Split the LobStorage class into client-side and server-side code.

This is a cleanup targetted at allowing us to fix a deadlock issue.

h2/src/main/org/h2/command/dml/ScriptBase.java

@@ -25,7 +25,7 @@ import org.h2.store.DataHandler;
 import org.h2.store.FileStore;
 import org.h2.store.FileStoreInputStream;
 import org.h2.store.FileStoreOutputStream;
-import org.h2.store.LobStorage;
+import org.h2.store.LobStorageBackend;
 import org.h2.store.fs.FileUtils;
 import org.h2.tools.CompressTool;
 import org.h2.util.IOUtils;
@@ -232,7 +232,7 @@ abstract class ScriptBase extends Prepared implements DataHandler {
         return null;
     }
 
-    public LobStorage getLobStorage() {
+    public LobStorageBackend getLobStorage() {
         return null;
     }
 

h2/src/main/org/h2/engine/Database.java

@@ -40,7 +40,7 @@ import org.h2.store.DataHandler;
 import org.h2.store.FileLock;
 import org.h2.store.FileStore;
 import org.h2.store.InDoubtTransaction;
-import org.h2.store.LobStorage;
+import org.h2.store.LobStorageBackend;
 import org.h2.store.PageStore;
 import org.h2.store.WriterThread;
 import org.h2.store.fs.FileUtils;
@@ -167,7 +167,7 @@ public class Database implements DataHandler {
     private SourceCompiler compiler;
     private volatile boolean metaTablesInitialized;
     private boolean flushOnEachCommit;
-    private LobStorage lobStorage;
+    private LobStorageBackend lobStorage;
     private final int pageSize;
     private int defaultTableType = Table.TYPE_CACHED;
     private final DbSettings dbSettings;
@@ -1102,11 +1102,11 @@ public class Database implements DataHandler {
         }
         // remove all session variables
         if (persistent) {
-            boolean lobStorageIsUsed = infoSchema.findTableOrView(systemSession, LobStorage.LOB_DATA_TABLE) != null;
+            boolean lobStorageIsUsed = infoSchema.findTableOrView(systemSession, LobStorageBackend.LOB_DATA_TABLE) != null;
             if (lobStorageIsUsed) {
                 try {
                     getLobStorage();
-                    lobStorage.removeAllForTable(LobStorage.TABLE_ID_SESSION_VARIABLE);
+                    lobStorage.removeAllForTable(LobStorageBackend.TABLE_ID_SESSION_VARIABLE);
                 } catch (DbException e) {
                     trace.error(e, "close");
                 }
@@ -2314,9 +2314,9 @@ public class Database implements DataHandler {
         return compiler;
     }
 
-    public LobStorage getLobStorage() {
+    public LobStorageBackend getLobStorage() {
         if (lobStorage == null) {
-            lobStorage = new LobStorage(this);
+            lobStorage = new LobStorageBackend(this);
         }
         return lobStorage;
     }

h2/src/main/org/h2/engine/Session.java

@@ -30,7 +30,7 @@ import org.h2.result.Row;
 import org.h2.schema.Schema;
 import org.h2.store.DataHandler;
 import org.h2.store.InDoubtTransaction;
-import org.h2.store.LobStorage;
+import org.h2.store.LobStorageBackend;
 import org.h2.table.Table;
 import org.h2.util.New;
 import org.h2.util.SmallLRUCache;
@@ -145,7 +145,7 @@ public class Session extends SessionWithState {
             old = variables.remove(name);
         } else {
             // link LOB values, to make sure we have our own object
-            value = value.link(database, LobStorage.TABLE_ID_SESSION_VARIABLE);
+            value = value.link(database, LobStorageBackend.TABLE_ID_SESSION_VARIABLE);
             old = variables.put(name, value);
         }
         if (old != null) {
@@ -967,6 +967,10 @@ public class Session extends SessionWithState {
         return database;
     }
 
+    public LobStorageBackend getLobStorageBackend() {
+        return database.getLobStorage();
+    }
+    
     /**
      * Remember that the given LOB value must be un-linked (disconnected from
      * the table) at commit.

