util: refactor format method.Performance improved.

Method format refactored to make it more maintenable, replacing the switch by a function factory, that returns the appropiated function given the character (d, i , f, j, s). Also, performance when formatting an string that contains several consecutive % symbols is improved. The test: `const numSamples = 10000000; const strPercents = '%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%s%%%%%%%%%%%%%%%%%i%%%%%%%%%%%%%%%%%%%%%%%%%%'; var s; console.time('Percents'); for (let i = 0; i < numSamples; i++){s = util.format(strPercents, 'test', 12)} console.timeEnd('Percents');` Original time: 28399.708ms After refactor: 23763.788ms Improved: 16% PR-URL: #12407 Reviewed-By: Benjamin Gruenbaum <[email protected]> Reviewed-By: Roman Reiss <[email protected]> Reviewed-By: James M Snell <[email protected]> Reviewed-By: Anna Henningsen <[email protected]> Reviewed-By: Brian White <[email protected]>

Author: jesus-seijas-sp

lib/util.js

@@ -68,71 +68,59 @@ exports.format = function(f){
 returnobjects.join(' ');
 }
 
-varargLen=arguments.length;
-
-if(argLen===1)returnf;
+if(arguments.length===1)returnf;
 
 varstr='';
 vara=1;
 varlastPos=0;
 for(vari=0;i<f.length;){
 if(f.charCodeAt(i)===37/*'%'*/&&i+1<f.length){
+if(f.charCodeAt(i+1)!==37/*'%'*/&&a>=arguments.length){
+++i;
+continue;
+}
 switch(f.charCodeAt(i+1)){
 case100: // 'd'
-if(a>=argLen)
-break;
 if(lastPos<i)
 str+=f.slice(lastPos,i);
 str+=Number(arguments[a++]);
-lastPos=i=i+2;
-continue;
+break;
 case105: // 'i'
-if(a>=argLen)
-break;
 if(lastPos<i)
 str+=f.slice(lastPos,i);
 str+=parseInt(arguments[a++]);
-lastPos=i=i+2;
-continue;
+break;
 case102: // 'f'
-if(a>=argLen)
-break;
 if(lastPos<i)
 str+=f.slice(lastPos,i);
 str+=parseFloat(arguments[a++]);
-lastPos=i=i+2;
-continue;
+break;
 case106: // 'j'
-if(a>=argLen)
-break;
 if(lastPos<i)
 str+=f.slice(lastPos,i);
 str+=tryStringify(arguments[a++]);
-lastPos=i=i+2;
-continue;
+break;
 case115: // 's'
-if(a>=argLen)
-break;
 if(lastPos<i)
 str+=f.slice(lastPos,i);
 str+=String(arguments[a++]);
-lastPos=i=i+2;
-continue;
+break;
 case37: // '%'
 if(lastPos<i)
 str+=f.slice(lastPos,i);
 str+='%';
-lastPos=i=i+2;
-continue;
+break;
 }
+lastPos=i=i+2;
+continue;
 }
 ++i;
 }
 if(lastPos===0)
 str=f;
 elseif(lastPos<f.length)
 str+=f.slice(lastPos);
-while(a<argLen){
+while(a<arguments.length){
 constx=arguments[a++];
 if(x===null||(typeofx!=='object'&&typeofx!=='symbol')){
 str+=' '+x;

test/parallel/test-util-format.js

@@ -106,6 +106,8 @@ assert.strictEqual(util.format('%%s%s', 'foo'), '%sfoo');
 assert.strictEqual(util.format('%s:%s'),'%s:%s');
 assert.strictEqual(util.format('%s:%s',undefined),'undefined:%s');
 assert.strictEqual(util.format('%s:%s','foo'),'foo:%s');
+assert.strictEqual(util.format('%s:%i','foo'),'foo:%i');
+assert.strictEqual(util.format('%s:%f','foo'),'foo:%f');
 assert.strictEqual(util.format('%s:%s','foo','bar'),'foo:bar');
 assert.strictEqual(util.format('%s:%s','foo','bar','baz'),'foo:bar baz');
 assert.strictEqual(util.format('%%%s%%','hi'),'%hi%');
@@ -114,6 +116,12 @@ assert.strictEqual(util.format('%sbc%%def', 'a'), 'abc%def');
 assert.strictEqual(util.format('%d:%d',12,30),'12:30');
 assert.strictEqual(util.format('%d:%d',12),'12:%d');
 assert.strictEqual(util.format('%d:%d'),'%d:%d');
+assert.strictEqual(util.format('%i:%i',12,30),'12:30');
+assert.strictEqual(util.format('%i:%i',12),'12:%i');
+assert.strictEqual(util.format('%i:%i'),'%i:%i');
+assert.strictEqual(util.format('%f:%f',12,30),'12:30');
+assert.strictEqual(util.format('%f:%f',12),'12:%f');
+assert.strictEqual(util.format('%f:%f'),'%f:%f');
 assert.strictEqual(util.format('o: %j, a: %j',{},[]),'o:{}, a: []');
 assert.strictEqual(util.format('o: %j, a: %j',{}),'o:{}, a: %j');
 assert.strictEqual(util.format('o: %j, a: %j'),'o: %j, a: %j');