buffer: refactor checks for SlowBuffer creation

Mnwa · addaleax · commit 1d4940888d5f · 2019-01-09T00:50:01.000+01:00
PR-URL: #25266 Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: James M Snell <jasnell@gmail.com>
diff --git a/lib/buffer.js b/lib/buffer.js
@@ -93,7 +93,7 @@ const constants = Object.defineProperties({}, {
 });
 
 Buffer.poolSize = 8 * 1024;
-var poolSize, poolOffset, allocPool;
+let poolSize, poolOffset, allocPool;
 
 setupBufferJS(Buffer.prototype, bindingObj);
 
@@ -212,7 +212,7 @@ Buffer.from = function from(value, encodingOrOffset, length) {
 if (valueOf !== null && valueOf !== undefined && valueOf !== value)
 return Buffer.from(valueOf, encodingOrOffset, length);
 
- var b = fromObject(value);
+ const b = fromObject(value);
 if (b)
 return b;
 
@@ -298,13 +298,10 @@ Buffer.allocUnsafeSlow = function allocUnsafeSlow(size) {
 // If --zero-fill-buffers command line argument is set, a zero-filled
 // buffer is returned.
 function SlowBuffer(length) {
- const len = +length;
- // eslint-disable-next-line eqeqeq
- if (len != length)
- length = 0;
- else
- assertSize(len);
- return createUnsafeBuffer(len);
+ if (typeof length !== 'number')
+ length = +length;
+ assertSize(length);
+ return createUnsafeBuffer(length);
 }
 
 Object.setPrototypeOf(SlowBuffer.prototype, Uint8Array.prototype);
@@ -317,7 +314,7 @@ function allocate(size) {
 if (size < (Buffer.poolSize >>> 1)) {
 if (size > (poolSize - poolOffset))
 createPool();
- var b = new FastBuffer(allocPool, poolOffset, size);
+ const b = new FastBuffer(allocPool, poolOffset, size);
 poolOffset += size;
 alignPool();
 return b;
@@ -326,7 +323,7 @@ function allocate(size) {
 }
 
 function fromString(string, encoding) {
- var length;
+ let length;
 if (typeof encoding !== 'string' || encoding.length === 0) {
 if (string.length === 0)
 return new FastBuffer();
@@ -345,7 +342,7 @@ function fromString(string, encoding) {
 
 if (length > (poolSize - poolOffset))
 createPool();
- var b = new FastBuffer(allocPool, poolOffset, length);
+ let b = new FastBuffer(allocPool, poolOffset, length);
 const actual = b.write(string, encoding);
 if (actual !== length) {
 // byteLength() may overestimate. That's a rare case, though.
@@ -447,7 +444,7 @@ Buffer.isEncoding = function isEncoding(encoding) {
 Buffer[kIsEncodingSymbol] = Buffer.isEncoding;
 
 Buffer.concat = function concat(list, length) {
- var i;
+ let i;
 if (!Array.isArray(list)) {
 throw new ERR_INVALID_ARG_TYPE(
 'list', ['Array', 'Buffer', 'Uint8Array'], list);
@@ -464,10 +461,10 @@ Buffer.concat = function concat(list, length) {
 length = length >>> 0;
 }
 
- var buffer = Buffer.allocUnsafe(length);
- var pos = 0;
+ const buffer = Buffer.allocUnsafe(length);
+ let pos = 0;
 for (i = 0; i < list.length; i++) {
- var buf = list[i];
+ const buf = list[i];
 if (!isUint8Array(buf)) {
 // TODO(BridgeAR): This should not be of type ERR_INVALID_ARG_TYPE.
 // Instead, find the proper error code for this.
@@ -772,7 +769,7 @@ function bidirectionalIndexOf(buffer, val, byteOffset, encoding, dir) {
 }
 
 function slowIndexOf(buffer, val, byteOffset, encoding, dir) {
- var loweredCase = false;
+ let loweredCase = false;
 for (;;) {
 switch (encoding) {
 case 'utf8':
@@ -907,7 +904,7 @@ Buffer.prototype.write = function write(string, offset, length, encoding) {
 length = undefined;
 }
 
- var remaining = this.length - offset;
+ const remaining = this.length - offset;
 if (length === undefined || length > remaining)
 length = remaining;
 

-Original file line number
+Diff line change
 });
 Buffer.poolSize=8*1024;
 -varpoolSize,poolOffset,allocPool;
 +letpoolSize,poolOffset,allocPool;
 setupBufferJS(Buffer.prototype,bindingObj);
 if(valueOf!==null&&valueOf!==undefined&&valueOf!==value)
 returnBuffer.from(valueOf,encodingOrOffset,length);
 -varb=fromObject(value);
 +constb=fromObject(value);
 if(b)
 returnb;
 // If --zero-fill-buffers command line argument is set, a zero-filled
 // buffer is returned.
 functionSlowBuffer(length){
 -constlen=+length;
 -// eslint-disable-next-line eqeqeq
 -if(len!=length)
 -length=0;
 -else
 -assertSize(len);
 -returncreateUnsafeBuffer(len);
 +if(typeoflength!=='number')
 +length=+length;
 +assertSize(length);
 +returncreateUnsafeBuffer(length);
+}
 Object.setPrototypeOf(SlowBuffer.prototype,Uint8Array.prototype);
 if(size<(Buffer.poolSize>>>1)){
 if(size>(poolSize-poolOffset))
 createPool();
 -varb=newFastBuffer(allocPool,poolOffset,size);
 +constb=newFastBuffer(allocPool,poolOffset,size);
 poolOffset+=size;
 alignPool();
 returnb;
+}
 functionfromString(string,encoding){
 -varlength;
 +letlength;
 if(typeofencoding!=='string'||encoding.length===0){
 if(string.length===0)
 returnnewFastBuffer();
 if(length>(poolSize-poolOffset))
 createPool();
 -varb=newFastBuffer(allocPool,poolOffset,length);
 +letb=newFastBuffer(allocPool,poolOffset,length);
 constactual=b.write(string,encoding);
 if(actual!==length){
 // byteLength() may overestimate. That's a rare case, though.
 Buffer[kIsEncodingSymbol]=Buffer.isEncoding;
 Buffer.concat=functionconcat(list,length){
 -vari;
 +leti;
 if(!Array.isArray(list)){
 thrownewERR_INVALID_ARG_TYPE(
 'list',['Array','Buffer','Uint8Array'],list);
 length=length>>>0;
+}
 -varbuffer=Buffer.allocUnsafe(length);
 -varpos=0;
 +constbuffer=Buffer.allocUnsafe(length);
 +letpos=0;
 for(i=0;i<list.length;i++){
 -varbuf=list[i];
 +constbuf=list[i];
 if(!isUint8Array(buf)){
 // TODO(BridgeAR): This should not be of type ERR_INVALID_ARG_TYPE.
 // Instead, find the proper error code for this.
+}
 functionslowIndexOf(buffer,val,byteOffset,encoding,dir){
 -varloweredCase=false;
 +letloweredCase=false;
 for(;;){
 switch(encoding){
 case'utf8':
 length=undefined;
+}
 -varremaining=this.length-offset;
 +constremaining=this.length-offset;
 if(length===undefined||length>remaining)
 length=remaining;