Log changed images for classification

Sources/App/CapServer.swift

@@ -18,12 +18,17 @@ final class CapServer: ServerOwner {
     
     private let classifierFile: URL
     
+    private let changedImagesFile: URL
+    
     private let fm = FileManager.default
     
     // MARK: Caps
 
     private var writers: Set<String>
     
+    /// The changed images not yet written to disk
+    private var unwrittenImageChanges: [(cap: Int, image: Int)] = []
+    
     var classifierVersion: Int = 0 {
         didSet {
             writeClassifierVersion()
@@ -70,6 +75,7 @@ final class CapServer: ServerOwner {
         self.htmlFile = folder.appendingPathComponent("count.html")
         self.classifierVersionFile = folder.appendingPathComponent("classifier.version")
         self.classifierFile = folder.appendingPathComponent("classifier.mlmodel")
+        self.changedImagesFile = folder.appendingPathComponent("changes.txt")
         self.writers = Set(writers)
     }
 
@@ -243,9 +249,54 @@ final class CapServer: ServerOwner {
         }
         try data.write(to: f)
         caps[cap]!.count = try count(of: cap)
+        addChangedImageToLog(cap: cap, image: id)
         log("Added image \(id) for cap \(cap)")
     }
     
+    private func writeChangedImagesToDisk() throws {
+        guard !unwrittenImageChanges.isEmpty else {
+            return
+        }
+        if !fm.fileExists(atPath: changedImagesFile.path) {
+            try Data().write(to: changedImagesFile)
+        }
+        
+        let handle = try FileHandle(forWritingTo: changedImagesFile)
+        try handle.seekToEnd()
+        var entries = unwrittenImageChanges
+        defer {
+            unwrittenImageChanges = entries
+            try? handle.close()
+        }
+        let df = DateFormatter()
+        df.dateFormat = "yy-MM-dd-HH-mm-ss"
+        let dateString = df.string(from: Date())
+        while let entry = entries.popLast() {
+            let content = "\(dateString):\(entry.cap):\(entry.image)".data(using: .utf8)!
+            try handle.write(contentsOf: content)
+        }
+    }
+    
+    private func addChangedImageToLog(cap: Int, image: Int) {
+        unwrittenImageChanges.append((cap, image))
+        do {
+            try writeChangedImagesToDisk()
+        } catch {
+            log("Failed to save changed image list: \(error)")
+        }
+    }
+    
+    func deleteChangedImageListFile() {
+        guard fm.fileExists(atPath: changedImagesFile.path) else {
+            return
+        }
+        do {
+            try fm.removeItem(at: changedImagesFile)
+        } catch {
+            log("Failed to delete changed images file: \(error)")
+        }
+    }
+    
     func switchMainImage(to version: Int, for cap: Int) throws {
         let file2 = file(of: cap, version: version)
         guard fm.fileExists(atPath: file2.path) else {

Sources/App/routes.swift

@@ -78,4 +78,10 @@ func routes(_ app: Application) {
         }
         server.updateTrainedClasses(content: content)
     }
+    
+    // Reset the changed images list
+    app.postCatching("changes") { request in
+        try authorize(request)
+        server.deleteChangedImageListFile()
+    }
 }