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| 1 | +import { bind } from 'helpful-decorators'; |
| 2 | +import { createAssetObject } from './classes'; |
| 3 | +import type { BufferReaderExtended } from './utils/reader'; |
| 4 | +import { createExtendedBufferReader } from './utils/reader'; |
| 5 | + |
| 6 | +interface AssetHeader { |
| 7 | + metadataSize: number; |
| 8 | + fileSize: number; |
| 9 | + version: number; |
| 10 | + dataOffset: number; |
| 11 | + endianness: number; |
| 12 | +} |
| 13 | + |
| 14 | +interface TypeInfo { |
| 15 | + classId: number; |
| 16 | +} |
| 17 | + |
| 18 | +export interface ObjectInfo { |
| 19 | + getReader: () => BufferReaderExtended; |
| 20 | + buildType: string; |
| 21 | + assetVersion: number; |
| 22 | + bytesStart: number; |
| 23 | + bytesSize: number; |
| 24 | + typeId: number; |
| 25 | + classId: number; |
| 26 | + isDestroyed: number; |
| 27 | + stripped: number; |
| 28 | + pathId: number; |
| 29 | + version: string; |
| 30 | +} |
| 31 | + |
| 32 | +export class Asset { |
| 33 | + private readonly reader: BufferReaderExtended; |
| 34 | + private readonly header: AssetHeader; |
| 35 | + private readonly fileEndianness: number = 0; |
| 36 | + private readonly unityVersion: string = ''; |
| 37 | + private readonly targetPlatform: number = 0; |
| 38 | + private readonly enableTypeTree: boolean = false; |
| 39 | + private readonly enableBigId: boolean = false; |
| 40 | + private readonly types: TypeInfo[] = []; |
| 41 | + private readonly objectInfos: ObjectInfo[] = []; |
| 42 | + |
| 43 | + constructor(data: Buffer) { |
| 44 | + const r = createExtendedBufferReader(data); |
| 45 | + this.reader = r; |
| 46 | + |
| 47 | + const header: AssetHeader = (this.header = { |
| 48 | + metadataSize: r.nextUInt32BE(), |
| 49 | + fileSize: r.nextUInt32BE(), |
| 50 | + version: r.nextUInt32BE(), |
| 51 | + dataOffset: r.nextUInt32BE(), |
| 52 | + endianness: 0, |
| 53 | + }); |
| 54 | + |
| 55 | + if (header.version >= 9) { |
| 56 | + this.fileEndianness = header.endianness = r.nextUInt8(); |
| 57 | + r.move(3); |
| 58 | + } else { |
| 59 | + r.seek(header.fileSize - header.metadataSize); |
| 60 | + this.fileEndianness = r.nextUInt8(); |
| 61 | + } |
| 62 | + r.setEndianness(this.fileEndianness); |
| 63 | + |
| 64 | + if (header.version >= 22) { |
| 65 | + header.metadataSize = r.nextUInt32(); |
| 66 | + header.fileSize = r.nextInt64(); |
| 67 | + header.dataOffset = r.nextInt64(); |
| 68 | + r.move(8); |
| 69 | + } |
| 70 | + if (header.version >= 7) { |
| 71 | + this.unityVersion = r.nextStringZero(); |
| 72 | + } |
| 73 | + if (header.version >= 8) { |
| 74 | + this.targetPlatform = r.nextInt32(); |
| 75 | + } |
| 76 | + if (header.version >= 13) { |
| 77 | + this.enableTypeTree = !!r.nextUInt8(); |
| 78 | + } |
| 79 | + |
| 80 | + const typeCount = r.nextInt32(); |
| 81 | + for (let i = 0; i < typeCount; i++) { |
| 82 | + this.readType(false); |
| 83 | + } |
| 84 | + |
| 85 | + if (header.version >= 7 && header.version < 14) { |
| 86 | + this.enableBigId = !!r.nextInt32(); |
