Sesame-iOS/Sesame/HistoryManager.swift

93 lines
2.6 KiB
Swift
Raw Normal View History

import Foundation
import CBORCoding
protocol HistoryManagerProtocol {
func loadEntries() -> [HistoryItem]
func save(item: HistoryItem) throws
}
final class HistoryManager: HistoryManagerProtocol {
private let encoder = CBOREncoder(dateEncodingStrategy: .secondsSince1970)
private var fm: FileManager {
.default
}
static var documentDirectory: URL {
try! FileManager.default.url(
for: .documentDirectory,
in: .userDomainMask,
appropriateFor: nil, create: true)
}
private let fileUrl: URL
init() {
self.fileUrl = HistoryManager.documentDirectory.appendingPathComponent("history2.bin")
}
func loadEntries() -> [HistoryItem] {
guard fm.fileExists(atPath: fileUrl.path) else {
print("No history data found")
return []
}
let content: Data
do {
content = try Data(contentsOf: fileUrl)
} catch {
print("Failed to read history data: \(error)")
return []
}
let decoder = CBORDecoder()
var index = 0
var entries = [HistoryItem]()
while index < content.count {
let length = Int(content[index])
index += 1
if index + length > content.count {
print("Missing bytes in history file: needed \(length), has only \(content.count - index)")
return entries
}
let entryData = content[index..<index+length]
index += length
do {
let entry: HistoryItem = try decoder.decode(from: entryData)
entries.append(entry)
} catch {
print("Failed to decode history (index: \(index), length \(length)): \(error)")
return entries
}
}
return entries.sorted().reversed()
}
func save(item: HistoryItem) throws {
let entryData = try encoder.encode(item)
let data = Data([UInt8(entryData.count)]) + entryData
guard fm.fileExists(atPath: fileUrl.path) else {
try data.write(to: fileUrl)
print("First history item written (\(data[0]))")
return
}
let handle = try FileHandle(forWritingTo: fileUrl)
try handle.seekToEnd()
try handle.write(contentsOf: data)
try handle.close()
print("History item written (\(data[0]))")
}
}
final class HistoryManagerMock: HistoryManagerProtocol {
func loadEntries() -> [HistoryItem] {
[.mock]
}
func save(item: HistoryItem) throws {
}
}