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buffer-es6.mjs
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buffer-es6.mjs
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var lookup = [];
var revLookup = [];
var Arr = typeof Uint8Array !== 'undefined' ? Uint8Array : Array;
var inited = false;
function init() {
inited = true;
var code = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
for (var i = 0, len = code.length; i < len; ++i) {
lookup[i] = code[i];
revLookup[code.charCodeAt(i)] = i;
}
revLookup['-'.charCodeAt(0)] = 62;
revLookup['_'.charCodeAt(0)] = 63;
}
function toByteArray(b64) {
if (!inited) {
init();
}
var i, j, l, tmp, placeHolders, arr;
var len = b64.length;
if (len % 4 > 0) {
throw new Error('Invalid string. Length must be a multiple of 4');
}
// the number of equal signs (place holders)
// if there are two placeholders, than the two characters before it
// represent one byte
// if there is only one, then the three characters before it represent 2 bytes
// this is just a cheap hack to not do indexOf twice
placeHolders = b64[len - 2] === '=' ? 2 : b64[len - 1] === '=' ? 1 : 0;
// base64 is 4/3 + up to two characters of the original data
arr = new Arr((len * 3) / 4 - placeHolders);
// if there are placeholders, only get up to the last complete 4 chars
l = placeHolders > 0 ? len - 4 : len;
var L = 0;
for (i = 0, j = 0; i < l; i += 4, j += 3) {
tmp =
(revLookup[b64.charCodeAt(i)] << 18) |
(revLookup[b64.charCodeAt(i + 1)] << 12) |
(revLookup[b64.charCodeAt(i + 2)] << 6) |
revLookup[b64.charCodeAt(i + 3)];
arr[L++] = (tmp >> 16) & 0xff;
arr[L++] = (tmp >> 8) & 0xff;
arr[L++] = tmp & 0xff;
}
if (placeHolders === 2) {
tmp =
(revLookup[b64.charCodeAt(i)] << 2) |
(revLookup[b64.charCodeAt(i + 1)] >> 4);
arr[L++] = tmp & 0xff;
} else if (placeHolders === 1) {
tmp =
(revLookup[b64.charCodeAt(i)] << 10) |
(revLookup[b64.charCodeAt(i + 1)] << 4) |
(revLookup[b64.charCodeAt(i + 2)] >> 2);
arr[L++] = (tmp >> 8) & 0xff;
arr[L++] = tmp & 0xff;
}
return arr;
}
function tripletToBase64(num) {
return (
lookup[(num >> 18) & 0x3f] +
lookup[(num >> 12) & 0x3f] +
lookup[(num >> 6) & 0x3f] +
lookup[num & 0x3f]
);
}
function encodeChunk(uint8, start, end) {
var tmp;
var output = [];
for (var i = start; i < end; i += 3) {
tmp = (uint8[i] << 16) + (uint8[i + 1] << 8) + uint8[i + 2];
output.push(tripletToBase64(tmp));
}
return output.join('');
}
function fromByteArray(uint8) {
if (!inited) {
init();
}
var tmp;
var len = uint8.length;
var extraBytes = len % 3; // if we have 1 byte left, pad 2 bytes
var output = '';
var parts = [];
var maxChunkLength = 16383; // must be multiple of 3
// go through the array every three bytes, we'll deal with trailing stuff later
for (var i = 0, len2 = len - extraBytes; i < len2; i += maxChunkLength) {
parts.push(
encodeChunk(
uint8,
i,
i + maxChunkLength > len2 ? len2 : i + maxChunkLength
)
);
}
// pad the end with zeros, but make sure to not forget the extra bytes
if (extraBytes === 1) {
tmp = uint8[len - 1];
