khanwinter.com
A fast, safe, and efficient CBOR serialization library for Swift on any platform.
swiftpackageindex.com/thecoolwinter/CBOR/1.1.1/documentation/cbor
atproto
swift
cbor
Introduce `decodeMultiple` API
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FUZZ.md
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FUZZ.md
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Sources/CBOR/Decoder/CBORDecoder.swift
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Sources/CBOR/Decoder/CBORDecoder.swift
···
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}
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}
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/// Decodes multiple instances of the given type from CBOR binary data.
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///
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/// Some BLOBs are made up of multiple CBOR-encoded datas concatenated without valid CBOR dividers (eg in an array
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/// container). This method decodes that kind of data. It will attempt to decode an instance of the given type,
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/// once done, if there's more data, it will continue to attempt to decode more instances.
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///
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/// - Parameters:
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/// - type: The decodable type to deserialize.
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/// - data: The CBOR data to decode from.
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/// - Returns: An instance of the decoded type.
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/// - Throws: A ``DecodingError`` with context and a debug description for a failed deserialization operation.
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public func decodeMultiple<T: Decodable>(_ type: T.Type, from data: Data) throws -> [T] {
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do {
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return try data.withUnsafeBytes {
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let data = $0[...]
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let reader = DataReader(data: data)
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let scanner = CBORScanner(data: reader, options: options)
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let results = try scanner.scan()
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guard !results.isEmpty else {
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throw ScanError.unexpectedEndOfData
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}
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let context = DecodingContext(options: options, results: results)
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var nextRegion: DataRegion? = results.load(at: 0)
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var accumulator: [T] = []
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while let region = nextRegion {
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let value = try SingleValueCBORDecodingContainer(context: context, data: region).decode(T.self)
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accumulator.append(value)
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let nextMapIndex = results.siblingIndex(region.mapOffset)
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if nextMapIndex < results.count {
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nextRegion = results.load(at: results.siblingIndex(region.mapOffset))
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} else {
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nextRegion = nil
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}
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}
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return accumulator
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}
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} catch {
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if let error = error as? ScanError {
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try throwScanError(error)
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} else {
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throw error
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}
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}
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}
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private func throwScanError(_ error: ScanError) throws -> Never {
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switch error {
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case .unexpectedEndOfData:
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Sources/CBOR/Decoder/Scanner/CBORScanner+Results.swift
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Sources/CBOR/Decoder/Scanner/CBORScanner+Results.swift
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Sources/Fuzzing/main.swift
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Sources/Fuzzing/main.swift
···
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func tryDecode<T: Decodable>(_ type: T.Type) {
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do {
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blackhole(try CBORDecoder(rejectIndeterminateLengths: false).decode(T.self, from: data))
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blackhole(try CBORDecoder(rejectIndeterminateLengths: true).decode(T.self, from: data))
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blackhole(try CBORDecoder(rejectIndeterminateLengths: false).decodeMultiple(T.self, from: data))
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blackhole(try CBORDecoder(rejectIndeterminateLengths: true).decodeMultiple(T.self, from: data))
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} catch {
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// ignore decode errors
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}
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Tests/CBORTests/DecodeMultipleTests.swift
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Tests/CBORTests/DecodeMultipleTests.swift
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//
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// DecodeMultipleTests.swift
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// CBOR
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//
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// Created by Khan Winter on 9/10/25.
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//
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import Testing
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#if canImport(FoundationEssentials)
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import FoundationEssentials
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#else
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import Foundation
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#endif
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@testable import CBOR
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@Suite
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struct DecodeMultipleTests {
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@Test
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func decodeMultipleInts() throws {
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var value: [UInt8] = try CBORDecoder().decodeMultiple(UInt8.self, from: [0])
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#expect(value == [0])
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value = try CBORDecoder().decodeMultiple(UInt8.self, from: [1, 1])
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#expect(value == [1, 1])
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// Just below max arg size
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value = try CBORDecoder().decodeMultiple(UInt8.self, from: [23, 23])
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#expect(value == [23, 23])
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// Just above max arg size
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value = try CBORDecoder().decodeMultiple(UInt8.self, from: [24, 24, 24, 24])
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#expect(value == [24, 24])
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// Max Int
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value = try CBORDecoder().decodeMultiple(UInt8.self, from: [24, UInt8.max])
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#expect(value == [UInt8.max])
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#expect(throws: DecodingError.self) { try CBORDecoder().decodeMultiple(UInt8.self, from: [128, 128]) }
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#expect(throws: DecodingError.self) { try CBORDecoder().decodeMultiple(UInt8.self, from: [23, 128]) }
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}
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@Test
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func mutlipleMaps() throws {
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let data = "A262414201614102A262414201614102".asHexData()
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let dictionary = try CBORDecoder().decodeMultiple([String: Int].self, from: data)
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#expect(dictionary == [["AB": 1, "A": 2], ["AB": 1, "A": 2]])
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}
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}