perf: Proto encode telemetry data

Package.resolved

@@ -1,6 +1,15 @@
 {
   "object": {
     "pins": [
+      {
+        "package": "SwiftProtobuf",
+        "repositoryURL": "https://github.com/apple/swift-protobuf.git",
+        "state": {
+          "branch": null,
+          "revision": "ebc7251dd5b37f627c93698e4374084d98409633",
+          "version": "1.28.2"
+        }
+      },
       {
         "package": "OpenFeature",
         "repositoryURL": "[email protected]:open-feature/swift-sdk.git",

Package.swift

@@ -19,11 +19,14 @@ let package = Package(
     ],
     dependencies: [
         .package(url: "[email protected]:open-feature/swift-sdk.git", from: "0.1.0"),
+        .package(url: "https://github.com/apple/swift-protobuf.git", from: "1.0.0"),
     ],
     targets: [
         .target(
             name: "Confidence",
-            dependencies: [],
+            dependencies: [
+                .product(name: "SwiftProtobuf", package: "swift-protobuf")
+            ],
             plugins: []
         ),
         .target(

Sources/Confidence/Apply/FlagApplierWithRetries.swift

@@ -140,7 +140,7 @@ final class FlagApplierWithRetries: FlagApplier {
         request: ApplyFlagsRequest
     ) async -> ApplyFlagResult {
         do {
-            let header = telemetry.getSnapshot()
+            let header: Data = telemetry.getSnapshot()
             return try await httpClient.post(path: ":apply", data: request, header: header)
         } catch {
             return .failure(handleError(error: error))

Sources/Confidence/Http/HttpClient.swift

@@ -4,7 +4,7 @@ typealias HttpClientResult<T> = Result<HttpClientResponse<T>, Error>
 
 internal protocol HttpClient {
     func post<T: Decodable>(path: String, data: Encodable) async throws -> HttpClientResult<T>
-    func post<T: Decodable>(path: String, data: Encodable, header: Encodable) async throws -> HttpClientResult<T>
+    func post<T: Decodable>(path: String, data: Encodable, header: Data) async throws -> HttpClientResult<T>
 }
 
 struct HttpClientResponse<T> {

Sources/Confidence/Http/NetworkClient.swift

@@ -29,7 +29,7 @@ final class NetworkClient: HttpClient {
         self.timeoutIntervalForRequests = timeoutIntervalForRequests
     }
 
-    func post<T>(path: String, data: any Encodable, header: any Encodable) async throws -> HttpClientResult<T> where T : Decodable {
+    func post<T>(path: String, data: any Encodable, header: Data) async throws -> HttpClientResult<T> where T : Decodable {
         let request = try buildRequest(path: path, data: data, header: header)
         return try await post(request: request)
     }
@@ -107,7 +107,7 @@ extension NetworkClient {
         return URL(string: "\(normalisedBase)\(normalisedPath)")
     }
 
-    private func buildRequest(path: String, data: Encodable, header: Encodable? = nil) throws -> URLRequest {
+    private func buildRequest(path: String, data: Encodable, header: Data? = nil) throws -> URLRequest {
         guard let url = constructURL(base: baseUrl, path: path) else {
             throw ConfidenceError.internalError(message: "Could not create service url")
         }
@@ -123,26 +123,10 @@ extension NetworkClient {
         encoder.dateEncodingStrategy = .iso8601
 
         if let header = header {
-            let jsonHeaderData = try encoder.encode(header)
-
-            if let headerJsonString = String(data: jsonHeaderData, encoding: .utf8) {
-                request.addValue(headerJsonString, forHTTPHeaderField: "Confidence-Metadata")
-            }
-        }
-        // TMP - TESTING
-        if let headers = request.allHTTPHeaderFields, let metadata = headers["Confidence-Metadata"] {
-            if let data = metadata.data(using: .utf8) {
-                do {
-                    let jsonObject = try JSONSerialization.jsonObject(with: data, options: [])
-                    let prettyData = try JSONSerialization.data(withJSONObject: jsonObject, options: .prettyPrinted)
-
-                    if let prettyPrintedString = String(data: prettyData, encoding: .utf8) {
-                        print(prettyPrintedString)
-                    }
-                } catch {
-                    print("Failed to pretty print JSON: \(error)")
-                }
-            }
+            request.addValue(header.base64EncodedString(), forHTTPHeaderField: "Confidence-Metadata")
+            // TMP - TESTING
+            let telemetryData = try LibraryData(serializedBytes: header)
+            print(telemetryData)
         }
 
         let jsonData = try encoder.encode(data)

Sources/Confidence/Telemetry/TelemetryManager.swift

@@ -3,27 +3,39 @@ import Foundation
 protocol TelemetryManager {
     func incrementStaleAccess()
     func incrementFlagTypeMismatch()
-    func getSnapshot() -> TelemetryPayload
+    func getSnapshot() -> Data
 }
 
 class Telemetry: TelemetryManager {
     private let queue = DispatchQueue(label: "com.confidence.telemetry_manager")
-    private var staleAccessCounter = 0;
-    private var flagTypeMismatchCounter = 0;
+    private var staleAccessCounter: Int32 = 0;
+    private var flagTypeMismatchCounter: Int32 = 0;
 
     public init() {}
 
     static public let shared: TelemetryManager = Telemetry.init()
 
-    public func getSnapshot() -> TelemetryPayload {
-        TelemetryPayload(
-            libraryId: ConfidenceMetadata.defaultMetadata.id,
-            libraryVersion: ConfidenceMetadata.defaultMetadata.version,
-            countTraces: [
-                CountTrace.init(traceId: TraceId.staleAccess, count: getStaleAccessAndReset()),
-                CountTrace.init(traceId: TraceId.typeMismatch, count: getFlagTypeMismatchAndReset()),
-            ],
-            durationsTraces: [])
+    public func getSnapshot() -> Data {
+        // Initialize your data using the generated types
+        var countTrace1 = CountTrace()
+        countTrace1.traceID = .traceStale
+        countTrace1.count = getStaleAccessAndReset()
+
+        var countTrace2 = CountTrace()
+        countTrace2.traceID = .traceTypeMismatch
+        countTrace2.count = getFlagTypeMismatchAndReset()
+
+        var libraryData = LibraryData()
+        libraryData.countTraces = [countTrace1, countTrace2]
+        libraryData.libraryID = .sdkSwiftCore
+        libraryData.libraryVersion = "1.0.1"
+        libraryData.durationsTraces = []
+        do {
+            return try libraryData.serializedData()
+        } catch {
+            print("Failed to encode telemetry data: \(error)")
+            return Data()
+        }
     }
 
     public func incrementStaleAccess() {
@@ -38,15 +50,15 @@ class Telemetry: TelemetryManager {
         }
     }
 
-    private func getStaleAccessAndReset() -> Int {
+    private func getStaleAccessAndReset() -> Int32 {
         return queue.sync {
             let currentCounter = staleAccessCounter
             staleAccessCounter = 0;
             return currentCounter
         }
     }
 
-    private func getFlagTypeMismatchAndReset() -> Int {
+    private func getFlagTypeMismatchAndReset() -> Int32 {
         return queue.sync {
             let currentCounter = flagTypeMismatchCounter
             flagTypeMismatchCounter = 0;