output += lookup[tmp >> 2];
output += lookup[(tmp << 4) & 0x3f];
output += '==';
} else if (extraBytes === 2) {
tmp = (uint8[len - 2] << 8) + uint8[len - 1];
output += lookup[tmp >> 10];
output += lookup[(tmp >> 4) & 0x3f];
output += lookup[(tmp << 2) & 0x3f];
output += '=';
}
parts.push(output);
return parts.join('');
}
function read(buffer, offset, isLE, mLen, nBytes) {
var e, m;
var eLen = nBytes * 8 - mLen - 1;
var eMax = (1 << eLen) - 1;
var eBias = eMax >> 1;
var nBits = -7;
var i = isLE ? nBytes - 1 : 0;
var d = isLE ? -1 : 1;
var s = buffer[offset + i];
i += d;
e = s & ((1 << -nBits) - 1);
s >>= -nBits;
nBits += eLen;
for (; nBits > 0; e = e * 256 + buffer[offset + i], i += d, nBits -= 8) {}
m = e & ((1 << -nBits) - 1);
e >>= -nBits;
nBits += mLen;
for (; nBits > 0; m = m * 256 + buffer[offset + i], i += d, nBits -= 8) {}
if (e === 0) {
e = 1 - eBias;
} else if (e === eMax) {
return m ? NaN : (s ? -1 : 1) * Infinity;
} else {
m = m + Math.pow(2, mLen);
e = e - eBias;
}
return (s ? -1 : 1) * m * Math.pow(2, e - mLen);
}
function write(buffer, value, offset, isLE, mLen, nBytes) {
var e, m, c;
var eLen = nBytes * 8 - mLen - 1;
var eMax = (1 << eLen) - 1;
var eBias = eMax >> 1;
var rt = mLen === 23 ? Math.pow(2, -24) - Math.pow(2, -77) : 0;
var i = isLE ? 0 : nBytes - 1;
var d = isLE ? 1 : -1;
var s = value < 0 || (value === 0 && 1 / value < 0) ? 1 : 0;
value = Math.abs(value);
if (isNaN(value) || value === Infinity) {
m = isNaN(value) ? 1 : 0;
e = eMax;
} else {
e = Math.floor(Math.log(value) / Math.LN2);
if (value * (c = Math.pow(2, -e)) < 1) {
e--;
c *= 2;
}
if (e + eBias >= 1) {
value += rt / c;
} else {
value += rt * Math.pow(2, 1 - eBias);
}
if (value * c >= 2) {
e++;
c /= 2;
}
if (e + eBias >= eMax) {
m = 0;
e = eMax;
} else if (e + eBias >= 1) {
m = (value * c - 1) * Math.pow(2, mLen);
e = e + eBias;
} else {
m = value * Math.pow(2, eBias - 1) * Math.pow(2, mLen);
e = 0;
}
}
for (
;
mLen >= 8;
buffer[offset + i] = m & 0xff, i += d, m /= 256, mLen -= 8
) {}
e = (e << mLen) | m;
eLen += mLen;
for (
;
eLen > 0;
buffer[offset + i] = e & 0xff, i += d, e /= 256, eLen -= 8
) {}
buffer[offset + i - d] |= s * 128;
}
var toString = {}.toString;
var isArray =
Array.isArray ||
function (arr) {
return toString.call(arr) == '[object Array]';
};
/*!
* The buffer module from node.js, for the browser.
*
* @author Feross Aboukhadijeh <feross@feross.org> <http://feross.org>
* @license MIT
*/
export var INSPECT_MAX_BYTES = 50;
/**
* If `Buffer.TYPED_ARRAY_SUPPORT`:
* === true Use Uint8Array implementation (fastest)
* === false Use Object implementation (most compatible, even IE6)
*
* Browsers that support typed arrays are IE 10+, Firefox 4+, Chrome 7+, Safari 5.1+,
* Opera 11.6+, iOS 4.2+.
*
* Due to various browser bugs, sometimes the Object implementation will be used even
* when the browser supports typed arrays.
*
* Note:
*
* - Firefox 4-29 lacks support for adding new properties to `Uint8Array` instances,
* See: https://bugzilla.mozilla.org/show_bug.cgi?id=695438.
