A persistent multi-version map (work in progress): r-tree

h2/src/test/org/h2/test/store/RtreeMap.java

@@ -14,7 +14,7 @@ import org.h2.dev.store.btree.DataType;
 import org.h2.dev.store.btree.Page;
 
 /**
- * An r-tree implementation.
+ * An r-tree implementation. It uses the quadratic split algorithm.
  *
  * @param <K> the key class
  * @param <V> the value class
@@ -38,10 +38,6 @@ public class RtreeMap<K, V> extends BtreeMap<K, V> {
         return (V) getSpatial(root, key);
     }
 
-    private boolean overlap(Page p, int index, Object key) {
-        return keyType.isOverlap(p.getKey(index), key);
-    }
-
     private boolean contains(Page p, int index, Object key) {
         return keyType.contains(p.getKey(index), key);
     }
@@ -205,6 +201,7 @@ public class RtreeMap<K, V> extends BtreeMap<K, V> {
                     throw KEY_ALREADY_EXISTS;
                 }
             }
+            p = p.copyOnWrite(writeVersion);
             p.insert(p.getKeyCount(), key, value, 0, 0);
             return p;
         }

h2/src/test/org/h2/test/store/TestBtreeMapStore.java

@@ -65,19 +65,33 @@ public class TestBtreeMapStore extends TestBase {
         FileUtils.delete(fileName);
         BtreeMapStore s;
         s = openStore(fileName);
-        // s.setMaxPageSize(100);
+        // s.setMaxPageSize(50);
         RtreeMap<SpatialKey, String> r = s.openMap("data", "r", "s2", "");
         Random rand = new Random(1);
-        for (int i = 0; i < 1000; i++) {
+        int len = 1000;
+        for (int i = 0; i < len; i++) {
             float x = rand.nextFloat(), y = rand.nextFloat();
             float p = (float) (rand.nextFloat() * 0.01);
             SpatialKey k = SpatialKey.create(i, x - p, x + p, y - p, y + p);
             r.put(k, "" + i);
-            if (i > 0 && i % 10000 == 0) {
+            if (i > 0 && (i % 100) == 0) {
+                s.store();
+            }
+            if (i > 0 && (i % 10000) == 0) {
                 render(r, getBaseDir() + "/test.png");
             }
         }
+        s.store();
         s.close();
+        s = openStore(fileName);
+        r = s.openMap("data", "r", "s2", "");
+        rand = new Random(1);
+        for (int i = 0; i < len; i++) {
+            float x = rand.nextFloat(), y = rand.nextFloat();
+            float p = (float) (rand.nextFloat() * 0.01);
+            SpatialKey k = SpatialKey.create(i, x - p, x + p, y - p, y + p);
+            assertEquals("" + i, r.get(k));
+        }
     }
 
     private void testRtree() {
@@ -422,6 +436,8 @@ public class TestBtreeMapStore extends TestBase {
         String fileName = getBaseDir() + "/testBtreeStore.h3";
         FileUtils.delete(fileName);
         BtreeMapStore s = openStore(fileName);
+        s.close();
+        s = openStore(fileName);
         BtreeMap<Integer, String> m = s.openMap("data", Integer.class, String.class);
         int count = 2000;
         // Profiler p = new Profiler();

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

@@ -41,12 +41,10 @@ TODO:
 - ability to diff / merge versions
 - map.getVersion and opening old maps read-only
 - limited support for writing to old versions (branches)
-- Serializer instead of DataType, (serialize, deserialize)
 - implement complete java.util.Map interface
 - maybe rename to MVStore, MVMap, TestMVStore
 - atomic test-and-set (when supporting concurrent writes)
 - support background writes (store old version)
-- re-use map ids that were not used for a very long time
 - file header could be a regular chunk, end of file the second
 - possibly split chunk data into immutable and mutable
 - test with very small chunks, possibly speed up very small transactions
@@ -285,7 +283,9 @@ public class BtreeMapStore {
                 writeHeader();
             } else {
                 readHeader();
-                readMeta();
+                if (rootChunkStart > 0) {
+                    readMeta();
+                }
             }
         } catch (Exception e) {
             throw convert(e);