pouchdb-find/lib/abstract-mapreduce/utils.js

Easy-to-use query language for PouchDB

'use strict';
/* istanbul ignore if */
exports.Promise = require('pouchdb/extras/promise');

exports.inherits = require('inherits');
exports.extend = require('pouchdb-extend');
var argsarray = require('argsarray');

/* istanbul ignore next */
exports.promisedCallback = function (promise, callback) {
  if (callback) {
    promise.then(function (res) {
      process.nextTick(function () {
        callback(null, res);
      });
    }, function (reason) {
      process.nextTick(function () {
        callback(reason);
      });
    });
  }
  return promise;
};

/* istanbul ignore next */
exports.callbackify = function (fun) {
  return argsarray(function (args) {
    var cb = args.pop();
    var promise = fun.apply(this, args);
    if (typeof cb === 'function') {
      exports.promisedCallback(promise, cb);
    }
    return promise;
  });
};

// Promise finally util similar to Q.finally
/* istanbul ignore next */
exports.fin = function (promise, cb) {
  return promise.then(function (res) {
    var promise2 = cb();
    if (typeof promise2.then === 'function') {
      return promise2.then(function () {
        return res;
      });
    }
    return res;
  }, function (reason) {
    var promise2 = cb();
    if (typeof promise2.then === 'function') {
      return promise2.then(function () {
        throw reason;
      });
    }
    throw reason;
  });
};

exports.sequentialize = function (queue, promiseFactory) {
  return function () {
    var args = arguments;
    var that = this;
    return queue.add(function () {
      return promiseFactory.apply(that, args);
    });
  };
};

exports.flatten = function (arrs) {
  var res = [];
  for (var i = 0, len = arrs.length; i < len; i++) {
    res = res.concat(arrs[i]);
  }
  return res;
};

// uniq an array of strings, order not guaranteed
// similar to underscore/lodash _.uniq
exports.uniq = function (arr) {
  var map = {};

  for (var i = 0, len = arr.length; i < len; i++) {
    map['$' + arr[i]] = true;
  }

  var keys = Object.keys(map);
  var output = new Array(keys.length);

  for (i = 0, len = keys.length; i < len; i++) {
    output[i] = keys[i].substring(1);
  }
  return output;
};

var crypto = require('crypto');
var Md5 = require('spark-md5');

exports.MD5 = function (string) {
  /* istanbul ignore else */
  if (!process.browser) {
    return crypto.createHash('md5').update(string).digest('hex');
  } else {
    return Md5.hash(string);
  }
};