From a089699c8915636ba4f158d77dba9b012bc93208 Mon Sep 17 00:00:00 2001
From: Andrew Dolgov <fox@madoka.volgo-balt.ru>
Date: Fri, 4 Mar 2011 19:02:28 +0300
Subject: build custom layer of Dojo to speed up loading of tt-rss (refs #293)

---
 lib/dojo/data/util/sorter.js | 146 +++++++++++++++++++++++++++----------------
 1 file changed, 91 insertions(+), 55 deletions(-)

(limited to 'lib/dojo/data/util/sorter.js')

diff --git a/lib/dojo/data/util/sorter.js b/lib/dojo/data/util/sorter.js
index ace781274..c0261c848 100644
--- a/lib/dojo/data/util/sorter.js
+++ b/lib/dojo/data/util/sorter.js
@@ -5,62 +5,98 @@
 */
 
 
-if(!dojo._hasResource["dojo.data.util.sorter"]){
-dojo._hasResource["dojo.data.util.sorter"]=true;
+if(!dojo._hasResource["dojo.data.util.sorter"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
+dojo._hasResource["dojo.data.util.sorter"] = true;
 dojo.provide("dojo.data.util.sorter");
-dojo.data.util.sorter.basicComparator=function(a,b){
-var r=-1;
-if(a===null){
-a=undefined;
-}
-if(b===null){
-b=undefined;
-}
-if(a==b){
-r=0;
-}else{
-if(a>b||a==null){
-r=1;
-}
-}
-return r;
-};
-dojo.data.util.sorter.createSortFunction=function(_1,_2){
-var _3=[];
-function _4(_5,_6,_7,s){
-return function(_8,_9){
-var a=s.getValue(_8,_5);
-var b=s.getValue(_9,_5);
-return _6*_7(a,b);
-};
-};
-var _a;
-var _b=_2.comparatorMap;
-var bc=dojo.data.util.sorter.basicComparator;
-for(var i=0;i<_1.length;i++){
-_a=_1[i];
-var _c=_a.attribute;
-if(_c){
-var _d=(_a.descending)?-1:1;
-var _e=bc;
-if(_b){
-if(typeof _c!=="string"&&("toString" in _c)){
-_c=_c.toString();
-}
-_e=_b[_c]||bc;
-}
-_3.push(_4(_c,_d,_e,_2));
-}
-}
-return function(_f,_10){
-var i=0;
-while(i<_3.length){
-var ret=_3[i++](_f,_10);
-if(ret!==0){
-return ret;
-}
-}
-return 0;
+
+dojo.data.util.sorter.basicComparator = function(	/*anything*/ a, 
+													/*anything*/ b){
+	//	summary:  
+	//		Basic comparision function that compares if an item is greater or less than another item
+	//	description:  
+	//		returns 1 if a > b, -1 if a < b, 0 if equal.
+	//		'null' values (null, undefined) are treated as larger values so that they're pushed to the end of the list.
+	//		And compared to each other, null is equivalent to undefined.
+	
+	//null is a problematic compare, so if null, we set to undefined.
+	//Makes the check logic simple, compact, and consistent
+	//And (null == undefined) === true, so the check later against null
+	//works for undefined and is less bytes.
+	var r = -1;
+	if(a === null){
+		a = undefined;
+	}
+	if(b === null){
+		b = undefined;
+	}
+	if(a == b){
+		r = 0; 
+	}else if(a > b || a == null){
+		r = 1; 
+	}
+	return r; //int {-1,0,1}
 };
+
+dojo.data.util.sorter.createSortFunction = function(	/* attributes array */sortSpec,
+														/*dojo.data.core.Read*/ store){
+	//	summary:  
+	//		Helper function to generate the sorting function based off the list of sort attributes.
+	//	description:  
+	//		The sort function creation will look for a property on the store called 'comparatorMap'.  If it exists
+	//		it will look in the mapping for comparisons function for the attributes.  If one is found, it will
+	//		use it instead of the basic comparator, which is typically used for strings, ints, booleans, and dates.
+	//		Returns the sorting function for this particular list of attributes and sorting directions.
+	//
+	//	sortSpec: array
+	//		A JS object that array that defines out what attribute names to sort on and whether it should be descenting or asending.
+	//		The objects should be formatted as follows:
+	//		{
+	//			attribute: "attributeName-string" || attribute,
+	//			descending: true|false;   // Default is false.
+	//		}
+	//	store: object
+	//		The datastore object to look up item values from.
+	//
+	var sortFunctions=[];
+
+	function createSortFunction(attr, dir, comp, s){
+		//Passing in comp and s (comparator and store), makes this
+		//function much faster.
+		return function(itemA, itemB){
+			var a = s.getValue(itemA, attr);
+			var b = s.getValue(itemB, attr);
+			return dir * comp(a,b); //int
+		};
+	}
+	var sortAttribute;
+	var map = store.comparatorMap;
+	var bc = dojo.data.util.sorter.basicComparator;
+	for(var i = 0; i < sortSpec.length; i++){
+		sortAttribute = sortSpec[i];
+		var attr = sortAttribute.attribute;
+		if(attr){
+			var dir = (sortAttribute.descending) ? -1 : 1;
+			var comp = bc;
+			if(map){
+				if(typeof attr !== "string" && ("toString" in attr)){
+					 attr = attr.toString();
+				}
+				comp = map[attr] || bc;
+			}
+			sortFunctions.push(createSortFunction(attr, 
+				dir, comp, store));
+		}
+	}
+	return function(rowA, rowB){
+		var i=0;
+		while(i < sortFunctions.length){
+			var ret = sortFunctions[i++](rowA, rowB);
+			if(ret !== 0){
+				return ret;//int
+			}
+		}
+		return 0; //int  
+	}; // Function
 };
+
 }
-- 
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