diff --git a/core/src/main/java/com/google/bitcoin/core/Transaction.java b/core/src/main/java/com/google/bitcoin/core/Transaction.java
index fa7f61ab..678628fd 100644
--- a/core/src/main/java/com/google/bitcoin/core/Transaction.java
+++ b/core/src/main/java/com/google/bitcoin/core/Transaction.java
@@ -265,20 +265,14 @@ public class Transaction extends ChildMessage implements Serializable {
// This can cause event listeners on TransactionConfidence to run. After these lines complete, the wallets
// state may have changed!
TransactionConfidence transactionConfidence = getConfidence();
- transactionConfidence.setAppearedAtChainHeight(block.getHeight());
-
- // Reset the confidence block depth.
- transactionConfidence.setDepthInBlocks(1);
-
// Reset the work done.
try {
transactionConfidence.setWorkDone(block.getHeader().getWork());
} catch (VerificationException e) {
throw new RuntimeException(e); // Cannot happen.
}
-
- // The transaction is now on the best chain.
- transactionConfidence.setConfidenceType(ConfidenceType.BUILDING);
+ // This sets type to BUILDING and depth to one.
+ transactionConfidence.setAppearedAtChainHeight(block.getHeight());
}
}
diff --git a/core/src/main/java/com/google/bitcoin/core/TransactionConfidence.java b/core/src/main/java/com/google/bitcoin/core/TransactionConfidence.java
index 5545ca24..7f6e0af5 100644
--- a/core/src/main/java/com/google/bitcoin/core/TransactionConfidence.java
+++ b/core/src/main/java/com/google/bitcoin/core/TransactionConfidence.java
@@ -17,6 +17,8 @@
package com.google.bitcoin.core;
import com.google.common.base.Preconditions;
+import com.google.common.util.concurrent.ListenableFuture;
+import com.google.common.util.concurrent.SettableFuture;
import java.io.Serializable;
import java.math.BigInteger;
@@ -191,12 +193,13 @@ public class TransactionConfidence implements Serializable {
/**
* The chain height at which the transaction appeared, if it has been seen in the best chain. Automatically sets
- * the current type to {@link ConfidenceType#BUILDING}.
+ * the current type to {@link ConfidenceType#BUILDING} and depth to one.
*/
public synchronized void setAppearedAtChainHeight(int appearedAtChainHeight) {
if (appearedAtChainHeight < 0)
throw new IllegalArgumentException("appearedAtChainHeight out of range");
this.appearedAtChainHeight = appearedAtChainHeight;
+ this.depth = 1;
setConfidenceType(ConfidenceType.BUILDING);
}
@@ -314,23 +317,16 @@ public class TransactionConfidence implements Serializable {
}
/**
- * Depth in the chain is an approximation of how much time has elapsed since the transaction has been confirmed. On
- * average there is supposed to be a new block every 10 minutes, but the actual rate may vary. The reference
+ * Depth in the chain is an approximation of how much time has elapsed since the transaction has been confirmed.
+ * On average there is supposed to be a new block every 10 minutes, but the actual rate may vary. The reference
* (Satoshi) implementation considers a transaction impractical to reverse after 6 blocks, but as of EOY 2011 network
* security is high enough that often only one block is considered enough even for high value transactions. For low
- * value transactions like songs, or other cheap items, no blocks at all may be necessary.
+ * value transactions like songs, or other cheap items, no blocks at all may be necessary.
*
- * If the transaction appears in the top block, the depth is one. If the transaction does not appear in the best
- * chain yet, throws IllegalStateException, so use {@link com.google.bitcoin.core.TransactionConfidence#getConfidenceType()}
- * to check first.
- *
- * @throws IllegalStateException if confidence type != BUILDING.
- * @return depth
+ * If the transaction appears in the top block, the depth is one. If it's anything else (pending, dead, unknown)
+ * the depth is zero.
*/
public synchronized int getDepthInBlocks() {
- if (getConfidenceType() != ConfidenceType.BUILDING) {
- throw new IllegalStateException("Confidence type is not BUILDING");
- }
return depth;
}
@@ -345,15 +341,10 @@ public class TransactionConfidence implements Serializable {
* Returns the estimated amount of work (number of hashes performed) on this transaction. Work done is a measure of
* security that is related to depth in blocks, but more predictable: the network will always attempt to produce six
* blocks per hour by adjusting the difficulty target. So to know how much real computation effort is needed to
- * reverse a transaction, counting blocks is not enough.
