New experimental page store.

h2/src/main/org/h2/index/PageBtree.java

@@ -8,7 +8,7 @@ package org.h2.index;
 
 import java.sql.SQLException;
 import org.h2.result.SearchRow;
-import org.h2.store.DataPage;
+import org.h2.store.Data;
 import org.h2.store.Record;
 
 /**
@@ -34,7 +34,7 @@ abstract class PageBtree extends Record {
     /**
      * The data page.
      */
-    protected final DataPage data;
+    protected final Data data;
 
     /**
      * The row offsets.
@@ -66,7 +66,7 @@ abstract class PageBtree extends Record {
      */
     protected boolean written;
 
-    PageBtree(PageBtreeIndex index, int pageId, int parentPageId, DataPage data) {
+    PageBtree(PageBtreeIndex index, int pageId, int parentPageId, Data data) {
         this.index = index;
         this.parentPageId = parentPageId;
         this.data = data;
@@ -248,7 +248,8 @@ abstract class PageBtree extends Record {
      * @return number of double words (4 bytes)
      */
     public int getMemorySize() {
-        return index.getPageStore().getPageSize() >> 2;
+        // double the byte array size
+        return index.getPageStore().getPageSize() >> 1;
     }
 
 }

h2/src/main/org/h2/index/PageBtreeIndex.java

@@ -13,7 +13,7 @@ import org.h2.engine.Session;
 import org.h2.message.Message;
 import org.h2.result.Row;
 import org.h2.result.SearchRow;
-import org.h2.store.DataPage;
+import org.h2.store.Data;
 import org.h2.store.PageStore;
 import org.h2.store.Record;
 import org.h2.table.Column;
@@ -53,7 +53,7 @@ public class PageBtreeIndex extends BaseIndex {
             // it should not for new tables, otherwise redo of other operations
             // must ensure this page is not used for other things
             store.addMeta(this, session, headPos);
-            PageBtreeLeaf root = new PageBtreeLeaf(this, headPos, Page.ROOT, store.createDataPage());
+            PageBtreeLeaf root = new PageBtreeLeaf(this, headPos, Page.ROOT, store.createData());
             store.updateRecord(root, true, root.data);
         } else {
             this.headPos = headPos;
@@ -93,9 +93,11 @@ public class PageBtreeIndex extends BaseIndex {
                 }
             }
         }
+        // safe memory
+        SearchRow newRow = getSearchRow(row);
         while (true) {
             PageBtree root = getPage(headPos);
-            int splitPoint = root.addRowTry(row);
+            int splitPoint = root.addRowTry(newRow);
             if (splitPoint == 0) {
                 break;
             }
@@ -110,7 +112,7 @@ public class PageBtreeIndex extends BaseIndex {
             page1.setPageId(id);
             page1.setParentPageId(headPos);
             page2.setParentPageId(headPos);
-            PageBtreeNode newRoot = new PageBtreeNode(this, rootPageId, Page.ROOT, store.createDataPage());
+            PageBtreeNode newRoot = new PageBtreeNode(this, rootPageId, Page.ROOT, store.createData());
             newRoot.init(page1, pivot, page2);
             store.updateRecord(page1, true, page1.data);
             store.updateRecord(page2, true, page2.data);
@@ -120,6 +122,22 @@ public class PageBtreeIndex extends BaseIndex {
         rowCount++;
     }
 
+    /**
+     * Create a search row for this row.
+     *
+     * @param row the row
+     * @return the search row
+     */
+    private SearchRow getSearchRow(Row row) {
+        SearchRow r = table.getTemplateSimpleRow(columns.length == 1);
+        r.setPosAndVersion(row);
+        for (int j = 0; j < columns.length; j++) {
+            int idx = columns[j].getColumnId();
+            r.setValue(idx, row.getValue(idx));
+        }
+        return r;
+    }
+
     /**
      * Read the given page.
      *
@@ -137,7 +155,7 @@ public class PageBtreeIndex extends BaseIndex {
             }
             return (PageBtree) rec;
         }
-        DataPage data = store.readPage(id);
+        Data data = store.readPage(id);
         data.reset();
         int parentPageId = data.readInt();
         int type = data.readByte() & 255;
@@ -266,7 +284,7 @@ public class PageBtreeIndex extends BaseIndex {
     private void removeAllRows() throws SQLException {
         PageBtree root = getPage(headPos);
         root.freeChildren();
-        root = new PageBtreeLeaf(this, headPos, Page.ROOT, store.createDataPage());
+        root = new PageBtreeLeaf(this, headPos, Page.ROOT, store.createData());
         store.removeRecord(headPos);
         store.updateRecord(root, true, null);
         rowCount = 0;
@@ -297,7 +315,7 @@ public class PageBtreeIndex extends BaseIndex {
      * @param data the data page
      * @return the row
      */
-    Row readRow(DataPage data) throws SQLException {
+    Row readRow(Data data) throws SQLException {
         return tableData.readRow(data);
     }
 
@@ -324,7 +342,7 @@ public class PageBtreeIndex extends BaseIndex {
      * @param onlyPosition whether only the position of the row is stored
      * @return the row
      */
-    SearchRow readRow(DataPage data, int offset, boolean onlyPosition) throws SQLException {
+    SearchRow readRow(Data data, int offset, boolean onlyPosition) throws SQLException {
         data.setPos(offset);
         int pos = data.readInt();
         if (onlyPosition) {
@@ -347,7 +365,7 @@ public class PageBtreeIndex extends BaseIndex {
      * @param onlyPosition whether only the position of the row is stored
      * @param row the row to write
      */
-    void writeRow(DataPage data, int offset, SearchRow row, boolean onlyPosition) throws SQLException {
+    void writeRow(Data data, int offset, SearchRow row, boolean onlyPosition) throws SQLException {
         data.setPos(offset);
         data.writeInt(row.getPos());
         if (!onlyPosition) {
@@ -366,8 +384,8 @@ public class PageBtreeIndex extends BaseIndex {
      * @param onlyPosition whether only the position of the row is stored
      * @return the number of bytes
      */
-    int getRowSize(DataPage dummy, SearchRow row, boolean onlyPosition) throws SQLException {
-        int rowsize = DataPage.LENGTH_INT;
+    int getRowSize(Data dummy, SearchRow row, boolean onlyPosition) throws SQLException {
+        int rowsize = Data.LENGTH_INT;
         if (!onlyPosition) {
             for (Column col : columns) {
                 Value v = row.getValue(col.getColumnId());

h2/src/main/org/h2/index/PageBtreeLeaf.java

@@ -11,6 +11,7 @@ import org.h2.constant.ErrorCode;
 import org.h2.constant.SysProperties;
 import org.h2.message.Message;
 import org.h2.result.SearchRow;
+import org.h2.store.Data;
 import org.h2.store.DataPage;
 import org.h2.store.PageStore;
 
