2 files changed, 19 insertions, 5 deletions
diff --git a/src/main/java/io/trygvis/btree/HeapFile.java b/src/main/java/io/trygvis/btree/HeapFile.java
index 7a960c8..6bd0451 100644
--- a/src/main/java/io/trygvis/btree/HeapFile.java
+++ b/src/main/java/io/trygvis/btree/HeapFile.java
@@ -37,15 +37,18 @@ public class HeapFile implements Closeable {
         return HeapPage.heapPageFromBytes(page, buffer);
     }
 
-    public void writePage(HeapPage page) throws IOException {
+    public long writePage(HeapPage page) throws IOException {
         long position;
         if (page.pageNumber == -1) {
-            position = file.length();
+            position = channel.size();
         } else {
             position = page.pageNumber * PAGE_SIZE;
         }
+        page.bytes.rewind();
         channel.write(page.bytes, position);
         channel.force(true);
+
+        return position / PAGE_SIZE;
     }
 
     public long pageCount() throws IOException {
diff --git a/src/main/java/io/trygvis/btree/HeapPage.java b/src/main/java/io/trygvis/btree/HeapPage.java
index 499a244..a931260 100644
--- a/src/main/java/io/trygvis/btree/HeapPage.java
+++ b/src/main/java/io/trygvis/btree/HeapPage.java
@@ -22,7 +22,12 @@ public class HeapPage {
     }
 
     public static HeapPage heapPageFromBytes(int pageNumber, ByteBuffer bytes) {
-        int freePosition = bytes.getInt();
+        int freePosition = bytes.getInt(FREE_POSITION_INDEX);
+
+        if (freePosition > bytes.capacity() || freePosition < headerSize) {
+            throw new RuntimeException("Invalid free position: " + freePosition);
+        }
+
         return new HeapPage(pageNumber, bytes, freePosition);
     }
 
@@ -31,8 +36,6 @@ public class HeapPage {
     }
 
     public void append(byte[] item) {
-//        System.out.println("io.trygvis.btree.HeapPage.append");
-
         int bytesFree = bytesFree();
         int bytesRequested = item.length;
 
@@ -58,6 +61,8 @@ public class HeapPage {
         return new Iterable<ByteBuffer>() {
             @Override
             public Iterator<ByteBuffer> iterator() {
+                System.out.println("io.trygvis.btree.HeapPage.iterator");
+
                 return new Iterator<ByteBuffer>() {
                     private int position;
 
@@ -65,21 +70,27 @@ public class HeapPage {
 
                     {
                         position = bytes.capacity();
+                        System.out.println("position = " + position);
                         next = findNext();
                     }
 
                     private ByteBuffer findNext() {
+                        System.out.println("io.trygvis.btree.HeapPage.findNext");
                         if (position == headerSize) {
+                            System.out.println("at end");
                             return null;
                         }
 
                         int size = bytes.getInt(position - itemSize);
 
                         if (size == 0) {
+                            System.out.println("at end");
                             return null;
                         }
 
                         position -= itemSize + size;
+
+                        System.out.println("item: size: " + size + ", new position: " + position);
                         ByteBuffer copy = bytes.duplicate();
                         copy.position(position);
                         copy.limit(position + size);