h2/src/main/org/h2/engine/SessionRemote.java

@@ -22,7 +22,8 @@ import org.h2.message.Trace;
 import org.h2.message.TraceSystem;
 import org.h2.store.DataHandler;
 import org.h2.store.FileStore;
-import org.h2.store.LobStorage;
+import org.h2.store.LobStorageFrontend;
+import org.h2.store.LobStorageInterface;
 import org.h2.store.fs.FileUtils;
 import org.h2.util.MathUtils;
 import org.h2.util.NetUtils;
@@ -82,7 +83,7 @@ public class SessionRemote extends SessionWithState implements DataHandler {
     private int lastReconnect;
     private SessionInterface embedded;
     private DatabaseEventListener eventListener;
-    private LobStorage lobStorage;
+    private LobStorageFrontend lobStorage;
     private boolean cluster;
 
     public SessionRemote(ConnectionInfo ci) {
@@ -681,9 +682,9 @@ public class SessionRemote extends SessionWithState implements DataHandler {
         // nothing to do
     }
 
-    public LobStorage getLobStorage() {
+    public LobStorageInterface getLobStorage() {
         if (lobStorage == null) {
-            lobStorage = new LobStorage(this);
+            lobStorage = new LobStorageFrontend(this);
         }
         return lobStorage;
     }

h2/src/main/org/h2/mvstore/db/ValueDataType.java

@@ -23,7 +23,8 @@ import org.h2.mvstore.type.DataType;
 import org.h2.result.SortOrder;
 import org.h2.store.Data;
 import org.h2.store.DataHandler;
-import org.h2.store.LobStorage;
+import org.h2.store.LobStorageBackend;
+import org.h2.store.LobStorageInterface;
 import org.h2.tools.SimpleResultSet;
 import org.h2.util.DateTimeUtils;
 import org.h2.value.CompareMode;
@@ -592,12 +593,12 @@ public class ValueDataType implements DataType {
             if (smallLen >= 0) {
                 byte[] small = DataUtils.newBytes(smallLen);
                 buff.get(small, 0, smallLen);
-                return LobStorage.createSmallLob(type, small);
+                return LobStorageBackend.createSmallLob(type, small);
             } else if (smallLen == -3) {
                 int tableId = readVarInt(buff);
                 long lobId = readVarLong(buff);
                 long precision = readVarLong(buff);
-                LobStorage lobStorage = handler.getLobStorage();
+                LobStorageInterface lobStorage = handler.getLobStorage();
                 ValueLobDb lob = ValueLobDb.create(type, lobStorage, tableId, lobId, null, precision);
                 return lob;
             } else {

h2/src/main/org/h2/server/TcpServerThread.java

@@ -30,7 +30,7 @@ import org.h2.jdbc.JdbcSQLException;
 import org.h2.message.DbException;
 import org.h2.result.ResultColumn;
 import org.h2.result.ResultInterface;
-import org.h2.store.LobStorage;
+import org.h2.store.LobStorageInterface;
 import org.h2.util.IOUtils;
 import org.h2.util.SmallLRUCache;
 import org.h2.util.SmallMap;
@@ -427,7 +427,7 @@ public class TcpServerThread implements Runnable {
             }
             long offset = transfer.readLong();
             if (in.getPos() != offset) {
-                LobStorage lobStorage = session.getDataHandler().getLobStorage();
+                LobStorageInterface lobStorage = session.getDataHandler().getLobStorage();
                 InputStream lobIn = lobStorage.getInputStream(lobId, hmac, -1);
                 in = new CachedInputStream(lobIn);
                 lobs.put(lobId, in);

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

@@ -787,12 +787,12 @@ public class Data {
             if (smallLen >= 0) {
                 byte[] small = DataUtils.newBytes(smallLen);
                 read(small, 0, smallLen);
-                return LobStorage.createSmallLob(type, small);
+                return LobStorageBackend.createSmallLob(type, small);
             } else if (smallLen == -3) {
                 int tableId = readVarInt();
                 long lobId = readVarLong();
                 long precision = readVarLong();
-                LobStorage lobStorage = handler.getLobStorage();
+                LobStorageInterface lobStorage = handler.getLobStorage();
                 ValueLobDb lob = ValueLobDb.create(type, lobStorage, tableId, lobId, null, precision);
                 return lob;
             } else {

