Add isLocalResourcesSupportEnabled

CHANGELOG.md

@@ -12,6 +12,7 @@
 - Fix https://github.com/kean/Nuke/issues/763 SwiftUI Warning: Accessing StateObject's object without being installed on a View when using `onStart`
 - Fix https://github.com/kean/Nuke/issues/758 by adding support for initializing `ImageProcessors.CoreImageFilter` with `CIFilter` instances
 - Add support for disk cache lookup for intermediate processed images (as opposed to only final and original as before)
+- Add an optimization that loads local resources with `file` and `data` schemes quickly without using `DataLoader` and `URLSession`. If you rely on the existing behavior, this optimization can be turned off using the `isLocalResourcesSupportEnabled` configuration option. https://github.com/kean/Nuke/pull/779
 - Deprecate `ImagePipeline.Configuration.dataCachingQueue` and perform data cache lookups on the pipeline's queue, reducing the amount of context switching
 - Update the infrastructure for coalescing image-processing tasks to use the task-dependency used for other operations
 

Sources/Nuke/Pipeline/ImagePipelineConfiguration.swift

@@ -114,6 +114,10 @@ extension ImagePipeline {
         /// `Last-Modified`). Resumable downloads are enabled by default.
         public var isResumableDataEnabled = true
 
+        /// If enabled, the pipeline will load the local resources (`file` and
+        /// `data` schemes) inline without using the data loader. By default, `true`.
+        public var isLocalResourcesSupportEnabled = true
+
         /// A queue on which all callbacks, like `progress` and `completion`
         /// callbacks are called. `.main` by default.
         public var callbackQueue = DispatchQueue.main

Sources/Nuke/Tasks/TaskFetchOriginalData.swift

@@ -13,12 +13,22 @@ final class TaskFetchOriginalData: ImagePipelineTask<(Data, URLResponse?)> {
     private var data = Data()
 
     override func start() {
-        guard let urlRequest = request.urlRequest else {
+        guard let urlRequest = request.urlRequest, let url = urlRequest.url else {
             // A malformed URL prevented a URL request from being initiated.
             send(error: .dataLoadingFailed(error: URLError(.badURL)))
             return
         }
 
+        if url.isLocalResource && pipeline.configuration.isLocalResourcesSupportEnabled {
+            do {
+                let data = try Data(contentsOf: url)
+                send(value: (data, nil), isCompleted: true)
+            } catch {
+                send(error: .dataLoadingFailed(error: error))
+            }
+            return
+        }
+
         if let rateLimiter = pipeline.rateLimiter {
             // Rate limiter is synchronized on pipeline's queue. Delayed work is
             // executed asynchronously also on the same queue.

Tests/NukeTests/ImagePipelineTests/ImagePipelineDataCacheTests.swift

@@ -624,17 +624,17 @@ class ImagePipelineDataCachePolicyTests: XCTestCase {
         XCTAssertEqual(dataCache.store.count, 2)
     }
 
-    // MARK: Local Storage
-    
+    // MARK: Local Resources
+
     func testImagesFromLocalStorageNotCached() {
         // GIVEN
         pipeline = pipeline.reconfigured {
             $0.dataCachePolicy = .automatic
         }
 
         // GIVEN request without a processor
-        let request = ImageRequest(url: URL(string: "file://example/image.jpeg"))
-        
+        let request = ImageRequest(url: Test.url(forResource: "fixture", extension: "jpeg"))
+
         // WHEN
         expect(pipeline).toLoadImage(with: request)
         wait()
@@ -652,8 +652,8 @@ class ImagePipelineDataCachePolicyTests: XCTestCase {
         }
 
         // GIVEN request with a processor
-        let request = ImageRequest(url: URL(string: "file://example/image.jpeg") ,processors: [.resize(width: 100)])
-        
+        let request = ImageRequest(url: Test.url(forResource: "fixture", extension: "jpeg") ,processors: [.resize(width: 100)])
+
         // WHEN
         expect(pipeline).toLoadImage(with: request)
         wait()
@@ -671,8 +671,8 @@ class ImagePipelineDataCachePolicyTests: XCTestCase {
         }
 
         // GIVEN request without a processor
-        let request = ImageRequest(url: URL(string: "data://example/image.jpeg"))
-        
+        let request = ImageRequest(url: Test.url(forResource: "fixture", extension: "jpeg"))
+
         // WHEN
         expect(pipeline).toLoadImage(with: request)
         wait()
@@ -682,7 +682,28 @@ class ImagePipelineDataCachePolicyTests: XCTestCase {
         XCTAssertEqual(dataCache.writeCount, 0)
         XCTAssertEqual(dataCache.store.count, 0)
     }
-
+
+    func testImagesFromData() {
+        // GIVEN
+        pipeline = pipeline.reconfigured {
+            $0.dataCachePolicy = .automatic
+        }
+
+        // GIVEN request without a processor
+        let data = Test.data(name: "fixture", extension: "jpeg")
+        let url = URL(string: "data:image/jpeg;base64,\(data.base64EncodedString())")
+        let request = ImageRequest(url: url)
+
+        // WHEN
+        expect(pipeline).toLoadImage(with: request)
+        wait()
+
+        // THEN original image data is stored in disk cache
+        XCTAssertEqual(encoder.encodeCount, 0)
+        XCTAssertEqual(dataCache.writeCount, 0)
+        XCTAssertEqual(dataCache.store.count, 0)
+    }
+
     // MARK: Misc
 
     func testSetCustomImageEncoder() {