zby-live-sdk/src/channel/pomelo/latestQueue.js

This is a live SDK for weclassroom.

function DoubleLinkList() {
  function DNode(data) {
    this.data = data;
    this.next = null;
    this.prev = null;
  }

  this.head = null;
  this.tail = null;
  this.length = 0;

  this.insert_head = function (data) {
    var temp_node = new DNode(data);
    if (this.head == null) {
      this.head = temp_node;
      this.tail = temp_node;
    } else {
      temp_node.next = this.head;
      this.head.prev = temp_node;
      this.head = temp_node;
    }
    this.length += 1;

    return temp_node;
  };

  this.insert_tail = function (data) {
    var node = new DNode(data);
    if (this.tail == null) {
      this.head = node;
      this.tail = node;
    } else {
      node.prev = this.tail;
      this.tail.next = node;
      this.tail = node;
    }
    this.length += 1;

    return node;
  };

  this.delete = function (node) {
    if (node.prev != null && node.next != null) {
      node.prev.next = node.next;
      node.next.prev = node.prev;
    } else if (node.prev != null) {
      this.tail = node.prev;
      this.tail.next = null;

    } else if (node.next != null) {
      this.head = node.next;
      this.head.prev = null;
    } else {
      this.head = null;
      this.tail = null;
    }

    this.length -= 1;
  };

  this.touch = function (node) {
    if (node.prev != null && node.next != null) {
      node.prev.next = node.next;
      node.next.prev = node.prev;
    } else if (node.prev != null) {
      this.tail = node.prev;
      this.tail.next = null;
    } else if (node.next != null) {
      this.head = node.next;
      this.head.prev = null;
    } else {
      this.head = null;
      this.tail = null;
    }


    node.prev = null;
    node.next = null;
    if (this.tail == null) {
      this.head = node;
      this.tail = node;
    } else {
      node.prev = this.tail;
      this.tail.next = node;
      this.tail = node;
    }
  };

  this.getLength = function () {
    return this.length;
  };

  this.getHead = function () {
    return this.head;
  };

  this.getTail = function () {
    return this.tail;
  };
}

export default function LatestQueue() {
  this.latestDList = new DoubleLinkList();
  this.latestDict = {};

  function LatestNode(msgId, timestamp) {
    this.msgId = msgId;
    this.timestamp = timestamp;
  }

  this.insert = function (msgId, timestamp) {
    if (this.latestDict[msgId]) {
      return;
    }

    const latestNode = new LatestNode(msgId, timestamp);

    this.latestDList.insert_tail(latestNode);
    this.latestDict[msgId] = latestNode;
  };

  this.isRepeat = function (msgId) {
    return !!this.latestDict[msgId];
  };

  this.delete = function (latestInterval, maxDeleteNum) {
    let tempDNode = this.latestDList.getHead();
    let currentDeleteNum = 0;
    let currentTimeStamp = Date.now();
    while (tempDNode != null) {
      if (currentTimeStamp - tempDNode.data.timestamp >= latestInterval) {
        delete this.latestDict[tempDNode.data.msgId];
        this.latestDList.delete(tempDNode);
        currentDeleteNum += 1;
      }

      if (currentDeleteNum >= maxDeleteNum) {
        break;
      }

      tempDNode = tempDNode.next;
    }

    return currentDeleteNum;
  };

  this.getLength = function () {
    return this.latestDList.getLength();
  };
}