*
* - Chrome 9-10 is missing the `TypedArray.prototype.subarray` function.
*
* - IE10 has a broken `TypedArray.prototype.subarray` function which returns arrays of
* incorrect length in some situations.
* We detect these buggy browsers and set `Buffer.TYPED_ARRAY_SUPPORT` to `false` so they
* get the Object implementation, which is slower but behaves correctly.
*/
const win = typeof window === 'undefined' ? global : window;
Buffer.TYPED_ARRAY_SUPPORT =
win.TYPED_ARRAY_SUPPORT !== undefined ? win.TYPED_ARRAY_SUPPORT : true;
/*
* Export kMaxLength after typed array support is determined.
*/
var _kMaxLength = getKMaxLength();
export const kMaxLength = _kMaxLength;
function getKMaxLength() {
return Buffer.TYPED_ARRAY_SUPPORT ? 0x7fffffff : 0x3fffffff;
}
function createBuffer(that, length) {
if (getKMaxLength() < length) {
throw new RangeError('Invalid typed array length');
}
if (Buffer.TYPED_ARRAY_SUPPORT) {
// Return an augmented `Uint8Array` instance, for best performance
that = new Uint8Array(length);
that.__proto__ = Buffer.prototype;
} else {
// Fallback: Return an object instance of the Buffer class
if (that === null) {
that = new Buffer(length);
}
that.length = length;
}
return that;
}
/**
* The Buffer constructor returns instances of `Uint8Array` that have their
* prototype changed to `Buffer.prototype`. Furthermore, `Buffer` is a subclass of
* `Uint8Array`, so the returned instances will have all the node `Buffer` methods
* and the `Uint8Array` methods. Square bracket notation works as expected -- it
* returns a single octet.
*
* The `Uint8Array` prototype remains unmodified.
*/
export function Buffer(arg, encodingOrOffset, length) {
if (!Buffer.TYPED_ARRAY_SUPPORT && !(this instanceof Buffer)) {
return new Buffer(arg, encodingOrOffset, length);
}
// Common case.
if (typeof arg === 'number') {
if (typeof encodingOrOffset === 'string') {
throw new Error(
'If encoding is specified then the first argument must be a string'
);
}
return allocUnsafe(this, arg);
}
return from(this, arg, encodingOrOffset, length);
}
Buffer.poolSize = 8192; // not used by this implementation
// TODO: Legacy, not needed anymore. Remove in next major version.
Buffer._augment = function (arr) {
arr.__proto__ = Buffer.prototype;
return arr;
};
function from(that, value, encodingOrOffset, length) {
if (typeof value === 'number') {
throw new TypeError('"value" argument must not be a number');
}
if (typeof ArrayBuffer !== 'undefined' && value instanceof ArrayBuffer) {
return fromArrayBuffer(that, value, encodingOrOffset, length);
}
if (typeof value === 'string') {
return fromString(that, value, encodingOrOffset);
}
return fromObject(that, value);
}
/**
* Functionally equivalent to Buffer(arg, encoding) but throws a TypeError
* if value is a number.
* Buffer.from(str[, encoding])
* Buffer.from(array)
* Buffer.from(buffer)
* Buffer.from(arrayBuffer[, byteOffset[, length]])
**/
Buffer.from = function (value, encodingOrOffset, length) {
return from(null, value, encodingOrOffset, length);
};
if (Buffer.TYPED_ARRAY_SUPPORT) {
Buffer.prototype.__proto__ = Uint8Array.prototype;
Buffer.__proto__ = Uint8Array;
}
function assertSize(size) {
if (typeof size !== 'number') {
throw new TypeError('"size" argument must be a number');
} else if (size < 0) {
throw new RangeError('"size" argument must not be negative');
}
}
function alloc(that, size, fill, encoding) {
assertSize(size);
if (size <= 0) {
return createBuffer(that, size);
}
if (fill !== undefined) {
// Only pay attention to encoding if it's a string. This
// prevents accidentally sending in a number that would
// be interpretted as a start offset.
return typeof encoding === 'string'
? createBuffer(that, size).fill(fill, encoding)
: createBuffer(that, size).fill(fill);
}
return createBuffer(that, size);
}
/**
* Creates a new filled Buffer instance.
