diff --git a/core/src/main/java/com/google/bitcoin/core/Script.java b/core/src/main/java/com/google/bitcoin/core/Script.java
index 1603fce3..c8795284 100644
--- a/core/src/main/java/com/google/bitcoin/core/Script.java
+++ b/core/src/main/java/com/google/bitcoin/core/Script.java
@@ -35,23 +35,6 @@ import static com.google.common.base.Preconditions.checkArgument;
// TODO: Make this class a superclass with derived classes giving accessor methods for the various common templates.
-/**
- * A chunk in a script
- */
-class ScriptChunk {
- public boolean isOpCode;
- public byte[] data;
- public int startLocationInProgram;
- public ScriptChunk(boolean isOpCode, byte[] data, int startLocationInProgram) {
- this.isOpCode = isOpCode;
- this.data = data;
- this.startLocationInProgram = startLocationInProgram;
- }
- public boolean equalsOpCode(int opCode) {
- return isOpCode && data.length == 1 && (0xFF & data[0]) == opCode;
- }
-}
-
/**
* Programs embedded inside transactions that control redemption of payments.
*
@@ -66,11 +49,28 @@ class ScriptChunk {
public class Script {
private static final Logger log = LoggerFactory.getLogger(Script.class);
+ /**
+ * An element that is either an opcode or a raw byte array (signature, pubkey, etc).
+ */
+ public static class Chunk {
+ public boolean isOpCode;
+ public byte[] data;
+ public int startLocationInProgram;
+ public Chunk(boolean isOpCode, byte[] data, int startLocationInProgram) {
+ this.isOpCode = isOpCode;
+ this.data = data;
+ this.startLocationInProgram = startLocationInProgram;
+ }
+ public boolean equalsOpCode(int opCode) {
+ return isOpCode && data.length == 1 && (0xFF & data[0]) == opCode;
+ }
+ }
+
private byte[] program;
private int cursor;
- // The program is a set of byte[]s where each element is either [opcode] or [data, data, data ...]
- List chunks;
+ // The program is a set of chunks where each element is either [opcode] or [data, data, data ...]
+ List chunks;
// Only for internal use
private Script() {}
@@ -89,7 +89,7 @@ public class Script {
*/
public String toString() {
StringBuilder buf = new StringBuilder();
- for (ScriptChunk chunk : chunks) {
+ for (Chunk chunk : chunks) {
if (chunk.isOpCode) {
buf.append(getOpCodeName(chunk.data[0]));
buf.append(" ");
@@ -151,28 +151,28 @@ public class Script {
System.arraycopy(programBytes, offset, program, 0, length);
offset = 0;
- chunks = new ArrayList(10); // Arbitrary choice of initial size.
+ chunks = new ArrayList(10); // Arbitrary choice of initial size.
cursor = offset;
while (cursor < offset + length) {
int startLocationInProgram = cursor - offset;
int opcode = readByte();
if (opcode >= 0 && opcode < OP_PUSHDATA1) {
// Read some bytes of data, where how many is the opcode value itself.
- chunks.add(new ScriptChunk(false, getData(opcode), startLocationInProgram)); // opcode == len here.
+ chunks.add(new Chunk(false, getData(opcode), startLocationInProgram)); // opcode == len here.
} else if (opcode == OP_PUSHDATA1) {
int len = readByte();
- chunks.add(new ScriptChunk(false, getData(len), startLocationInProgram));
+ chunks.add(new Chunk(false, getData(len), startLocationInProgram));
} else if (opcode == OP_PUSHDATA2) {
// Read a short, then read that many bytes of data.
int len = readByte() | (readByte() << 8);
- chunks.add(new ScriptChunk(false, getData(len), startLocationInProgram));
+ chunks.add(new Chunk(false, getData(len), startLocationInProgram));
} else if (opcode == OP_PUSHDATA4) {
// Read a uint32, then read that many bytes of data.
// Though this is allowed, because its value cannot be > 520, it should never actually be used
long len = readByte() | (readByte() << 8) | (readByte() << 16) | (readByte() << 24);
- chunks.add(new ScriptChunk(false, getData((int)len), startLocationInProgram));
+ chunks.add(new Chunk(false, getData((int)len), startLocationInProgram));
} else {
- chunks.add(new ScriptChunk(true, new byte[]{(byte) opcode}, startLocationInProgram));
+ chunks.add(new Chunk(true, new byte[]{(byte) opcode}, startLocationInProgram));
}
}
}
@@ -369,10 +369,10 @@ public class Script {
////////////////////// Interface used during verification of transactions/blocks ////////////////////////////////
- private static int getSigOpCount(List chunks, boolean accurate) throws ScriptException {
+ private static int getSigOpCount(List chunks, boolean accurate) throws ScriptException {
int sigOps = 0;
int lastOpCode = OP_INVALIDOPCODE;
- for (ScriptChunk chunk : chunks) {
+ for (Chunk chunk : chunks) {
if (chunk.isOpCode) {
int opcode = 0xFF & chunk.data[0];
switch (opcode) {
@@ -475,13 +475,13 @@ public class Script {
*/
public boolean isSentToMultiSig() {
if (chunks.size() < 4) return false;
- ScriptChunk chunk = chunks.get(chunks.size() - 1);
+ Chunk chunk = chunks.get(chunks.size() - 1);
// Must end in OP_CHECKMULTISIG[VERIFY].
if (!chunk.isOpCode) return false;
if (!(chunk.equalsOpCode(OP_CHECKMULTISIG) || chunk.equalsOpCode(OP_CHECKMULTISIGVERIFY))) return false;
try {
// Second to last chunk must be an OP_N opcode and there should be that many data chunks (keys).
- ScriptChunk m = chunks.get(chunks.size() - 2);
+ Chunk m = chunks.get(chunks.size() - 2);
if (!m.isOpCode) return false;
int numKeys = decodeFromOpN(m.data[0]);
if (chunks.size() != 3 + numKeys) return false;
@@ -577,7 +577,7 @@ public class Script {
LinkedList altstack = new LinkedList();
LinkedList ifStack = new LinkedList();
- for (ScriptChunk chunk : script.chunks) {
+ for (Chunk chunk : script.chunks) {
boolean shouldExecute = !ifStack.contains(false);
if (!chunk.isOpCode) {
@@ -1225,7 +1225,7 @@ public class Script {
// TODO: Check if we can take out enforceP2SH if there's a checkpoint at the enforcement block.
if (enforceP2SH && scriptPubKey.isPayToScriptHash()) {
- for (ScriptChunk chunk : chunks)
+ for (Chunk chunk : chunks)
if (chunk.isOpCode && (chunk.data[0] & 0xff) > OP_16)
throw new ScriptException("Attempted to spend a P2SH scriptPubKey with a script that contained script ops");