buffer: use a default offset

If none is provided, use zero as a default offset for all read/write
operations on the buffer.

PR-URL: https://github.com/nodejs/node/pull/19749
Refs: https://github.com/nodejs/node/pull/18395
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

1 files changed, 55 insertions, 53 deletions

diff --git a/lib/internal/buffer.js b/lib/internal/buffer.js
index 2c65194bfa..59ee776250 100644
--- a/lib/internal/buffer.js
+++ b/lib/internal/buffer.js
@@ -19,7 +19,9 @@ const float64Array = new Float64Array(1);
 const uInt8Float64Array = new Uint8Array(float64Array.buffer);
 
 // Check endianness.
-float32Array[0] = -1;
+float32Array[0] = -1; // 0xBF800000
+// Either it is [0, 0, 128, 191] or [191, 128, 0, 0]. It is not possible to
+// check this with `os.endianness()` because that is determined at compile time.
 const bigEndian = uInt8Float32Array[3] === 0;
 
 function checkBounds(buf, offset, byteLength) {
@@ -67,13 +69,13 @@ function readUIntLE(offset, byteLength) {
     return this.readUInt32LE(offset);
   if (byteLength === 2)
     return this.readUInt16LE(offset);
-  if (byteLength === 1)
+  if (byteLength === 1 || byteLength === undefined)
     return this.readUInt8(offset);
 
   boundsError(byteLength, 6, 'byteLength');
 }
 
-function readUInt48LE(buf, offset) {
+function readUInt48LE(buf, offset = 0) {
   checkNumberType(offset);
   const first = buf[offset];
   const last = buf[offset + 5];
@@ -87,7 +89,7 @@ function readUInt48LE(buf, offset) {
     (buf[++offset] + last * 2 ** 8) * 2 ** 32;
 }
 
-function readUInt40LE(buf, offset) {
+function readUInt40LE(buf, offset = 0) {
   checkNumberType(offset);
   const first = buf[offset];
   const last = buf[offset + 4];
@@ -101,7 +103,7 @@ function readUInt40LE(buf, offset) {
     last * 2 ** 32;
 }
 
-function readUInt32LE(offset) {
+function readUInt32LE(offset = 0) {
   checkNumberType(offset);
   const first = this[offset];
   const last = this[offset + 3];
@@ -114,7 +116,7 @@ function readUInt32LE(offset) {
     last * 2 ** 24;
 }
 
-function readUInt24LE(buf, offset) {
+function readUInt24LE(buf, offset = 0) {
   checkNumberType(offset);
   const first = buf[offset];
   const last = buf[offset + 2];
@@ -124,7 +126,7 @@ function readUInt24LE(buf, offset) {
   return first + buf[++offset] * 2 ** 8 + last * 2 ** 16;
 }
 
-function readUInt16LE(offset) {
+function readUInt16LE(offset = 0) {
   checkNumberType(offset);
   const first = this[offset];
   const last = this[offset + 1];
@@ -134,7 +136,7 @@ function readUInt16LE(offset) {
   return first + last * 2 ** 8;
 }
 
-function readUInt8(offset) {
+function readUInt8(offset = 0) {
   checkNumberType(offset);
   const val = this[offset];
   if (val === undefined)
@@ -154,13 +156,13 @@ function readUIntBE(offset, byteLength) {
     return this.readUInt32BE(offset);
   if (byteLength === 2)
     return this.readUInt16BE(offset);
-  if (byteLength === 1)
+  if (byteLength === 1 || byteLength === undefined)
     return this.readUInt8(offset);
 
   boundsError(byteLength, 6, 'byteLength');
 }
 
-function readUInt48BE(buf, offset) {
+function readUInt48BE(buf, offset = 0) {
   checkNumberType(offset);
   const first = buf[offset];
   const last = buf[offset + 5];
@@ -174,7 +176,7 @@ function readUInt48BE(buf, offset) {
     last;
 }
 
-function readUInt40BE(buf, offset) {
+function readUInt40BE(buf, offset = 0) {
   checkNumberType(offset);
   const first = buf[offset];
   const last = buf[offset + 4];
@@ -188,7 +190,7 @@ function readUInt40BE(buf, offset) {
     last;
 }
 
