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Mini Shell
Mini Shell
'use strict';
const Promise = require('bluebird');
const { parseArgs, shuffle } = require('./util');
class Query {
/**
* Query constructor.
*
* @param {Array} data
*/
constructor(data) {
this.data = data;
this.length = data.length;
}
/**
* Returns the number of elements.
*
* @return Number
*/
count() {
return this.length;
}
/**
* Iterates over all documents.
*
* @param {Function} iterator
*/
forEach(iterator) {
const { data, length } = this;
for (let i = 0; i < length; i++) {
iterator(data[i], i);
}
}
/**
* Returns an array containing all documents.
*
* @return {Array}
*/
toArray() {
return this.data;
}
/**
* Returns the document at the specified index. `num` can be a positive or
* negative number.
*
* @param {Number} i
* @return {Document|Object}
*/
eq(i) {
const index = i < 0 ? this.length + i : i;
return this.data[index];
}
/**
* Returns the first document.
*
* @return {Document|Object}
*/
first() {
return this.eq(0);
}
/**
* Returns the last document.
*
* @return {Document|Object}
*/
last() {
return this.eq(-1);
}
/**
* Returns the specified range of documents.
*
* @param {Number} start
* @param {Number} [end]
* @return {Query}
*/
slice(start, end) {
return new this.constructor(this.data.slice(start, end));
}
/**
* Limits the number of documents returned.
*
* @param {Number} i
* @return {Query}
*/
limit(i) {
return this.slice(0, i);
}
/**
* Specifies the number of items to skip.
*
* @param {Number} i
* @return {Query}
*/
skip(i) {
return this.slice(i);
}
/**
* Returns documents in a reversed order.
*
* @return {Query}
*/
reverse() {
return new this.constructor(this.data.slice().reverse());
}
/**
* Returns documents in random order.
*
* @return {Query}
*/
shuffle() {
return new this.constructor(shuffle(this.data));
}
/**
* Finds matching documents.
*
* @param {Object} query
* @param {Object} [options]
* @param {Number} [options.limit=0] Limits the number of documents returned.
* @param {Number} [options.skip=0] Skips the first elements.
* @param {Boolean} [options.lean=false] Returns a plain JavaScript object.
* @return {Query|Array}
*/
find(query, options = {}) {
const filter = this._schema._execQuery(query);
const { data, length } = this;
const { lean = false } = options;
let { limit = length, skip } = options;
const arr = [];
for (let i = 0; limit && i < length; i++) {
const item = data[i];
if (filter(item)) {
if (skip) {
skip--;
} else {
arr.push(lean ? item.toObject() : item);
limit--;
}
}
}
return lean ? arr : new this.constructor(arr);
}
/**
* Finds the first matching documents.
*
* @param {Object} query
* @param {Object} [options]
* @param {Number} [options.skip=0] Skips the first elements.
* @param {Boolean} [options.lean=false] Returns a plain JavaScript object.
* @return {Document|Object}
*/
findOne(query, options = {}) {
options.limit = 1;
const result = this.find(query, options);
return options.lean ? result[0] : result.data[0];
}
/**
* Sorts documents.
*
* Example:
*
* ``` js
* query.sort('date', -1);
* query.sort({date: -1, title: 1});
* query.sort('-date title');
* ```
*
* If the `order` equals to `-1`, `desc` or `descending`, the data will be
* returned in reversed order.
*
* @param {String|Object} orderby
* @param {String|Number} [order]
* @return {Query}
*/
sort(orderby, order) {
const sort = parseArgs(orderby, order);
const fn = this._schema._execSort(sort);
return new this.constructor(this.data.slice().sort(fn));
}
/**
* Creates an array of values by iterating each element in the collection.
*
* @param {Function} iterator
* @return {Array}
*/
map(iterator) {
const { data, length } = this;
const result = new Array(length);
for (let i = 0; i < length; i++) {
result[i] = iterator(data[i], i);
}
return result;
}
/**
* Reduces a collection to a value which is the accumulated result of iterating
* each element in the collection.
*
* @param {Function} iterator
* @param {*} [initial] By default, the initial value is the first document.
* @return {*}
*/
reduce(iterator, initial) {
const { data, length } = this;
let result, i;
if (initial === undefined) {
i = 1;
result = data[0];
} else {
i = 0;
result = initial;
}
for (; i < length; i++) {
result = iterator(result, data[i], i);
}
return result;
}
/**
* Reduces a collection to a value which is the accumulated result of iterating
* each element in the collection from right to left.
*
* @param {Function} iterator
* @param {*} [initial] By default, the initial value is the last document.
* @return {*}
*/
reduceRight(iterator, initial) {
const { data, length } = this;
let result, i;
if (initial === undefined) {
i = length - 2;
result = data[length - 1];
} else {
i = length - 1;
result = initial;
}
for (; i >= 0; i--) {
result = iterator(result, data[i], i);
}
return result;
}
/**
* Creates a new array with all documents that pass the test implemented by the
* provided function.
*
* @param {Function} iterator
* @return {Query}
*/
filter(iterator) {
const { data, length } = this;
const arr = [];
for (let i = 0; i < length; i++) {
const item = data[i];
if (iterator(item, i)) arr.push(item);
}
return new this.constructor(arr);
}
/**
* Tests whether all documents pass the test implemented by the provided
* function.
*
* @param {Function} iterator
* @return {Boolean}
*/
every(iterator) {
const { data, length } = this;
for (let i = 0; i < length; i++) {
if (!iterator(data[i], i)) return false;
}
return true;
}
/**
* Tests whether some documents pass the test implemented by the provided
* function.
*
* @param {Function} iterator
* @return {Boolean}
*/
some(iterator) {
const { data, length } = this;
for (let i = 0; i < length; i++) {
if (iterator(data[i], i)) return true;
}
return false;
}
/**
* Update all documents.
*
* @param {Object} data
* @param {Function} [callback]
* @return {Promise}
*/
update(data, callback) {
const model = this._model;
const stack = this._schema._parseUpdate(data);
return Promise.mapSeries(this.data, item => model._updateWithStack(item._id, stack)).asCallback(callback);
}
/**
* Replace all documents.
*
* @param {Object} data
* @param {Function} [callback]
* @return {Promise}
*/
replace(data, callback) {
const model = this._model;
return Promise.map(this.data, item => model.replaceById(item._id, data)).asCallback(callback);
}
/**
* Remove all documents.
*
* @param {Function} [callback]
* @return {Promise}
*/
remove(callback) {
const model = this._model;
return Promise.mapSeries(this.data, item => model.removeById(item._id)).asCallback(callback);
}
/**
* Populates document references.
*
* @param {String|Object} expr
* @return {Query}
*/
populate(expr) {
const stack = this._schema._parsePopulate(expr);
const { data, length } = this;
const model = this._model;
for (let i = 0; i < length; i++) {
data[i] = model._populate(data[i], stack);
}
return this;
}
}
Query.prototype.size = Query.prototype.count;
Query.prototype.each = Query.prototype.forEach;
Query.prototype.random = Query.prototype.shuffle;
module.exports = Query;
Zerion Mini Shell 1.0