@@ -30,7 +31,7 @@ class PageBtreeLeaf extends PageBtree {
     private static final int OFFSET_LENGTH = 2;
     private static final int OFFSET_START = 11;
 
-    PageBtreeLeaf(PageBtreeIndex index, int pageId, int parentPageId, DataPage data) {
+    PageBtreeLeaf(PageBtreeIndex index, int pageId, int parentPageId, Data data) {
         super(index, pageId, parentPageId, data);
         start = OFFSET_START;
     }
@@ -140,7 +141,7 @@ class PageBtreeLeaf extends PageBtree {
 
     PageBtree split(int splitPoint) throws SQLException {
         int newPageId = index.getPageStore().allocatePage();
-        PageBtreeLeaf p2 = new PageBtreeLeaf(index, newPageId, parentPageId, index.getPageStore().createDataPage());
+        PageBtreeLeaf p2 = new PageBtreeLeaf(index, newPageId, parentPageId, index.getPageStore().createData());
         for (int i = splitPoint; i < entryCount;) {
             p2.addRowTry(getRow(splitPoint));
             removeRow(splitPoint);
@@ -213,7 +214,7 @@ class PageBtreeLeaf extends PageBtree {
         written = true;
     }
 
-    DataPage getDataPage() throws SQLException {
+    Data getData() throws SQLException {
         write();
         return data;
     }

h2/src/main/org/h2/index/PageBtreeNode.java

@@ -10,7 +10,10 @@ import java.sql.SQLException;
 import org.h2.constant.SysProperties;
 import org.h2.message.Message;
 import org.h2.result.SearchRow;
+import org.h2.store.Data;
 import org.h2.store.DataPage;
+import org.h2.store.PageStore;
+import org.h2.util.MemoryUtils;
 
 /**
  * A b-tree node page that contains index data.
@@ -38,7 +41,7 @@ class PageBtreeNode extends PageBtree {
 
     private int rowCount = UNKNOWN_ROWCOUNT;
 
-    PageBtreeNode(PageBtreeIndex index, int pageId, int parentPageId, DataPage data) {
+    PageBtreeNode(PageBtreeIndex index, int pageId, int parentPageId, Data data) {
         super(index, pageId, parentPageId, data);
         start = CHILD_OFFSET_PAIR_START;
     }
@@ -51,8 +54,8 @@ class PageBtreeNode extends PageBtree {
         rowCount = rowCountStored = data.readInt();
         childPageIds = new int[entryCount + 1];
         childPageIds[entryCount] = data.readInt();
-        rows = new SearchRow[entryCount];
-        offsets = new int[entryCount];
+        rows = PageStore.newSearchRows(entryCount);
+        offsets = MemoryUtils.newInts(entryCount);
         for (int i = 0; i < entryCount; i++) {
             childPageIds[i] = data.readInt();
             offsets[i] = data.readInt();
@@ -164,7 +167,7 @@ class PageBtreeNode extends PageBtree {
 
     PageBtree split(int splitPoint) throws SQLException {
         int newPageId = index.getPageStore().allocatePage();
-        PageBtreeNode p2 = new PageBtreeNode(index, newPageId, parentPageId, index.getPageStore().createDataPage());
+        PageBtreeNode p2 = new PageBtreeNode(index, newPageId, parentPageId, index.getPageStore().createData());
         if (onlyPosition) {
             // TODO optimize: maybe not required
             p2.onlyPosition = true;
@@ -204,7 +207,7 @@ class PageBtreeNode extends PageBtree {
         entryCount = 0;
         childPageIds = new int[] { page1.getPageId() };
         rows = new SearchRow[0];
-        offsets = new int[0];
+        offsets = MemoryUtils.EMPTY_INTS;
         addChild(0, page2.getPageId(), pivot);
         check();
     }
@@ -336,8 +339,8 @@ class PageBtreeNode extends PageBtree {
         if (entryCount < 0) {
             Message.throwInternalError();
         }
-        SearchRow[] newRows = new SearchRow[entryCount];
-        int[] newOffsets = new int[entryCount];
+        SearchRow[] newRows = PageStore.newSearchRows(entryCount);
+        int[] newOffsets = MemoryUtils.newInts(entryCount);
         int[] newChildPageIds = new int[entryCount + 1];
         System.arraycopy(offsets, 0, newOffsets, 0, Math.min(entryCount, i));
         System.arraycopy(rows, 0, newRows, 0, Math.min(entryCount, i));

h2/src/main/org/h2/index/PageData.java

@@ -7,10 +7,9 @@
 package org.h2.index;
 
 import java.sql.SQLException;
-
 import org.h2.engine.Session;
 import org.h2.result.Row;
-import org.h2.store.DataPage;
+import org.h2.store.Data;
 import org.h2.store.Record;
 
 /**
@@ -36,7 +35,7 @@ abstract class PageData extends Record {
     /**
      * The data page.
      */
-    protected final DataPage data;
+    protected final Data data;
 
     /**
      * The number of entries.
@@ -53,7 +52,7 @@ abstract class PageData extends Record {
      */
     protected boolean written;
 
-    PageData(PageScanIndex index, int pageId, int parentPageId, DataPage data) {
+    PageData(PageScanIndex index, int pageId, int parentPageId, Data data) {
         this.index = index;
         this.parentPageId = parentPageId;
         this.data = data;
@@ -204,7 +203,8 @@ abstract class PageData extends Record {
      * @return number of double words (4 bytes)
      */
     public int getMemorySize() {
-        return index.getPageStore().getPageSize() >> 2;
+        // double the byte array size
+        return index.getPageStore().getPageSize() >> 1;
     }
 
     int getParentPageId() {

h2/src/main/org/h2/index/PageDataLeaf.java

@@ -6,11 +6,13 @@
  */
 package org.h2.index;
 
