io.neow3j.contract.ScriptBuilder Maven / Gradle / Ivy
package io.neow3j.contract;
import io.neow3j.constants.NeoConstants;
import io.neow3j.constants.OpCode;
import io.neow3j.utils.ArrayUtils;
import io.neow3j.utils.BigIntegers;
import io.neow3j.utils.Numeric;
import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.math.BigInteger;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.util.List;
import static java.nio.charset.StandardCharsets.UTF_8;
public class ScriptBuilder {
private DataOutputStream stream;
private ByteBuffer buffer;
private ByteArrayOutputStream byteStream;
public ScriptBuilder() {
byteStream = new ByteArrayOutputStream();
stream = new DataOutputStream(byteStream);
buffer = ByteBuffer.wrap(new byte[8]).order(ByteOrder.LITTLE_ENDIAN);
}
/**
* Appends an OpCode to the script.
* @param opCode The OpCode to append.
* @return this ScriptBuilder object.
*/
public ScriptBuilder opCode(OpCode opCode) {
writeByte(opCode.getValue());
return this;
}
/**
* Appends an app call to the script.
* @param scriptHash The script hash of the contract to call in big-endian order.
* @param operation The operation to call.
* @param params The parameters that will be used in the app call. Need to be in correct order.
* @return this ScriptBuilder object.
*/
public ScriptBuilder appCall(byte[] scriptHash, String operation,
List params) {
if (params == null || params.isEmpty()) {
if (operation == null) {
return appCall(scriptHash);
} else {
return appCall(scriptHash, operation);
}
} else if (operation == null) {
return appCall(scriptHash, params);
}
for (int i = params.size() - 1; i >= 0; i--) {
pushParam(params.get(i));
}
pushInteger(params.size());
opCode(OpCode.PACK);
pushData(operation);
appCall(scriptHash);
return this;
}
/**
* Appends an app call to the script.
* @param scriptHash The script hash of the contract to call in big-endian order.
* @param params The parameters that will be used in the app call. Need to be in correct order.
* @return this ScriptBuilder object.
*/
public ScriptBuilder appCall(byte[] scriptHash, List params) {
for (int i = params.size() - 1; i >= 0; i--) {
pushParam(params.get(i));
}
appCall(scriptHash);
return this;
}
/**
* Appends an app call to the script.
* @param scriptHash The script hash of the contract to call in big-endian order.
* @param operation The operation to call.
* @return this ScriptBuilder object.
*/
public ScriptBuilder appCall(byte[] scriptHash, String operation) {
pushBoolean(false);
pushData(operation);
appCall(scriptHash);
return this;
}
/**
* Appends an app call to the script.
* @param scriptHash The script hash of the contract to call in big-endian order.
* @return this ScriptBuilder object.
*/
public ScriptBuilder appCall(byte[] scriptHash) {
return call(scriptHash, OpCode.APPCALL);
}
/**
* Appends a tail call to the script.
* @param scriptHash The script hash of the contract to call in big-endian order.
* @return this ScriptBuilder object.
*/
public ScriptBuilder tailCall(byte[] scriptHash) {
return call(scriptHash, OpCode.TAILCALL);
}
private ScriptBuilder call(byte[] scriptHash, OpCode opCode) {
if (scriptHash.length != NeoConstants.SCRIPTHASH_LENGHT_BYTES) {
throw new IllegalArgumentException("Script hash must be 160 bits long.");
}
writeByte(opCode.getValue());
// Needs to be written in little-endian order
writeReversed(scriptHash);
return this;
}
public ScriptBuilder sysCall(String operation) {
if (operation.length() == 0)
throw new IllegalArgumentException("Provided operation string is empty.");
writeByte(OpCode.SYSCALL.getValue());
byte[] operationBytes = operation.getBytes(UTF_8);
if (operationBytes.length > 252)
throw new IllegalArgumentException("Provided operation is too long.");
byte[] callArgument = ArrayUtils.concatenate((byte)operationBytes.length, operationBytes);
writeByte(OpCode.SYSCALL.getValue());
write(callArgument);
return this;
}
public ScriptBuilder pushParam(ContractParameter param) {
Object value = param.getValue();
switch (param.getParamType()) {
case SIGNATURE:
pushData(Numeric.hexStringToByteArray((String) value));
case BYTE_ARRAY:
String valueString = (String)value;
if (Numeric.isValidHexString(valueString)) {
pushData(Numeric.hexStringToByteArray((String) value));
} else {
pushData(valueString);
}
break;
case BOOLEAN:
pushBoolean((boolean)value);
break;
case INTEGER:
pushInteger(new BigInteger((String)value));
break;
case HASH160:
case HASH256:
byte[] bytes = Numeric.hexStringToByteArray((String) value);
// Needs to be added in little-endian order.
