpoint_descriptor aed;      // Audio endpoint descriptor

interface_descriptor id2;           // HID interface descriptor

hid_descriptor hd;                  // HID descriptor

endpoint_descriptor ed1;            // GET_REPORT input endpoint

endpoint_descriptor ed2;            // SET_REPORT output endpoint

} complete_configuration;              // End of complete_configuration

configuration_descriptor：

{                                   // Standard configuration descriptor

0x09,                            // bLength (9)

0x02,                            // bDescriptorType (CONFIGURATION)

0x9100,                          // wTotallength (145)

0x03,                            // bNumInterfaces (3)

0x01,                            // bConfigurationValue (1)

0x00,                            // iConfiguration (none)

0x80,                            // bmAttributes (bus-powered)

0x32,                            // bMaxPower (100 mA)

},

有3个interface，configuration No is 1， 没有字符串描述
第一个interface 是  interface_descriptor id0;              // Audio control interface
{                                   // Audio control interface
  0x09,                            // bLength (9)
  0x04,                            // bDescriptorType (INTERFACE)
  0x00,                            // bInterfaceNumber (0)
  0x00,                            // bAlternateSetting (none)
  0x00,                            // bNumEndpoints (none)
  0x01,                            // bInterfaceClass (AUDIO)
  0x01,                            // bInterfaceSubClass (AUDIO_CONTROL)
  0x00,                            // bInterfaceProtocol (none)
  0x00                             // iInterface (none)

},

interface 序号是0， endpoints 个数为0， AUDIO CLASS, AUDIO_CONTROL

包含一个Header， Input_terminal  further unit,OUTPUT_TERMINAL

因为interface是audio 类，后边跟类描述符

{                                       // Audio class-specific interface header

0x09,                            // bLength (9)

0x24,                            // bDescriptorType (CS_INTERFACE)

0x01,                            // bDescriptorSubtype (HEADER)

0x0001,                          // bcdADC (1.0)

0x2B00,                          // wTotalLength (43)

0x01,                            // bInCollection (1 streaming interface)

0x01                             // baInterfaceNr (interface 1 is stream)

},

{                                   // Audio class-specific input terminal

0x0C,                            // bLength (12)

0x24,                            // bDescriptorType (CS_INTERFACE)

0x02,                            // bDescriptorSubtype (INPUT_TERMINAL)

0x01,                            // bTerminalID (1)

0x1007,                          // wTerminalType (radio receiver)

0x00,                            // bAssocTerminal (none)

0x02,                            // bNrChannels (2)

0x0300,                          // wChannelConfig (left, right)

0x00,                            // iChannelNames (none)

0x00                             // iTerminal (none)

},

{                                   // Audio class-specific feature unit

0x0D,                            // bLength (13)

0x24,                            // bDescriptorType (CS_INTERFACE)

0x06,                            // bDescriptorSubtype (FEATURE_UNIT)

0x02,                            // bUnitID (2)

0x01,                            // bSourceID (input terminal 1)

0x02,                            // bControlSize (2 bytes)

0x0100,                          // Master controls

0x0000,                          // Channel 0 controls

0x0000,                          // Channel 1 controls

0x00                             // iFeature (none)

},

{                                   // Audio class-specific output terminal

0x09,                            // bLength (9)

0x24,                            // bDescriptorType (CS_INTERFACE)

0x03,                            // bDescriptorSubtype (OUTPUT_TERMINAL)

0x03,                            // bTerminalID (3)

0x0101,                          // wTerminalType (USB streaming)

0x00,                            // bAssocTerminal (none)

0x02,                            // bSourceID (feature unit 2)

0x00                             // iTerminal (none)

},
第二个interface     {                                   // Audio zero-bandwidth interface

0x09,                            // bLength (9)

0x04,                            // bDescriptorType (INTERFACE)

0x01,                            // bInterfaceNumber (1)

0x00,                            // bAlternateSetting (0)

0x00,                            // bNumEndpoints (0)

0x01,                            // bInterfaceClass (AUDIO)

0x02,                            // bInterfaceSubClass (AUDIO_STREAMING)

0x00,                            // bInterfaceProtocol (none)

0x00                             // iInterface (none)

},
第三个interface

{                                   // Audio streaming interface (alternate)

0x09,                            // bLength (9)

0x04,                            // bDescriptorType (INTERFACE)

0x01,                            // bInterfaceNumber (1)

0x01,                            // bAlternateSetting (1)

0x01,                            // bNumEndpoints (1)

0x01,                            // bInterfaceClass (AUDIO)

0x02,                            // bInterfaceSubClass (AUDIO_STREAMING)

0x00,                            // bInterfaceProtocol (none)

0x00                             // iInterface (none)

},

{                                   // Audio class-specific stream interface

0x07,                            // bLength (7)

0x24,                            // bDescriptorType (CS_INTERFACE)

0x01,                            // bDescriptorSubtype (AS_GENERAL)

0x03,                            // bTerminalLink (terminal 3)

0x00,                            // bDelay (none)

0x0100                           // wFormatTag (PCM format)

},

{                                   // Audio class-specific type I format

0x0B,                            // bLength (11)

0x24,                            // bDescriptorType (CS_INTERFACE)

