From 4a25366df4303bebdbd771dcec202e8368fdb61f Mon Sep 17 00:00:00 2001
From: "Brian S. O'Neill" <bronee@gmail.com>
Date: Sat, 25 Jul 2009 17:47:01 +0000
Subject: Make cursors more resilient against concurrent close, preventing
NoSuchElementException from being thrown inappropriately.
---
.../amazon/carbonado/cursor/DifferenceCursor.java | 2 ++
.../carbonado/cursor/IntersectionCursor.java | 2 ++
.../com/amazon/carbonado/cursor/LimitCursor.java | 11 +++++++----
.../carbonado/cursor/MultiTransformedCursor.java | 22 ++++++++++------------
.../com/amazon/carbonado/cursor/SkipCursor.java | 10 ++++++++--
.../com/amazon/carbonado/cursor/SortedCursor.java | 1 +
.../cursor/SymmetricDifferenceCursor.java | 2 ++
.../amazon/carbonado/cursor/ThrottledCursor.java | 4 ++++
.../com/amazon/carbonado/cursor/UnionCursor.java | 2 ++
.../carbonado/repo/indexed/IndexedCursor.java | 1 +
10 files changed, 39 insertions(+), 18 deletions(-)
(limited to 'src')
diff --git a/src/main/java/com/amazon/carbonado/cursor/DifferenceCursor.java b/src/main/java/com/amazon/carbonado/cursor/DifferenceCursor.java
index a04aec0..867f2f0 100644
--- a/src/main/java/com/amazon/carbonado/cursor/DifferenceCursor.java
+++ b/src/main/java/com/amazon/carbonado/cursor/DifferenceCursor.java
@@ -108,6 +108,8 @@ public class DifferenceCursor<S> extends AbstractCursor<S> {
}
}
}
+ } catch (NoSuchElementException e) {
+ return false;
} catch (FetchException e) {
try {
close();
diff --git a/src/main/java/com/amazon/carbonado/cursor/IntersectionCursor.java b/src/main/java/com/amazon/carbonado/cursor/IntersectionCursor.java
index 6eb3179..4d542e9 100644
--- a/src/main/java/com/amazon/carbonado/cursor/IntersectionCursor.java
+++ b/src/main/java/com/amazon/carbonado/cursor/IntersectionCursor.java
@@ -106,6 +106,8 @@ public class IntersectionCursor<S> extends AbstractCursor<S> {
return true;
}
}
+ } catch (NoSuchElementException e) {
+ return false;
} catch (FetchException e) {
try {
close();
diff --git a/src/main/java/com/amazon/carbonado/cursor/LimitCursor.java b/src/main/java/com/amazon/carbonado/cursor/LimitCursor.java
index 925c582..1dc50be 100644
--- a/src/main/java/com/amazon/carbonado/cursor/LimitCursor.java
+++ b/src/main/java/com/amazon/carbonado/cursor/LimitCursor.java
@@ -50,11 +50,14 @@ public class LimitCursor<S> extends AbstractCursor<S> {
}
public boolean hasNext() throws FetchException {
- if (mSource.hasNext()) {
- if (mRemaining > 0) {
- return true;
+ try {
+ if (mSource.hasNext()) {
+ if (mRemaining > 0) {
+ return true;
+ }
+ mSource.close();
}
- mSource.close();
+ } catch (NoSuchElementException e) {
}
return false;
}
diff --git a/src/main/java/com/amazon/carbonado/cursor/MultiTransformedCursor.java b/src/main/java/com/amazon/carbonado/cursor/MultiTransformedCursor.java
index fafb55f..fdeb941 100644
--- a/src/main/java/com/amazon/carbonado/cursor/MultiTransformedCursor.java
+++ b/src/main/java/com/amazon/carbonado/cursor/MultiTransformedCursor.java
@@ -72,21 +72,19 @@ public abstract class MultiTransformedCursor<S, T> extends AbstractCursor<T> {
mNextCursor.close();
mNextCursor = null;
}
- try {
- int count = 0;
- while (mCursor.hasNext()) {
- Cursor<T> nextCursor = transform(mCursor.next());
- if (nextCursor != null) {
- if (nextCursor.hasNext()) {
- mNextCursor = nextCursor;
- return true;
- }
- nextCursor.close();
+ int count = 0;
+ while (mCursor.hasNext()) {
+ Cursor<T> nextCursor = transform(mCursor.next());
+ if (nextCursor != null) {
+ if (nextCursor.hasNext()) {
+ mNextCursor = nextCursor;
+ return true;
}
- interruptCheck(++count);
+ nextCursor.close();
}
- } catch (NoSuchElementException e) {
+ interruptCheck(++count);
}
+ } catch (NoSuchElementException e) {
} catch (FetchException e) {
try {
close();
