update trimLeft & trimRight for better performance

Author: Keyang

src/ProcessorLocal.ts

@@ -3,12 +3,14 @@ import P from "bluebird";
 import { prepareData } from "./dataClean";
 import getEol from "./getEol";
 import { stringToLines } from "./fileline";
-import { bufFromString, filterArray } from "./util";
+import { bufFromString, filterArray,trimLeft } from "./util";
 import { RowSplit } from "./rowSplit";
 import lineToJson from "./lineToJson";
 import { ParseRuntime } from "./ParseRuntime";
 import CSVError from "./CSVError";
 
+
+
 export class ProcessorLocal extends Processor {
   flush(): P<ProcessLineResult[]> {
     if (this.runtime.csvLineBuffer && this.runtime.csvLineBuffer.length > 0) {
@@ -83,7 +85,7 @@ export class ProcessorLocal extends Processor {
     }
     // trim csv file has initial blank lines.
     if (params.ignoreEmpty && !runtime.started) {
-      csv = csv.replace(/^\s+/, "");
+      csv = trimLeft(csv);
     }
     const stringToLineResult = stringToLines(csv, runtime);
     if (!finalChunk) {

src/rowSplit.ts

@@ -2,7 +2,7 @@ import { CSVParseParam } from "./Parameters";
 import { Converter } from "./Converter";
 import { Fileline } from "./fileline";
 import getEol from "./getEol";
-import { filterArray } from "./util";
+import { filterArray,trimLeft,trimRight } from "./util";
 
 const defaulDelimiters = [",", "|", "\t", ";", ":"];
 export class RowSplit {
@@ -59,7 +59,7 @@ export class RowSplit {
     for (let i = 0, rowLen = rowArr.length; i < rowLen; i++) {
       let e = rowArr[i];
       if (!inquote && trim) {
-        e = e.replace(/^\s+/, "");
+        e = trimLeft(e);
       }
       const len = e.length;
       if (!inquote) {
@@ -80,7 +80,7 @@ export class RowSplit {
           }
         } else {
           if (trim) {
-            e = e.replace(/\s+$/, "");
+            e = trimRight(e);
           }
           row.push(e);
           continue;
@@ -92,7 +92,7 @@ export class RowSplit {
           quoteBuff += delimiter + e;
           quoteBuff = this.escapeQuote(quoteBuff);
           if (trim) {
-            quoteBuff = quoteBuff.replace(/\s+$/, "");
+            quoteBuff = trimRight(quoteBuff);
           }
           row.push(quoteBuff);
           quoteBuff = "";
@@ -139,7 +139,7 @@ export class RowSplit {
     const quote = this.quote;
     const escape = this.escape;
     if (this.conv.parseParam.trim) {
-      str = str.replace(/\s+$/, "");
+      str = trimRight(str);
     }
     let count = 0;
     let idx = str.length - 1;

src/util.ts

@@ -22,4 +22,16 @@ export function filterArray(arr: any[], filter: number[]): any[] {
     }
   }
   return rtn;
-}
+}
+
+export const trimLeft=String.prototype.trimLeft?function trimLeftNative(str:string){
+  return str.trimLeft();
+}:function trimLeftRegExp(str:string){
+  return str.replace(/^\s+/, "");
+}
+
+export const trimRight=String.prototype.trimRight?function trimRightNative(str:string){
+  return str.trimRight();
+}:function trimRightRegExp(str:string){
+  return str.replace(/\s+$/, "");
+}

v2/ProcessorLocal.js

@@ -2,3 +2,5 @@
 export declare function bufFromString(str: string): Buffer;
 export declare function emptyBuffer(): Buffer;
 export declare function filterArray(arr: any[], filter: number[]): any[];
+export declare const trimLeft: (str: string) => string;
+export declare const trimRight: (str: string) => string;