Init Commit

src/main/java/zmodem/xfer/zm/proto/Escape.java

@@ -0,0 +1,99 @@
+package zmodem.xfer.zm.proto;
+
+import zmodem.xfer.zm.util.ZModemCharacter;
+
+import java.util.HashMap;
+import java.util.Map;
+
+
+public class Escape {
+
+    private int len = 0;
+    private Action action = Action.ESCAPE;
+
+
+    public Escape(Action a) {
+        this(a, 0);
+    }
+
+
+    public Escape(Action a, int l) {
+        len = l;
+        action = a;
+    }
+
+    public Action action() {
+        return action;
+    }
+
+
+    public int len() {
+        return len;
+    }
+
+
+    private static Map<Byte, Escape> _specials = new HashMap<Byte, Escape>();
+
+    static {
+        _specials.put(ZModemCharacter.ZBIN.value(), new Escape(Action.HEADER, 7));
+        _specials.put(ZModemCharacter.ZHEX.value(), new Escape(Action.HEADER, 16));
+        _specials.put(ZModemCharacter.ZBIN32.value(), new Escape(Action.HEADER, 9));
+        _specials.put(ZModemCharacter.ZCRCE.value(), new Escape(Action.DATA, 2));
+        _specials.put(ZModemCharacter.ZCRCG.value(), new Escape(Action.DATA, 2));
+        _specials.put(ZModemCharacter.ZCRCQ.value(), new Escape(Action.DATA, 2));
+        _specials.put(ZModemCharacter.ZCRCW.value(), new Escape(Action.DATA, 2));
+    }
+
+
+    public static Escape detect(byte b, boolean acceptsHeader) {
+        Escape r = _specials.get(b);
+
+
+        if (r == null || ((!acceptsHeader) && r.action() == Action.HEADER))
+            return new Escape(Action.ESCAPE);
+
+        return r;
+    }
+
+    public static boolean mustEscape(byte b, byte previous, boolean escapeCtl) {
+        switch (b) {
+            case 0xd:
+            case (byte) 0x8d:
+                if (escapeCtl && previous == '@')
+                    return true;
+                break;
+            case 0x18:
+            case 0x10:
+            case 0x11:
+            case 0x13:
+            case (byte) 0x7f:
+            case (byte) 0x90:
+            case (byte) 0x91:
+            case (byte) 0x93:
+            case (byte) 0xff:
+                return true;
+            default:
+                if (escapeCtl && ((b & 0x60) == 0))
+                    return true;
+        }
+        return false;
+    }
+
+    public static byte escapeIt(byte b) {
+        if (b == (byte) 0x7f)
+            return ZModemCharacter.ZRUB0.value();
+        if (b == (byte) 0xff)
+            return ZModemCharacter.ZRUB1.value();
+        if (b == (byte) ZModemCharacter.ZRUB0.value())
+            return 0x7f;
+        if (b == (byte) ZModemCharacter.ZRUB1.value())
+            return (byte) 0xff;
+
+        return (byte) (b ^ 0x40);
+    }
+
+    @Override
+    public String toString() {
+        return "Action=" + action + ", len=" + len;
+    }
+}