MVStore: rename pageSize to pageSplitSize

h2/src/main/org/h2/mvstore/MVMap.java

@@ -125,7 +125,7 @@ public class MVMap<K, V> extends AbstractMap<K, V>
      * @return the new sibling
      */
     protected Page splitRootIfNeeded(Page p, long writeVersion) {
-        if (p.getMemory() <= store.getPageSize() || p.getKeyCount() <= 1) {
+        if (p.getMemory() <= store.getPageSplitSize() || p.getKeyCount() <= 1) {
             return p;
         }
         int at = p.getKeyCount() / 2;
@@ -167,7 +167,7 @@ public class MVMap<K, V> extends AbstractMap<K, V>
             index++;
         }
         Page c = copyOnWrite(p.getChildPage(index), writeVersion);
-        if (c.getMemory() > store.getPageSize() && c.getKeyCount() > 1) {
+        if (c.getMemory() > store.getPageSplitSize() && c.getKeyCount() > 1) {
             // split on the way down
             int at = c.getKeyCount() / 2;
             Object k = c.getKey(at);

h2/src/main/org/h2/mvstore/MVStore.java

@@ -51,7 +51,7 @@ TestMVStoreDataLoss
 TransactionStore:
 
 MVStore:
-- rolling docs review: at "Features"
+- rolling docs review: at "Transactions"
 - move setters to the builder, except for setRetainVersion, setReuseSpace,
     and settings that are persistent (setStoreVersion)
 - automated 'kill process' and 'power failure' test
@@ -107,8 +107,10 @@ MVStore:
 - autocommit (to avoid having to call commit,
     as it could be called too often or it is easily forgotten)
 - remove features that are not really needed; simplify the code
-    possibly using a layering / tool mechanism
-- rename "store" to "save", as store collides with storeVersion
+    possibly using a separate layer or tools
+- rename "store" to "save", as "store" is used in "storeVersion"
+- MVStoreTool.dump should dump the data if possible;
+    possibly using a callback for serialization
 
 */
 
@@ -141,7 +143,7 @@ public class MVStore {
     private final String fileName;
     private final char[] filePassword;
 
-    private final int pageSize;
+    private final int pageSplitSize;
 
     private FileChannel file;
     private FileLock fileLock;
@@ -250,15 +252,15 @@ public class MVStore {
         this.fileName = f;
         this.readOnly = config.containsKey("readOnly");
         this.compress = config.containsKey("compress");
-        Object o = config.get("pageSize");
-        pageSize = o == null ? 6 * 1024 : (Integer) o;
+        Object o = config.get("pageSplitSize");
+        pageSplitSize = o == null ? 6 * 1024 : (Integer) o;
         o = config.get("backgroundExceptionListener");
         this.backgroundExceptionListener = (ExceptionListener) o;
         if (fileName != null) {
             o = config.get("cacheSize");
             int mb = o == null ? 16 : (Integer) o;
             int maxMemoryBytes = mb * 1024 * 1024;
-            int averageMemory = pageSize / 2;
+            int averageMemory = pageSplitSize / 2;
             int segmentCount = 16;
             int stackMoveDistance = maxMemoryBytes / averageMemory * 2 / 100;
             cache = new CacheLongKeyLIRS<Page>(
@@ -267,7 +269,7 @@ public class MVStore {
             o = config.get("writeBufferSize");
             mb = o == null ? 4 : (Integer) o;
             int writeBufferSize =  mb * 1024 * 1024;
-            maxUnsavedPages = writeBufferSize / pageSize;
+            maxUnsavedPages = writeBufferSize / pageSplitSize;
             o = config.get("writeDelay");
             writeDelay = o == null ? 1000 : (Integer) o;
         } else {
@@ -742,14 +744,14 @@ public class MVStore {
         if (closed) {
             return;
         }
-        closed = true;
-        if (file == null) {
-            return;
-        }
         // can not synchronize on this yet, because
         // the thread also synchronized on this, which
         // could result in a deadlock
         stopBackgroundThread();
+        closed = true;
+        if (file == null) {
+            return;
+        }
         synchronized (this) {
             try {
                 if (shrinkIfPossible) {
@@ -1408,8 +1410,8 @@ public class MVStore {
         return compress;
     }
 
-    public int getPageSize() {
-        return pageSize;
+    public int getPageSplitSize() {
+        return pageSplitSize;
     }
 
     public boolean getReuseSpace() {
@@ -2027,15 +2029,16 @@ public class MVStore {
         }
 
         /**
-         * Set the amount of memory a page should contain at most, in bytes. Larger
-         * pages are split. The default is 6 KB. This is not a limit in the page
-         * size (pages with one entry can get larger), it is just the point where
-         * pages are split.
+         * Set the amount of memory a page should contain at most, in bytes,
+         * before it is split. The default is 6 KB. This is not a limit in the
+         * page size, as pages with one entry can get larger. It is just the
+         * point where pages that contain more than one entry are split.
          *
-         * @param pageSize the page size
+         * @param pageSplitSize the page size
+         * @return this
          */
-        public Builder pageSize(int pageSize) {
-            return set("pageSize", pageSize);
+        public Builder pageSplitSize(int pageSplitSize) {
+            return set("pageSplitSize", pageSplitSize);
         }
 
         /**
@@ -2043,6 +2046,7 @@ public class MVStore {
          * thread.
          *
          * @param backgroundExceptionListener the listener
+         * @return this
          */
         public Builder backgroundExceptionListener(
                 ExceptionListener backgroundExceptionListener) {

h2/src/main/org/h2/mvstore/rtree/MVRTreeMap.java

@@ -227,9 +227,9 @@ public class MVRTreeMap<V> extends MVMap<SpatialKey, V> {
             Page p = copyOnWrite(root, v);
             Object result;
             if (alwaysAdd || get(key) == null) {
-                if (p.getMemory() > store.getPageSize() && p.getKeyCount() > 1) {
+                if (p.getMemory() > store.getPageSplitSize() && p.getKeyCount() > 1) {
                     // only possible if this is the root, else we would have split earlier
-                    // (this requires maxPageSize is fixed)
+                    // (this requires pageSplitSize is fixed)
                     long totalCount = p.getTotalCount();
                     Page split = split(p, v);
                     Object k1 = getBounds(p);
@@ -313,7 +313,7 @@ public class MVRTreeMap<V> extends MVMap<SpatialKey, V> {
             }
         }
         Page c = copyOnWrite(p.getChildPage(index), writeVersion);
-        if (c.getMemory() > store.getPageSize() && c.getKeyCount() > 1) {
+        if (c.getMemory() > store.getPageSplitSize() && c.getKeyCount() > 1) {
             // split on the way down
             Page split = split(c, writeVersion);
             p = copyOnWrite(p, writeVersion);