- *
- * @throws IllegalStateException if confidence type is not BUILDING
+ * reverse a transaction, counting blocks is not enough. If a transaction has not confirmed, the result is zero.
* @return estimated number of hashes needed to reverse the transaction.
*/
public synchronized BigInteger getWorkDone() {
- if (getConfidenceType() != ConfidenceType.BUILDING) {
- throw new IllegalStateException("Confidence type is not BUILDING");
- }
return workDone;
}
@@ -423,4 +414,27 @@ public class TransactionConfidence implements Serializable {
public synchronized void setSource(Source source) {
this.source = source;
}
+
+ /**
+ * Returns a future that completes when the transaction has been confirmed by "depth" blocks. For instance setting
+ * depth to one will wait until it appears in a block on the best chain, and zero will wait until it has been seen
+ * on the network.
+ */
+ public ListenableFuture getDepthFuture(final int depth) {
+ final SettableFuture result = SettableFuture.create();
+ synchronized (this) {
+ if (getDepthInBlocks() >= depth) {
+ result.set(transaction);
+ }
+ addEventListener(new Listener() {
+ @Override public void onConfidenceChanged(Transaction tx) {
+ if (getDepthInBlocks() >= depth) {
+ removeEventListener(this);
+ result.set(transaction);
+ }
+ }
+ });
+ }
+ return result;
+ }
}
diff --git a/core/src/test/java/com/google/bitcoin/core/ChainSplitTest.java b/core/src/test/java/com/google/bitcoin/core/ChainSplitTest.java
index b417616f..9c9d4586 100644
--- a/core/src/test/java/com/google/bitcoin/core/ChainSplitTest.java
+++ b/core/src/test/java/com/google/bitcoin/core/ChainSplitTest.java
@@ -449,14 +449,8 @@ public class ChainSplitTest {
txns.get(1).getConfidence().getAppearedAtChainHeight();
fail();
} catch (IllegalStateException e) {}
- try {
- txns.get(1).getConfidence().getDepthInBlocks();
- fail();
- } catch (IllegalStateException e) {}
- try {
- txns.get(1).getConfidence().getWorkDone();
- fail();
- } catch (IllegalStateException e) {}
+ assertEquals(0, txns.get(1).getConfidence().getDepthInBlocks());
+ assertEquals(BigInteger.ZERO, txns.get(1).getConfidence().getWorkDone());
// ... and back to the first chain.
Block b7 = b3.createNextBlock(coinsTo);
diff --git a/core/src/test/java/com/google/bitcoin/core/WalletTest.java b/core/src/test/java/com/google/bitcoin/core/WalletTest.java
index 3a4c56bc..89cd708e 100644
--- a/core/src/test/java/com/google/bitcoin/core/WalletTest.java
+++ b/core/src/test/java/com/google/bitcoin/core/WalletTest.java
@@ -181,6 +181,8 @@ public class WalletTest extends TestWithWallet {
assertFalse(availFuture.isDone());
assertFalse(estimatedFuture.isDone());
Transaction t1 = sendMoneyToWallet(wallet, v1, toAddress, null);
+ final ListenableFuture depthFuture = t1.getConfidence().getDepthFuture(1);
+ assertFalse(depthFuture.isDone());
assertEquals(BigInteger.ZERO, wallet.getBalance());
assertEquals(v1, wallet.getBalance(Wallet.BalanceType.ESTIMATED));
assertFalse(availFuture.isDone());
@@ -194,6 +196,7 @@ public class WalletTest extends TestWithWallet {
assertEquals("Incorrect confirmed tx ALL pool size", 1, wallet.getPoolSize(WalletTransaction.Pool.ALL));
assertTrue(availFuture.isDone());
assertTrue(estimatedFuture.isDone());
+ assertTrue(depthFuture.isDone());
}
private void basicSanityChecks(Wallet wallet, Transaction t, Address fromAddress, Address destination) throws ScriptException {