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

@@ -90,7 +90,7 @@ public interface DataHandler {
      *
      * @return the lob storage mechanism
      */
-    LobStorage getLobStorage();
+    LobStorageInterface getLobStorage();
 
     /**
      * Get a database connection to be used for LOB access.

h2/src/main/org/h2/store/LobStorage.java → h2/src/main/org/h2/store/LobStorageBackend.java

@@ -6,7 +6,6 @@
  */
 package org.h2.store;
 
-import java.io.BufferedInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.Reader;
@@ -18,7 +17,6 @@ import java.sql.Statement;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
-
 import org.h2.constant.ErrorCode;
 import org.h2.constant.SysProperties;
 import org.h2.engine.Constants;
@@ -34,8 +32,9 @@ import org.h2.value.ValueLobDb;
 
 /**
  * This class stores LOB objects in the database.
+ * This is the back-end i.e. the server side of the LOB storage.
  */
-public class LobStorage {
+public class LobStorageBackend implements LobStorageInterface {
 
     /**
      * The table id for session variables (LOBs not assigned to a table).
@@ -75,7 +74,7 @@ public class LobStorage {
     private final DataHandler handler;
     private boolean init;
 
-    public LobStorage(DataHandler handler) {
+    public LobStorageBackend(DataHandler handler) {
         this.handler = handler;
     }
 
@@ -89,9 +88,6 @@ public class LobStorage {
         synchronized (handler) {
             conn = handler.getLobConnection();
             init = true;
-            if (conn == null) {
-                return;
-            }
             try {
                 Statement stat = conn.createStatement();
                 // stat.execute("SET UNDO_LOG 0");
@@ -266,75 +262,6 @@ public class LobStorage {
         }
     }
 
-    /**
-     * An input stream that reads from a remote LOB.
-     */
-    public static class RemoteInputStream extends InputStream {
-
-        /**
-         * The data handler.
-         */
-        private final DataHandler handler;
-
-        /**
-         * The lob id.
-         */
-        private final long lob;
-
-        private final byte[] hmac;
-
-        /**
-         * The position.
-         */
-        private long pos;
-
-        /**
-         * The remaining bytes in the lob.
-         */
-        private long remainingBytes;
-
-        public RemoteInputStream(DataHandler handler, long lob, byte[] hmac, long byteCount) {
-            this.handler = handler;
-            this.lob = lob;
-            this.hmac = hmac;
-            remainingBytes = byteCount;
-        }
-
-        public int read() throws IOException {
-            byte[] buff = new byte[1];
-            int len = read(buff, 0, 1);
-            return len < 0 ? len : (buff[0] & 255);
-        }
-
-        public int read(byte[] buff) throws IOException {
-            return read(buff, 0, buff.length);
-        }
-
-        public int read(byte[] buff, int off, int length) throws IOException {
-            if (length == 0) {
-                return 0;
-            }
-            length = (int) Math.min(length, remainingBytes);
-            if (length == 0) {
-                return -1;
-            }
-            length = handler.readLob(lob, hmac, pos, buff, off, length);
-            remainingBytes -= length;
-            if (length == 0) {
-                return -1;
-            }
-            pos += length;
-            return length;
-        }
-
-        public long skip(long n) {
-            remainingBytes -= n;
-            pos += n;
-            return n;
-        }
-
-    }
-
     /**
      * An input stream that reads from a LOB.
      */
@@ -499,9 +426,6 @@ public class LobStorage {
     public void removeLob(long lob) {
         try {
             synchronized (handler) {
-                if (conn == null) {
-                    return;
-                }
                 String sql = "SELECT BLOCK, HASH FROM " + LOB_MAP + " D WHERE D.LOB = ? " +
                         "AND NOT EXISTS(SELECT 1 FROM " + LOB_MAP + " O " +
                         "WHERE O.BLOCK = D.BLOCK AND O.LOB <> ?)";
@@ -552,12 +476,6 @@ public class LobStorage {
      */
     public InputStream getInputStream(long lobId, byte[] hmac, long byteCount) throws IOException {
         init();
-        if (conn == null) {
-            if (byteCount < 0) {
-                byteCount = Long.MAX_VALUE;
-            }
-            return new BufferedInputStream(new RemoteInputStream(handler, lobId, hmac, byteCount));
-        }
         if (byteCount == -1) {
             synchronized (handler) {
                 try {
@@ -861,13 +779,6 @@ public class LobStorage {
     public Value createBlob(InputStream in, long maxLength) {
         if (SysProperties.LOB_IN_DATABASE) {
             init();
-            if (conn == null) {
-                // remote connections:
-                // need to use a temp file, because the input stream could come from
-                // the same database, which would create a weird situation (trying
-                // to read a block while write something)
-                return ValueLobDb.createTempBlob(in, maxLength, handler);
-            }
             return addLob(in, maxLength, Value.BLOB);
         }
         return ValueLob.createBlob(in, maxLength, handler);
@@ -883,13 +794,6 @@ public class LobStorage {
     public Value createClob(Reader reader, long maxLength) {
         if (SysProperties.LOB_IN_DATABASE) {
             init();
-            if (conn == null) {
-                // remote connections:
-                // need to use a temp file, because the input stream could come from
-                // the same database, which would create a weird situation (trying
-                // to read a block while write something)
-                return ValueLobDb.createTempClob(reader, maxLength, handler);
-            }
             long max = maxLength == -1 ? Long.MAX_VALUE : maxLength;
             CountingReaderInputStream in = new CountingReaderInputStream(reader, max);
             ValueLobDb lob = addLob(in, Long.MAX_VALUE, Value.CLOB);