+import java.lang.ref.SoftReference;
 import java.sql.SQLException;
 import org.h2.constant.ErrorCode;
 import org.h2.engine.Session;
 import org.h2.message.Message;
 import org.h2.result.Row;
+import org.h2.store.Data;
 import org.h2.store.DataPage;
 import org.h2.store.PageStore;
 
@@ -41,6 +43,11 @@ class PageDataLeaf extends PageData {
      */
     Row[] rows;
 
+    /**
+     * For pages with overflow: the soft reference to the row
+     */
+    SoftReference<Row> rowRef;
+
     /**
      * The page id of the first overflow page (0 if no overflow).
      */
@@ -51,7 +58,12 @@ class PageDataLeaf extends PageData {
      */
     int start;
 
-    PageDataLeaf(PageScanIndex index, int pageId, int parentPageId, DataPage data) {
+    /**
+     * The size of the row in bytes for large rows.
+     */
+    private int overflowRowSize;
+
+    PageDataLeaf(PageScanIndex index, int pageId, int parentPageId, Data data) {
         super(index, pageId, parentPageId, data);
         start = KEY_OFFSET_PAIR_START;
     }
@@ -139,10 +151,13 @@ class PageDataLeaf extends PageData {
             int previous = getPos();
             int dataOffset = pageSize;
             int page = index.getPageStore().allocatePage();
+            firstOverflowPageId = page;
+            this.overflowRowSize = pageSize + rowLength;
+            write();
+            // free up the space used by the row
+            rowRef = new SoftReference<Row>(rows[0]);
+            rows[0] = null;
             do {
-                if (firstOverflowPageId == 0) {
-                    firstOverflowPageId = page;
-                }
                 int type, size, next;
                 if (remaining <= pageSize - PageDataLeafOverflow.START_LAST) {
                     type = Page.TYPE_DATA_OVERFLOW | Page.FLAG_LAST;
@@ -153,13 +168,14 @@ class PageDataLeaf extends PageData {
                     size = pageSize - PageDataLeafOverflow.START_MORE;
                     next = index.getPageStore().allocatePage();
                 }
-                PageDataLeafOverflow overflow = new PageDataLeafOverflow(this, page, type, previous, next, dataOffset, size);
+                PageDataLeafOverflow overflow = new PageDataLeafOverflow(this, page, type, previous, next, data, dataOffset, size);
                 index.getPageStore().updateRecord(overflow, true, null);
                 dataOffset += size;
                 remaining -= size;
                 previous = page;
                 page = next;
             } while (remaining > 0);
+            data.truncate(index.getPageStore().getPageSize());
         }
         return 0;
     }
@@ -204,21 +220,31 @@ class PageDataLeaf extends PageData {
         Row r = rows[at];
         if (r == null) {
             if (firstOverflowPageId != 0) {
+                if (rowRef != null) {
+                    r = rowRef.get();
+                    if (r != null) {
+                        return r;
+                    }
+                }
                 PageStore store = index.getPageStore();
                 int pageSize = store.getPageSize();
                 data.setPos(pageSize);
                 int next = firstOverflowPageId;
                 int offset = pageSize;
-                data.setPos(pageSize);
                 do {
                     PageDataLeafOverflow page = index.getPageOverflow(next, this, offset);
                     next = page.readInto(data);
                 } while (next != 0);
+                overflowRowSize = data.length();
             }
             data.setPos(offsets[at]);
             r = index.readRow(data);
             r.setPos(keys[at]);
-            rows[at] = r;
+            if (firstOverflowPageId != 0) {
+                rowRef = new SoftReference<Row>(r);
+            } else {
+                rows[at] = r;
+            }
         }
         return r;
     }
@@ -229,7 +255,7 @@ class PageDataLeaf extends PageData {
 
     PageData split(int splitPoint) throws SQLException {
         int newPageId = index.getPageStore().allocatePage();
-        PageDataLeaf p2 = new PageDataLeaf(index, newPageId, parentPageId, index.getPageStore().createDataPage());
+        PageDataLeaf p2 = new PageDataLeaf(index, newPageId, parentPageId, index.getPageStore().createData());
         for (int i = splitPoint; i < entryCount;) {
             p2.addRowTry(getRowAt(splitPoint));
             removeRow(splitPoint);
@@ -311,6 +337,7 @@ class PageDataLeaf extends PageData {
     public void write(DataPage buff) throws SQLException {
         write();
         index.getPageStore().writePage(getPos(), data);
+        data.truncate(index.getPageStore().getPageSize());
     }
 
     PageStore getPageStore() {
@@ -329,6 +356,7 @@ class PageDataLeaf extends PageData {
         }
         readAllRows();
         data.reset();
+        data.checkCapacity(overflowRowSize);
         data.writeInt(parentPageId);
         int type;
         if (firstOverflowPageId == 0) {
@@ -348,16 +376,11 @@ class PageDataLeaf extends PageData {
         }
         for (int i = 0; i < entryCount; i++) {
             data.setPos(offsets[i]);
-            rows[i].write(data);
+            getRowAt(i).write(data);
         }
         written = true;
     }
 
-    DataPage getDataPage() throws SQLException {
-        write();
-        return data;
-    }
-
     public String toString() {
         return "page[" + getPos() + "] data leaf table:" + index.getId() + " entries:" + entryCount;
     }

h2/src/main/org/h2/index/PageDataLeafOverflow.java

@@ -9,8 +9,8 @@ package org.h2.index;
 import java.sql.SQLException;
 import org.h2.constant.ErrorCode;
 import org.h2.message.Message;
+import org.h2.store.Data;
 import org.h2.store.DataPage;
-import org.h2.store.PageStore;
 import org.h2.store.Record;
 
 /**
@@ -35,7 +35,10 @@ public class PageDataLeafOverflow extends Record {
      */
     static final int START_MORE = 9;
 
-    private final PageDataLeaf leaf;
+    /**
+     * The index.
+     */
+    private final PageScanIndex index;
 
