feat(mobile): hash assets in isolate (#18924)

mobile/ios/Runner/Sync/Messages.g.swift

@@ -307,6 +307,7 @@ protocol NativeSyncApi {
   func getAlbums() throws -> [PlatformAlbum]
   func getAssetsCountSince(albumId: String, timestamp: Int64) throws -> Int64
   func getAssetsForAlbum(albumId: String, updatedTimeCond: Int64?) throws -> [PlatformAsset]
+  func hashPaths(paths: [String]) throws -> [FlutterStandardTypedData?]
 }
 
 /// Generated setup class from Pigeon to handle messages through the `binaryMessenger`.
@@ -442,5 +443,22 @@ class NativeSyncApiSetup {
     } else {
       getAssetsForAlbumChannel.setMessageHandler(nil)
     }
+    let hashPathsChannel = taskQueue == nil
+      ? FlutterBasicMessageChannel(name: "dev.flutter.pigeon.immich_mobile.NativeSyncApi.hashPaths\(channelSuffix)", binaryMessenger: binaryMessenger, codec: codec)
+      : FlutterBasicMessageChannel(name: "dev.flutter.pigeon.immich_mobile.NativeSyncApi.hashPaths\(channelSuffix)", binaryMessenger: binaryMessenger, codec: codec, taskQueue: taskQueue)
+    if let api = api {
+      hashPathsChannel.setMessageHandler { message, reply in
+        let args = message as! [Any?]
+        let pathsArg = args[0] as! [String]
+        do {
+          let result = try api.hashPaths(paths: pathsArg)
+          reply(wrapResult(result))
+        } catch {
+          reply(wrapError(error))
+        }
+      }
+    } else {
+      hashPathsChannel.setMessageHandler(nil)
+    }
   }
 }

mobile/ios/Runner/Sync/MessagesImpl.swift

@@ -1,4 +1,5 @@
 import Photos
+import CryptoKit
 
 struct AssetWrapper: Hashable, Equatable {
   let asset: PlatformAsset
@@ -34,6 +35,8 @@ class NativeSyncApiImpl: NativeSyncApi {
   private let changeTokenKey = "immich:changeToken"
   private let albumTypes: [PHAssetCollectionType] = [.album, .smartAlbum]
   
+  private let hashBufferSize = 2 * 1024 * 1024
+  
   init(with defaults: UserDefaults = .standard) {
     self.defaults = defaults
   }
@@ -243,4 +246,24 @@ class NativeSyncApiImpl: NativeSyncApi {
     }
     return assets
   }
+  
+  func hashPaths(paths: [String]) throws -> [FlutterStandardTypedData?] {
+      return paths.map { path in
+          guard let file = FileHandle(forReadingAtPath: path) else {
+              print("Cannot open file: \(path)")
+              return nil
+          }
+          
+          var hasher = Insecure.SHA1()
+          while autoreleasepool(invoking: {
+              let chunk = file.readData(ofLength: hashBufferSize)
+              guard !chunk.isEmpty else { return false }
+              hasher.update(data: chunk)
+              return true
+          }) { }
+          
+          let digest = hasher.finalize()
+          return FlutterStandardTypedData(bytes: Data(digest))
+      }
+  }
 }