| 87 | + } |
| 88 | + |
| 89 | + const objectCount = r.nextUInt32(); |
| 90 | + for (let i = 0; i < objectCount; i++) { |
| 91 | + const info: ObjectInfo = { |
| 92 | + getReader: this.cloneReader, |
| 93 | + buildType: '', |
| 94 | + assetVersion: 0, |
| 95 | + bytesStart: 0, |
| 96 | + bytesSize: 0, |
| 97 | + typeId: 0, |
| 98 | + classId: 0, |
| 99 | + isDestroyed: 0, |
| 100 | + stripped: 0, |
| 101 | + pathId: 0, |
| 102 | + version: '', |
| 103 | + }; |
| 104 | + |
| 105 | + if (this.enableBigId) r.move(8); |
| 106 | + else if (header.version < 14) r.move(4); |
| 107 | + else { |
| 108 | + r.align(4); |
| 109 | + r.move(8); |
| 110 | + } |
| 111 | + info.bytesStart = header.version >= 22 ? r.nextInt64() : r.nextUInt32(); |
| 112 | + info.bytesStart += header.dataOffset; |
| 113 | + info.bytesSize = r.nextUInt32(); |
| 114 | + info.typeId = r.nextInt32(); |
| 115 | + if (header.version < 16) info.classId = r.nextUInt16(); |
| 116 | + else info.classId = this.types[info.typeId].classId; |
| 117 | + if (header.version < 11) info.isDestroyed = r.nextUInt16(); |
| 118 | + if (header.version >= 11 && header.version < 17) r.move(2); |
| 119 | + if (header.version === 15 || header.version === 16) info.stripped = r.nextUInt8(); |
| 120 | + |
| 121 | + this.objectInfos.push(info); |
| 122 | + } |
| 123 | + |
| 124 | + // 未实现 |
| 125 | + } |
| 126 | + |
| 127 | + public objects() { |
| 128 | + return this.objectInfos.map(createAssetObject); |
| 129 | + } |
| 130 | + |
| 131 | + @bind |
| 132 | + private cloneReader() { |
| 133 | + return this.reader.clone(); |
| 134 | + } |
| 135 | + |
| 136 | + // 未完整实现，只用于跳过 |
| 137 | + private readType(isRefType: boolean) { |
| 138 | + const r = this.reader; |
| 139 | + const { version } = this.header; |
| 140 | + |
| 141 | + const info: TypeInfo = { |
| 142 | + classId: r.nextInt32(), |
| 143 | + }; |
| 144 | + |
| 145 | + if (version >= 16) r.move(1); |
| 146 | + if (version >= 17) r.move(2); |
| 147 | + if (version >= 13) r.move(16); |
| 148 | + if (this.enableTypeTree) { |
| 149 | + if (version >= 12 || version === 10) this.readTypeTreeBlob(); |
| 150 | + else throw new Error(`Unsupported asset version: ${version}`); |
| 151 | + if (version >= 21) { |
| 152 | + if (isRefType) { |
| 153 | + r.nextStringZero(); |
| 154 | + r.nextStringZero(); |
| 155 | + r.nextStringZero(); |
| 156 | + } else { |
| 157 | + const size = r.nextInt32(); |
| 158 | + r.move(size * 4); |
| 159 | + } |
| 160 | + } |
| 161 | + } |
| 162 | + |
| 163 | + this.types.push(info); |
| 164 | + } |
| 165 | + |
| 166 | + // 未实现，只用于跳过 |
| 167 | + private readTypeTreeBlob() { |
| 168 | + const r = this.reader; |
| 169 | + |
| 170 | + const nodeNumber = r.nextInt32(); |
| 171 | + const stringBufferSize = r.nextInt32(); |
| 172 | + |
| 173 | + for (let i = 0; i < nodeNumber; i++) { |
| 174 | + r.move(24); |
| 175 | + if (this.header.version >= 19) r.move(8); |
| 176 | + } |
| 177 | + r.move(stringBufferSize); |
| 178 | + } |
| 179 | +} |
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