     /**
      * The page type.
@@ -57,22 +60,24 @@ public class PageDataLeafOverflow extends Record {
      */
     private int size;
 
-    /**
-     * The first content byte starts at the given position
-     * in the leaf page when the page size is unlimited.
-     */
-    private final int offset;
-
-    private DataPage data;
+    private Data data;
 
-    PageDataLeafOverflow(PageDataLeaf leaf, int pageId, int type, int previous, int next, int offset, int size) {
-        this.leaf = leaf;
+    PageDataLeafOverflow(PageDataLeaf leaf, int pageId, int type, int previous, int next, Data allData, int offset, int size) {
+        this.index = leaf.index;
         setPos(pageId);
         this.type = type;
         this.parentPage = previous;
         this.nextPage = next;
-        this.offset = offset;
         this.size = size;
+        data = index.getPageStore().createData();
+        data.writeInt(parentPage);
+        data.writeByte((byte) type);
+        if (type == Page.TYPE_DATA_OVERFLOW) {
+            data.writeInt(nextPage);
+        } else {
+            data.writeShortInt(size);
+        }
+        data.write(allData.getBytes(), offset, size);
     }
 
     /**
@@ -80,14 +85,13 @@ public class PageDataLeafOverflow extends Record {
      *
      * @param leaf the leaf page
      * @param pageId the page id
-     * @param data the data page
+     * @param dataAll the data page with the complete value
      * @param offset the offset
      */
-    public PageDataLeafOverflow(PageDataLeaf leaf, int pageId, DataPage data, int offset) {
-        this.leaf = leaf;
+    public PageDataLeafOverflow(PageDataLeaf leaf, int pageId, Data data, int offset) {
+        this.index = leaf.index;
         setPos(pageId);
         this.data = data;
-        this.offset = offset;
     }
 
     /**
@@ -100,7 +104,7 @@ public class PageDataLeafOverflow extends Record {
             size = data.readShortInt();
             nextPage = 0;
         } else if (type == Page.TYPE_DATA_OVERFLOW) {
-            size = leaf.getPageStore().getPageSize() - START_MORE;
+            size = index.getPageStore().getPageSize() - START_MORE;
             nextPage = data.readInt();
         } else {
             throw Message.getSQLException(ErrorCode.FILE_CORRUPTED_1, "page:" + getPos() + " type:" + type);
@@ -113,7 +117,8 @@ public class PageDataLeafOverflow extends Record {
      * @param target the target data page
      * @return the next page, or 0 if no next page
      */
-    int readInto(DataPage target) {
+    int readInto(Data target) {
+        target.checkCapacity(size);
         if (type == (Page.TYPE_DATA_OVERFLOW | Page.FLAG_LAST)) {
             target.write(data.getBytes(), START_LAST, size);
             return 0;
@@ -127,22 +132,11 @@ public class PageDataLeafOverflow extends Record {
     }
 
     public int getByteCount(DataPage dummy) {
-        return leaf.getByteCount(dummy);
+        return index.getPageStore().getPageSize();
     }
 
     public void write(DataPage buff) throws SQLException {
-        PageStore store = leaf.getPageStore();
-        DataPage overflow = store.createDataPage();
-        DataPage data = leaf.getDataPage();
-        overflow.writeInt(parentPage);
-        overflow.writeByte((byte) type);
-        if (type == Page.TYPE_DATA_OVERFLOW) {
-            overflow.writeInt(nextPage);
-        } else {
-            overflow.writeShortInt(size);
-        }
-        overflow.write(data.getBytes(), offset, size);
-        store.writePage(getPos(), overflow);
+        index.getPageStore().writePage(getPos(), data);
     }
 
     public String toString() {
@@ -155,7 +149,8 @@ public class PageDataLeafOverflow extends Record {
      * @return number of double words (4 bytes)
      */
     public int getMemorySize() {
-        return leaf.getMemorySize();
+        // double the byte array size
+        return index.getPageStore().getPageSize() >> 1;
     }
 
     int getParent() {

h2/src/main/org/h2/index/PageDataNode.java

@@ -11,7 +11,9 @@ import java.sql.SQLException;
 import org.h2.engine.Session;
 import org.h2.message.Message;
 import org.h2.result.Row;
+import org.h2.store.Data;
 import org.h2.store.DataPage;
+import org.h2.util.MemoryUtils;
 
 /**
  * A leaf page that contains data of one or multiple rows.
@@ -39,7 +41,7 @@ class PageDataNode extends PageData {
 
     private int rowCount = UNKNOWN_ROWCOUNT;
 
-    PageDataNode(PageScanIndex index, int pageId, int parentPageId, DataPage data) {
+    PageDataNode(PageScanIndex index, int pageId, int parentPageId, Data data) {
         super(index, pageId, parentPageId, data);
     }
 
@@ -49,7 +51,7 @@ class PageDataNode extends PageData {
         rowCount = rowCountStored = data.readInt();
         childPageIds = new int[entryCount + 1];
         childPageIds[entryCount] = data.readInt();
-        keys = new int[entryCount];
+        keys = MemoryUtils.newInts(entryCount);
         for (int i = 0; i < entryCount; i++) {
             childPageIds[i] = data.readInt();
             keys[i] = data.readInt();
@@ -117,7 +119,7 @@ class PageDataNode extends PageData {
 
