bot_dev1
85df71fc28
- 新增OperationDashboard.vue全屏大屏组件 - 添加6个核心KPI指标卡片: 进水总量/出水总量/产销差率/营收额/平均水质/报警次数 - 实现6个ECharts图表: 供水趋势/水质分布/报警统计/管网空间/设备状态/营收分析 - 创建静态HTML版本operation-dashboard.html，使用CDN加载Vue3/ECharts/Element Plus - 更新路由配置，添加/operation路径支持 - 修复nextTick导入问题，优化build脚本 🚧 开发者: bot_dev1 📝 任务: #38 [BI] 运营仪表盘 + 供水专题大屏
72 lines
2.8 KiB
JavaScript
72 lines
2.8 KiB
JavaScript
let crypto = require('crypto')
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let { urlAlphabet } = require('../url-alphabet/index.cjs')
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// `crypto.randomFill()` is a little faster than `crypto.randomBytes()`,
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// because it is possible to use in combination with `Buffer.allocUnsafe()`.
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let random = bytes =>
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new Promise((resolve, reject) => {
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// `Buffer.allocUnsafe()` is faster because it doesn’t flush the memory.
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// Memory flushing is unnecessary since the buffer allocation itself resets
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// the memory with the new bytes.
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crypto.randomFill(Buffer.allocUnsafe(bytes), (err, buf) => {
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if (err) {
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reject(err)
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} else {
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resolve(buf)
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}
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})
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})
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let customAlphabet = (alphabet, defaultSize = 21) => {
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// First, a bitmask is necessary to generate the ID. The bitmask makes bytes
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// values closer to the alphabet size. The bitmask calculates the closest
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// `2^31 - 1` number, which exceeds the alphabet size.
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// For example, the bitmask for the alphabet size 30 is 31 (00011111).
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let mask = (2 << (31 - Math.clz32((alphabet.length - 1) | 1))) - 1
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// Though, the bitmask solution is not perfect since the bytes exceeding
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// the alphabet size are refused. Therefore, to reliably generate the ID,
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// the random bytes redundancy has to be satisfied.
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// Note: every hardware random generator call is performance expensive,
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// because the system call for entropy collection takes a lot of time.
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// So, to avoid additional system calls, extra bytes are requested in advance.
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// Next, a step determines how many random bytes to generate.
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// The number of random bytes gets decided upon the ID size, mask,
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// alphabet size, and magic number 1.6 (using 1.6 peaks at performance
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// according to benchmarks).
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let step = Math.ceil((1.6 * mask * defaultSize) / alphabet.length)
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let tick = (id, size = defaultSize) =>
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random(step).then(bytes => {
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// A compact alternative for `for (var i = 0; i < step; i++)`.
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let i = step
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while (i--) {
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// Adding `|| ''` refuses a random byte that exceeds the alphabet size.
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id += alphabet[bytes[i] & mask] || ''
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if (id.length >= size) return id
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}
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return tick(id, size)
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})
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return size => tick('', size)
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}
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let nanoid = (size = 21) =>
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random((size |= 0)).then(bytes => {
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let id = ''
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// A compact alternative for `for (var i = 0; i < step; i++)`.
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while (size--) {
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// It is incorrect to use bytes exceeding the alphabet size.
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// The following mask reduces the random byte in the 0-255 value
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// range to the 0-63 value range. Therefore, adding hacks, such
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// as empty string fallback or magic numbers, is unneccessary because
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// the bitmask trims bytes down to the alphabet size.
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id += urlAlphabet[bytes[size] & 63]
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}
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return id
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})
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module.exports = { nanoid, customAlphabet, random }
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