node-gamedig/lib/reader.js
CosminPerRam cee42e7a88
chore: Convert all files to LF endings (#400)
* Convert to LF?

* Modify gitattributes

* Force LF

* Git --renormalize

* Update .gitattributes to enforce eol=lf

* Redo CRLF -> LF on remaining files
2023-11-12 13:14:43 +02:00

173 lines
4.3 KiB
JavaScript

import Iconv from 'iconv-lite'
import Long from 'long'
import { Buffer } from 'node:buffer'
import Varint from 'varint'
function readUInt64BE (buffer, offset) {
const high = buffer.readUInt32BE(offset)
const low = buffer.readUInt32BE(offset + 4)
return new Long(low, high, true)
}
function readUInt64LE (buffer, offset) {
const low = buffer.readUInt32LE(offset)
const high = buffer.readUInt32LE(offset + 4)
return new Long(low, high, true)
}
export default class Reader {
/**
* @param {Core} query
* @param {Buffer} buffer
**/
constructor (query, buffer) {
this.defaultEncoding = query.options.encoding || query.encoding
this.defaultDelimiter = query.delimiter
this.defaultByteOrder = query.byteorder
this.buffer = buffer
this.i = 0
}
setOffset (offset) {
this.i = offset
}
offset () {
return this.i
}
skip (i) {
this.i += i
}
pascalString (bytesForSize, adjustment = 0) {
const length = this.uint(bytesForSize) + adjustment
return this.string(length)
}
string (arg) {
let encoding = this.defaultEncoding
let length = null
let delimiter = this.defaultDelimiter
if (typeof arg === 'string') delimiter = arg
else if (typeof arg === 'number') length = arg
else if (typeof arg === 'object') {
if ('encoding' in arg) encoding = arg.encoding
if ('length' in arg) length = arg.length
if ('delimiter' in arg) delimiter = arg.delimiter
}
if (encoding === 'latin1') encoding = 'win1252'
const start = this.i
let end = start
if (length === null) {
// terminated by the delimiter
let delim = delimiter
if (typeof delim === 'string') delim = delim.charCodeAt(0)
while (true) {
if (end >= this.buffer.length) {
end = this.buffer.length
break
}
if (this.buffer.readUInt8(end) === delim) break
end++
}
this.i = end + 1
} else if (length <= 0) {
return ''
} else {
end = start + length
if (end >= this.buffer.length) {
end = this.buffer.length
}
this.i = end
}
const slice = this.buffer.slice(start, end)
const enc = encoding
if (enc === 'utf8' || enc === 'ucs2' || enc === 'binary') {
return slice.toString(enc)
} else {
return Iconv.decode(slice, enc)
}
}
int (bytes) {
let r = 0
if (this.remaining() >= bytes) {
if (this.defaultByteOrder === 'be') {
if (bytes === 1) r = this.buffer.readInt8(this.i)
else if (bytes === 2) r = this.buffer.readInt16BE(this.i)
else if (bytes === 4) r = this.buffer.readInt32BE(this.i)
} else {
if (bytes === 1) r = this.buffer.readInt8(this.i)
else if (bytes === 2) r = this.buffer.readInt16LE(this.i)
else if (bytes === 4) r = this.buffer.readInt32LE(this.i)
}
}
this.i += bytes
return r
}
/** @returns {number} */
uint (bytes) {
let r = 0
if (this.remaining() >= bytes) {
if (this.defaultByteOrder === 'be') {
if (bytes === 1) r = this.buffer.readUInt8(this.i)
else if (bytes === 2) r = this.buffer.readUInt16BE(this.i)
else if (bytes === 4) r = this.buffer.readUInt32BE(this.i)
else if (bytes === 8) r = readUInt64BE(this.buffer, this.i)
} else {
if (bytes === 1) r = this.buffer.readUInt8(this.i)
else if (bytes === 2) r = this.buffer.readUInt16LE(this.i)
else if (bytes === 4) r = this.buffer.readUInt32LE(this.i)
else if (bytes === 8) r = readUInt64LE(this.buffer, this.i)
}
}
this.i += bytes
return r
}
float () {
let r = 0
if (this.remaining() >= 4) {
if (this.defaultByteOrder === 'be') r = this.buffer.readFloatBE(this.i)
else r = this.buffer.readFloatLE(this.i)
}
this.i += 4
return r
}
varint () {
const out = Varint.decode(this.buffer, this.i)
this.i += Varint.decode.bytes
return out
}
/** @returns Buffer */
part (bytes) {
let r
if (this.remaining() >= bytes) {
r = this.buffer.slice(this.i, this.i + bytes)
} else {
r = Buffer.from([])
}
this.i += bytes
return r
}
remaining () {
return this.buffer.length - this.i
}
rest () {
return this.buffer.slice(this.i)
}
done () {
return this.i >= this.buffer.length
}
}