Add RedisDataConvertible

Author: Mordil

Sources/NIORedis/Data/RedisDataConvertible.swift

@@ -0,0 +1,143 @@
+import Foundation
+
+/// Capable of converting to / from `RedisData`.
+public protocol RedisDataConvertible {
+    /// Create an instance of `Self` from `RedisData`.
+    static func convertFromRedisData(_ data: RedisData) throws -> Self
+
+    /// Convert self to `RedisData`.
+    func convertToRedisData() throws -> RedisData
+}
+
+extension RedisData: RedisDataConvertible {
+    /// See `RedisDataConvertible`.
+    public func convertToRedisData() throws -> RedisData {
+        return self
+    }
+
+    /// See `RedisDataConvertible`.
+    public static func convertFromRedisData(_ data: RedisData) throws -> RedisData {
+        return data
+    }
+}
+
+extension String: RedisDataConvertible {
+    /// See `RedisDataConvertible`.
+    public static func convertFromRedisData(_ data: RedisData) throws -> String {
+        guard let string = data.string else {
+            throw RedisError(identifier: "string", reason: "Could not convert to string: \(data).")
+        }
+        return string
+    }
+
+    /// See `RedisDataConvertible`.
+    public func convertToRedisData() throws -> RedisData {
+        return .bulkString(Data(self.utf8))
+    }
+}
+
+extension FixedWidthInteger {
+    /// See `RedisDataConvertible`.
+    public static func convertFromRedisData(_ data: RedisData) throws -> Self {
+        guard let int = data.int else {
+            guard let string = data.string else {
+                throw RedisError(identifier: "string", reason: "Could not convert to string: \(data)")
+            }
+
+            guard let int = Self(string) else {
+                throw RedisError(identifier: "int", reason: "Could not convert to int: \(data)")
+            }
+
+            return int
+        }
+
+        return Self(int)
+    }
+
+    /// See `RedisDataConvertible`.
+    public func convertToRedisData() throws -> RedisData {
+        return .bulkString(Data(self.description.utf8))
+    }
+}
+
+extension Int: RedisDataConvertible {}
+extension Int8: RedisDataConvertible {}
+extension Int16: RedisDataConvertible {}
+extension Int32: RedisDataConvertible {}
+extension Int64: RedisDataConvertible {}
+extension UInt: RedisDataConvertible {}
+extension UInt8: RedisDataConvertible {}
+extension UInt16: RedisDataConvertible {}
+extension UInt32: RedisDataConvertible {}
+extension UInt64: RedisDataConvertible {}
+
+extension Double: RedisDataConvertible {
+    /// See `RedisDataConvertible`.
+    public static func convertFromRedisData(_ data: RedisData) throws -> Double {
+        guard let string = data.string else {
+            throw RedisError(identifier: "string", reason: "Could not convert to string: \(data).")
+        }
+
+        guard let float = Double(string) else {
+            throw RedisError(identifier: "double", reason: "Could not convert to double: \(data).")
+        }
+
+        return float
+    }
+
+    /// See `RedisDataConvertible`.
+    public func convertToRedisData() throws -> RedisData {
+        return .bulkString(Data(self.description.utf8))
+    }
+}
+
+extension Float: RedisDataConvertible {
+    /// See `RedisDataConvertible`.
+    public static func convertFromRedisData(_ data: RedisData) throws -> Float {
+        guard let string = data.string else {
+            throw RedisError(identifier: "string", reason: "Could not convert to string: \(data).")
+        }
+
+        guard let float = Float(string) else {
+            throw RedisError(identifier: "float", reason: "Could not convert to float: \(data).")
+        }
+
+        return float
+    }
+
+    /// See `RedisDataConvertible`.
+    public func convertToRedisData() throws -> RedisData {
+        return .bulkString(Data(self.description.utf8))
+    }
+}
+
+extension Data: RedisDataConvertible {
+    /// See `RedisDataConvertible`.
+    public static func convertFromRedisData(_ data: RedisData) throws -> Data {
+        guard let theData = data.data else {
+            throw RedisError(identifier: "data", reason: "Could not convert to data: \(data).")
+        }
+        return theData
+    }
+
+    /// See `RedisDataConvertible`.
+    public func convertToRedisData() throws -> RedisData {
+        return .bulkString(self)
+    }
+}
+
+extension Array: RedisDataConvertible where Element: RedisDataConvertible {
+    /// See `RedisDataConvertible`.
+    public static func convertFromRedisData(_ data: RedisData) throws -> Array<Element> {
+        guard let array = data.array else {
+            throw RedisError(identifier: "array", reason: "Could not convert to array: \(data).")
+        }
+        return try array.map { try Element.convertFromRedisData($0) }
+    }
+
+    /// See `RedisDataConvertible`.
+    public func convertToRedisData() throws -> RedisData {
+        let dataArray = try map { try $0.convertToRedisData() }
+        return RedisData.array(dataArray)
+    }
+}