-function readUInt32BE(offset) {
+function readUInt32BE(offset = 0) {
   checkNumberType(offset);
   const first = this[offset];
   const last = this[offset + 3];
@@ -201,7 +203,7 @@ function readUInt32BE(offset) {
     last;
 }
 
-function readUInt24BE(buf, offset) {
+function readUInt24BE(buf, offset = 0) {
   checkNumberType(offset);
   const first = buf[offset];
   const last = buf[offset + 2];
@@ -211,7 +213,7 @@ function readUInt24BE(buf, offset) {
   return first * 2 ** 16 + buf[++offset] * 2 ** 8 + last;
 }
 
-function readUInt16BE(offset) {
+function readUInt16BE(offset = 0) {
   checkNumberType(offset);
   const first = this[offset];
   const last = this[offset + 1];
@@ -232,13 +234,13 @@ function readIntLE(offset, byteLength) {
     return this.readInt32LE(offset);
   if (byteLength === 2)
     return this.readInt16LE(offset);
-  if (byteLength === 1)
+  if (byteLength === 1 || byteLength === undefined)
     return this.readInt8(offset);
 
   boundsError(byteLength, 6, 'byteLength');
 }
 
-function readInt48LE(buf, offset) {
+function readInt48LE(buf, offset = 0) {
   checkNumberType(offset);
   const first = buf[offset];
   const last = buf[offset + 5];
@@ -253,7 +255,7 @@ function readInt48LE(buf, offset) {
     buf[++offset] * 2 ** 24;
 }
 
-function readInt40LE(buf, offset) {
+function readInt40LE(buf, offset = 0) {
   checkNumberType(offset);
   const first = buf[offset];
   const last = buf[offset + 4];
@@ -267,7 +269,7 @@ function readInt40LE(buf, offset) {
     buf[++offset] * 2 ** 24;
 }
 
-function readInt32LE(offset) {
+function readInt32LE(offset = 0) {
   checkNumberType(offset);
   const first = this[offset];
   const last = this[offset + 3];
@@ -280,7 +282,7 @@ function readInt32LE(offset) {
     (last << 24); // Overflow
 }
 
-function readInt24LE(buf, offset) {
+function readInt24LE(buf, offset = 0) {
   checkNumberType(offset);
   const first = buf[offset];
   const last = buf[offset + 2];
@@ -291,7 +293,7 @@ function readInt24LE(buf, offset) {
   return val | (val & 2 ** 23) * 0x1fe;
 }
 
-function readInt16LE(offset) {
+function readInt16LE(offset = 0) {
   checkNumberType(offset);
   const first = this[offset];
   const last = this[offset + 1];
@@ -302,7 +304,7 @@ function readInt16LE(offset) {
   return val | (val & 2 ** 15) * 0x1fffe;
 }
 
-function readInt8(offset) {
+function readInt8(offset = 0) {
   checkNumberType(offset);
   const val = this[offset];
   if (val === undefined)
@@ -322,13 +324,13 @@ function readIntBE(offset, byteLength) {
     return this.readInt32BE(offset);
   if (byteLength === 2)
     return this.readInt16BE(offset);
-  if (byteLength === 1)
+  if (byteLength === 1 || byteLength === undefined)
     return this.readInt8(offset);
 
   boundsError(byteLength, 6, 'byteLength');
 }
 
-function readInt48BE(buf, offset) {
+function readInt48BE(buf, offset = 0) {
   checkNumberType(offset);
   const first = buf[offset];
   const last = buf[offset + 5];
@@ -343,7 +345,7 @@ function readInt48BE(buf, offset) {
     last;
 }
 
-function readInt40BE(buf, offset) {
+function readInt40BE(buf, offset = 0) {
   checkNumberType(offset);
   const first = buf[offset];
   const last = buf[offset + 4];
@@ -357,7 +359,7 @@ function readInt40BE(buf, offset) {
     last;
 }
 
-function readInt32BE(offset) {
+function readInt32BE(offset = 0) {
   checkNumberType(offset);
   const first = this[offset];
   const last = this[offset + 3];
@@ -370,7 +372,7 @@ function readInt32BE(offset) {
     last;
 }
 
