Added (incomplete) support for parsing name scripts.

core/src/main/java/org/libdohj/script/NameScript.java

@@ -0,0 +1,181 @@
+/*
+ * Copyright 2016 Jeremy Rand.
+ *
+ * Licensed 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.
+ */
+
+package org.libdohj.script;
+
+import org.bitcoinj.core.ScriptException;
+import org.bitcoinj.script.Script;
+import org.bitcoinj.script.ScriptBuilder;
+import org.bitcoinj.script.ScriptChunk;
+import static org.bitcoinj.script.ScriptOpCodes.*;
+
+import java.util.ArrayList;
+import java.util.List;
+
+// TODO: review this
+
+public class NameScript {
+
+    public static final int OP_NAME_NEW = OP_1;
+    public static final int OP_NAME_FIRSTUPDATE = OP_2;
+    public static final int OP_NAME_UPDATE = OP_3;
+
+    protected int op;
+    
+    protected ArrayList<ScriptChunk> args;
+    
+    protected Script address;
+
+    public NameScript(Script baseScript) {
+        op = OP_NOP;
+        args = new ArrayList<ScriptChunk>();
+        address = baseScript;
+        
+        ScriptChunk nameOp;
+        int pc = 0;
+        
+        List<ScriptChunk> chunks = baseScript.getChunks();
+        
+        try {
+            nameOp = chunks.get(pc);
+        } catch (IndexOutOfBoundsException e) {
+            return;
+        }
+        pc++;
+        
+        while(true) {
+            ScriptChunk arg;
+            
+            try {
+                arg = chunks.get(pc);
+            } catch (IndexOutOfBoundsException e) {
+                return;
+            }
+            pc++;
+            
+            if(arg.opcode == OP_DROP || arg.opcode == OP_2DROP || arg.opcode == OP_NOP) {
+                break;
+            }
+            if( ! (arg.opcode >= 0 && arg.opcode <= OP_PUSHDATA4) ) {
+                return;
+            }
+            
+            args.add(arg);
+        }
+        
+        // Move the pc to after any DROP or NOP.
+        try {
+            while(chunks.get(pc).opcode == OP_DROP || chunks.get(pc).opcode == OP_2DROP || chunks.get(pc).opcode == OP_NOP) {
+                pc++;
+            }
+        } catch (IndexOutOfBoundsException e) {
+        }
+        
+        /* Now, we have the args and the operation.  Check if we have indeed
+        a valid name operation and valid argument counts.  Only now set the
+        op and address members, if everything is valid.  */
+        
+        switch (nameOp.opcode) {
+            case OP_NAME_NEW:
+                if(args.size() != 1) {
+                    return;
+                }
+                break;
+            case OP_NAME_FIRSTUPDATE:
+                if(args.size() != 3) {
+                    return;
+                }
+                break;
+            case OP_NAME_UPDATE:
+                if(args.size() != 2) {
+                    return;
+                }
+                break;
+            default:
+                return;
+        }
+        
+        op = nameOp.opcode;
+        
+        ScriptBuilder addressBuilder = new ScriptBuilder();
+        while(pc < chunks.size()) {
+            addressBuilder.addChunk(chunks.get(pc));
+            pc++;
+        }
+        address = addressBuilder.build();
+    }
+    
+    public boolean isNameOp() {
+        switch(op) {
+            case OP_NAME_NEW:
+            case OP_NAME_FIRSTUPDATE:
+            case OP_NAME_UPDATE:
+                return true;
+            
+            case OP_NOP:
+                return false;
+            
+            default:
+                throw new ScriptException("Invalid name op");
+        }
+    }
+    
+    public Script getAddress() {
+        return address;
+    }
+    
+    // TODO: getNameOp
+    
+    public boolean isAnyUpdate() {
+        switch(op) {
+            case OP_NAME_NEW:
+                return false;
+            
+            case OP_NAME_FIRSTUPDATE:
+            case OP_NAME_UPDATE:
+                return true;
+            
+            default:
+                throw new ScriptException("Not a name op");
+        }
+    }
+    
+    public ScriptChunk getOpName() {
+        switch(op) {
+            case OP_NAME_FIRSTUPDATE:
+            case OP_NAME_UPDATE:
+                return args.get(0);
+            
+            default:
+                throw new ScriptException("Not an AnyUpdate op");
+        }
+    }
+    
+    public ScriptChunk getOpValue() {
+        switch(op) {
+            case OP_NAME_FIRSTUPDATE:
+                return args.get(2);
+            
+            case OP_NAME_UPDATE:
+                return args.get(1);
+            
+            default:
+                throw new ScriptException("Not an AnyUpdate op");
+        }
+    }
+    
+    // TODO: getOpRand, getOpHash, isNameScript, buildNameNew, buildNameFirstupdate, buildNameUpdate
+}