diff --git a/src/main/java/com/amazon/carbonado/cursor/SkipCursor.java b/src/main/java/com/amazon/carbonado/cursor/SkipCursor.java
index c991933..c770751 100644
--- a/src/main/java/com/amazon/carbonado/cursor/SkipCursor.java
+++ b/src/main/java/com/amazon/carbonado/cursor/SkipCursor.java
@@ -18,6 +18,8 @@
package com.amazon.carbonado.cursor;
+import java.util.NoSuchElementException;
+
import com.amazon.carbonado.Cursor;
import com.amazon.carbonado.FetchException;
@@ -48,8 +50,12 @@ public class SkipCursor<S> extends AbstractCursor<S> {
}
public boolean hasNext() throws FetchException {
- doSkip();
- return mSource.hasNext();
+ try {
+ doSkip();
+ return mSource.hasNext();
+ } catch (NoSuchElementException e) {
+ return false;
+ }
}
public S next() throws FetchException {
diff --git a/src/main/java/com/amazon/carbonado/cursor/SortedCursor.java b/src/main/java/com/amazon/carbonado/cursor/SortedCursor.java
index 8de527d..d3bf24b 100644
--- a/src/main/java/com/amazon/carbonado/cursor/SortedCursor.java
+++ b/src/main/java/com/amazon/carbonado/cursor/SortedCursor.java
@@ -306,6 +306,7 @@ public class SortedCursor<S> extends AbstractCursor<S> {
} catch (UndeclaredThrowableException e) {
throw toFetchException(e);
}
+ } catch (NoSuchElementException e) {
} catch (FetchException e) {
try {
close();
diff --git a/src/main/java/com/amazon/carbonado/cursor/SymmetricDifferenceCursor.java b/src/main/java/com/amazon/carbonado/cursor/SymmetricDifferenceCursor.java
index b78cf79..4dc8700 100644
--- a/src/main/java/com/amazon/carbonado/cursor/SymmetricDifferenceCursor.java
+++ b/src/main/java/com/amazon/carbonado/cursor/SymmetricDifferenceCursor.java
@@ -113,6 +113,8 @@ public class SymmetricDifferenceCursor<S> extends AbstractCursor<S> {
return mCompareResult;
}
}
+ } catch (NoSuchElementException e) {
+ return 0;
} catch (FetchException e) {
try {
close();
diff --git a/src/main/java/com/amazon/carbonado/cursor/ThrottledCursor.java b/src/main/java/com/amazon/carbonado/cursor/ThrottledCursor.java
index a349782..0a40570 100644
--- a/src/main/java/com/amazon/carbonado/cursor/ThrottledCursor.java
+++ b/src/main/java/com/amazon/carbonado/cursor/ThrottledCursor.java
@@ -18,6 +18,8 @@
package com.amazon.carbonado.cursor;
+import java.util.NoSuchElementException;
+
import com.amazon.carbonado.Cursor;
import com.amazon.carbonado.FetchException;
import com.amazon.carbonado.FetchInterruptedException;
@@ -63,6 +65,8 @@ public class ThrottledCursor<S> extends AbstractCursor<S> {
public boolean hasNext() throws FetchException {
try {
return mCursor.hasNext();
+ } catch (NoSuchElementException e) {
+ return false;
} catch (FetchException e) {
try {
close();
diff --git a/src/main/java/com/amazon/carbonado/cursor/UnionCursor.java b/src/main/java/com/amazon/carbonado/cursor/UnionCursor.java
index c2bdd19..5f0e326 100644
--- a/src/main/java/com/amazon/carbonado/cursor/UnionCursor.java
+++ b/src/main/java/com/amazon/carbonado/cursor/UnionCursor.java
@@ -74,6 +74,8 @@ public class UnionCursor<S> extends AbstractCursor<S> {
if (mNextRight == null && mRightCursor.hasNext()) {
mNextRight = mRightCursor.next();
}
+ } catch (NoSuchElementException e) {
+ return false;
} catch (FetchException e) {
try {
close();
diff --git a/src/main/java/com/amazon/carbonado/repo/indexed/IndexedCursor.java b/src/main/java/com/amazon/carbonado/repo/indexed/IndexedCursor.java
index de105cc..872b5b4 100644
--- a/src/main/java/com/amazon/carbonado/repo/indexed/IndexedCursor.java
+++ b/src/main/java/com/amazon/carbonado/repo/indexed/IndexedCursor.java
@@ -152,6 +152,7 @@ class IndexedCursor<S extends Storable> extends AbstractCursor<S> {
}
}
}
+ } catch (NoSuchElementException e) {
} catch (FetchException e) {
try {
close();
--
cgit v1.2.3