79 lines
2.7 KiB
JavaScript
79 lines
2.7 KiB
JavaScript
import { normalize } from 'node:path'
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const CRC_TABLE = Array.from({ length: 256 }, (_, value) => {
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let crc = value
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for (let bit = 0; bit < 8; bit++) crc = (crc & 1) ? 0xedb88320 ^ (crc >>> 1) : crc >>> 1
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return crc >>> 0
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})
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function crc32(data) {
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let crc = 0xffffffff
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for (const byte of data) crc = CRC_TABLE[(crc ^ byte) & 0xff] ^ (crc >>> 8)
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return (crc ^ 0xffffffff) >>> 0
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}
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function archivePath(value) {
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const path = normalize(String(value || '').replace(/\\/g, '/')).replace(/\\/g, '/').replace(/^\.\//, '')
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if (!path || path.startsWith('/') || path === '..' || path.startsWith('../')) throw new Error('ZIP 文件路径无效')
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return path
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}
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function dosDateTime(date = new Date()) {
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const year = Math.max(1980, date.getFullYear())
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return {
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time: (date.getHours() << 11) | (date.getMinutes() << 5) | Math.floor(date.getSeconds() / 2),
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date: ((year - 1980) << 9) | ((date.getMonth() + 1) << 5) | date.getDate(),
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}
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}
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/** 创建无额外依赖的 ZIP（Store 模式）；PNG 和 .spine 本身已压缩，无需重复压缩。 */
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export function createZipArchive(files) {
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const localParts = []
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const centralParts = []
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let offset = 0
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const timestamp = dosDateTime()
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for (const file of files) {
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const name = Buffer.from(archivePath(file.name), 'utf8')
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const data = Buffer.isBuffer(file.data) ? file.data : Buffer.from(file.data)
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const crc = crc32(data)
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const local = Buffer.alloc(30)
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local.writeUInt32LE(0x04034b50, 0)
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local.writeUInt16LE(20, 4)
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local.writeUInt16LE(0x0800, 6)
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local.writeUInt16LE(0, 8)
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local.writeUInt16LE(timestamp.time, 10)
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local.writeUInt16LE(timestamp.date, 12)
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local.writeUInt32LE(crc, 14)
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local.writeUInt32LE(data.length, 18)
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local.writeUInt32LE(data.length, 22)
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local.writeUInt16LE(name.length, 26)
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localParts.push(local, name, data)
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const central = Buffer.alloc(46)
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central.writeUInt32LE(0x02014b50, 0)
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central.writeUInt16LE(20, 4)
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central.writeUInt16LE(20, 6)
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central.writeUInt16LE(0x0800, 8)
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central.writeUInt16LE(0, 10)
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central.writeUInt16LE(timestamp.time, 12)
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central.writeUInt16LE(timestamp.date, 14)
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central.writeUInt32LE(crc, 16)
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central.writeUInt32LE(data.length, 20)
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central.writeUInt32LE(data.length, 24)
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central.writeUInt16LE(name.length, 28)
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central.writeUInt32LE(offset, 42)
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centralParts.push(central, name)
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offset += local.length + name.length + data.length
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}
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const centralDirectory = Buffer.concat(centralParts)
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const end = Buffer.alloc(22)
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end.writeUInt32LE(0x06054b50, 0)
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end.writeUInt16LE(files.length, 8)
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end.writeUInt16LE(files.length, 10)
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end.writeUInt32LE(centralDirectory.length, 12)
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end.writeUInt32LE(offset, 16)
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return Buffer.concat([...localParts, centralDirectory, end])
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}
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