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

+/*
+ * Copyright 2004-2013 H2 Group. Multiple-Licensed under the H2 License,
+ * Version 1.0, and under the Eclipse Public License, Version 1.0
+ * (http://h2database.com/html/license.html).
+ * Initial Developer: H2 Group
+ */
+package org.h2.store;
+
+import java.io.BufferedInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.Reader;
+import org.h2.constant.SysProperties;
+import org.h2.engine.Constants;
+import org.h2.value.Value;
+import org.h2.value.ValueLob;
+import org.h2.value.ValueLobDb;
+
+/**
+ * This class stores LOB objects in the database.
+ * This is the front-end i.e. the client side of the LOB storage.
+ */
+public class LobStorageFrontend implements LobStorageInterface {
+
+    private final DataHandler handler;
+
+    public LobStorageFrontend(DataHandler handler) {
+        this.handler = handler;
+    }
+
+    /**
+     * Create a LOB object that fits in memory.
+     *
+     * @param type the value type
+     * @param small the byte array
+     * @return the LOB
+     */
+    public static Value createSmallLob(int type, byte[] small) {
+        if (SysProperties.LOB_IN_DATABASE) {
+            int precision;
+            if (type == Value.CLOB) {
+                precision = new String(small, Constants.UTF8).length();
+            } else {
+                precision = small.length;
+            }
+            return ValueLobDb.createSmallLob(type, small, precision);
+        }
+        return ValueLob.createSmallLob(type, small);
+    }
+
+    /**
+     * Delete a LOB from the database.
+     *
+     * @param lob the lob id
+     */
+    public void removeLob(long lob) {
+        // TODO ideally, this should not be called at all, but that's a refactoring for another day
+    }
+    
+    /**
+     * Get the input stream for the given lob.
+     *
+     * @param lobId the lob id
+     * @param hmac the message authentication code (for remote input streams)
+     * @param byteCount the number of bytes to read, or -1 if not known
+     * @return the stream
+     */
+    public InputStream getInputStream(long lobId, byte[] hmac, long byteCount) throws IOException {
+        if (byteCount < 0) {
+            byteCount = Long.MAX_VALUE;
+        }
+        return new BufferedInputStream(new LobStorageRemoteInputStream(handler, lobId, hmac, byteCount));
+    }
+
+    /**
+     * Copy a lob.
+     *
+     * @param type the type
+     * @param oldLobId the old lob id
+     * @param tableId the new table id
+     * @param length the length
+     * @return the new lob
+     */
+    public ValueLobDb copyLob(int type, long oldLobId, int tableId, long length) {
+        // TODO ideally, this should not be called at all, but that's a refactoring for another day
+        // this should never be called
+        throw new UnsupportedOperationException();
+    }
+
+    /**
+     * Create a BLOB object.
+     *
+     * @param in the input stream
+     * @param maxLength the maximum length (-1 if not known)
+     * @return the LOB
+     */
+    public Value createBlob(InputStream in, long maxLength) {
+        if (SysProperties.LOB_IN_DATABASE) {
+            // need to use a temp file, because the input stream could come from
+            // the same database, which would create a weird situation (trying
+            // to read a block while write something)
+            return ValueLobDb.createTempBlob(in, maxLength, handler);
+        }
+        return ValueLob.createBlob(in, maxLength, handler);
+    }
+
+    /**
+     * Create a CLOB object.
+     *
+     * @param reader the reader
+     * @param maxLength the maximum length (-1 if not known)
+     * @return the LOB
+     */
+    public Value createClob(Reader reader, long maxLength) {
+        if (SysProperties.LOB_IN_DATABASE) {
+            // need to use a temp file, because the input stream could come from
+            // the same database, which would create a weird situation (trying
+            // to read a block while write something)
+            return ValueLobDb.createTempClob(reader, maxLength, handler);
+        }
+        return ValueLob.createClob(reader, maxLength, handler);
+    }
+
+    /**
+     * Set the table reference of this lob.
+     *
+     * @param lobId the lob
+     * @param table the table
+     */
+    public void setTable(long lobId, int table) {
+        // TODO ideally, this should not be called at all, but that's a refactoring for another day
+        // this should never be called
+        throw new UnsupportedOperationException();
+    }
+
+}

