[SPARK-52061] Add getOption/isModifiable and set variants to RuntimeConf

### What changes were proposed in this pull request?

This PR aims to add `getOption`, `isModifiable` and more `set` API variants to `RuntimeConf`.

### Why are the changes needed?

For feature parity.

### Does this PR introduce _any_ user-facing change?

No.

### How was this patch tested?

Pass the CIs.

### Was this patch authored or co-authored using generative AI tooling?

No.

Closes #119 from dongjoon-hyun/SPARK-52061.

Authored-by: Dongjoon Hyun <[email protected]>
Signed-off-by: Dongjoon Hyun <[email protected]>

Author: dongjoon-hyun

Sources/SparkConnect/RuntimeConf.swift

@@ -35,23 +35,69 @@ public actor RuntimeConf {
     try await client.setConf(map: [key: value])
   }
 
+  /// Set a new configuration.
+  /// - Parameters:
+  ///   - key: A string for the configuration key.
+  ///   - value: A boolean value for the configuration.
+  public func set(_ key: String, _ value: Bool) async throws {
+    try await client.setConf(map: [key: String(value)])
+  }
+
+  /// Set a new configuration.
+  /// - Parameters:
+  ///   - key: A string for the configuration key.
+  ///   - value: A Int64 value for the configuration.
+  public func set(_ key: String, _ value: Int64) async throws {
+    try await client.setConf(map: [key: String(value)])
+  }
+
   /// Reset a configuration.
   /// - Parameters:
   ///   - key: A string for the configuration key.
   public func unset(_ key: String) async throws {
     try await client.unsetConf(keys: [key])
   }
 
-  /// Get a configuration.
+  /// Returns the value of Spark runtime configuration property for the given key. If the key is
+  /// not set yet, return its default value if possible, otherwise `NoSuchElementException` will be
+  /// thrown.
   /// - Parameter key: A string for the configuration look-up.
   /// - Returns: A string for the configuration.
   public func get(_ key: String) async throws -> String {
     return try await client.getConf(key)
   }
 
+  /// Returns the value of Spark runtime configuration property for the given key. If the key is
+  /// not set yet, return the user given `value`. This is useful when its default value defined
+  /// by Apache Spark is not the desired one.
+  /// - Parameters:
+  ///   - key: A string for the configuration key.
+  ///   - value: A default string value for the configuration.
+  public func get(_ key: String, _ value: String) async throws -> String {
+    return try await client.getConfWithDefault(key, value)
+  }
+
   /// Get all configurations.
   /// - Returns: A map of configuration key-values.
   public func getAll() async throws -> [String: String] {
     return try await client.getConfAll()
   }
+
+  /// Returns the value of Spark runtime configuration property for the given key. If the key is
+  /// not set yet, return its default value if possible, otherwise `nil` will be returned.
+  /// - Parameter key: A string for the configuration look-up.
+  /// - Returns: A string for the configuration or nil.
+  public func getOption(_ key: String) async throws -> String? {
+    return try await client.getConfOption(key)
+  }
+
+  /// Indicates whether the configuration property with the given key is modifiable in the current
+  /// session.
+  /// - Parameter key: A string for the configuration look-up.
+  /// - Returns: `true` if the configuration property is modifiable. For static SQL, Spark Core, invalid
+  /// (not existing) and other non-modifiable configuration properties, the returned value is
+  /// `false`.
+  public func isModifiable(_ key: String) async throws -> Bool {
+    return try await client.isModifiable(key)
+  }
 }