* alloc(size[, fill[, encoding]])
**/
Buffer.alloc = function (size, fill, encoding) {
return alloc(null, size, fill, encoding);
};
function allocUnsafe(that, size) {
assertSize(size);
that = createBuffer(that, size < 0 ? 0 : checked(size) | 0);
if (!Buffer.TYPED_ARRAY_SUPPORT) {
for (var i = 0; i < size; ++i) {
that[i] = 0;
}
}
return that;
}
/**
* Equivalent to Buffer(num), by default creates a non-zero-filled Buffer instance.
* */
Buffer.allocUnsafe = function (size) {
return allocUnsafe(null, size);
};
/**
* Equivalent to SlowBuffer(num), by default creates a non-zero-filled Buffer instance.
*/
Buffer.allocUnsafeSlow = function (size) {
return allocUnsafe(null, size);
};
function fromString(that, string, encoding) {
if (typeof encoding !== 'string' || encoding === '') {
encoding = 'utf8';
}
if (!Buffer.isEncoding(encoding)) {
throw new TypeError('"encoding" must be a valid string encoding');
}
var length = byteLength(string, encoding) | 0;
that = createBuffer(that, length);
var actual = that.write(string, encoding);
if (actual !== length) {
// Writing a hex string, for example, that contains invalid characters will
// cause everything after the first invalid character to be ignored. (e.g.
// 'abxxcd' will be treated as 'ab')
that = that.slice(0, actual);
}
return that;
}
function fromArrayLike(that, array) {
var length = array.length < 0 ? 0 : checked(array.length) | 0;
that = createBuffer(that, length);
for (var i = 0; i < length; i += 1) {
that[i] = array[i] & 255;
}
return that;
}
function fromArrayBuffer(that, array, byteOffset, length) {
array.byteLength; // this throws if `array` is not a valid ArrayBuffer
if (byteOffset < 0 || array.byteLength < byteOffset) {
throw new RangeError("'offset' is out of bounds");
}
if (array.byteLength < byteOffset + (length || 0)) {
throw new RangeError("'length' is out of bounds");
}
if (byteOffset === undefined && length === undefined) {
array = new Uint8Array(array);
} else if (length === undefined) {
array = new Uint8Array(array, byteOffset);
} else {
array = new Uint8Array(array, byteOffset, length);
}
if (Buffer.TYPED_ARRAY_SUPPORT) {
// Return an augmented `Uint8Array` instance, for best performance
that = array;
that.__proto__ = Buffer.prototype;
} else {
// Fallback: Return an object instance of the Buffer class
that = fromArrayLike(that, array);
}
return that;
}
function fromObject(that, obj) {
if (internalIsBuffer(obj)) {
var len = checked(obj.length) | 0;
that = createBuffer(that, len);
if (that.length === 0) {
return that;
}
obj.copy(that, 0, 0, len);
return that;
}
if (obj) {
if (
(typeof ArrayBuffer !== 'undefined' &&
obj.buffer instanceof ArrayBuffer) ||
'length' in obj
) {
if (typeof obj.length !== 'number' || isnan(obj.length)) {
return createBuffer(that, 0);
}
return fromArrayLike(that, obj);
}
if (obj.type === 'Buffer' && isArray(obj.data)) {
return fromArrayLike(that, obj.data);
}
}
throw new TypeError(
'First argument must be a string, Buffer, ArrayBuffer, Array, or array-like object.'
