aes70/src/OCP1/notification.js

A controller library for the AES70 protocol.

import { PDU } from './pdu.js';
import { OcaEvent } from './OcaEvent.js';
import { EncodedArguments } from './encoded_arguments.js';

/**
 * Notification packet.
 */
export class Notification extends PDU {
  constructor(
    target,
    method_level,
    method_index,
    context,
    event,
    param_count,
    parameters
  ) {
    super();
    this.target = target;
    this.method_level = method_level | 0;
    this.method_index = method_index | 0;
    this.context = context;
    this.event = event;
    this.param_count = param_count | 0;
    this.parameters = parameters || null;
  }

  static get messageType() {
    return 2;
  }

  encode_to(dst, pos) {
    dst.setUint32(pos, this.encoded_length());
    pos += 4;
    dst.setUint32(pos, this.target);
    pos += 4;
    dst.setUint16(pos, this.method_level);
    pos += 2;
    dst.setUint16(pos, this.method_index);
    pos += 2;
    dst.setUint8(pos, this.param_count);
    pos++;
    const context = this.context;
    if (context) {
      const len = context.byteLength;

      dst.setUint16(pos, len);
      pos += 2;
      if (len > 0) {
        new Uint8Array(dst.buffer).set(
          new Uint8Array(this.context),
          dst.byteOffset + pos
        );
        pos += len;
      }
    } else {
      dst.setUint16(pos, 0);
      pos += 2;
    }
    dst.setUint32(pos, this.event.EmitterONo);
    pos += 4;
    dst.setUint16(pos, this.event.EventID.DefLevel);
    pos += 2;
    dst.setUint16(pos, this.event.EventID.EventIndex);
    pos += 2;
    if (this.param_count > 1) {
      if (this.parameters instanceof EncodedArguments) {
        pos = this.parameters.encodeTo(dst, pos);
      } else {
        new Uint8Array(dst.buffer).set(
          new Uint8Array(this.parameters),
          dst.byteOffset + pos
        );
        pos += this.parameters.byteLength;
      }
    }
    return pos;
  }

  encoded_length() {
    return (
      23 +
      (this.param_count > 1 ? this.parameters.byteLength : 0) +
      (this.context ? this.context.byteLength : 0)
    );
  }

  decode_from(data, pos, data_len) {
    let len = data.getUint32(pos);
    pos += 4;
    this.target = data.getUint32(pos);
    pos += 4;
    this.method_level = data.getUint16(pos);
    pos += 2;
    this.method_index = data.getUint16(pos);
    pos += 2;
    this.param_count = data.getUint8(pos);
    pos++;
    const context_length = data.getUint16(pos);
    pos += 2;
    if (context_length) {
      this.context = data.buffer.slice(
        data.byteOffset + pos,
        data.byteOffset + pos + context_length
      );
      pos += context_length;
    } else {
      this.context = null;
    }

    let event;

    [pos, event] = OcaEvent.decodeFrom(data, pos);

    this.event = event;

    len -= 23 + context_length;
    if (len < 0) throw new Error('Bad Notification Length.');
    if (len > 0) {
      this.parameters = data.buffer.slice(
        data.byteOffset + pos,
        data.byteOffset + pos + len
      );
      pos += len;
    }
    return pos;
  }
}