morefun-forerunnerdb
Version:
A NoSQL document store database for browsers and Node.js.
308 lines (243 loc) • 10.3 kB
HTML
<html lang="en">
<head>
<meta charset="utf-8">
<title>JSDoc: Source: ActiveBucket.js</title>
<script src="scripts/prettify/prettify.js"> </script>
<script src="scripts/prettify/lang-css.js"> </script>
<!--[if lt IE 9]>
<script src="//html5shiv.googlecode.com/svn/trunk/html5.js"></script>
<![endif]-->
<link type="text/css" rel="stylesheet" href="styles/prettify-tomorrow.css">
<link type="text/css" rel="stylesheet" href="styles/jsdoc-default.css">
</head>
<body>
<div id="main">
<h1 class="page-title">Source: ActiveBucket.js</h1>
<section>
<article>
<pre class="prettyprint source linenums"><code>"use strict";
var Shared = require('./Shared'),
Path = require('./Path'),
sharedPathSolver;
/**
* Creates an always-sorted multi-key bucket that allows ForerunnerDB to
* know the index that a document will occupy in an array with minimal
* processing, speeding up things like sorted views.
* @param {object} orderBy An order object.
* @constructor
*/
var ActiveBucket = function (orderBy) {
this._primaryKey = '_id';
this._keyArr = [];
this._data = [];
this._objLookup = {};
this._count = 0;
this._keyArr = sharedPathSolver.parse(orderBy, true);
};
Shared.addModule('ActiveBucket', ActiveBucket);
Shared.mixin(ActiveBucket.prototype, 'Mixin.Sorting');
sharedPathSolver = new Path();
/**
* Gets / sets the primary key used by the active bucket.
* @returns {String} The current primary key.
*/
Shared.synthesize(ActiveBucket.prototype, 'primaryKey');
/**
* Quicksorts a single document into the passed array and
* returns the index that the document should occupy.
* @param {object} obj The document to calculate index for.
* @param {array} arr The array the document index will be
* calculated for.
* @param {string} item The string key representation of the
* document whose index is being calculated.
* @param {function} fn The comparison function that is used
* to determine if a document is sorted below or above the
* document we are calculating the index for.
* @returns {number} The index the document should occupy.
*/
ActiveBucket.prototype.qs = function (obj, arr, item, fn) {
// If the array is empty then return index zero
if (!arr.length) {
return 0;
}
var lastMidwayIndex = -1,
midwayIndex,
lookupItem,
result,
start = 0,
end = arr.length - 1;
// Loop the data until our range overlaps
while (end >= start) {
// Calculate the midway point (divide and conquer)
midwayIndex = Math.floor((start + end) / 2);
if (lastMidwayIndex === midwayIndex) {
// No more items to scan
break;
}
// Get the item to compare against
lookupItem = arr[midwayIndex];
if (lookupItem !== undefined) {
// Compare items
result = fn(this, obj, item, lookupItem);
if (result > 0) {
start = midwayIndex + 1;
}
if (result < 0) {
end = midwayIndex - 1;
}
}
lastMidwayIndex = midwayIndex;
}
if (result > 0) {
return midwayIndex + 1;
} else {
return midwayIndex;
}
};
/**
* Calculates the sort position of an item against another item.
* @param {object} sorter An object or instance that contains
* sortAsc and sortDesc methods.
* @param {object} obj The document to compare.
* @param {string} a The first key to compare.
* @param {string} b The second key to compare.
* @returns {number} Either 1 for sort a after b or -1 to sort
* a before b.
* @private
*/
ActiveBucket.prototype._sortFunc = function (sorter, obj, a, b) {
var aVals = a.split('.:.'),
bVals = b.split('.:.'),
arr = sorter._keyArr,
count = arr.length,
index,
sortType,
castType;
for (index = 0; index < count; index++) {
sortType = arr[index];
castType = typeof sharedPathSolver.get(obj, sortType.path);
if (castType === 'number') {
aVals[index] = Number(aVals[index]);
bVals[index] = Number(bVals[index]);
}
// Check for non-equal items
if (aVals[index] !== bVals[index]) {
// Return the sorted items
if (sortType.value === 1) {
return sorter.sortAsc(aVals[index], bVals[index]);
}
if (sortType.value === -1) {
return sorter.sortDesc(aVals[index], bVals[index]);
}
}
}
};
/**
* Inserts a document into the active bucket.
* @param {object} obj The document to insert.
* @returns {number} The index the document now occupies.
*/
ActiveBucket.prototype.insert = function (obj) {
var key,
keyIndex;
key = this.documentKey(obj);
keyIndex = this._data.indexOf(key);
if (keyIndex === -1) {
// Insert key
keyIndex = this.qs(obj, this._data, key, this._sortFunc);
this._data.splice(keyIndex, 0, key);
} else {
this._data.splice(keyIndex, 0, key);
}
this._objLookup[obj[this._primaryKey]] = key;
this._count++;
return keyIndex;
};
/**
* Removes a document from the active bucket.
* @param {object} obj The document to remove.
* @returns {boolean} True if the document was removed
* successfully or false if it wasn't found in the active
* bucket.
