whistle/lib/util/data-server.js

HTTP, HTTPS, Websocket debugging proxy

var util = require('../rules/util');
var TIMEOUT = 36000;
var CLEAR_INTERVAL = 5000;
var CACHE_TIME = CLEAR_INTERVAL * 2;
var MAX_LENGTH = 512;
var MIN_LENGTH = 412;
var COUNT = 100;
var count = 0;
var ids = [];
var data = {};
var proxy, binded, timeout, interval;

function disable() {
  proxy.removeListener('request', handleRequest);
  ids = [];
  data = {};
  interval && clearInterval(interval);
  interval = null;
  binded = false;
}

function enable() {
  !binded && proxy.on('request', handleRequest);

  binded = true;
  clearTimeout(timeout);
  timeout = setTimeout(disable, TIMEOUT);
  if (!interval) {
    interval = setInterval(clearCache, CLEAR_INTERVAL);
  }
}

/**
* 如果超过最大缓存数，清理如下请求数据：
* 1. 已经请求结束且结束时间超过10秒
* 2. 请求#1前面的未结束且未被ui读取过的请求
*/
function clearCache() {
  var len = ids.length;
  if (len <= MAX_LENGTH) {
    return;
  }

  var index = -1; //已经完成，且缓存超过10s的最后一个请求
  var now = Date.now();
  var i, curData;
  for (i = len - 1; i >= 0; i--) {
    curData = data[ids[i]];
    if (curData.endTime && now - curData.endTime > TIMEOUT) {
      index = i;
      break;
    }
  }

  if (index < 0) {
    return;
  }

  var _ids = [];
  ++index;
  for (i = 0; i < index; i++) {
    var id = ids[i];
    curData = data[id];
    if (curData.read && (!curData.endTime || now - curData.endTime < CACHE_TIME
        || now - curData.startTime < TIMEOUT)) {
      _ids.push(id);
    } else {
      delete data[id];
      if (--len <= MIN_LENGTH) {
        _ids.push.apply(_ids, ids.slice(i + 1, index));
        break;
      }
    }
  }
  ids = _ids.concat(ids.slice(index));
}

function getIds(startTime, count, lastRowId) {
  var len = ids.length;
  if (!len) {
    return [];
  }

  var notStartTime = !startTime;
  startTime = ((startTime || Date.now() - 3000) + '').split('-');
  count = Math.min(count || COUNT, len);

  startTime[0] = parseInt(startTime[0], 10) || 0;
  startTime[1] = parseInt(startTime[1], 10) || 0;
  if (notStartTime && lastRowId) {
    lastRowId = (lastRowId + '').split('-');
    lastRowId[0] = parseInt(lastRowId[0], 10) || 0;
    if (lastRowId[0] >= startTime[0]) {
      startTime[0] = lastRowId[0];
      startTime[1] = parseInt(lastRowId[1], 10) || 0;
    }
  }

  if (compareId(ids[0], startTime)) {

    return ids.slice(0, count);
  }

  var end = len - 1;
  if (!end || !compareId(ids[end], startTime)) {

    return  [];
  }

  var index = getIndex(startTime, 0, end);
  return ids.slice(index, index + count);
}

function compareId(curId, refId) {
  curId = curId.split('-');
  return curId[0] > refId[0] || (curId[0] == refId[0] && curId[1] > refId[1]);
}

function getIndex(startTime, start, end) {
  if (end - start <= 1) {
    return compareId(ids[start], startTime) ? start : end;
  }

  var mid = Math.floor((start + end) / 2);
  var id = ids[mid];
  return compareId(id, startTime) ? getIndex(startTime, start, mid) : getIndex(startTime, mid + 1, end);
}

function getList(ids) {
  var result = [];
  for (var i = 0, len = ids && ids.length; i < len; i++) {
    var id = ids[i];
    var curData = data[id];
    if (curData) {
      curData.read = true;
      result[i] = curData;
    }
  }

  return result;
}

function handleRequest(req) {
  var curData = req.data;
  if (!util.filterUrl(curData.url)) {
    return;
  }
  var id = curData.id = curData.id || (curData.startTime + '-' + ++count);
  data[id] = curData;
  ids.indexOf(id) === -1 && ids.push(id);
}

module.exports = function init(_proxy) {
  proxy = _proxy;
/**
* options: {
* 		startTime: timestamp || timestamp + '-' + count
* 		count: 获取新数据的数量
* 		ids: 请未结束的id列表
* }
*
* @param options
*/
  proxy.getData = function get(options) {
    enable();
    options = options || {};
    var data = {};
    var newIds = options.startTime == -1 ? [] : getIds(options.startTime, options.count, options.lastRowId);
    var list = getList(newIds).concat(getList(options.ids));
    for (var i = 0, len = list.length; i < len; i++) {
      var item = list[i];
      if (item) {
        data[item.id] = item;
      }
    }

    return {
      ids: options.ids || [],
      newIds: newIds,
      data: data
    };
  };
};