add generic functions for (u)int ops - copied from node commit 83d7d9e

diff --git a/index.js b/index.js
index ebe1406694bc4b5cf74a92ab1252f1ada2958a98..7e24fcaa6a2e193c7e1ccf7e83a55e33a0076071 100644 (file)
--- a/index.js
+++ b/index.js
@@ -544,6 +544,35 @@ function checkOffset (offset, ext, length) {
     throw new RangeError('Trying to access beyond buffer length')
 }
 
+Buffer.prototype.readUIntLE = function(offset, byteLength, noAssert) {
+  offset = offset >>> 0
+  byteLength = byteLength >>> 0
+  if (!noAssert)
+    checkOffset(offset, byteLength, this.length)
+
+  var val = this[offset]
+  var mul = 1
+  var i = 0
+  while (++i < byteLength && (mul *= 0x100))
+    val += this[offset + i] * mul
+
+  return val
+}
+
+Buffer.prototype.readUIntBE = function(offset, byteLength, noAssert) {
+  offset = offset >>> 0
+  byteLength = byteLength >>> 0
+  if (!noAssert)
+    checkOffset(offset, byteLength, this.length)
+
+  var val = this[offset + --byteLength]
+  var mul = 1
+  while (byteLength > 0 && (mul *= 0x100))
+    val += this[offset + --byteLength] * mul;
+
+  return val
+}
+
 Buffer.prototype.readUInt8 = function (offset, noAssert) {
   if (!noAssert)
     checkOffset(offset, 1, this.length)
@@ -582,6 +611,44 @@ Buffer.prototype.readUInt32BE = function (offset, noAssert) {
       this[offset + 3])
 }
 
+Buffer.prototype.readIntLE = function(offset, byteLength, noAssert) {
+  offset = offset >>> 0
+  byteLength = byteLength >>> 0
+  if (!noAssert)
+    checkOffset(offset, byteLength, this.length)
+
+  var val = this[offset]
+  var mul = 1
+  var i = 0
+  while (++i < byteLength && (mul *= 0x100))
+    val += this[offset + i] * mul
+  mul *= 0x80
+
+  if (val >= mul)
+    val -= Math.pow(2, 8 * byteLength)
+
+  return val
+}
+
+Buffer.prototype.readIntBE = function(offset, byteLength, noAssert) {
+  offset = offset >>> 0
+  byteLength = byteLength >>> 0
+  if (!noAssert)
+    checkOffset(offset, byteLength, this.length)
+
+  var i = byteLength
+  var mul = 1
+  var val = this[offset + --i]
+  while (i > 0 && (mul *= 0x100))
+    val += this[offset + --i] * mul
+  mul *= 0x80
+
+  if (val >= mul)
+    val -= Math.pow(2, 8 * byteLength)
+
+  return val
+}
+
 Buffer.prototype.readInt8 = function (offset, noAssert) {
   if (!noAssert)
     checkOffset(offset, 1, this.length)
@@ -654,6 +721,38 @@ function checkInt (buf, value, offset, ext, max, min) {
   if (offset + ext > buf.length) throw new RangeError('index out of range')
 }
 
+Buffer.prototype.writeUIntLE = function(value, offset, byteLength, noAssert) {
+  value = +value
+  offset = offset >>> 0
+  byteLength = byteLength >>> 0
+  if (!noAssert)
+    checkInt(this, value, offset, byteLength, Math.pow(2, 8 * byteLength), 0)
+
+  var mul = 1
+  var i = 0
+  this[offset] = value
+  while (++i < byteLength && (mul *= 0x100))
+    this[offset + i] = (value / mul) >>> 0
+
+  return offset + byteLength
+}
+
+Buffer.prototype.writeUIntBE = function(value, offset, byteLength, noAssert) {
+  value = +value
+  offset = offset >>> 0
+  byteLength = byteLength >>> 0
+  if (!noAssert)
+    checkInt(this, value, offset, byteLength, Math.pow(2, 8 * byteLength), 0)
+
+  var i = byteLength - 1
+  var mul = 1
+  this[offset + i] = value
+  while (--i >= 0 && (mul *= 0x100))
+    this[offset + i] = (value / mul) >>> 0
+
+  return offset + byteLength
+}
+
 Buffer.prototype.writeUInt8 = function (value, offset, noAssert) {
   value = +value
   offset = offset >>> 0
@@ -731,6 +830,50 @@ Buffer.prototype.writeUInt32BE = function (value, offset, noAssert) {
   return offset + 4
 }
 
+Buffer.prototype.writeIntLE = function(value, offset, byteLength, noAssert) {
+  value = +value
+  offset = offset >>> 0
+  if (!noAssert) {
+    checkInt(this,
+             value,
+             offset,
+             byteLength,
+             Math.pow(2, 8 * byteLength - 1) - 1,
+             -Math.pow(2, 8 * byteLength - 1))
+  }
+
+  var i = 0
+  var mul = 1
+  var sub = value < 0 ? 1 : 0
+  this[offset] = value
+  while (++i < byteLength && (mul *= 0x100))
+    this[offset + i] = ((value / mul) >> 0) - sub
+
+  return offset + byteLength
+}
+
+Buffer.prototype.writeIntBE = function(value, offset, byteLength, noAssert) {
+  value = +value
+  offset = offset >>> 0
+  if (!noAssert) {
+    checkInt(this,
+             value,
+             offset,
+             byteLength,
+             Math.pow(2, 8 * byteLength - 1) - 1,
+             -Math.pow(2, 8 * byteLength - 1))
+  }
+
+  var i = byteLength - 1
+  var mul = 1
+  var sub = value < 0 ? 1 : 0
+  this[offset + i] = value
+  while (--i >= 0 && (mul *= 0x100))
+    this[offset + i] = ((value / mul) >> 0) - sub
+
+  return offset + byteLength
+}
+
 Buffer.prototype.writeInt8 = function (value, offset, noAssert) {
   value = +value
   offset = offset >>> 0
@@ -949,11 +1092,15 @@ Buffer._augment = function (arr) {
   arr.compare = BP.compare
   arr.copy = BP.copy
   arr.slice = BP.slice
+  arr.readUIntLE = BP.readUIntLE
+  arr.readUIntBE = BP.readUIntBE
   arr.readUInt8 = BP.readUInt8
   arr.readUInt16LE = BP.readUInt16LE
   arr.readUInt16BE = BP.readUInt16BE
   arr.readUInt32LE = BP.readUInt32LE
   arr.readUInt32BE = BP.readUInt32BE
+  arr.readIntLE = BP.readIntLE
+  arr.readIntBE = BP.readIntBE
   arr.readInt8 = BP.readInt8
   arr.readInt16LE = BP.readInt16LE
   arr.readInt16BE = BP.readInt16BE
@@ -964,10 +1111,14 @@ Buffer._augment = function (arr) {
   arr.readDoubleLE = BP.readDoubleLE
   arr.readDoubleBE = BP.readDoubleBE
   arr.writeUInt8 = BP.writeUInt8
+  arr.writeUIntLE = BP.writeUIntLE
+  arr.writeUIntBE = BP.writeUIntBE
   arr.writeUInt16LE = BP.writeUInt16LE
   arr.writeUInt16BE = BP.writeUInt16BE
   arr.writeUInt32LE = BP.writeUInt32LE
   arr.writeUInt32BE = BP.writeUInt32BE
+  arr.writeIntLE = BP.writeIntLE
+  arr.writeIntBE = BP.writeIntBE
   arr.writeInt8 = BP.writeInt8
   arr.writeInt16LE = BP.writeInt16LE
   arr.writeInt16BE = BP.writeInt16BE