     PageData split(int splitPoint) throws SQLException {
         int newPageId = index.getPageStore().allocatePage();
-        PageDataNode p2 = new PageDataNode(index, newPageId, parentPageId, index.getPageStore().createDataPage());
+        PageDataNode p2 = new PageDataNode(index, newPageId, parentPageId, index.getPageStore().createData());
         int firstChild = childPageIds[splitPoint];
         for (int i = splitPoint; i < entryCount;) {
             p2.addChild(p2.entryCount, childPageIds[splitPoint + 1], keys[splitPoint]);
@@ -273,7 +275,7 @@ class PageDataNode extends PageData {
         if (entryCount < 0) {
             Message.throwInternalError();
         }
-        int[] newKeys = new int[entryCount];
+        int[] newKeys = MemoryUtils.newInts(entryCount);
         int[] newChildPageIds = new int[entryCount + 1];
         System.arraycopy(keys, 0, newKeys, 0, Math.min(entryCount, i));
         System.arraycopy(childPageIds, 0, newChildPageIds, 0, i);

h2/src/main/org/h2/index/PageScanIndex.java

@@ -12,7 +12,6 @@ import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
-
 import org.h2.constant.ErrorCode;
 import org.h2.constant.SysProperties;
 import org.h2.engine.Constants;
@@ -21,7 +20,7 @@ import org.h2.log.UndoLogRecord;
 import org.h2.message.Message;
 import org.h2.result.Row;
 import org.h2.result.SearchRow;
-import org.h2.store.DataPage;
+import org.h2.store.Data;
 import org.h2.store.PageStore;
 import org.h2.store.Record;
 import org.h2.table.Column;
@@ -67,7 +66,7 @@ public class PageScanIndex extends BaseIndex implements RowIndex {
             // it should not for new tables, otherwise redo of other operations
             // must ensure this page is not used for other things
             store.addMeta(this, session, headPos);
-            PageDataLeaf root = new PageDataLeaf(this, headPos, Page.ROOT, store.createDataPage());
+            PageDataLeaf root = new PageDataLeaf(this, headPos, Page.ROOT, store.createData());
             store.updateRecord(root, true, root.data);
         } else {
             this.headPos = headPos;
@@ -129,7 +128,7 @@ public class PageScanIndex extends BaseIndex implements RowIndex {
             page1.setPageId(id);
             page1.setParentPageId(headPos);
             page2.setParentPageId(headPos);
-            PageDataNode newRoot = new PageDataNode(this, rootPageId, Page.ROOT, store.createDataPage());
+            PageDataNode newRoot = new PageDataNode(this, rootPageId, Page.ROOT, store.createData());
             newRoot.init(page1, pivot, page2);
             store.updateRecord(page1, true, page1.data);
             store.updateRecord(page2, true, page2.data);
@@ -164,7 +163,7 @@ public class PageScanIndex extends BaseIndex implements RowIndex {
         if (rec != null) {
             return (PageDataLeafOverflow) rec;
         }
-        DataPage data = store.readPage(id);
+        Data data = store.readPage(id);
         data.reset();
         PageDataLeafOverflow result = new PageDataLeafOverflow(leaf, id, data, offset);
         result.read();
@@ -189,7 +188,7 @@ public class PageScanIndex extends BaseIndex implements RowIndex {
             }
             return (PageData) rec;
         }
-        DataPage data = store.readPage(id);
+        Data data = store.readPage(id);
         data.reset();
         int parentPageId = data.readInt();
         int type = data.readByte() & 255;
@@ -302,7 +301,7 @@ public class PageScanIndex extends BaseIndex implements RowIndex {
     private void removeAllRows() throws SQLException {
         PageData root = getPage(headPos, 0);
         root.freeChildren();
-        root = new PageDataLeaf(this, headPos, Page.ROOT, store.createDataPage());
+        root = new PageDataLeaf(this, headPos, Page.ROOT, store.createData());
         store.removeRecord(headPos);
         store.updateRecord(root, true, null);
         rowCount = 0;
@@ -328,7 +327,7 @@ public class PageScanIndex extends BaseIndex implements RowIndex {
      * @param data the data page
      * @return the row
      */
-    Row readRow(DataPage data) throws SQLException {
+    Row readRow(Data data) throws SQLException {
         return tableData.readRow(data);
     }
 

h2/src/main/org/h2/store/DataPage.java

@@ -15,8 +15,8 @@ import java.sql.Timestamp;
 import org.h2.constant.SysProperties;
 import org.h2.engine.Constants;
 import org.h2.message.Message;
-import org.h2.util.ByteUtils;
 import org.h2.util.MathUtils;
+import org.h2.util.MemoryUtils;
 import org.h2.value.Value;
 import org.h2.value.ValueArray;
 import org.h2.value.ValueBoolean;
@@ -68,19 +68,19 @@ public class DataPage {
     /**
      * The data handler responsible for lob objects.
      */
-    private DataHandler handler;
+    protected DataHandler handler;
 
     /**
      * The data itself.
      */
-    private byte[] data;
+    protected byte[] data;
 
     /**
      * The current write or read position.
      */
-    private int pos;
+    protected int pos;
 
-    private DataPage(DataHandler handler, byte[] data) {
+    protected DataPage(DataHandler handler, byte[] data) {
         this.handler = handler;
         this.data = data;
     }
@@ -266,7 +266,7 @@ public class DataPage {
      */
     public void checkCapacity(int plus) {
         if (pos + plus >= data.length) {
-            byte[] d = ByteUtils.newBytes((data.length + plus) * 2);
+            byte[] d = MemoryUtils.newBytes((data.length + plus) * 2);
             // must copy everything, because pos could be 0 and data may be
             // still required
             System.arraycopy(data, 0, d, 0, data.length);
@@ -607,13 +607,13 @@ public class DataPage {
         }
         case Value.JAVA_OBJECT: {
             int len = readInt();
-            byte[] b = ByteUtils.newBytes(len);
+            byte[] b = MemoryUtils.newBytes(len);
             read(b, 0, len);
             return ValueJavaObject.getNoCopy(b);
         }
         case Value.BYTES: {
             int len = readInt();
-            byte[] b = ByteUtils.newBytes(len);
+            byte[] b = MemoryUtils.newBytes(len);
             read(b, 0, len);
             return ValueBytes.getNoCopy(b);
         }
@@ -633,7 +633,7 @@ public class DataPage {
         case Value.CLOB: {
             int smallLen = readInt();
             if (smallLen >= 0) {
-                byte[] small = ByteUtils.newBytes(smallLen);
+                byte[] small = MemoryUtils.newBytes(smallLen);
                 read(small, 0, smallLen);
                 return ValueLob.createSmallLob(dataType, small);
             }

h2/src/main/org/h2/store/DiskFile.java

@@ -27,7 +27,6 @@ import org.h2.log.RedoLogRecord;
 import org.h2.message.Message;
 import org.h2.message.Trace;
 import org.h2.util.BitField;
-import org.h2.util.ByteUtils;
 import org.h2.util.Cache;
 import org.h2.util.CacheLRU;
 import org.h2.util.CacheObject;
@@ -35,6 +34,7 @@ import org.h2.util.CacheWriter;
 import org.h2.util.FileUtils;
 import org.h2.util.IntArray;
 import org.h2.util.MathUtils;
+import org.h2.util.MemoryUtils;
 import org.h2.util.New;
 import org.h2.util.ObjectArray;
 
