A persistent tree map (work in progress).

h2/src/test/org/h2/test/unit/TestTreeMapStore.java

@@ -10,8 +10,6 @@ import java.util.Random;
 import java.util.TreeMap;
 import org.h2.dev.store.btree.BtreeMap;
 import org.h2.dev.store.btree.BtreeMapStore;
-import org.h2.dev.store.tree.StoredMap;
-import org.h2.dev.store.tree.TreeMapStore;
 import org.h2.jaqu.bytecode.Null;
 import org.h2.store.fs.FileUtils;
 import org.h2.test.TestBase;
@@ -31,10 +29,7 @@ public class TestTreeMapStore extends TestBase {
     }
 
     public void test() throws Exception {
-        // btree
         testBtreeStore();
-
-        // left leaning red-black tree
         testDefragment();
         testReuseSpace();
         testRandom();
@@ -84,13 +79,12 @@ public class TestTreeMapStore extends TestBase {
         FileUtils.delete(fileName);
         long initialLength = 0;
         for (int j = 0; j < 20; j++) {
-            TreeMapStore s = TreeMapStore.open(fileName);
-            StoredMap<Integer, String> m = s.openMap("data", Integer.class, String.class);
+            BtreeMapStore s = BtreeMapStore.open(fileName);
+            BtreeMap<Integer, String> m = s.openMap("data", Integer.class, String.class);
             for (int i = 0; i < 10; i++) {
                 m.put(j + i, "Hello " + j);
             }
             s.store();
-            // s.log(s.toString());
             s.compact();
             s.close();
             long len = FileUtils.size(fileName);
@@ -108,8 +102,8 @@ public class TestTreeMapStore extends TestBase {
         FileUtils.delete(fileName);
         long initialLength = 0;
         for (int j = 0; j < 10; j++) {
-            TreeMapStore s = TreeMapStore.open(fileName);
-            StoredMap<Integer, String> m = s.openMap("data", Integer.class, String.class);
+            BtreeMapStore s = BtreeMapStore.open(fileName);
+            BtreeMap<Integer, String> m = s.openMap("data", Integer.class, String.class);
             for (int i = 0; i < 10; i++) {
                 m.put(i, "Hello");
             }
@@ -131,8 +125,8 @@ public class TestTreeMapStore extends TestBase {
     private void testRandom() {
         String fileName = getBaseDir() + "/data.h3";
         FileUtils.delete(fileName);
-        TreeMapStore s = TreeMapStore.open(fileName);
-        StoredMap<Integer, Integer> m = s.openMap("data", Integer.class, Integer.class);
+        BtreeMapStore s = BtreeMapStore.open(fileName);
+        BtreeMap<Integer, Integer> m = s.openMap("data", Integer.class, Integer.class);
         TreeMap<Integer, Integer> map = new TreeMap<Integer, Integer>();
         Random r = new Random(1);
         for (int i = 0; i < 100; i++) {
@@ -159,14 +153,14 @@ public class TestTreeMapStore extends TestBase {
     private void testKeyValueClasses() {
         String fileName = getBaseDir() + "/data.h3";
         FileUtils.delete(fileName);
-        TreeMapStore s = TreeMapStore.open(fileName);
-        StoredMap<Integer, String> is = s.openMap("intString", Integer.class, String.class);
+        BtreeMapStore s = BtreeMapStore.open(fileName);
+        BtreeMap<Integer, String> is = s.openMap("intString", Integer.class, String.class);
         is.put(1, "Hello");
-        StoredMap<Integer, Integer> ii = s.openMap("intInt", Integer.class, Integer.class);
+        BtreeMap<Integer, Integer> ii = s.openMap("intInt", Integer.class, Integer.class);
         ii.put(1, 10);
-        StoredMap<String, Integer> si = s.openMap("stringInt", String.class, Integer.class);
+        BtreeMap<String, Integer> si = s.openMap("stringInt", String.class, Integer.class);
         si.put("Test", 10);
-        StoredMap<String, String> ss = s.openMap("stringString", String.class, String.class);
+        BtreeMap<String, String> ss = s.openMap("stringString", String.class, String.class);
         ss.put("Hello", "World");
         try {
             s.openMap("invalid", Null.class, Integer.class);
@@ -181,7 +175,7 @@ public class TestTreeMapStore extends TestBase {
             // expected
         }
         s.close();
-        s = TreeMapStore.open(fileName);
+        s = BtreeMapStore.open(fileName);
         is = s.openMap("intString", Integer.class, String.class);
         assertEquals("Hello", is.get(1));
         ii = s.openMap("intInt", Integer.class, Integer.class);
@@ -196,8 +190,8 @@ public class TestTreeMapStore extends TestBase {
     private void testIterate() {
         String fileName = getBaseDir() + "/data.h3";
         FileUtils.delete(fileName);
-        TreeMapStore s = TreeMapStore.open(fileName);
-        StoredMap<Integer, String> m = s.openMap("data", Integer.class, String.class);
+        BtreeMapStore s = BtreeMapStore.open(fileName);
+        BtreeMap<Integer, String> m = s.openMap("data", Integer.class, String.class);
         Iterator<Integer> it = m.keyIterator(null);
         assertFalse(it.hasNext());
         for (int i = 0; i < 10; i++) {
@@ -229,8 +223,8 @@ public class TestTreeMapStore extends TestBase {
     private void testSimple() {
         String fileName = getBaseDir() + "/data.h3";
         FileUtils.delete(fileName);
-        TreeMapStore s = TreeMapStore.open(fileName);
-        StoredMap<Integer, String> m = s.openMap("data", Integer.class, String.class);
+        BtreeMapStore s = BtreeMapStore.open(fileName);
+        BtreeMap<Integer, String> m = s.openMap("data", Integer.class, String.class);
         for (int i = 0; i < 3; i++) {
             m.put(i, "hello " + i);
         }
@@ -244,7 +238,7 @@ public class TestTreeMapStore extends TestBase {
 
