finished component: MutableField

src/main/java/component/MutableField.java

@@ -0,0 +1,98 @@
+package component;
+
+import encoding.*;
+
+/*
+ * @Author: Wang Feng
+ * @Description: 表示一个MIN包格式中的可变区
+ * @Version: 1.0.0
+ * @Date: 20:48 2021/3/9
+ * @Copyright: MIN-Group；国家重大科技基础设施——未来网络北大实验室；深圳市信息论与未来网络重点实验室
+ */
+public class MutableField implements TlvComponentBase,IEncodingAble {
+    private MutableProtectField mutableProtectField;
+    private MutableDangerousField mutableDangerousField;
+
+    public MutableField(){
+        mutableProtectField=new MutableProtectField();
+        mutableDangerousField=new MutableDangerousField();
+    }
+
+    /**
+     * 将可变区线速编码为一个 TLV
+     * @param encoder
+     * @return
+     */
+    @Override
+    public int wireEncode(Encoder encoder) {
+        int totalLength=0;
+
+        // 编码 TLV—VALUE
+        int tmplen=this.mutableDangerousField.wireEncode(encoder);
+        if(tmplen==0){
+            return 0;
+        }
+        totalLength+=tmplen;
+        tmplen=this.mutableProtectField.wireEncode(encoder);
+        if(tmplen==0){
+            return 0;
+        }
+        totalLength+=tmplen;
+
+        // 如果可变保护区和可变非受保护区均为空，则可以去掉可变区
+        if(totalLength==0){
+            return 0;
+        }
+
+        // 编码 TLV-LENGTH
+        tmplen=encoder.prependVarNumber(new VlInt(totalLength));
+        if(tmplen==0){
+            return 0;
+        }
+        totalLength+=tmplen;
+
+        // 编码 TLV-TYPE
+        tmplen=encoder.prependVarNumber(new VlInt(TLV.TlvMutableField));
+        if(tmplen==0){
+            return 0;
+        }
+        totalLength+=tmplen;
+
+        return totalLength;
+    }
+
+    /**
+     * 从 TLV Block 中解码出一个 MutableField
+     * @param block
+     * @return
+     */
+    @Override
+    public boolean wireDecode(Block block) {
+        // 检查 Type 是否正确
+        if(!TLV.expectType(block.getTlvType(),new VlInt(TLV.TlvMutableField))){
+            return false;
+        }
+
+        // 解析子 TLV
+        if(!block.parseSubElements()){
+            return false;
+        }
+
+        for (int i = 0; i < block.getSubElements().length(); i++) {
+            Block subBlock=block.getSubElements().getBlock(i);
+            if(subBlock.getTlvType().isEqual(TLV.TlvMutableProtectField)){
+                if(!this.mutableProtectField.wireDecode(subBlock)){
+                    return false;
+                }
+            }else if(subBlock.getTlvType().isEqual(TLV.TlvMutableDangerousField)){
+                if(!this.mutableDangerousField.wireDecode(subBlock)){
+                    return false;
+                }
+            }else{
+                return false;
+            }
+        }
+
+        return false;
+    }
+}