Sources/SparkConnect/SparkConnectClient.swift

@@ -206,6 +206,73 @@ public actor SparkConnectClient {
     }
   }
 
+  /// Create a ``ConfigRequest`` instance for `GetWithDefault` operation.
+  /// - Parameter pairs: A key-value dictionary.
+  /// - Returns: A `ConfigRequest` instance.
+  func getConfigRequestGetWithDefault(_ pairs: [String: String]) -> ConfigRequest {
+    var request = ConfigRequest()
+    request.operation = ConfigRequest.Operation()
+    var getWithDefault = ConfigRequest.GetWithDefault()
+    getWithDefault.pairs = pairs.toSparkConnectKeyValue
+    request.operation.opType = .getWithDefault(getWithDefault)
+    return request
+  }
+
+  /// Returns the value of Spark runtime configuration property for the given key. If the key is
+  /// not set yet, return the user given `value`. This is useful when its default value defined
+  /// by Apache Spark is not the desired one.
+  /// - Parameters:
+  ///   - key: A string for the configuration key.
+  ///   - value: A default value for the configuration.
+  func getConfWithDefault(_ key: String, _ value: String) async throws -> String {
+    try await withGPRC { client in
+      let service = SparkConnectService.Client(wrapping: client)
+      var request = getConfigRequestGetWithDefault([key: value])
+      request.clientType = clientType
+      request.userContext = userContext
+      request.sessionID = self.sessionID!
+      let response = try await service.config(request)
+      let result = if response.pairs[0].hasValue {
+        response.pairs[0].value
+      } else {
+        value
+      }
+      return result
+    }
+  }
+
+  /// Create a ``ConfigRequest`` instance for `GetOption` operation.
+  /// - Parameter keys: An array of keys to get.
+  /// - Returns: A `ConfigRequest` instance.
+  func getConfigRequestGetOption(_ keys: [String]) -> ConfigRequest {
+    var request = ConfigRequest()
+    request.operation = ConfigRequest.Operation()
+    var getOption = ConfigRequest.GetOption()
+    getOption.keys = keys
+    request.operation.opType = .getOption(getOption)
+    return request
+  }
+
+  /// Request the server to get a value of the given key.
+  /// - Parameter key: A string for key to look up.
+  /// - Returns: A string or nil for the value of the key.
+  func getConfOption(_ key: String) async throws -> String? {
+    try await withGPRC { client in
+      let service = SparkConnectService.Client(wrapping: client)
+      var request = getConfigRequestGetOption([key])
+      request.clientType = clientType
+      request.userContext = userContext
+      request.sessionID = self.sessionID!
+      let response = try await service.config(request)
+      let result: String? = if response.pairs[0].hasValue {
+        response.pairs[0].value
+      } else {
+        nil
+      }
+      return result
+    }
+  }
+
   /// Create a ``ConfigRequest`` for `GetAll` operation.
   /// - Returns: A `ConfigRequest` instance.
   func getConfigRequestGetAll() -> ConfigRequest {
@@ -234,6 +301,35 @@ public actor SparkConnectClient {
     }
   }
 
+  /// Create a ``ConfigRequest`` for `IsModifiable` operation.
+  /// - Returns: A `ConfigRequest` instance.
+  func getConfigRequestIsModifiable(_ keys: [String]) -> ConfigRequest {
+    var request = ConfigRequest()
+    request.operation = ConfigRequest.Operation()
+    var isModifiable = ConfigRequest.IsModifiable()
+    isModifiable.keys = keys
+    request.operation.opType = .isModifiable(isModifiable)
+    return request
+  }
+
+  /// Indicates whether the configuration property with the given key is modifiable in the current
+  /// session.
+  /// - Parameter key: A string for the configuration look-up.
+  /// - Returns: `true` if the configuration property is modifiable. For static SQL, Spark Core, invalid
+  /// (not existing) and other non-modifiable configuration properties, the returned value is
+  /// `false`.
+  func isModifiable(_ key: String) async throws -> Bool {
+    try await withGPRC { client in
+      let service = SparkConnectService.Client(wrapping: client)
+      var request = getConfigRequestIsModifiable([key])
+      request.clientType = clientType
+      request.userContext = userContext
+      request.sessionID = self.sessionID!
+      let response = try await service.config(request)
+      return response.pairs[0].value == "true"
+    }
+  }
+
   func getLocalRelation() -> Plan {
     var localRelation = Spark_Connect_LocalRelation()
     localRelation.schema = ""

Tests/SparkConnectTests/RuntimeConfTests.swift

@@ -42,6 +42,26 @@ struct RuntimeConfTests {
     await client.stop()
   }
 
+  @Test
+  func getWithDefault() async throws {
+    let client = SparkConnectClient(remote: TEST_REMOTE)
+    try await client.connect(UUID().uuidString)
+    let conf = RuntimeConf(client)
+    #expect(try await conf.get("spark.sql.adaptive.customCostEvaluatorClass", "XYZ") == "XYZ")
+    #expect(try await conf.get("spark.test.non-exist", "my_default") == "my_default")
+    await client.stop()
+  }
+
+  @Test
+  func getOption() async throws {
+    let client = SparkConnectClient(remote: TEST_REMOTE)
+    try await client.connect(UUID().uuidString)
+    let conf = RuntimeConf(client)
+    #expect(try await conf.getOption("spark.app.name") != nil)
+    #expect(try await conf.getOption("spark.test.non-exist") == nil)
+    await client.stop()
+  }
+
   @Test
   func set() async throws {
     let client = SparkConnectClient(remote: TEST_REMOTE)
@@ -86,4 +106,15 @@ struct RuntimeConfTests {
     #expect(map["spark.master"] != nil)
     await client.stop()
   }
+
+  @Test
+  func isModifiable() async throws {
+    let client = SparkConnectClient(remote: TEST_REMOTE)
+    try await client.connect(UUID().uuidString)
+    let conf = RuntimeConf(client)
+    #expect(try await conf.isModifiable("spark.sql.adaptive.customCostEvaluatorClass"))
+    #expect(try await conf.isModifiable("spark.sql.warehouse.dir") == false)
+    #expect(try await conf.isModifiable("spark.test.non-exist") == false)
+    await client.stop()
+  }
 }