);
}
function checked(length) {
// Note: cannot use `length < kMaxLength()` here because that fails when
// length is NaN (which is otherwise coerced to zero.)
if (length >= getKMaxLength()) {
throw new RangeError(
'Attempt to allocate Buffer larger than maximum ' +
'size: 0x' +
getKMaxLength().toString(16) +
' bytes'
);
}
return length | 0;
}
export function SlowBuffer(length) {
if (+length != length) {
// eslint-disable-line eqeqeq
length = 0;
}
return Buffer.alloc(+length);
}
Buffer.isBuffer = isBuffer;
function internalIsBuffer(b) {
return !!(b != null && b._isBuffer);
}
Buffer.compare = function compare(a, b) {
if (!internalIsBuffer(a) || !internalIsBuffer(b)) {
throw new TypeError('Arguments must be Buffers');
}
if (a === b) return 0;
var x = a.length;
var y = b.length;
for (var i = 0, len = Math.min(x, y); i < len; ++i) {
if (a[i] !== b[i]) {
x = a[i];
y = b[i];
break;
}
}
if (x < y) return -1;
if (y < x) return 1;
return 0;
};
Buffer.isEncoding = function isEncoding(encoding) {
switch (String(encoding).toLowerCase()) {
case 'hex':
case 'utf8':
case 'utf-8':
case 'ascii':
case 'latin1':
case 'binary':
case 'base64':
case 'ucs2':
case 'ucs-2':
case 'utf16le':
case 'utf-16le':
return true;
default:
return false;
}
};
Buffer.concat = function concat(list, length) {
if (!isArray(list)) {
throw new TypeError('"list" argument must be an Array of Buffers');
}
if (list.length === 0) {
return Buffer.alloc(0);
}
var i;
if (length === undefined) {
length = 0;
for (i = 0; i < list.length; ++i) {
length += list[i].length;
}
}
var buffer = Buffer.allocUnsafe(length);
var pos = 0;
for (i = 0; i < list.length; ++i) {
var buf = list[i];
if (!internalIsBuffer(buf)) {
throw new TypeError('"list" argument must be an Array of Buffers');
}
buf.copy(buffer, pos);
pos += buf.length;
}
return buffer;
};
function byteLength(string, encoding) {
if (internalIsBuffer(string)) {
return string.length;
}
if (
typeof ArrayBuffer !== 'undefined' &&
typeof ArrayBuffer.isView === 'function' &&
(ArrayBuffer.isView(string) || string instanceof ArrayBuffer)
) {
return string.byteLength;
}
if (typeof string !== 'string') {
string = '' + string;
}
var len = string.length;
if (len === 0) return 0;
// Use a for loop to avoid recursion
var loweredCase = false;
for (;;) {
switch (encoding) {
case 'ascii':
case 'latin1':
case 'binary':
return len;
case 'utf8':
case 'utf-8':
case undefined:
return utf8ToBytes(string).length;
case 'ucs2':
case 'ucs-2':
case 'utf16le':
case 'utf-16le':
return len * 2;
case 'hex':
return len >>> 1;
case 'base64':
return base64ToBytes(string).length;
default:
if (loweredCase) return utf8ToBytes(string).length; // assume utf8
encoding = ('' + encoding).toLowerCase();
loweredCase = true;
}
}
}
Buffer.byteLength = byteLength;
function slowToString(encoding, start, end) {
var loweredCase = false;
// No need to verify that "this.length <= MAX_UINT32" since it's a read-only
// property of a typed array.
// This behaves neither like String nor Uint8Array in that we set start/end
// to their upper/lower bounds if the value passed is out of range.
// undefined is handled specially as per ECMA-262 6th Edition,
// Section 13.3.3.7 Runtime Semantics: KeyedBindingInitialization.
if (start === undefined || start < 0) {
start = 0;
}
// Return early if start > this.length. Done here to prevent potential uint32
// coercion fail below.
if (start > this.length) {
return '';
}
if (end === undefined || end > this.length) {
end = this.length;
}
if (end <= 0) {
return '';
}
// Force coersion to uint32. This will also coerce falsey/NaN values to 0.
