import get from 'lodash-es/get.js'
import errToStr from './_errToStr.mjs'
import isbol from './isbol.mjs'
import isu8arr from './isu8arr.mjs'
import getBufferSize from './getBufferSize.mjs'
import bufReadDbl from './bufReadDbl.mjs'
import u8arr2str from './u8arr2str.mjs'
import stru8arr2obj from './stru8arr2obj.mjs'
//checkLenHead, 檢查封包標頭記載之分塊資訊區長度, 回傳不符原因字串, 符合則回傳空字串
//取自封包標頭(網路/檔案來源, 不可信), 須為非負整數且不逾封包資料區之位元組數: 小數與負數經slice被靜默截斷或自尾端算而得同一分割(非正規編碼), NaN與Infinity亦然
function checkLenHead(lenHead, size) {
if (!Number.isInteger(lenHead) || lenHead < 0 || lenHead > size) {
return 'head length must be a non-negative integer not exceeding the packet'
}
return ''
}
//checkPks, 檢查分塊資訊, 回傳不符原因字串, 全符合則回傳空字串
//分塊資訊取自封包標頭(網路/檔案來源, 不可信), 須在迭代與配置記憶體前驗證(R-OBJ-ITER-01規則6), 否則偽造{"length":N}會使迭代依N次並逐次配置Uint8Array
// 1. 須為真陣列(Array.isArray), 帶length鍵之物件或字串等不得依其length迭代
// 2. 各項須為非負有限整數(Number.isInteger擋小數、字串、null、Infinity等, 1e999經JSON.parse為Infinity)
// 3. 累計總量不得逾各分塊區(封包標頭之後)之位元組數, 邊累加邊比對, 超過即停止
// 4. 分塊數量須與主區塊可容納之二進位標記數相符(見下)
function checkPks(inds, size) {
if (!Array.isArray(inds)) {
return 'not an array'
}
for (let k = 0; k < inds.length; k++) {
let n = inds[k]
if (!Number.isInteger(n) || n < 0) {
return 'every item must be a non-negative finite integer'
}
}
let sum = 0
for (let k = 0; k < inds.length; k++) {
sum += inds[k]
if (sum > size) {
return 'total length exceeds the packet'
}
}
// 4. 分塊數量: 首個分塊為主區塊(results文字), 其後每個分塊在主區塊內必有一個二進位標記字串(JSON字串形式至少25位元組, 如"[BlazeForUint8Array]::0"),
// 故分塊數(扣除主區塊)乘25不得逾主區塊長度; 否則大量零長度或1位元組分塊(標頭每項約2位元組)會各配置一個Uint8Array而放大配置量(約為封包位元組數之百倍堆積)
if (inds.length > 1 && (inds.length - 1) * 25 > inds[0]) {
return 'too many chunks for the main block'
}
return ''
}
//sliceU8arr, 依各分塊長度切出各分塊, inds須已通過checkPks
function sliceU8arr(u8a, inds) {
let i = 0
let j = 0
let r = []
for (let k = 0; k < inds.length; k++) {
j = i + inds[k]
let t = u8a.slice(i, j)
i = j
r.push(t)
}
return r
}
/**
* Uint8Array轉物件或陣列資料
*
* Unit Test: {@link https://github.com/yuda-lyu/wsemi/blob/master/test/u8arr2obj.test.mjs Github}
* @memberOf wsemi
* @param {Uint8Array} u8a 輸入Uint8Array
* @param {Object} [opt={}] 輸入設定物件，預設{}
* @param {Boolean} [opt.returnWithStateAndMsg=false] 輸入是否回傳含狀態與訊息物件布林值，若為true則回傳{ state, msg }物件，state為'success'或'error'，msg於success時為回傳結果、於error時為錯誤訊息字串，預設false
* @returns {Object|Array} 回傳物件或陣列資料，其內二進位數據依標記所記之原型別還原，Uint8Array、Uint16Array、ArrayBuffer皆原型別原數值返回；輸入非Uint8Array或封包損毀時回傳空物件，封包標頭記載之分塊資訊區長度非非負整數或逾封包資料區長度(含封包短於8位元組)、分塊資訊非真陣列、含非負有限整數以外之項、總量逾封包長度、或分塊數量逾主區塊可容納之二進位標記數(每個分塊在主區塊內至少有一個25位元組之標記)亦視為損毀(msg為'invalid pks, <原因>')；同一二進位索引被引用多次亦視為損毀；若opt.returnWithStateAndMsg為true則回傳{ state, msg }物件
* @example
*
* let u8a = new Uint8Array([
* 64, 24, 0, 0, 0, 0, 0, 0, 91, 54, 54, 44,
* 51, 93, 123, 34, 97, 34, 58, 91, 49, 50, 51, 44,
* 52, 53, 46, 54, 55, 44, 34, 116, 101, 115, 116, 228,
* 184, 173, 230, 150, 135, 34, 93, 44, 34, 98, 34, 58,
