WIP Refactoring and cleanup of BTree storage classes

Author: adamretter

exist-core/src/main/java/org/exist/storage/NativeBroker.java

@@ -427,7 +427,7 @@ public DOMFile getDOMFile() {
         return domDb;
     }
 
-    public BTree getStorage(final byte id) {
+    public AbstractBTree<?, ?> getStorage(final byte id) {
         //Notice that there is no entry for the symbols table
         switch(id) {
             case DOM_DBX_ID:
@@ -452,7 +452,7 @@ public int getDefaultIndexDepth() {
     @Override
     public void backupToArchive(final RawDataBackup backup) throws IOException, EXistException {
         for(final byte i : ALL_STORAGE_FILES) {
-            final Paged paged = getStorage(i);
+            final AbstractPagedFile<?, ?> paged = getStorage(i);
             if(paged == null) {
                 LOG.warn("Storage file is null: {}", i);
                 continue;
@@ -3704,7 +3704,7 @@ public void repairPrimary() {
     }
 
     protected void rebuildIndex(final byte indexId) {
-        final BTree btree = getStorage(indexId);
+        final AbstractBTree<?, ?> btree = getStorage(indexId);
         try(final ManagedLock<ReentrantLock> btreeLock = lockManager.acquireBtreeWriteLock(btree.getLockName())) {
             LOG.info("Rebuilding index {}", FileUtils.fileName(btree.getFile()));
             btree.rebuild();

exist-core/src/main/java/org/exist/storage/btree/AbstractBTree.java

@@ -0,0 +1,201 @@
+/*
+ * Copyright (C) 2014 Evolved Binary Ltd
+ *
+ * Changes made by Evolved Binary are proprietary and are not Open Source.
+ *
+ * NOTE: Parts of this file contain code from The eXist-db Authors.
+ *       The original license header is included below.
+ *
+ * ----------------------------------------------------------------------------
+ *
+ * NOTE: This file is in part based on code from The dbXML Group.
+ * The original license statement is also included below.
+ *
+ * eXist-db Open Source Native XML Database
+ * Copyright (C) 2001 The eXist-db Authors
+ *
+ * info@exist-db.org
+ * http://www.exist-db.org
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * ---------------------------------------------------------------------
+ *
+ * dbXML License, Version 1.0
+ *
+ * Copyright (c) 1999-2001 The dbXML Group, L.L.C.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution,
+ *    if any, must include the following acknowledgment:
+ *       "This product includes software developed by
+ *        The dbXML Group (http://www.dbxml.com/)."
+ *    Alternately, this acknowledgment may appear in the software itself,
+ *    if and wherever such third-party acknowledgments normally appear.
+ *
+ * 4. The names "dbXML" and "The dbXML Group" must
+ *    not be used to endorse or promote products derived from this
+ *    software without prior written permission. For written
+ *    permission, please contact info@dbxml.com.
+ *
+ * 5. Products derived from this software may not be called "dbXML",
+ *    nor may "dbXML" appear in their name, without prior written
+ *    permission of The dbXML Group.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE DBXML GROUP OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+package org.exist.storage.btree;
+
+import org.exist.storage.journal.Lsn;
+import org.exist.util.ByteConversion;
+
+import java.io.IOException;
+
+/**
+ * Base class for page headers.
+ *
+ * @author <a href="mailto:adam@evolvedbinary.com">Adam Retter</a>
+ * @author <a href="mailto:wolfgang@exist-db.org">Wolfgang Meier</a>
+ */
+public abstract class AbstractPageHeader implements PageHeader {
+
+    public static final int LENGTH_PAGE_STATUS = 1; //sizeof byte
+    public static final int LENGTH_PAGE_DATA_LENGTH = 4; //sizeof int
+    public static final int LENGTH_PAGE_NEXT_PAGE = 8; //sizeof long
+    public static final int LENGTH_PAGE_LSN = Lsn.RAW_LENGTH;
+
+    private int dataLen = 0;
+    private long nextPage = Page.NO_PAGE;
+    private boolean dirty = false;
+
+    /**
+     * The status of the current page.
+     */
+    private PageStatus status = PageStatus.UNUSED;
+
+    private Lsn lsn = Lsn.LSN_INVALID;
+
+    public AbstractPageHeader() {
+    }
+
+    public AbstractPageHeader(final byte[] data, final int offset) throws IOException {
+        read(data, offset);
+    }
+
+    @Override
+    public int getDataLen() {
+        return this.dataLen;
+    }
+
+    @Override
+    public void updateDataLen(final int newDataLength) {
+        this.dataLen = newDataLength;
+        setDirty(true);
+    }
+
+    @Override
+    public long getNextPage() {
+        return this.nextPage;
+    }
+
+    @Override
+    public void updateNextPage(final long newNextPage) {
+        this.nextPage = newNextPage;
+        setDirty(true);
+    }
+
+    @Override
+    public boolean isDirty() {
+        return this.dirty;
+    }
+
+    @Override
+    public void setDirty(final boolean dirty) {
+        this.dirty = dirty;
+    }
+
+    @Override
+    public PageStatus getStatus() {
+        return this.status;
+    }
+
+    @Override
+    public void updateStatus(final PageStatus newStatus) {
+        this.status = newStatus;
+        setDirty(true);
+    }
+
+    @Override
+    public Lsn getLsn() {
+        return this.lsn;
+    }
+
+    @Override
+    public void setLsn(final Lsn lsn) {
+        this.lsn = lsn;
+    }
+
+    public int read(final byte[] data, int offset) throws IOException {
+        status = PageStatus.fromValue(data[offset]);
+        offset += LENGTH_PAGE_STATUS;
+        dataLen = ByteConversion.byteToInt(data, offset);
+        offset += LENGTH_PAGE_DATA_LENGTH;
+        nextPage = ByteConversion.byteToLong(data, offset);
+        offset += LENGTH_PAGE_NEXT_PAGE;
+        lsn = Lsn.read(data, offset);
+        offset += LENGTH_PAGE_LSN;
+
+        // TODO(AR) should we mark this an non-dirty?
+        //  setDirty(false);
+
+        return offset;
+    }
+
+    public int write(final byte[] data, int offset) throws IOException {
+        data[offset] = status.getValue();
+        offset += LENGTH_PAGE_STATUS;
+        ByteConversion.intToByte(dataLen, data, offset);
+        offset += LENGTH_PAGE_DATA_LENGTH;
+        ByteConversion.longToByte(nextPage, data, offset);
+        offset += LENGTH_PAGE_NEXT_PAGE;
+        lsn.write(data, offset);
+        offset += LENGTH_PAGE_LSN;
+        setDirty(false);
+        return offset;
+    }
+}