0x02,                            // bDescriptorSubtype (FORMAT_TYPE)

0x01,                            // bFormatType (TYPE_I)

0x02,                            // bNrChannels (2)

0x02,                            // bSubFrameSize (2)

// The next field should be 10, but 16 works with more standard software

0x10,                            // bBitResolution (16)

0x01,                            // bSamFreqType (1 sampling frequency)

0x80,                            // 48,000 Hz (byte 0)

0xBB,                            // 48,000 Hz (byte 1)

0x00                             // 48,000 Hz (byte 2)

},

{                                   // Audio streaming isochronous endpoint

0x09,                            // bLength (9)

0x05,                            // bDescriptorType (ENDPOINT)

0x83,                            // bEndpointAddress (EP3 in)

0x05,                            // bmAttributes (asynchronous)

0x0002,                          // wMaxPacketSize (512)

0x01,                            // bInterval (1 millisecond)

0x00,                            // bRefresh (0)

0x00                             // bSynchAddress (no synchronization)

},

{                                   // Audio isochronous endpoint

0x07,                            // bLength (7)

0x25,                            // bDescriptorType (CS_ENDPOINT)

0x01,                            // bDescriptorSubtype (EP_GENERAL)

0x00,                            // bmAttributes (none)

0x02,                            // bLockDelayUnits (PCM samples)

0x0000                           // wLockDelay (0)

},
HID interface 还有endpoints

{                                   // HID interface

0x09,                            // bLength (9)

0x04,                            // bDescriptorType (INTERFACE)

0x02,                            // bInterfaceNumber (2)

0x00,                            // bAlternateSetting (0)

0x02,                            // bNumEndpoints (2)

0x03,                            // bInterfaceClass (HID)

0x00,                            // bInterfaceSubClass (none)

0x00,                            // bInterfaceProtocol (none)

0x00                             // iInterface (none)

},

{                                   // HID descriptor

0x09,                            // bLength (9)

0x21,                            // bDescriptorType (HID_DESCRIPTOR)

0x1101,                          // bcdHID (1.11)

0x00,                            // bCountryCode (none)

0x01,                            // bNumDescriptors (1 class descriptor)

0x22,                            // bClassDescriptorType (report descr.)

LE(HID_REPORT_SIZE)              // wDescriptorLength (203)

},

{                                   // HID interrupt in endpoint

0x07,                            // bLength (7)

0x05,                            // bDescriptorType (ENDPOINT)

0x81,                            // bEndpointAddress (EP1 in)

0x03,                            // bmAttributes (interrupt)

0x4000,                          // wMaxPacketSize (64)

0x0A                             // bInterval (10 milliseconds)

},

{                                   // HID interrupt out endpoint

0x07,                            // bLength (7)

0x05,                            // bDescriptorType (ENDPOINT)

0x02,                            // bEndpointAddress (EP2 out)

0x03,                            // bmAttributes (interrupt)

0x4000,                          // wMaxPacketSize (64)

0x01                             // bInterval (1 millisecond)

}
HID report descriptor 一般独立于 configuration之外

HidReportDesc

{
0x06, 0x00, 0xFF,                   // USAGE_PAGE (Vendor Defined Page 1)

0x09, 0x01,                         // USAGE (Vendor Usage 1)

0xA1, 0x01,                         // COLLECTION (Application)

0xC0                                // END_COLLECTION
};

const log = (target, name, descriptor) => {
  //ES6实现AOP
  const _handler = descriptor.value;
  descriptor.value = function(){
    console.log(arguments);
   _handler.apply(this,arguments);
  };
  return descriptor;
}

class Math {
  @log
  add(a, b) {
    return a + b;
  }
  add2(a, b) {
    return a + b;
  }
  add3(a, b) {
    return a + b;
  }
}
//传统方式
!function(){
const _handler = Math.prototype.add2;
Math.prototype.add2 = function(){
    console.log(arguments);
   _handler.apply(this,arguments);
};
}();

const math = new Math();
math.add(1, 2);
math.add2(1, 2);

 

A deployment descriptor (DD) refers to a configuration file for an artifact that is deployed to some container/engine.
In the Java Platform, Enterprise Edition, a deployment descriptor describes how a component, module or application (such as a web application or enterprise application) should be deployed.[1] It directs a deployment tool to deploy a module or application with specific container options, security settings and describes specific configuration requirements. XML is used for the syntax of these deployment descriptor files.
For web applications, the deployment descriptor must be called web.xml and must reside in the WEB-INF directory in the web application root. For Java EE applications, the deployment descriptor must be named application.xml and must be placed directly in the META-INF directory at the top level of the application .ear file.
In Java EE, there are two types of deployment descriptors: “Java EE deployment descriptors” and “runtime deployment descriptors”.[1] The Java EE deployment descriptors are defined by the language specification,[2] whereas the runtime descriptors are defined by the vendor of each container implementation. For example, the web.xml file is a standard Java EE deployment descriptor, specified in the Java Servlet specification, but the sun-web.xml file contains configuration data specific to the Sun GlassFish Enterprise Server implementation.[3]
Reference:

https://en.wikipedia.org/wiki/Deployment_descriptor