instantiate json encoder and decoder once

Author: nathanborror

Sources/OpenAI/Client.swift

@@ -9,10 +9,20 @@ public final class Client {
 
     internal(set) public var session: URLSession
 
+    private let encoder: JSONEncoder
+    private let decoder: JSONDecoder
+
     public init(session: URLSession = URLSession(configuration: .default), host: URL? = nil, apiKey: String) {
         self.session = session
         self.host = host ?? Self.defaultHost
         self.apiKey = apiKey
+        self.encoder = JSONEncoder()
+        self.decoder = JSONDecoder()
+        self.decoder.dateDecodingStrategy = .custom { decoder in
+            let container = try decoder.singleValueContainer()
+            let dateInt = try container.decode(Int.self)
+            return Date(timeIntervalSince1970: TimeInterval(dateInt))
+        }
     }
 
     public enum Error: Swift.Error, CustomStringConvertible {
@@ -185,7 +195,7 @@ extension Client {
                 req.httpBody = try encodeMultipartFormData(body, boundary: boundary)
             } else {
                 req.setValue("application/json; charset=utf-8", forHTTPHeaderField: "Content-Type")
-                req.httpBody = try JSONEncoder().encode(body)
+                req.httpBody = try encoder.encode(body)
             }
         }
         return req
@@ -218,14 +228,4 @@ extension Client {
         data.append("--\(boundary)--\r\n".data(using: .utf8)!)
         return data
     }
-
-    private var decoder: JSONDecoder {
-        let decoder = JSONDecoder()
-        decoder.dateDecodingStrategy = .custom { decoder in
-            let container = try decoder.singleValueContainer()
-            let dateInt = try container.decode(Int.self)
-            return Date(timeIntervalSince1970: TimeInterval(dateInt))
-        }
-        return decoder
-    }
 }

Sources/OpenAI/StreamingSession.swift

@@ -16,13 +16,15 @@ final class StreamingSession<ResultType: Codable>: NSObject, Identifiable, URLSe
 
     private let session: URLSession
     private let request: URLRequest
+    private let decoder: JSONDecoder
 
     private var streamingBuffer = ""
     private let streamingCompletionMarker = "[DONE]"
 
     init(session: URLSession, request: URLRequest) {
         self.session = session
         self.request = request
+        self.decoder = JSONDecoder()
     }
 
     func perform() {
@@ -58,7 +60,6 @@ final class StreamingSession<ResultType: Codable>: NSObject, Identifiable, URLSe
                 onProcessingError?(self, StreamingError.unknownContent)
                 return
             }
-            let decoder = JSONDecoder()
             do {
                 let object = try decoder.decode(ResultType.self, from: jsonData)
                 onReceiveContent?(self, object)