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-rw-r--r--src/main/java/io/trygvis/btree/HeapFile.java7
-rw-r--r--src/main/java/io/trygvis/btree/HeapPage.java17
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);