@@ -575,7 +575,7 @@ public class DiskFile implements CacheWriter {
                 Message.throwInternalError("0 blocks to read pos=" + pos);
             }
             if (blockCount > 1) {
-                byte[] b2 = ByteUtils.newBytes(blockCount * BLOCK_SIZE);
+                byte[] b2 = MemoryUtils.newBytes(blockCount * BLOCK_SIZE);
                 System.arraycopy(buff, 0, b2, 0, BLOCK_SIZE);
                 buff = b2;
                 file.readFully(buff, BLOCK_SIZE, blockCount * BLOCK_SIZE - BLOCK_SIZE);

h2/src/main/org/h2/store/FileStoreInputStream.java

@@ -14,7 +14,7 @@ import org.h2.constant.SysProperties;
 import org.h2.engine.Constants;
 import org.h2.message.Message;
 import org.h2.tools.CompressTool;
-import org.h2.util.ByteUtils;
+import org.h2.util.MemoryUtils;
 
 /**
  * An input stream that is backed by a file store.
@@ -120,7 +120,7 @@ public class FileStoreInputStream extends InputStream {
             readInt();
             if (compress != null) {
                 int uncompressed = readInt();
-                byte[] buff = ByteUtils.newBytes(remainingInBuffer);
+                byte[] buff = MemoryUtils.newBytes(remainingInBuffer);
                 page.read(buff, 0, remainingInBuffer);
                 page.reset();
                 page.checkCapacity(uncompressed);

h2/src/main/org/h2/store/PageFreeList.java

@@ -28,7 +28,7 @@ public class PageFreeList extends Record {
     private final BitField used = new BitField();
     private final int pageCount;
     private boolean full;
-    private DataPage data;
+    private Data data;
 
     PageFreeList(PageStore store, int pageId) {
         setPos(pageId);
@@ -91,7 +91,7 @@ public class PageFreeList extends Record {
      * Read the page from the disk.
      */
     void read() throws SQLException {
-        data = store.createDataPage();
+        data = store.createData();
         store.readPage(getPos(), data);
         int p = data.readInt();
         int t = data.readByte();
@@ -113,7 +113,7 @@ public class PageFreeList extends Record {
     }
 
     public void write(DataPage buff) throws SQLException {
-        data = store.createDataPage();
+        data = store.createData();
         data.writeInt(0);
         int type = Page.TYPE_FREE_LIST;
         data.writeByte((byte) type);

h2/src/main/org/h2/store/PageLog.java

@@ -111,7 +111,7 @@ public class PageLog {
     private DataInputStream in;
     private int firstTrunkPage;
     private int firstDataPage;
-    private DataPage data;
+    private Data data;
     private int logId, logPos;
     private int firstLogId;
     private BitField undo = new BitField();
@@ -120,7 +120,7 @@ public class PageLog {
 
     PageLog(PageStore store) {
         this.store = store;
-        data = store.createDataPage();
+        data = store.createData();
         trace = store.getTrace();
     }
 
@@ -196,7 +196,7 @@ public class PageLog {
         pageIn = new PageInputStream(store, firstTrunkPage, firstDataPage);
         in = new DataInputStream(pageIn);
         int logId = 0;
-        DataPage data = store.createDataPage();
+        Data data = store.createData();
         try {
             pos = 0;
             while (true) {
@@ -268,14 +268,14 @@ public class PageLog {
                     }
                 }
             }
-            if (stage == RECOVERY_STAGE_REDO) {
-                sessionStates = New.hashMap();
-            }
         } catch (EOFException e) {
             trace.debug("log recovery stopped: " + e.toString());
         } catch (IOException e) {
             throw Message.convertIOException(e, "recover");
         }
+        if (stage == RECOVERY_STAGE_REDO) {
+            sessionStates = New.hashMap();
+        }
     }
 
     /**
@@ -304,7 +304,7 @@ public class PageLog {
      * @param data a temporary buffer
      * @return the row
      */
-    public static Row readRow(DataInputStream in, DataPage data) throws IOException, SQLException {
+    public static Row readRow(DataInputStream in, Data data) throws IOException, SQLException {
         int pos = in.readInt();
         int len = in.readInt();
         data.reset();
@@ -328,7 +328,7 @@ public class PageLog {
      * @param pageId the page id
      * @param page the old page data
      */
-    void addUndo(int pageId, DataPage page) throws SQLException {
+    void addUndo(int pageId, Data page) throws SQLException {
         try {
             if (undo.get(pageId)) {
                 return;
@@ -398,17 +398,17 @@ public class PageLog {
             int pageSize = store.getPageSize();
             byte[] t = StringUtils.utf8Encode(transaction);
             int len = t.length;
-            if (1 + DataPage.LENGTH_INT * 2 + len >= PageStreamData.getCapacity(pageSize)) {
+            if (1 + Data.LENGTH_INT * 2 + len >= PageStreamData.getCapacity(pageSize)) {
                 throw Message.getInvalidValueException("transaction name too long", transaction);
             }
-            pageOut.fillDataPage();
+            pageOut.fillPage();
             out.write(PREPARE_COMMIT);
             out.writeInt(session.getId());
             out.writeInt(len);
             out.write(t);
             flushOut();
             // store it on a separate log page
-            pageOut.fillDataPage();
+            pageOut.fillPage();
             if (log.getFlushOnEachCommit()) {
                 flush();
             }
@@ -461,6 +461,7 @@ public class PageLog {
             row.setLastLog(logId, logPos);
 
             data.reset();
+            data.checkCapacity(row.getByteCount(data));
             row.write(data);
             out.write(add ? ADD : REMOVE);
             out.writeInt(session.getId());
@@ -497,7 +498,7 @@ public class PageLog {
         }
         undo = new BitField();
         logId++;
-        pageOut.fillDataPage();
+        pageOut.fillPage();
         int currentDataPage = pageOut.getCurrentDataPageId();
         logIdPageMap.put(logId, currentDataPage);
     }
@@ -636,4 +637,14 @@ public class PageLog {
         d.write(null);
     }
 