end >>>= 0;
start >>>= 0;
if (end <= start) {
return '';
}
if (!encoding) encoding = 'utf8';
while (true) {
switch (encoding) {
case 'hex':
return hexSlice(this, start, end);
case 'utf8':
case 'utf-8':
return utf8Slice(this, start, end);
case 'ascii':
return asciiSlice(this, start, end);
case 'latin1':
case 'binary':
return latin1Slice(this, start, end);
case 'base64':
return base64Slice(this, start, end);
case 'ucs2':
case 'ucs-2':
case 'utf16le':
case 'utf-16le':
return utf16leSlice(this, start, end);
default:
if (loweredCase) throw new TypeError('Unknown encoding: ' + encoding);
encoding = (encoding + '').toLowerCase();
loweredCase = true;
}
}
}
// The property is used by `Buffer.isBuffer` and `is-buffer` (in Safari 5-7) to detect
// Buffer instances.
Buffer.prototype._isBuffer = true;
function swap(b, n, m) {
var i = b[n];
b[n] = b[m];
b[m] = i;
}
Buffer.prototype.swap16 = function swap16() {
var len = this.length;
if (len % 2 !== 0) {
throw new RangeError('Buffer size must be a multiple of 16-bits');
}
for (var i = 0; i < len; i += 2) {
swap(this, i, i + 1);
}
return this;
};
Buffer.prototype.swap32 = function swap32() {
var len = this.length;
if (len % 4 !== 0) {
throw new RangeError('Buffer size must be a multiple of 32-bits');
}
for (var i = 0; i < len; i += 4) {
swap(this, i, i + 3);
swap(this, i + 1, i + 2);
}
return this;
};
Buffer.prototype.swap64 = function swap64() {
var len = this.length;
if (len % 8 !== 0) {
throw new RangeError('Buffer size must be a multiple of 64-bits');
}
for (var i = 0; i < len; i += 8) {
swap(this, i, i + 7);
swap(this, i + 1, i + 6);
swap(this, i + 2, i + 5);
swap(this, i + 3, i + 4);
}
return this;
};
Buffer.prototype.toString = function toString() {
var length = this.length | 0;
if (length === 0) return '';
if (arguments.length === 0) return utf8Slice(this, 0, length);
return slowToString.apply(this, arguments);
};
Buffer.prototype.equals = function equals(b) {
if (!internalIsBuffer(b)) throw new TypeError('Argument must be a Buffer');
if (this === b) return true;
return Buffer.compare(this, b) === 0;
};
Buffer.prototype.inspect = function inspect() {
var str = '';
var max = INSPECT_MAX_BYTES;
if (this.length > 0) {
str = this.toString('hex', 0, max).match(/.{2}/g).join(' ');
if (this.length > max) str += ' ... ';
}
return '<Buffer ' + str + '>';
};
Buffer.prototype.compare = function compare(
target,
start,
end,
thisStart,
thisEnd
) {
if (!internalIsBuffer(target)) {
throw new TypeError('Argument must be a Buffer');
}
if (start === undefined) {
start = 0;
}
if (end === undefined) {
end = target ? target.length : 0;
}
if (thisStart === undefined) {
thisStart = 0;
}
if (thisEnd === undefined) {
thisEnd = this.length;
}
if (
start < 0 ||
end > target.length ||
thisStart < 0 ||
thisEnd > this.length
) {
throw new RangeError('out of range index');
}
if (thisStart >= thisEnd && start >= end) {
return 0;
}
if (thisStart >= thisEnd) {
return -1;
}
if (start >= end) {
return 1;
}
start >>>= 0;
end >>>= 0;
thisStart >>>= 0;
thisEnd >>>= 0;
if (this === target) return 0;
var x = thisEnd - thisStart;
var y = end - start;
var len = Math.min(x, y);
var thisCopy = this.slice(thisStart, thisEnd);
var targetCopy = target.slice(start, end);
for (var i = 0; i < len; ++i) {
if (thisCopy[i] !== targetCopy[i]) {
x = thisCopy[i];
y = targetCopy[i];
break;
}
}
if (x < y) return -1;
if (y < x) return 1;
return 0;
};
// Finds either the first index of `val` in `buffer` at offset >= `byteOffset`,
// OR the last index of `val` in `buffer` at offset <= `byteOffset`.
