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Tusker
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Code Issues 78 Pull Requests Releases Wiki Activity

Use MultiThreadedDictionary for ImageCache request groups 

Prevents a crash due a race condition if multiple requets complete
simultaneously and attempt to modify the dictionary
This commit is contained in:
Shadowfacts 2020-10-17 13:10:10 -04:00
parent a805da9faa
commit 3ff9fdabdb
Signed by: shadowfacts
GPG Key ID: 94A5AB95422746E5
7 changed files with 59 additions and 44 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
Tusker.xcodeproj/project.pbxproj
View File

@ -140,7 +140,7 @@
D64BC19223C271D9000D0238 /* MastodonActivity.swift in Sources */ = {isa = PBXBuildFile; fileRef = D64BC19123C271D9000D0238 /* MastodonActivity.swift */; };
D64D0AAD2128D88B005A6F37 /* LocalData.swift in Sources */ = {isa = PBXBuildFile; fileRef = D64D0AAC2128D88B005A6F37 /* LocalData.swift */; };
D64D0AB12128D9AE005A6F37 /* OnboardingViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D64D0AB02128D9AE005A6F37 /* OnboardingViewController.swift */; };
D64D8CA92463B494006B0BAA /* CachedDictionary.swift in Sources */ = {isa = PBXBuildFile; fileRef = D64D8CA82463B494006B0BAA /* CachedDictionary.swift */; };
D64D8CA92463B494006B0BAA /* MultiThreadDictionary.swift in Sources */ = {isa = PBXBuildFile; fileRef = D64D8CA82463B494006B0BAA /* MultiThreadDictionary.swift */; };
D64F80E2215875CC00BEF393 /* XCBActionType.swift in Sources */ = {isa = PBXBuildFile; fileRef = D64F80E1215875CC00BEF393 /* XCBActionType.swift */; };
D6531DEE246B81C9000F9538 /* GifvAttachmentView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6531DED246B81C9000F9538 /* GifvAttachmentView.swift */; };
D6531DF0246B867E000F9538 /* GifvAttachmentViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6531DEF246B867E000F9538 /* GifvAttachmentViewController.swift */; };
@ -471,7 +471,7 @@
D64BC19123C271D9000D0238 /* MastodonActivity.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MastodonActivity.swift; sourceTree = "<group>"; };
D64D0AAC2128D88B005A6F37 /* LocalData.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LocalData.swift; sourceTree = "<group>"; };
D64D0AB02128D9AE005A6F37 /* OnboardingViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = OnboardingViewController.swift; sourceTree = "<group>"; };
D64D8CA82463B494006B0BAA /* CachedDictionary.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CachedDictionary.swift; sourceTree = "<group>"; };
D64D8CA82463B494006B0BAA /* MultiThreadDictionary.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MultiThreadDictionary.swift; sourceTree = "<group>"; };
D64F80E1215875CC00BEF393 /* XCBActionType.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = XCBActionType.swift; sourceTree = "<group>"; };
D6531DED246B81C9000F9538 /* GifvAttachmentView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = GifvAttachmentView.swift; sourceTree = "<group>"; };
D6531DEF246B867E000F9538 /* GifvAttachmentViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = GifvAttachmentViewController.swift; sourceTree = "<group>"; };
@ -1360,7 +1360,7 @@
D6945C2E23AC47C3005C403C /* SavedDataManager.swift */,
D6C693EE216192C2007D6A6D /* TuskerNavigationDelegate.swift */,
D6DFC69F242C4CCC00ACC392 /* WeakArray.swift */,
D64D8CA82463B494006B0BAA /* CachedDictionary.swift */,
D64D8CA82463B494006B0BAA /* MultiThreadDictionary.swift */,
D60E2F2B24423EAD005F8713 /* LazilyDecoding.swift */,
D6CA6A91249FAD8900AD45C1 /* AudioSessionHelper.swift */,
D6E4269C2532A3E100C02E1C /* FuzzyMatcher.swift */,
@ -1928,7 +1928,7 @@
D641C773213CAA25004B4513 /* NotificationsTableViewController.swift in Sources */,
D6412B0524B0227D00F5412E /* ProfileViewController.swift in Sources */,
D64BC18A23C16487000D0238 /* UnpinStatusActivity.swift in Sources */,
D64D8CA92463B494006B0BAA /* CachedDictionary.swift in Sources */,
D64D8CA92463B494006B0BAA /* MultiThreadDictionary.swift in Sources */,
D6757A7C2157E01900721E32 /* XCBManager.swift in Sources */,
D6F1F84D2193B56E00F5FE67 /* Cache.swift in Sources */,
D6F0B12B24A3071C001E48C3 /* MainSplitViewController.swift in Sources */,