+    void truncate() throws SQLException {
+        do {
+            // TODO keep trunk page in the cache
+            PageStreamTrunk t = new PageStreamTrunk(store, firstTrunkPage);
+            t.read();
+            firstTrunkPage = t.getNextTrunk();
+            t.free();
+        } while (firstTrunkPage != 0);
+    }
+
 }

h2/src/main/org/h2/store/PageOutputStream.java

@@ -173,7 +173,7 @@ public class PageOutputStream extends OutputStream {
      * Fill the data page with zeros and write it.
      * This is required for a checkpoint.
      */
-    void fillDataPage() throws SQLException {
+    void fillPage() throws SQLException {
         if (trace.isDebugEnabled()) {
             trace.debug("pageOut.storePage fill " + data.getPos());
         }

h2/src/main/org/h2/store/PageStreamData.java

@@ -27,7 +27,7 @@ public class PageStreamData extends Record {
 
     private final PageStore store;
     private int trunk;
-    private DataPage data;
+    private Data data;
     private int remaining;
     private int length;
 
@@ -41,7 +41,7 @@ public class PageStreamData extends Record {
      * Read the page from the disk.
      */
     void read() throws SQLException {
-        data = store.createDataPage();
+        data = store.createData();
         store.readPage(getPos(), data);
         trunk = data.readInt();
         data.setPos(4);
@@ -61,7 +61,7 @@ public class PageStreamData extends Record {
      * Write the header data.
      */
     void initWrite() {
-        data = store.createDataPage();
+        data = store.createData();
         data.writeInt(trunk);
         data.writeByte((byte) Page.TYPE_STREAM_DATA);
         data.writeInt(0);

h2/src/main/org/h2/store/PageStreamTrunk.java

@@ -10,6 +10,7 @@ import java.sql.SQLException;
 import org.h2.constant.ErrorCode;
 import org.h2.index.Page;
 import org.h2.message.Message;
+import org.h2.util.MemoryUtils;
 
 /**
  * A trunk page of a stream. It contains the page numbers of the stream, and
@@ -31,7 +32,7 @@ public class PageStreamTrunk extends Record {
     private int nextTrunk;
     private int[] pageIds;
     private int pageCount;
-    private DataPage data;
+    private Data data;
     private int index;
 
     PageStreamTrunk(PageStore store, int parent, int pageId, int next, int[] pageIds) {
@@ -52,13 +53,13 @@ public class PageStreamTrunk extends Record {
      * Read the page from the disk.
      */
     void read() throws SQLException {
-        data = store.createDataPage();
+        data = store.createData();
         store.readPage(getPos(), data);
         parent = data.readInt();
         int t = data.readByte();
         if (t == Page.TYPE_EMPTY) {
             // end of file
-            pageIds = new int[0];
+            pageIds = MemoryUtils.EMPTY_INTS;
             return;
         }
         if (t != Page.TYPE_STREAM_TRUNK) {
@@ -93,7 +94,7 @@ public class PageStreamTrunk extends Record {
     }
 
     public void write(DataPage buff) throws SQLException {
-        data = store.createDataPage();
+        data = store.createData();
         data.writeInt(parent);
         data.writeByte((byte) Page.TYPE_STREAM_TRUNK);
         data.writeInt(nextTrunk);
@@ -135,7 +136,7 @@ public class PageStreamTrunk extends Record {
      * @return the number of pages freed
      */
     int free() throws SQLException {
-        DataPage empty = store.createDataPage();
+        Data empty = store.createData();
         store.freePage(getPos(), false, null);
         int freed = 1;
         for (int i = 0; i < pageCount; i++) {

h2/src/main/org/h2/tools/Recover.java

@@ -34,6 +34,7 @@ import org.h2.message.Trace;
 import org.h2.result.Row;
 import org.h2.result.SimpleRow;
 import org.h2.security.SHA256;
+import org.h2.store.Data;
 import org.h2.store.DataHandler;
 import org.h2.store.DataPage;
 import org.h2.store.DiskFile;
@@ -49,6 +50,7 @@ import org.h2.util.FileUtils;
 import org.h2.util.IOUtils;
 import org.h2.util.IntArray;
 import org.h2.util.MathUtils;
+import org.h2.util.MemoryUtils;
 import org.h2.util.New;
 import org.h2.util.ObjectArray;
 import org.h2.util.RandomUtils;
@@ -496,7 +498,7 @@ public class Recover extends Tool implements DataHandler {
                 // Math.abs(Integer.MIN_VALUE) == Integer.MIN_VALUE
                 blocks = MathUtils.convertLongToInt(Math.abs(s.readInt()));
                 if (blocks > 1) {
-                    byte[] b2 = ByteUtils.newBytes(blocks * blockSize);
+                    byte[] b2 = MemoryUtils.newBytes(blocks * blockSize);
                     System.arraycopy(buff, 0, b2, 0, blockSize);
                     buff = b2;
                     try {
@@ -532,7 +534,7 @@ public class Recover extends Tool implements DataHandler {
                     case 'S': {
                         char fileType = (char) s.readByte();
                         int sumLength = s.readInt();
-                        byte[] summary = ByteUtils.newBytes(sumLength);
+                        byte[] summary = MemoryUtils.newBytes(sumLength);
                         if (sumLength > 0) {
                             s.read(summary, 0, sumLength);
                         }
@@ -858,7 +860,7 @@ public class Recover extends Tool implements DataHandler {
     }
 
     private void dumpPageLogStream(PrintWriter writer, FileStore store, int logFirstTrunkPage, int logFirstDataPage, int pageSize) throws IOException, SQLException {
-        DataPage s = DataPage.create(this, pageSize);
+        Data s = Data.create(this, pageSize);
         DataInputStream in = new DataInputStream(
                 new PageInputStream(writer, this, store, logFirstTrunkPage, logFirstDataPage, pageSize)
         );

h2/src/test/org/h2/test/TestAll.java

@@ -332,13 +332,15 @@ kill -9 `jps -l | grep "org.h2.test.TestAll" | cut -d " " -f 1`
                 new TestTimer().runTest(test);
             }
         } else {
-            test.runTests();
-
             int todo;
-//            System.setProperty(SysProperties.H2_PAGE_STORE, "true");
-//            test.pageStore = true;
-//            test.runTests();
+            System.setProperty(SysProperties.H2_PAGE_STORE, "true");
+            test.pageStore = true;
+            test.runTests();
+            TestPerformance.main(new String[]{ "-init", "-db", "1"});
 