-function readInt24BE(buf, offset) {
+function readInt24BE(buf, offset = 0) {
   checkNumberType(offset);
   const first = buf[offset];
   const last = buf[offset + 2];
@@ -381,7 +383,7 @@ function readInt24BE(buf, offset) {
   return val | (val & 2 ** 23) * 0x1fe;
 }
 
-function readInt16BE(offset) {
+function readInt16BE(offset = 0) {
   checkNumberType(offset);
   const first = this[offset];
   const last = this[offset + 1];
@@ -393,7 +395,7 @@ function readInt16BE(offset) {
 }
 
 // Read floats
-function readFloatBackwards(offset) {
+function readFloatBackwards(offset = 0) {
   checkNumberType(offset);
   const first = this[offset];
   const last = this[offset + 3];
@@ -407,7 +409,7 @@ function readFloatBackwards(offset) {
   return float32Array[0];
 }
 
-function readFloatForwards(offset) {
+function readFloatForwards(offset = 0) {
   checkNumberType(offset);
   const first = this[offset];
   const last = this[offset + 3];
@@ -421,7 +423,7 @@ function readFloatForwards(offset) {
   return float32Array[0];
 }
 
-function readDoubleBackwards(offset) {
+function readDoubleBackwards(offset = 0) {
   checkNumberType(offset);
   const first = this[offset];
   const last = this[offset + 7];
@@ -439,7 +441,7 @@ function readDoubleBackwards(offset) {
   return float64Array[0];
 }
 
-function readDoubleForwards(offset) {
+function readDoubleForwards(offset = 0) {
   checkNumberType(offset);
   const first = this[offset];
   const last = this[offset + 7];
@@ -458,7 +460,7 @@ function readDoubleForwards(offset) {
 }
 
 // Write integers.
-function writeUIntLE(value, offset, byteLength) {
+function writeUIntLE(value, offset = 0, byteLength) {
   if (byteLength === 6)
     return writeU_Int48LE(this, value, offset, 0, 0xffffffffffff);
   if (byteLength === 5)
@@ -469,7 +471,7 @@ function writeUIntLE(value, offset, byteLength) {
     return writeU_Int32LE(this, value, offset, 0, 0xffffffff);
   if (byteLength === 2)
     return writeU_Int16LE(this, value, offset, 0, 0xffff);
-  if (byteLength === 1)
+  if (byteLength === 1 || byteLength === undefined)
     return writeU_Int8(this, value, offset, 0, 0xff);
 
   boundsError(byteLength, 6, 'byteLength');
@@ -522,7 +524,7 @@ function writeU_Int32LE(buf, value, offset, min, max) {
   return offset;
 }
 
-function writeUInt32LE(value, offset) {
+function writeUInt32LE(value, offset = 0) {
   return writeU_Int32LE(this, value, offset, 0, 0xffffffff);
 }
 
@@ -547,7 +549,7 @@ function writeU_Int16LE(buf, value, offset, min, max) {
   return offset;
 }
 
-function writeUInt16LE(value, offset) {
+function writeUInt16LE(value, offset = 0) {
   return writeU_Int16LE(this, value, offset, 0, 0xffff);
 }
 
@@ -565,11 +567,11 @@ function writeU_Int8(buf, value, offset, min, max) {
   return offset + 1;
 }
 
-function writeUInt8(value, offset) {
+function writeUInt8(value, offset = 0) {
   return writeU_Int8(this, value, offset, 0, 0xff);
 }
 
-function writeUIntBE(value, offset, byteLength) {
+function writeUIntBE(value, offset = 0, byteLength) {
   if (byteLength === 6)
     return writeU_Int48BE(this, value, offset, 0, 0xffffffffffffff);
   if (byteLength === 5)
@@ -580,7 +582,7 @@ function writeUIntBE(value, offset, byteLength) {
     return writeU_Int32BE(this, value, offset, 0, 0xffffffff);
   if (byteLength === 2)
     return writeU_Int16BE(this, value, offset, 0, 0xffff);
-  if (byteLength === 1)
+  if (byteLength === 1 || byteLength === undefined)
     return writeU_Int8(this, value, offset, 0, 0xff);
 
   boundsError(byteLength, 6, 'byteLength');
@@ -632,7 +634,7 @@ function writeU_Int32BE(buf, value, offset, min, max) {
   return offset + 4;
 }
 