*/
ActiveBucket.prototype.remove = function (obj) {
var key,
keyIndex;
key = this._objLookup[obj[this._primaryKey]];
if (key) {
keyIndex = this._data.indexOf(key);
if (keyIndex > -1) {
this._data.splice(keyIndex, 1);
delete this._objLookup[obj[this._primaryKey]];
this._count--;
return true;
} else {
return false;
}
}
return false;
};
/**
* Get the index that the passed document currently occupies
* or the index it will occupy if added to the active bucket.
* @param {object} obj The document to get the index for.
* @returns {number} The index.
*/
ActiveBucket.prototype.index = function (obj) {
var key,
keyIndex;
key = this.documentKey(obj);
keyIndex = this._data.indexOf(key);
if (keyIndex === -1) {
// Get key index
keyIndex = this.qs(obj, this._data, key, this._sortFunc);
}
return keyIndex;
};
/**
* The key that represents the passed document.
* @param {object} obj The document to get the key for.
* @returns {string} The document key.
*/
ActiveBucket.prototype.documentKey = function (obj) {
var key = '',
arr = this._keyArr,
count = arr.length,
index,
sortType;
for (index = 0; index < count; index++) {
sortType = arr[index];
if (key) {
key += '.:.';
}
key += sharedPathSolver.get(obj, sortType.path);
}
// Add the unique identifier on the end of the key
key += '.:.' + obj[this._primaryKey];
return key;
};
/**
* Get the number of documents currently indexed in the active
* bucket instance.
* @returns {number} The number of documents.
*/
ActiveBucket.prototype.count = function () {
return this._count;
};
Shared.finishModule('ActiveBucket');
module.exports = ActiveBucket;</code></pre>
</article>
</section>
</div>
<nav>
<h2><a href="index.html">Home</a></h2><h3>Classes</h3><ul><li><a href="ActiveBucket.html">ActiveBucket</a></li><li><a href="Angular.html">Angular</a></li><li><a href="AutoBind.html">AutoBind</a></li><li><a href="Collection.html">Collection</a></li><li><a href="CollectionGroup.html">CollectionGroup</a></li><li><a href="Core.html">Core</a></li><li><a href="Db.html">Db</a></li><li><a href="Document.html">Document</a></li><li><a href="Grid.html">Grid</a></li><li><a href="Highchart.html">Highchart</a></li><li><a href="Index2d.html">Index2d</a></li><li><a href="IndexBinaryTree.html">IndexBinaryTree</a></li><li><a href="IndexHashMap.html">IndexHashMap</a></li><li><a href="Infinilist.html">Infinilist</a></li><li><a href="KeyValueStore.html">KeyValueStore</a></li><li><a href="Metrics.html">Metrics</a></li><li><a href="OldView.html">OldView</a></li><li><a href="Operation.html">Operation</a></li><li><a href="Overload.html">Overload</a></li><li><a href="Path.html">Path</a></li><li><a href="Persist.html">Persist</a></li><li><a href="Procedure.html">Procedure</a></li><li><a href="ReactorIO.html">ReactorIO</a></li><li><a href="Serialiser.html">Serialiser</a></li><li><a href="Shared.overload.html">overload</a></li><li><a href="View.html">View</a></li></ul><h3>Mixins</h3><ul><li><a href="ChainReactor.html">ChainReactor</a></li><li><a href="Common.html">Common</a></li><li><a href="Constants.html">Constants</a></li><li><a href="Events.html">Events</a></li><li><a href="Matching.html">Matching</a></li><li><a href="global.html#Shared">Shared</a></li><li><a href="Sorting.html">Sorting</a></li><li><a href="Tags.html">Tags</a></li><li><a href="Triggers.html">Triggers</a></li><li><a href="Updating.html">Updating</a></li></ul><h3>Global</h3><ul><li><a href="global.html#%2522boolean,function%2522">"boolean, function"</a></li><li><a href="global.html#%2522object,function%2522">"object, function"</a></li><li><a href="global.html#%2522object,object,function%2522">"object, object, function"</a></li><li><a href="global.html#%2522string,*,function%2522">"string, *, function"</a></li><li><a href="global.html#%2522string,function%2522">"string, function"</a></li><li><a href="global.html#%2522string,object,function%2522">"string, object, function"</a></li><li><a href="global.html#%2522string,object,object,function%2522">"string, object, object, function"</a></li><li><a href="global.html#%2522string,string,function%2522">"string, string, function"</a></li><li><a href="global.html#%2522string,string,object,function%2522">"string, string, object, function"</a></li><li><a href="global.html#%2522string,string,object,object,function%2522">"string, string, object, object, function"</a></li><li><a href="global.html#access">access</a></li><li><a href="global.html#boolean">boolean</a></li><li><a href="global.html#checksum">checksum</a></li><li><a href="global.html#Condition">Condition</a></li><li><a href="global.html#function">function</a></li><li><a href="global.html#MyModule">MyModule</a></li><li><a href="global.html#name">name</a></li><li><a href="global.html#NodeRAS">NodeRAS</a></li><li><a href="global.html#Section">Section</a></li><li><a href="global.html#server">server</a></li><li><a href="global.html#setData">setData</a></li></ul>
</nav>
<br class="clear">
<footer>
Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.4.0</a> on Wed Jun 15 2016 17:25:36 GMT+0100 (BST)
</footer>
<script> prettyPrint(); </script>
<script src="scripts/linenumber.js"> </script>
</body>
</html>