         s.close();
 
-        s = TreeMapStore.open(fileName);
+        s = BtreeMapStore.open(fileName);
         m = s.openMap("data", Integer.class, String.class);
         assertNull(m.get(0));
         for (int i = 1; i < 3; i++) {

h2/src/tools/org/h2/dev/store/btree/BtreeMap.java

@@ -90,7 +90,7 @@ public class BtreeMap<K, V> {
      * Get a value.
      *
      * @param key the key
-     * @return the value
+     * @return the value, or null if not found
      */
     @SuppressWarnings("unchecked")
     public V get(K key) {
@@ -100,6 +100,19 @@ public class BtreeMap<K, V> {
         return (V) root.find(key);
     }
 
+    /**
+     * Get the page for the given value.
+     *
+     * @param key the key
+     * @return the value, or null if not found
+     */
+    public Page getPage(K key) {
+        if (root == null) {
+            return null;
+        }
+        return root.findPage(key);
+    }
+
     /**
      * Remove a key-value pair.
      *
@@ -109,7 +122,9 @@ public class BtreeMap<K, V> {
         if (!isChanged()) {
             store.markChanged(name, this);
         }
-        root = Page.remove(root, key);
+        if (root != null) {
+            root = Page.remove(root, key);
+        }
     }
 
     /**

h2/src/tools/org/h2/dev/store/btree/BtreeMapStore.java

@@ -7,7 +7,6 @@
 package org.h2.dev.store.btree;
 
 import java.io.ByteArrayInputStream;
-import java.io.File;
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.nio.channels.FileChannel;
@@ -273,15 +272,16 @@ public class BtreeMapStore {
             if (x.liveCount == 0) {
                 meta.remove("block." + x.id);
             } else {
-                meta.put("block." + x.id, "temp " + x.toString());
+                meta.put("block." + x.id, "temp-" + x.toString());
             }
         }
         // modifying the meta can itself affect the metadata
         // TODO solve this in a better way
+        ArrayList<Integer> removedBlocks = New.arrayList();
         for (Block x : new ArrayList<Block>(blocks.values())) {
             if (x.liveCount == 0) {
                 meta.remove("block." + x.id);
-                blocks.remove(x.id);
+                removedBlocks.add(x.id);
             } else {
                 meta.put("block." + x.id, x.toString());
             }
@@ -289,7 +289,13 @@ public class BtreeMapStore {
         lenEstimate += meta.getRoot().lengthIncludingTempChildren();
         b.length = lenEstimate;
 
+        blocks.remove(b.id);
         long storePos = allocateBlock(lenEstimate);
+        blocks.put(b.id, b);
+
+        for (int id : removedBlocks) {
+            blocks.remove(id);
+        }
 
         long pageId = getId(blockId, 1 + 8);
         for (BtreeMap<?, ?> m : mapsChanged.values()) {
@@ -301,7 +307,6 @@ public class BtreeMapStore {
             }
         }
         int metaRootOffset = (int) (pageId - getId(blockId, 0));
-
         // add a dummy entry so the count is correct
         meta.put("block." + b.id, b.toString());
         int count = 0;
@@ -424,7 +429,6 @@ public class BtreeMapStore {
      * be re-written.
      */
     public void compact() {
-        if(true)throw new RuntimeException("not implemented yet");
         if (blocks.size() <= 1) {
             return;
         }
@@ -473,7 +477,7 @@ public class BtreeMapStore {
         }
         long oldMetaRootId = readMetaRootId(move.start);
         long offset = getPosition(oldMetaRootId);
-        log("  meta:" + move.id + "/" + offset);
+        log("  meta:" + move.id + "/" + offset + " start: " + move.start);
         BtreeMap<String, String> oldMeta = BtreeMap.open(this, "old-meta", String.class, String.class);
         oldMeta.setRoot(oldMetaRootId);
         Iterator<String> it = oldMeta.keyIterator(null);
@@ -509,19 +513,19 @@ public class BtreeMapStore {
             Iterator<?> dataIt = oldData.keyIterator(null);
             while (dataIt.hasNext()) {
                 Object o = dataIt.next();
-                int todo;
-                Page p = null; // data.getNode(o);
+                Page p = data.getPage(o);
                 if (p == null) {
                     // was removed later - ignore
                 } else if (p.getId() < 0) {
                     // temporarily changed - ok
+                    // TODO move old data if changed temporarily?
                 } else {
                     Block b = getBlock(p.getId());
                     if (old.contains(b)) {
                         log("       move key:" + o + " block:" + b.id);
+                        Object value = data.get(o);
                         data.remove(o);
-                        int todo2;
-                        // data.put(o, n.getData());
+                        data.put(o, value);
                     }
                 }
             }
@@ -657,6 +661,7 @@ public class BtreeMapStore {
      * @param string the string to log
      */
     public void log(String string) {
+        // TODO logging
         // System.out.println(string);
     }
 

h2/src/tools/org/h2/dev/store/btree/Page.java

@@ -135,6 +135,29 @@ class Page {
         return null;
     }
 
+    /**
+     * Get the value for the given key, or null if not found.
+     *
+     * @param key the key
+     * @return the page or null
+     */
+    Page findPage(Object key) {
+        int x = findKey(key);
+        if (children != null) {
+            if (x < 0) {
+                x = -x - 1;
+            } else {
+                x++;
+            }
+            Page p = map.readPage(children[x]);
+            return p.findPage(key);
+        }
+        if (x >= 0) {
+            return this;
+        }
+        return null;
+    }
+
     private int findKey(Object key) {
         int low = 0, high = keys.length - 1;
         while (low <= high) {
@@ -175,7 +198,6 @@ class Page {
      * @param key the key
      */
     static void min(Page p, ArrayList<CursorPos> parents, Object key) {
-        int todo;
         while (p != null) {
             int x = key == null ? 0 : p.findKey(key);
             if (p.children != null) {
@@ -184,11 +206,11 @@ class Page {
                 } else {
                     x++;
                 }
-                p = p.map.readPage(p.children[x]);
                 CursorPos c = new CursorPos();
                 c.page = p;
                 c.index = x;
                 parents.add(c);
+                p = p.map.readPage(p.children[x]);
             } else {
                 if (x < 0) {
                     x = -x - 1;
@@ -209,12 +231,11 @@ class Page {
      * @return the next key
      */
     public static Object nextKey(ArrayList<CursorPos> parents) {
-        int todoTest;
         if (parents.size() == 0) {
             return null;
         }
         while (true) {
-            // TODO avoid remove/add pairs is possible
+            // TODO avoid remove/add pairs if possible
             CursorPos p = parents.remove(parents.size() - 1);
             int index = p.index++;
             if (index < p.page.keys.length) {
@@ -229,7 +250,9 @@ class Page {
                 index = p.index++;
                 if (index < p.page.children.length) {
                     parents.add(p);
-                    min(p.page, parents, null);
+                    Page x = p.page;
+                    x = x.map.readPage(x.children[index]);
+                    min(x, parents, null);
                     break;
                 }
             }
@@ -321,6 +344,11 @@ class Page {
             int index = p.findKey(key);
             if (p.isLeaf()) {
                 if (index >= 0) {
+                    // create a copy
+                    // TODO might not be required, but needs a "modified" flag
+                    Object[] v2 = new Object[p.values.length];
+                    System.arraycopy(p.values, 0, v2, 0, v2.length);
+                    p.values = v2;
                     p.values[index] = value;
                     break;
                 }
@@ -398,26 +426,6 @@ class Page {
         return top;
     }
 
-    /**
-     * Remove a key.
-     *
-     * @param key the key
-     * @return the new page or null if the page is now empty
-     */
-    private Page remove(Object key) {
-        int index = findKey(key);
-        if (isLeaf()) {
-            if (index < 0) {
-                // not found
-                return this;
-            }
-        }
-
-        Page p = copyOnWrite();
-        p = p.remove(key);
-        return p;
-    }
-
     private void insert(int index, Object key, Object value, long child) {
         Object[] newKeys = new Object[keys.length + 1];
         copyWithGap(keys, newKeys, keys.length, index);