add TJSONProtocol support (#35)

Ported from C#.NET project

Package.swift

@@ -30,6 +30,7 @@ let package = Package(
             targets: ["Thrift"]),
     ],
     targets: [
-        .target(name: "Thrift", path: "Sources")
+        .target(name: "Thrift", path: "Sources"),
+        .testTarget(name: "ThriftTests", dependencies: ["Thrift"])
     ]
 )

Sources/TBase64Utils.swift

@@ -0,0 +1,89 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import Foundation
+
+public class TBase64Utils {
+    private static let EncodeTable: String = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
+    private static let NA: UInt8 = UInt8(255)
+
+    private static let DecodeTable: [UInt8] = [
+        NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA,
+        NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA,
+        NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, 62, NA, NA, NA, 63,
+        52, 53, 54, 55, 56, 57, 58, 59, 60, 61, NA, NA, NA, NA, NA, NA,
+        NA, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
+        15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, NA, NA, NA, NA, NA,
+        NA, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+        41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, NA, NA, NA, NA, NA,
+        NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA,
+        NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA,
+        NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA,
+        NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA,
+        NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA,
+        NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA,
+        NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA,
+        NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA,
+    ]
+
+    static func encode(src: [UInt8], srcOff: Int, len: Int, dst: inout [UInt8], dstOff: Int) {
+        if (src.count == 0) {
+            return
+        }
+        var index: UInt8 = 0
+
+        index = src[srcOff] >> 2 & 0x3F
+        dst[dstOff] = EncodeTable[Int(index)].asciiValue!
+
+        if (len == 3) {
+            index = ((src[srcOff] << 4) & 0x30) | ((src[srcOff + 1] >> 4) & 0x0F)
+            dst[dstOff + 1] = EncodeTable[Int(index)].asciiValue!
+
+            index = ((src[srcOff + 1] << 2) & 0x3C) | ((src[srcOff + 2] >> 6) & 0x03)
+            dst[dstOff + 2] = EncodeTable[Int(index)].asciiValue!
+
+            index = (src[srcOff + 2]  & 0x3F)
+            dst[dstOff + 3] = EncodeTable[Int(index)].asciiValue!
+        } else if (len == 2) {
+            index = ((src[srcOff] << 4) & 0x30) | ((src[srcOff + 1] >> 4) & 0x0F)
+            dst[dstOff + 1] = EncodeTable[Int(index)].asciiValue!
+
+            index = ((src[srcOff + 1] << 2) & 0x3C)
+            dst[dstOff + 2] = EncodeTable[Int(index)].asciiValue!
+        } else {
+            // len == 1
+            index = ((src[srcOff] << 4) & 0x30)
+            dst[dstOff + 1] = EncodeTable[Int(index)].asciiValue!
+        }
+    }
+
+    static func decode(src: [UInt8], srcOff: Int, len: Int, dst: inout [UInt8], dstOff: Int) {
+        if (src.count == 0) {
+            return
+        }
+
+        dst[dstOff] =  (DecodeTable[Int(src[srcOff] & 0x0FF)] << 2) | (DecodeTable[Int(src[srcOff + 1] & 0x0FF)] >> 4)
+        if (len > 2) {
+            dst[dstOff + 1] =  ((DecodeTable[Int(src[srcOff + 1] & 0x0FF)] << 4) & 0xF0) | (DecodeTable[Int(src[srcOff + 2] & 0x0FF)] >> 2)
+            if (len > 3) {
+                dst[dstOff + 2] =  ((DecodeTable[Int(src[srcOff + 2] & 0x0FF)] << 6) & 0xC0) | (DecodeTable[Int(src[srcOff + 3] & 0x0FF)])
+            }
+        }
+    }
+}