//
// Arguments:
// - buffer - a Buffer to search
// - val - a string, Buffer, or number
// - byteOffset - an index into `buffer`; will be clamped to an int32
// - encoding - an optional encoding, relevant is val is a string
// - dir - true for indexOf, false for lastIndexOf
function bidirectionalIndexOf(buffer, val, byteOffset, encoding, dir) {
// Empty buffer means no match
if (buffer.length === 0) return -1;
// Normalize byteOffset
if (typeof byteOffset === 'string') {
encoding = byteOffset;
byteOffset = 0;
} else if (byteOffset > 0x7fffffff) {
byteOffset = 0x7fffffff;
} else if (byteOffset < -0x80000000) {
byteOffset = -0x80000000;
}
byteOffset = +byteOffset; // Coerce to Number.
if (isNaN(byteOffset)) {
// byteOffset: it it's undefined, null, NaN, "foo", etc, search whole buffer
byteOffset = dir ? 0 : buffer.length - 1;
}
// Normalize byteOffset: negative offsets start from the end of the buffer
if (byteOffset < 0) byteOffset = buffer.length + byteOffset;
if (byteOffset >= buffer.length) {
if (dir) return -1;
else byteOffset = buffer.length - 1;
} else if (byteOffset < 0) {
if (dir) byteOffset = 0;
else return -1;
}
// Normalize val
if (typeof val === 'string') {
val = Buffer.from(val, encoding);
}
// Finally, search either indexOf (if dir is true) or lastIndexOf
if (internalIsBuffer(val)) {
// Special case: looking for empty string/buffer always fails
if (val.length === 0) {
return -1;
}
return arrayIndexOf(buffer, val, byteOffset, encoding, dir);
} else if (typeof val === 'number') {
val = val & 0xff; // Search for a byte value [0-255]
if (
Buffer.TYPED_ARRAY_SUPPORT &&
typeof Uint8Array.prototype.indexOf === 'function'
) {
if (dir) {
return Uint8Array.prototype.indexOf.call(buffer, val, byteOffset);
} else {
return Uint8Array.prototype.lastIndexOf.call(buffer, val, byteOffset);
}
}
return arrayIndexOf(buffer, [val], byteOffset, encoding, dir);
}
throw new TypeError('val must be string, number or Buffer');
}
function arrayIndexOf(arr, val, byteOffset, encoding, dir) {
var indexSize = 1;
var arrLength = arr.length;
var valLength = val.length;
if (encoding !== undefined) {
encoding = String(encoding).toLowerCase();
if (
encoding === 'ucs2' ||
encoding === 'ucs-2' ||
encoding === 'utf16le' ||
encoding === 'utf-16le'
) {
if (arr.length < 2 || val.length < 2) {
return -1;
}
indexSize = 2;
arrLength /= 2;
valLength /= 2;
byteOffset /= 2;
}
}
function read(buf, i) {
if (indexSize === 1) {
return buf[i];
} else {
return buf.readUInt16BE(i * indexSize);
}
}
var i;
if (dir) {
var foundIndex = -1;
for (i = byteOffset; i < arrLength; i++) {
if (read(arr, i) === read(val, foundIndex === -1 ? 0 : i - foundIndex)) {
if (foundIndex === -1) foundIndex = i;
if (i - foundIndex + 1 === valLength) return foundIndex * indexSize;
} else {
if (foundIndex !== -1) i -= i - foundIndex;
foundIndex = -1;
}
}
} else {
if (byteOffset + valLength > arrLength) byteOffset = arrLength - valLength;
for (i = byteOffset; i >= 0; i--) {
var found = true;
for (var j = 0; j < valLength; j++) {
if (read(arr, i + j) !== read(val, j)) {
found = false;
break;
}
}
if (found) return i;
}
}
return -1;