Formatting, linting, and hopefully a CI build.

Sources/StableDiffusionCore/Errors.swift

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+import Foundation
+
+public enum SdCoreError: Error {
+    case modelNotLoaded
+    case imageEncode
+    case modelNotFound
+}

Sources/StableDiffusionCore/ImageExtensions.swift

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+import CoreImage
+import Foundation
+import UniformTypeIdentifiers
+
+extension CGImage {
+    func toPngData() throws -> Data {
+        guard let data = CFDataCreateMutable(nil, 0) else {
+            throw SdCoreError.imageEncode
+        }
+
+        guard let destination = CGImageDestinationCreateWithData(data, "public.png" as CFString, 1, nil) else {
+            throw SdCoreError.imageEncode
+        }
+
+        CGImageDestinationAddImage(destination, self, nil)
+        if CGImageDestinationFinalize(destination) {
+            return data as Data
+        } else {
+            throw SdCoreError.imageEncode
+        }
+    }
+}

Sources/StableDiffusionCore/ModelManager.swift

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+import Foundation
+import StableDiffusion
+import StableDiffusionProtos
+
+public actor ModelManager {
+    private var modelInfos: [String: SdModelInfo] = [:]
+    private var modelUrls: [String: URL] = [:]
+    private var modelStates: [String: ModelState] = [:]
+
+    private let modelBaseURL: URL
+
+    public init(modelBaseURL: URL) {
+        self.modelBaseURL = modelBaseURL
+    }
+
+    public func reloadModels() throws {
+        modelInfos.removeAll()
+        modelStates.removeAll()
+        let contents = try FileManager.default.contentsOfDirectory(at: modelBaseURL.resolvingSymlinksInPath(), includingPropertiesForKeys: [.isDirectoryKey])
+        for subdirectoryURL in contents {
+            let values = try subdirectoryURL.resourceValues(forKeys: [.isDirectoryKey])
+            if values.isDirectory ?? false {
+                try addModel(url: subdirectoryURL)
+            }
+        }
+    }
+
+    public func listModels() -> [SdModelInfo] {
+        Array(modelInfos.values)
+    }
+
+    public func getModelState(name: String) -> ModelState? {
+        modelStates[name]
+    }
+
+    private func addModel(url: URL) throws {
+        var info = SdModelInfo()
+        info.name = url.lastPathComponent
+        let attention = getModelAttention(url)
+        info.attention = attention ?? "unknown"
+        modelInfos[info.name] = info
+        modelUrls[info.name] = url
+        modelStates[info.name] = try ModelState(url: url)
+    }
+
+    private func getModelAttention(_ url: URL) -> String? {
+        let unetMetadataURL = url.appending(components: "Unet.mlmodelc", "metadata.json")
+
+        struct ModelMetadata: Decodable {
+            let mlProgramOperationTypeHistogram: [String: Int]
+        }
+
+        do {
+            let jsonData = try Data(contentsOf: unetMetadataURL)
+            let metadatas = try JSONDecoder().decode([ModelMetadata].self, from: jsonData)
+
+            guard metadatas.count == 1 else {
+                return nil
+            }
+
+            return metadatas[0].mlProgramOperationTypeHistogram["Ios16.einsum"] != nil ? "split-einsum" : "original"
+        } catch {
+            return nil
+        }
+    }
+}

Sources/StableDiffusionCore/ModelState.swift

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+import CoreML
+import Foundation
+import StableDiffusion
+import StableDiffusionProtos
+
+public actor ModelState {
+    private let url: URL
+    private var pipeline: StableDiffusionPipeline?
+    private var tokenizer: BPETokenizer?
+
+    public init(url: URL) throws {
+        self.url = url
+    }
+
+    public func load() throws {
+        let config = MLModelConfiguration()
+        config.computeUnits = .all
+        pipeline = try StableDiffusionPipeline(
+            resourcesAt: url,
+            controlNet: [],
+            configuration: config,
+            disableSafety: true,
+            reduceMemory: false
+        )
+        let mergesUrl = url.appending(component: "merges.txt")
+        let vocabUrl = url.appending(component: "vocab.json")
+        tokenizer = try BPETokenizer(mergesAt: mergesUrl, vocabularyAt: vocabUrl)
+    }
+
+    public func generate(_ request: SdGenerateImagesRequest) throws -> SdGenerateImagesResponse {
+        guard let pipeline else {
+            throw SdCoreError.modelNotLoaded
+        }
+
+        var pipelineConfig = StableDiffusionPipeline.Configuration(prompt: request.prompt)
+        pipelineConfig.negativePrompt = request.negativePrompt
+        pipelineConfig.seed = UInt32.random(in: 0 ..< UInt32.max)
+
+        var response = SdGenerateImagesResponse()
+        for _ in 0 ..< request.imageCount {
+            let images = try pipeline.generateImages(configuration: pipelineConfig)
+
+            for cgImage in images {
+                guard let cgImage else { continue }
+                var image = SdImage()
+                image.content = try cgImage.toPngData()
+                response.images.append(image)
+            }
+        }
+        return response
+    }
+}