+            System.setProperty(SysProperties.H2_PAGE_STORE, "false");
+            test.pageStore = false;
+            test.runTests();
             TestPerformance.main(new String[]{ "-init", "-db", "1"});
         }
         System.out.println(TestBase.formatTime(System.currentTimeMillis() - time) + " total");

h2/src/test/org/h2/test/TestBase.java

@@ -19,6 +19,7 @@ import java.sql.Statement;
 import java.sql.Types;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
+import java.util.LinkedList;
 
 import org.h2.jdbc.JdbcConnection;
 import org.h2.message.TraceSystem;
@@ -47,6 +48,8 @@ public abstract class TestBase {
      */
     protected long start;
 
+    private LinkedList<byte[]> memory = new LinkedList<byte[]>();
+
     /**
      * Get the test directory for this test.
      *
@@ -1068,4 +1071,43 @@ public abstract class TestBase {
         return "-Dh2.pageStore=" + System.getProperty("h2.pageStore");
     }
 
+
+    protected void eatMemory(int remainingKB) {
+        byte[] reserve = new byte[remainingKB * 1024];
+        int max = 128 * 1024 * 1024;
+        int div = 2;
+        while (true) {
+            long free = Runtime.getRuntime().freeMemory();
+            long freeTry = free / div;
+            int eat = (int) Math.min(max, freeTry);
+            try {
+                byte[] block = new byte[eat];
+                memory.add(block);
+            } catch (OutOfMemoryError e) {
+                if (eat < 32) {
+                    break;
+                }
+                if (eat == max) {
+                    max /= 2;
+                    if (max < 128) {
+                        break;
+                    }
+                }
+                if (eat == freeTry) {
+                    div += 1;
+                } else {
+                    div = 2;
+                }
+            }
+        }
+        // silly code - makes sure there are no warnings
+        reserve[0] = reserve[1];
+        // actually it is anyway garbage collected
+        reserve = null;
+    }
+
+    protected void freeMemory() {
+        memory.clear();
+    }
+
 }

h2/src/test/org/h2/test/db/TestMemoryUsage.java

@@ -86,19 +86,32 @@ public class TestMemoryUsage extends TestBase {
         stat.execute("SET MAX_LENGTH_INPLACE_LOB 32768");
         stat.execute("SET CACHE_SIZE 8000");
         stat.execute("CREATE TABLE TEST(ID IDENTITY, DATA CLOB)");
-        System.gc();
-        System.gc();
-        int start = MemoryUtils.getMemoryUsed();
-        for (int i = 0; i < 4; i++) {
-            stat.execute("INSERT INTO TEST(DATA) SELECT SPACE(32000) FROM SYSTEM_RANGE(1, 200)");
-            System.gc();
-            System.gc();
-            int used = MemoryUtils.getMemoryUsed();
-            if ((used - start) > 16000) {
-                fail("Used: " + (used - start));
+        freeSoftReferences();
+        try {
+            int start = MemoryUtils.getMemoryUsed();
+            for (int i = 0; i < 4; i++) {
+                stat.execute("INSERT INTO TEST(DATA) SELECT SPACE(32000) FROM SYSTEM_RANGE(1, 200)");
+                freeSoftReferences();
+                int used = MemoryUtils.getMemoryUsed();
+                if ((used - start) > 16000) {
+                    fail("Used: " + (used - start));
+                }
             }
+        } finally {
+            conn.close();
+            freeMemory();
         }
-        conn.close();
+    }
+
+    void freeSoftReferences() {
+        try {
+            eatMemory(1);
+        } catch (OutOfMemoryError e) {
+            // ignore
+        }
+        System.gc();
+        System.gc();
+        freeMemory();
     }
 
     private void testCreateIndex() throws SQLException {

h2/src/test/org/h2/test/db/TestOutOfMemory.java

@@ -11,8 +11,6 @@ import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
-import java.util.LinkedList;
-
 import org.h2.constant.ErrorCode;
 import org.h2.test.TestBase;
 
@@ -22,8 +20,6 @@ import org.h2.test.TestBase;
  */
 public class TestOutOfMemory extends TestBase {
 
-    private LinkedList<byte[]> list = new LinkedList<byte[]>();
-
     /**
      * Run just this test.
      *
@@ -56,7 +52,7 @@ public class TestOutOfMemory extends TestBase {
             } catch (SQLException e) {
                 assertEquals(ErrorCode.OUT_OF_MEMORY, e.getErrorCode());
             }
-            list = null;
+            freeMemory();
             ResultSet rs = stat.executeQuery("select count(*) from stuff");
             rs.next();
             assertEquals(2000, rs.getInt(1));
@@ -66,38 +62,4 @@ public class TestOutOfMemory extends TestBase {
         deleteDb("outOfMemory");
     }
 
-    private void eatMemory(int remainingKB) {
-        byte[] reserve = new byte[remainingKB * 1024];
-        int max = 128 * 1024 * 1024;
-        int div = 2;
-        while (true) {
-            long free = Runtime.getRuntime().freeMemory();
-            long freeTry = free / div;
-            int eat = (int) Math.min(max, freeTry);
-            try {
-                byte[] block = new byte[eat];
-                list.add(block);
-            } catch (OutOfMemoryError e) {
-                if (eat < 32) {
-                    break;
-                }
-                if (eat == max) {
-                    max /= 2;
-                    if (max < 128) {
-                        break;
-                    }
-                }
-                if (eat == freeTry) {
-                    div += 1;
-                } else {
-                    div = 2;
-                }
-            }
-        }
-        // silly code - makes sure there are no warnings
-        reserve[0] = reserve[1];
-        // actually it is anyway garbage collected
-        reserve = null;
-    }
-
 }