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Add a Script.removeAllInstancesOf(script object)

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Matt Corallo 2012-08-01 20:55:15 +02:00 committed by Mike Hearn
parent d7dc953da8
commit 2f2850610e
1 changed files with 53 additions and 0 deletions
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53
core/src/main/java/com/google/bitcoin/core/Script.java
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@ -20,6 +20,7 @@ import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import static com.google.bitcoin.core.Utils.bytesToHexString;
@ -793,4 +794,56 @@ public class Script {
(program[1] & 0xff) == 0x14 &&
(program[22] & 0xff) == OP_EQUAL;
}
private static boolean equalsRange(byte[] a, int start, byte[] b) {
if (start + b.length > a.length)
return false;
for (int i = 0; i < b.length; i++)
if (a[i + start] != b[i])
return false;
return true;
}
/**
* Returns the script bytes of inputScript with all instances of the specified script object removed
*/
public static byte[] removeAllInstancesOf(byte[] inputScript, byte[] chunkToRemove) {
// We usually don't end up removing anything
UnsafeByteArrayOutputStream bos = new UnsafeByteArrayOutputStream(inputScript.length);
int cursor = 0;
while (cursor < inputScript.length) {
boolean skip = equalsRange(inputScript, cursor, chunkToRemove);
int opcode = inputScript[cursor++] & 0xFF;
int additionalBytes = 0;
if (opcode >= 0 && opcode < OP_PUSHDATA1) {
additionalBytes = opcode;
} else if (opcode == OP_PUSHDATA1) {
additionalBytes = inputScript[cursor] + 1;
} else if (opcode == OP_PUSHDATA2) {
additionalBytes = (inputScript[cursor] | (inputScript[cursor+1] << 8)) + 2;
} else if (opcode == OP_PUSHDATA4) {
additionalBytes = (inputScript[cursor] | (inputScript[cursor+1] << 8) |
(inputScript[cursor+1] << 16) | (inputScript[cursor+1] << 24)) + 4;
}
if (!skip) {
try {
bos.write(opcode);
bos.write(Arrays.copyOfRange(inputScript, cursor, cursor + additionalBytes));
} catch (IOException e) {
throw new RuntimeException(e);
}
}
cursor += additionalBytes;
}
return bos.toByteArray();
}
/**
* Returns the script bytes of inputScript with all instances of the given op code removed
*/
public static byte[] removeAllInstancesOfOp(byte[] inputScript, int opCode) {
return removeAllInstancesOf(inputScript, new byte[] {(byte)opCode});
}
}