1 files changed, 58 insertions, 0 deletions
diff --git a/src/main/java/io/trygvis/btree/HeapFile.java b/src/main/java/io/trygvis/btree/HeapFile.java
new file mode 100644
index 0000000..7a960c8
--- /dev/null
+++ b/src/main/java/io/trygvis/btree/HeapFile.java
@@ -0,0 +1,58 @@
+package io.trygvis.btree;
+
+import java.io.Closeable;
+import java.io.File;
+import java.io.IOException;
+import java.io.RandomAccessFile;
+import java.nio.ByteBuffer;
+import java.nio.channels.FileChannel;
+
+import static io.trygvis.btree.HeapPage.blankHeapPage;
+import static java.nio.ByteBuffer.allocateDirect;
+
+public class HeapFile implements Closeable {
+    private final int PAGE_SIZE;
+
+    private final RandomAccessFile file;
+    private final FileChannel channel;
+
+    public HeapFile(int PAGE_SIZE, File file) throws IOException {
+        this.PAGE_SIZE = PAGE_SIZE;
+        this.file = new RandomAccessFile(file, "rw");
+
+        channel = this.file.getChannel();
+    }
+
+    @Override
+    public void close() throws IOException {
+        channel.force(true);
+        file.close();
+    }
+
+    public HeapPage loadPage(int page) throws IOException {
+        ByteBuffer buffer = allocateDirect(PAGE_SIZE);
+
+        channel.read(buffer, page * PAGE_SIZE);
+
+        return HeapPage.heapPageFromBytes(page, buffer);
+    }
+
+    public void writePage(HeapPage page) throws IOException {
+        long position;
+        if (page.pageNumber == -1) {
+            position = file.length();
+        } else {
+            position = page.pageNumber * PAGE_SIZE;
+        }
+        channel.write(page.bytes, position);
+        channel.force(true);
+    }
+
+    public long pageCount() throws IOException {
+        return file.length() / PAGE_SIZE;
+    }
+
+    public HeapPage blankPage() {
+        return blankHeapPage(allocateDirect(PAGE_SIZE));
+    }
+}