pushData(ArrayUtils.reverseArray(bytes)) ;
break;
case PUBLIC_KEY:
// TODO 10.07.19 claude: Implement
throw new UnsupportedOperationException();
case STRING:
pushData((String)value);
break;
case ARRAY:
pushArray((ContractParameter[])value);
break;
default:
throw new IllegalArgumentException("Parameter type '" + param.getParamType() +
"' not supported.");
}
return this;
}
public ScriptBuilder pushInteger(int v) {
return pushInteger(BigInteger.valueOf(v));
}
public ScriptBuilder pushInteger(BigInteger number) {
if (number.intValue() == -1) {
writeByte(OpCode.PUSHM1.getValue());
} else if (number.intValue() == 0) {
writeByte(OpCode.PUSH0.getValue());
} else if (number.intValue() >= 1 && number.intValue() <= 16) {
// OpCodes PUSH1 to PUSH16
int base = (OpCode.PUSH1.getValue() - 1);
writeByte(base + number.intValue());
} else {
// If the number is larger than 16, it needs to be pushed as a data array.
pushData(BigIntegers.toLittleEndianByteArray(number));
}
return this;
}
public ScriptBuilder pushBoolean(boolean bool) {
if (bool) {
writeByte(OpCode.PUSHT.getValue());
} else {
writeByte(OpCode.PUSHF.getValue());
}
return this;
}
/**
* Adds the data to the script, prefixed with the correct code for its length.
* @param data The data to add to the script.
* @return this ScriptBuilder object.
*/
public ScriptBuilder pushData(String data) {
if (data != null) {
pushData(data.getBytes(UTF_8));
} else {
pushData("".getBytes());
}
return this;
}
/**
* Adds the data to the script, prefixed with the correct code for its length.
* @param data The data to add to the script.
* @return this ScriptBuilder object.
*/
public ScriptBuilder pushData(byte[] data) {
pushDataLength(data.length);
write(data);
return this;
}
public ScriptBuilder pushDataLength(int length) {
if (length <= OpCode.PUSHBYTES75.getValue()) {
// For up to 75 bytes of data we can use the OpCodes PUSHBYTES01 to PUSHBYTES75 directly.
writeByte(length);
} else if (length <= 255) {
// If the data is 76 to 255 (0xff) bytes long then write PUSHDATA1 + uint8
writeByte(OpCode.PUSHDATA1.getValue());
writeByte(length);
} else if (length <= 65535) {
// If the data is 256 to 65535 (0xffff) bytes long then write PUSHDATA2 + uint16
writeByte(OpCode.PUSHDATA2.getValue());
writeShort(length);
} else{
// If the data is bigger than 65536 then write PUSHDATA4 + uint32
writeByte(OpCode.PUSHDATA4.getValue());
writeInt(length);
}
return this;
}
public ScriptBuilder pushArray(ContractParameter[] params) {
for (int i = params.length-1; i >= 0; i--) {
pushParam(params[i]);
}
pushInteger(params.length);
opCode(OpCode.PACK);
return this;
}
private void writeByte(int v) {
try { stream.writeByte(v); }
catch (IOException e) {throw new IllegalStateException("Got IOException without doing IO.");}
}
private void writeShort(int v) {
buffer.putInt(0, v);
try { stream.write(buffer.array(), 0, 2); }
catch (IOException e) {throw new IllegalStateException("Got IOException without doing IO.");}
}
private void writeInt(int v) {
buffer.putInt(0, v);
try { stream.write(buffer.array(), 0, 4); }
catch (IOException e) {throw new IllegalStateException("Got IOException without doing IO.");}
}
private void write(byte[] data) {
try { stream.write(data); }
catch (IOException e) {throw new IllegalStateException("Got IOException without doing IO.");}
}
private void writeReversed(byte[] data) {
try { stream.write(ArrayUtils.reverseArray(data)); }
catch (IOException e) {throw new IllegalStateException("Got IOException without doing IO.");}
}
public byte[] toArray() {
try { stream.flush(); }
catch (IOException e) {throw new IllegalStateException("Got IOException without doing IO.");}
return byteStream.toByteArray();
}
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy