mirror of
https://github.com/tsolomko/SWCompression.git
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Timofey Solomko
59 lines
2.1 KiB
Swift
59 lines
2.1 KiB
Swift
// Copyright (c) 2026 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 BitByteData
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/// A type that represents an extra field from a ZIP container.
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public protocol ZipExtraField {
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/**
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ID of extra field. Must be equal to the key of extra field in `ZipContainer.customExtraFields` dictionary and
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instance `id` property
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*/
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static var id: UInt16 { get }
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/// Location of extra field. Must be equal to the value of `location` argument of `init?(_:_:location:)`.
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var location: ZipExtraFieldLocation { get }
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/// Size of extra field's data. Must be equal to the value of the second argument of `init?(_:_:location:)`.
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var size: Int { get }
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/**
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Creates an extra field instance reading `size` amount of data from `byteReader`.
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It is guaranteed that the offset of `byteReader` is equal to the position right after extra field header ID and
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length of extra field data. It is also guaranteed that header ID matches conforming type's static `id` property.
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Following conditions are checked after execution of this initializer. Failure to satisfy them in conforming type
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will result in runtime error.
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- Postcondition: `location` property of a created instance must be equal to the `location` argument.
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- Postcondition: `size` property of a created instance must be equal to the second argument.
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- Postcondition: exactly `size` amount of bytes must be read by initializer from `byteReader`.
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*/
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init?(_ byteReader: LittleEndianByteReader, _ size: Int, location: ZipExtraFieldLocation)
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}
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extension ZipExtraField {
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/**
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ID of extra field. Must be equal to the key of extra field in `ZipContainer.customExtraFields` dictionary and
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static `id` property
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*/
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public var id: UInt16 {
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return Self.id
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}
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}
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/// Location of ZIP extra field inside a container.
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public enum ZipExtraFieldLocation {
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/// ZIP extra field is located in container's Central Directory.
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case centralDirectory
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/// ZIP extra field is located in one of container's Local Headers.
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case localHeader
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}
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