mirror of
https://github.com/tsolomko/SWCompression.git
synced 2026-06-23 14:56:41 +00:00
Timofey Solomko
47 lines
1.1 KiB
Swift
47 lines
1.1 KiB
Swift
// Copyright (c) 2021 Timofey Solomko
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// Licensed under MIT License
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//
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// See LICENSE for license information
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import Foundation
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import BitByteData
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class SevenZipCoder {
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let idSize: Int
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let isComplex: Bool
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let hasAttributes: Bool
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let id: [UInt8]
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let compressionMethod: CompressionMethod
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let isEncryptionMethod: Bool
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let numInStreams: Int
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let numOutStreams: Int
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var propertiesSize: Int?
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var properties: [UInt8]?
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init(_ bitReader: MsbBitReader) throws {
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let flags = bitReader.byte()
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guard flags & 0xC0 == 0
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else { throw SevenZipError.internalStructureError }
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idSize = (flags & 0x0F).toInt()
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isComplex = flags & 0x10 != 0
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hasAttributes = flags & 0x20 != 0
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id = bitReader.bytes(count: idSize)
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compressionMethod = CompressionMethod(id)
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isEncryptionMethod = id[0] == 0x06
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numInStreams = isComplex ? bitReader.szMbd() : 1
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numOutStreams = isComplex ? bitReader.szMbd() : 1
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if hasAttributes {
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propertiesSize = bitReader.szMbd()
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properties = bitReader.bytes(count: propertiesSize!)
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}
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}
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}
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