ScriptOperationUtil.java

package com.yoghurt.crypto.transactions.shared.util;

import com.yoghurt.crypto.transactions.shared.domain.Operation;
import com.yoghurt.crypto.transactions.shared.domain.ScriptPart;
import com.yoghurt.crypto.transactions.shared.domain.ScriptPartType;
import com.yoghurt.crypto.transactions.shared.domain.ScriptType;
import com.yoghurt.crypto.transactions.shared.domain.TransactionPartType;

public final class ScriptOperationUtil {

  private ScriptOperationUtil() {}

  // TODO Get these out of some cache instead of iterating over the enum values
  public static Operation getOperation(final int opcode) {
    // Test for simple push data ops
    if(opcode > 0 && 75 >= opcode) {
      return Operation.OP_PUSHDATA;
    }

    // Iterate over all operations and give back a match
    for(final Operation op : Operation.values()) {
      if(op.getOpcode() == opcode) {
        return op;
      }
    }

    // Can't find it, return invalid op
    return Operation.OP_INVALIDOPCODE;
  }

  public static TransactionPartType getScriptPartType(final ScriptType type, final ScriptPartType partType) {
    switch (type) {
    case SCRIPT_PUB_KEY:
      switch (partType) {
      case OP_CODE:
        return TransactionPartType.SCRIPT_PUB_KEY_OP_CODE;
      case PUSH_DATA:
        return TransactionPartType.SCRIPT_PUB_KEY_PUSH_DATA;
      case PUSH_DATA_EXTRA:
        return TransactionPartType.SCRIPT_PUB_KEY_PUSH_DATA_EXTRA;
      }
    case SCRIPT_SIG:
      switch (partType) {
      case OP_CODE:
        return TransactionPartType.SCRIPT_SIG_OP_CODE;
      case PUSH_DATA:
        return TransactionPartType.SCRIPT_SIG_PUSH_DATA;
      case PUSH_DATA_EXTRA:
        return TransactionPartType.SCRIPT_SIG_PUSH_DATA_EXTRA;
      }
    }

    return null;
  }

  /**
   * Data push operations are 1-75, OP_PUSHDATA1, 2 and 4 (so up to opcode 78), excluding OP0 through 16.
   *
   * And also null (indicating coinbase input TODO: remind me why again?)
   */
  public static boolean isDataPushOperation(final Operation op) {
    return op == null || op == Operation.OP_PUSHDATA || isDataPushOperation(op.getOpcode());
  }

  public static boolean isDataPushOperation(final int opcode) {
    return opcode >= 1 && 78 >= opcode;
  }

  public static byte getOperationOpCode(final ScriptPart part) {
    if(part.getOperation() == Operation.OP_PUSHDATA) {
      return (byte) (part.getBytes().length & 0xFF);
    }

    return (byte) (part.getOperation().getOpcode() & 0xFF);
  }
}