-function writeUInt32BE(value, offset) {
+function writeUInt32BE(value, offset = 0) {
   return writeU_Int32BE(this, value, offset, 0, 0xffffffff);
 }
 
@@ -657,11 +659,11 @@ function writeU_Int16BE(buf, value, offset, min, max) {
   return offset;
 }
 
-function writeUInt16BE(value, offset) {
+function writeUInt16BE(value, offset = 0) {
   return writeU_Int16BE(this, value, offset, 0, 0xffffffff);
 }
 
-function writeIntLE(value, offset, byteLength) {
+function writeIntLE(value, offset = 0, byteLength) {
   if (byteLength === 6)
     return writeU_Int48LE(this, value, offset, -0x800000000000, 0x7fffffffffff);
   if (byteLength === 5)
@@ -672,25 +674,25 @@ function writeIntLE(value, offset, byteLength) {
     return writeU_Int32LE(this, value, offset, -0x80000000, 0x7fffffff);
   if (byteLength === 2)
     return writeU_Int16LE(this, value, offset, -0x8000, 0x7fff);
-  if (byteLength === 1)
+  if (byteLength === 1 || byteLength === undefined)
     return writeU_Int8(this, value, offset, -0x80, 0x7f);
 
   boundsError(byteLength, 6, 'byteLength');
 }
 
-function writeInt32LE(value, offset) {
+function writeInt32LE(value, offset = 0) {
   return writeU_Int32LE(this, value, offset, -0x80000000, 0x7fffffff);
 }
 
-function writeInt16LE(value, offset) {
+function writeInt16LE(value, offset = 0) {
   return writeU_Int16LE(this, value, offset, -0x8000, 0x7fff);
 }
 
-function writeInt8(value, offset) {
+function writeInt8(value, offset = 0) {
   return writeU_Int8(this, value, offset, -0x80, 0x7f);
 }
 
-function writeIntBE(value, offset, byteLength) {
+function writeIntBE(value, offset = 0, byteLength) {
   if (byteLength === 6)
     return writeU_Int48BE(this, value, offset, -0x800000000000, 0x7fffffffffff);
   if (byteLength === 5)
@@ -701,22 +703,22 @@ function writeIntBE(value, offset, byteLength) {
     return writeU_Int32BE(this, value, offset, -0x80000000, 0x7fffffff);
   if (byteLength === 2)
     return writeU_Int16BE(this, value, offset, -0x8000, 0x7fff);
-  if (byteLength === 1)
+  if (byteLength === 1 || byteLength === undefined)
     return writeU_Int8(this, value, offset, -0x80, 0x7f);
 
   boundsError(byteLength, 6, 'byteLength');
 }
 
-function writeInt32BE(value, offset) {
+function writeInt32BE(value, offset = 0) {
   return writeU_Int32BE(this, value, offset, -0x80000000, 0x7fffffff);
 }
 
-function writeInt16BE(value, offset) {
+function writeInt16BE(value, offset = 0) {
   return writeU_Int16BE(this, value, offset, -0x8000, 0x7fff);
 }
 
 // Write floats.
-function writeDoubleForwards(val, offset) {
+function writeDoubleForwards(val, offset = 0) {
   val = +val;
   checkBounds(this, offset, 7);
 
@@ -732,7 +734,7 @@ function writeDoubleForwards(val, offset) {
   return offset;
 }
 
-function writeDoubleBackwards(val, offset) {
+function writeDoubleBackwards(val, offset = 0) {
   val = +val;
   checkBounds(this, offset, 7);
 
@@ -748,7 +750,7 @@ function writeDoubleBackwards(val, offset) {
   return offset;
 }
 
-function writeFloatForwards(val, offset) {
+function writeFloatForwards(val, offset = 0) {
   val = +val;
   checkBounds(this, offset, 3);
 
@@ -760,7 +762,7 @@ function writeFloatForwards(val, offset) {
   return offset;
 }
 
-function writeFloatBackwards(val, offset) {
+function writeFloatBackwards(val, offset = 0) {
   val = +val;
   checkBounds(this, offset, 3);