Resource.swift 5.0 KB

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  1. //
  2. // Resource.swift
  3. // Kingfisher
  4. //
  5. // Created by Wei Wang on 15/4/6.
  6. //
  7. // Copyright (c) 2019 Wei Wang <onevcat@gmail.com>
  8. //
  9. // Permission is hereby granted, free of charge, to any person obtaining a copy
  10. // of this software and associated documentation files (the "Software"), to deal
  11. // in the Software without restriction, including without limitation the rights
  12. // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  13. // copies of the Software, and to permit persons to whom the Software is
  14. // furnished to do so, subject to the following conditions:
  15. //
  16. // The above copyright notice and this permission notice shall be included in
  17. // all copies or substantial portions of the Software.
  18. //
  19. // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20. // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21. // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  22. // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  23. // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  24. // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  25. // THE SOFTWARE.
  26. import Foundation
  27. /// Represents an image resource at a certain url and a given cache key.
  28. /// Kingfisher will use a `Resource` to download a resource from network and cache it with the cache key when
  29. /// using `Source.network` as its image setting source.
  30. public protocol Resource {
  31. /// The key used in cache.
  32. var cacheKey: String { get }
  33. /// The target image URL.
  34. var downloadURL: URL { get }
  35. }
  36. extension Resource {
  37. /// Converts `self` to a valid `Source` based on its `downloadURL` scheme. A `.provider` with
  38. /// `LocalFileImageDataProvider` associated will be returned if the URL points to a local file. Otherwise,
  39. /// `.network` is returned.
  40. public func convertToSource(overrideCacheKey: String? = nil) -> Source {
  41. let key = overrideCacheKey ?? cacheKey
  42. return downloadURL.isFileURL ?
  43. .provider(LocalFileImageDataProvider(fileURL: downloadURL, cacheKey: key)) :
  44. .network(KF.ImageResource(downloadURL: downloadURL, cacheKey: key))
  45. }
  46. }
  47. @available(*, deprecated, message: "This type conflicts with `GeneratedAssetSymbols.ImageResource` in Swift 5.9. Renamed to avoid issues in the future.", renamed: "KF.ImageResource")
  48. public typealias ImageResource = KF.ImageResource
  49. extension KF {
  50. /// ImageResource is a simple combination of `downloadURL` and `cacheKey`.
  51. /// When passed to image view set methods, Kingfisher will try to download the target
  52. /// image from the `downloadURL`, and then store it with the `cacheKey` as the key in cache.
  53. public struct ImageResource: Resource {
  54. // MARK: - Initializers
  55. /// Creates an image resource.
  56. ///
  57. /// - Parameters:
  58. /// - downloadURL: The target image URL from where the image can be downloaded.
  59. /// - cacheKey: The cache key. If `nil`, Kingfisher will use the `absoluteString` of `downloadURL` as the key.
  60. /// Default is `nil`.
  61. public init(downloadURL: URL, cacheKey: String? = nil) {
  62. self.downloadURL = downloadURL
  63. self.cacheKey = cacheKey ?? downloadURL.cacheKey
  64. }
  65. // MARK: Protocol Conforming
  66. /// The key used in cache.
  67. public let cacheKey: String
  68. /// The target image URL.
  69. public let downloadURL: URL
  70. }
  71. }
  72. /// URL conforms to `Resource` in Kingfisher.
  73. /// The `absoluteString` of this URL is used as `cacheKey`. And the URL itself will be used as `downloadURL`.
  74. /// If you need customize the url and/or cache key, use `ImageResource` instead.
  75. extension URL: Resource {
  76. public var cacheKey: String { return isFileURL ? localFileCacheKey : absoluteString }
  77. public var downloadURL: URL { return self }
  78. }
  79. extension URL {
  80. static let localFileCacheKeyPrefix = "kingfisher.local.cacheKey"
  81. // The special version of cache key for a local file on disk. Every time the app is reinstalled on the disk,
  82. // the system assigns a new container folder to hold the .app (and the extensions, .appex) folder. So the URL for
  83. // the same image in bundle might be different.
  84. //
  85. // This getter only uses the fixed part in the URL (until the bundle name folder) to provide a stable cache key
  86. // for the image under the same path inside the bundle.
  87. //
  88. // See #1825 (https://github.com/onevcat/Kingfisher/issues/1825)
  89. var localFileCacheKey: String {
  90. var validComponents: [String] = []
  91. for part in pathComponents.reversed() {
  92. validComponents.append(part)
  93. if part.hasSuffix(".app") || part.hasSuffix(".appex") {
  94. break
  95. }
  96. }
  97. let fixedPath = "\(Self.localFileCacheKeyPrefix)/\(validComponents.reversed().joined(separator: "/"))"
  98. if let q = query {
  99. return "\(fixedPath)?\(q)"
  100. } else {
  101. return fixedPath
  102. }
  103. }
  104. }