From bf9c0e6ce8568d0e37ea1d2947aba141ae4c7fe4 Mon Sep 17 00:00:00 2001
From: "Brian S. O'Neill" <bronee@gmail.com>
Date: Thu, 26 Jan 2012 02:53:21 +0000
Subject: Added option for index access to fetch ahead to reduce likelihood of
 deadlocks.

---
 .../com/amazon/carbonado/repo/indexed/IndexedCursor.java   | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

(limited to 'src/main/java/com/amazon/carbonado/repo')

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 bce6975..04eb478 100644
--- a/src/main/java/com/amazon/carbonado/repo/indexed/IndexedCursor.java
+++ b/src/main/java/com/amazon/carbonado/repo/indexed/IndexedCursor.java
@@ -32,6 +32,7 @@ import com.amazon.carbonado.Storage;
 import com.amazon.carbonado.Transaction;
 
 import com.amazon.carbonado.cursor.AbstractCursor;
+import com.amazon.carbonado.cursor.FetchAheadCursor;
 
 import com.amazon.carbonado.spi.RepairExecutor;
 
@@ -44,6 +45,13 @@ import com.amazon.carbonado.synthetic.SyntheticStorableReferenceAccess;
  * @author Brian S O'Neill
  */
 class IndexedCursor<S extends Storable> extends AbstractCursor<S> {
+    private static final int FETCH_AHEAD;
+
+    static {
+        String prefix = IndexedCursor.class.getName() + '.';
+        FETCH_AHEAD = Integer.getInteger(prefix + "fetchAhead", 0);
+    }
+
     private final Cursor<? extends Storable> mCursor;
     private final IndexedStorage<S> mStorage;
     private final SyntheticStorableReferenceAccess<S> mAccessor;
@@ -52,7 +60,11 @@ class IndexedCursor<S extends Storable> extends AbstractCursor<S> {
 
     IndexedCursor(Cursor<? extends Storable> indexEntryCursor,
                   IndexedStorage<S> storage,
-                  SyntheticStorableReferenceAccess<S> indexAccessor) {
+                  SyntheticStorableReferenceAccess<S> indexAccessor)
+    {
+        if (FETCH_AHEAD > 0) {
+            indexEntryCursor = new FetchAheadCursor(indexEntryCursor, FETCH_AHEAD);
+        }
         mCursor = indexEntryCursor;
         mStorage = storage;
         mAccessor = indexAccessor;
-- 
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