* 123, 34, 99, 34, 58, 34, 91, 66, 108, 97, 122, 101,
* 70, 111, 114, 85, 105, 110, 116, 56, 65, 114, 114, 97,
* 121, 93, 58, 58, 48, 34, 125, 125, 66, 97, 115
* ])
* let data = u8arr2obj(u8a)
* console.log(data)
* // => { a: [ 123, 45.67, 'test中文' ], b: { c: Uint8Array [ 66, 97, 115 ] } }
*
* console.log(u8arr2obj(new Uint8Array([1, 2, 3]), { returnWithStateAndMsg: true }))
* // => {
* // state: 'error',
* // msg: 'invalid pks, head length must be a non-negative integer not exceeding the packet'
* // }
*
*/
function u8arr2obj(u8a, opt = {}) {
let data = {}
//returnWithStateAndMsg
let returnWithStateAndMsg = get(opt, 'returnWithStateAndMsg', null)
if (!isbol(returnWithStateAndMsg)) {
returnWithStateAndMsg = false
}
//retError
let retError = (msg) => {
if (returnWithStateAndMsg) {
return {
state: 'error',
msg,
}
}
else {
return {}
}
}
//check
if (!isu8arr(u8a)) {
return retError('invalid u8a')
}
try {
//bHead, bOthers
let ibHead = 8 //預設用開頭8 bytes來儲存分塊資訊區之長度
let bHead = u8a.slice(0, ibHead) //分塊資訊區長度之二進位數據(Uint8Array)
let bOthers = u8a.slice(ibHead, getBufferSize(u8a)) //其他之二進位數據(Uint8Array)
//lenHead
let lenHead = bufReadDbl(bHead) //讀取分塊資訊區長度
let errHead = checkLenHead(lenHead, getBufferSize(bOthers)) //來自封包(不可信), 須先驗證才可用於切分
if (errHead !== '') {
return retError(`invalid pks, ${errHead}`)
}
let bvPks = bOthers.slice(0, lenHead) //分塊資訊區之二進位數據(Uint8Array)
let bbPks = bOthers.slice(lenHead, getBufferSize(bOthers)) //各分塊區之二進位數據(Uint8Array)
//vPks, 內部各轉換函數一律以returnWithStateAndMsg取狀態, 逐一判識後才把結果交給下一步, 錯誤訊息前置來源函數名以利分辨是哪一步出錯
let rcvPks = u8arr2str(bvPks, { returnWithStateAndMsg: true }) //取得分塊資訊區二進位數據(Uint8Array)內文字
if (rcvPks.state === 'error') {
return retError(`u8arr2str: ${rcvPks.msg}`)
}
let cvPks = rcvPks.msg
let vPks = JSON.parse(cvPks) //算得分塊資訊, 應為陣列, 各元素代表各分塊長度, 但來自封包不可信, 須經checkPks驗證
//check vPks, 須先驗證才可迭代, 不依其內容配置記憶體
let errPks = checkPks(vPks, getBufferSize(bbPks))
if (errPks !== '') {
return retError(`invalid pks, ${errPks}`)
}
//bPks
let bPks = sliceU8arr(bbPks, vPks) //依照各分塊長度切出分各分塊之二進位數據(Uint8Array)
//results, to sb.results
let bMain = bPks.shift() //bPks[0], 第1區塊為無Uint8Array序列化字串之二進位數據(Uint8Array)
let rresults = u8arr2str(bMain, { returnWithStateAndMsg: true }) //取得無Uint8Array序列化字串
if (rresults.state === 'error') {
return retError(`u8arr2str: ${rresults.msg}`)
}
let results = rresults.msg
//binarys , to sb.binarys
let binarys = bPks //others, 其他塊皆為Uint8Array之二進位數據(Uint8Array)
//data
let r = stru8arr2obj({ results, binarys }, { returnWithStateAndMsg: true }) //反序列化數據, 由無Uint8Array序列化字串與Uint8Array之二進位數據算得原本資料
if (r.state === 'error') {
return retError(`stru8arr2obj: ${r.msg}`)
}
data = r.msg
}
catch (err) {
return retError(errToStr(err)) //try內會讀呼叫端之Uint8Array(偽造標籤之物件、覆寫slice者等)可拋出任意值, 不可直接err.toString()
}
if (returnWithStateAndMsg) {
return {
state: 'success',
msg: data,
}
}
else {
return data
}
}
export default u8arr2obj