35
Tusker/CachedDictionary.swift
View File

@ -1,35 +0,0 @@
//
// CachedDictionary.swift
// Tusker
//
// Created by Shadowfacts on 5/6/20.
// Copyright © 2020 Shadowfacts. All rights reserved.
//
import Foundation
class CachedDictionary<Value> {
private let name: String
private var dict = [String: Value]()
private let queue: DispatchQueue
init(name: String) {
self.name = name
self.queue = DispatchQueue(label: "CachedDictionary (\(name)) Coordinator", attributes: .concurrent)
}
subscript(key: String) -> Value? {
get {
var result: Value? = nil
queue.sync {
result = dict[key]
}
return result
}
set(value) {
queue.async(flags: .barrier) {
self.dict[key] = value
}
}
}
}

4
Tusker/Caching/ImageCache.swift
View File

@ -24,7 +24,7 @@ class ImageCache {
private let cache: Cache<Data>
private var groups = [URL: RequestGroup]()
private var groups = MultiThreadDictionary<URL, RequestGroup>(name: "ImageCache request groups")
init(name: String, memoryExpiry expiry: Expiry) {
let storage = MemoryStorage<Data>(config: MemoryConfig(expiry: expiry))
@ -56,7 +56,7 @@ class ImageCache {
if let data = data {
try? self.cache.setObject(data, forKey: key)
}
self.groups.removeValue(forKey: url)
self.groups.removeValueWithoutReturning(forKey: url)
}
groups[url] = group
let request = group.addCallback(completion)

50
Tusker/MultiThreadDictionary.swift Normal file
View File

@ -0,0 +1,50 @@
//
// MultiThreadDictionary.swift
// Tusker
//
// Created by Shadowfacts on 5/6/20.
// Copyright © 2020 Shadowfacts. All rights reserved.
//
import Foundation
class MultiThreadDictionary<Key: Hashable, Value> {
private let name: String
private var dict = [Key: Value]()
private let queue: DispatchQueue
init(name: String) {
self.name = name
self.queue = DispatchQueue(label: "MultiThreadDictionary (\(name)) Coordinator", attributes: .concurrent)
}
subscript(key: Key) -> Value? {
get {
var result: Value? = nil
queue.sync {
result = dict[key]
}
return result
}
set(value) {
queue.async(flags: .barrier) {
self.dict[key] = value
}
}
}
func removeValueWithoutReturning(forKey key: Key) {
queue.async(flags: .barrier) {
self.dict.removeValue(forKey: key)
}
}
/// If the result of this function is unused, it is preferable to use `removeValueWithoutReturning` as it executes asynchronously and doesn't block the calling thread.
func removeValue(forKey key: Key) -> Value? {
var value: Value? = nil
queue.sync(flags: .barrier) {
value = dict.removeValue(forKey: key)
}
return value
}
}

2
Tusker/Views/AccountDisplayNameLabel.swift
View File

@ -41,7 +41,7 @@ struct AccountDisplayNameLabel<Account: AccountProtocol>: View {
let matches = emojiRegex.matches(in: account.displayName, options: [], range: fullRange)
guard !matches.isEmpty else { return }
let emojiImages = CachedDictionary<Image>(name: "AcccountDisplayNameLabel Emoji Images")
let emojiImages = MultiThreadDictionary<String, Image>(name: "AcccountDisplayNameLabel Emoji Images")
let group = DispatchGroup()

2
Tusker/Views/ContentTextView.swift
View File

@ -51,7 +51,7 @@ class ContentTextView: LinkTextView {
func setEmojis(_ emojis: [Emoji]) {
guard !emojis.isEmpty else { return }
let emojiImages = CachedDictionary<UIImage>(name: "ContentTextView Emoji Images")
let emojiImages = MultiThreadDictionary<String, UIImage>(name: "ContentTextView Emoji Images")
let group = DispatchGroup()

2
Tusker/Views/EmojiLabel.swift
View File

@ -26,7 +26,7 @@ class EmojiLabel: UILabel {
let matches = emojiRegex.matches(in: attributedText.string, options: [], range: attributedText.fullRange)
guard !matches.isEmpty else { return }
let emojiImages = CachedDictionary<UIImage>(name: "EmojiLabel Emoji Images")
let emojiImages = MultiThreadDictionary<String, UIImage>(name: "EmojiLabel Emoji Images")
let group = DispatchGroup()