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

+package org.h2.store;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.Reader;
+import org.h2.value.Value;
+import org.h2.value.ValueLobDb;
+
+public interface LobStorageInterface {
+
+    /**
+     * Create a CLOB object.
+     *
+     * @param reader the reader
+     * @param maxLength the maximum length (-1 if not known)
+     * @return the LOB
+     */
+    Value createClob(Reader reader, long maxLength);
+    
+    /**
+     * Create a BLOB object.
+     *
+     * @param in the input stream
+     * @param maxLength the maximum length (-1 if not known)
+     * @return the LOB
+     */
+    Value createBlob(InputStream in, long maxLength);
+    
+    /**
+     * Set the table reference of this lob.
+     *
+     * @param lobId the lob
+     * @param table the table
+     */
+    void setTable(long lobId, int table);
+    
+    /**
+     * Copy a lob.
+     *
+     * @param type the type
+     * @param oldLobId the old lob id
+     * @param tableId the new table id
+     * @param length the length
+     * @return the new lob
+     */
+    ValueLobDb copyLob(int type, long oldLobId, int tableId, long length);
+    
+    /**
+     * Get the input stream for the given lob.
+     *
+     * @param lobId the lob id
+     * @param hmac the message authentication code (for remote input streams)
+     * @param byteCount the number of bytes to read, or -1 if not known
+     * @return the stream
+     */
+    InputStream getInputStream(long lobId, byte[] hmac, long byteCount) throws IOException;
+    
+    /**
+     * Delete a LOB from the database.
+     *
+     * @param lob the lob id
+     */
+    void removeLob(long lob);
+  
+}

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

+package org.h2.store;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * An input stream that reads from a remote LOB.
+ */
+class LobStorageRemoteInputStream extends InputStream {
+
+    /**
+     * The data handler.
+     */
+    private final DataHandler handler;
+
+    /**
+     * The lob id.
+     */
+    private final long lob;
+
+    private final byte[] hmac;
+
+    /**
+     * The position.
+     */
+    private long pos;
+
+    /**
+     * The remaining bytes in the lob.
+     */
+    private long remainingBytes;
+
+    public LobStorageRemoteInputStream(DataHandler handler, long lob, byte[] hmac, long byteCount) {
+        this.handler = handler;
+        this.lob = lob;
+        this.hmac = hmac;
+        remainingBytes = byteCount;
+    }
+
+    public int read() throws IOException {
+        byte[] buff = new byte[1];
+        int len = read(buff, 0, 1);
+        return len < 0 ? len : (buff[0] & 255);
+    }
+
+    public int read(byte[] buff) throws IOException {
+        return read(buff, 0, buff.length);
+    }
+
+    public int read(byte[] buff, int off, int length) throws IOException {
+        if (length == 0) {
+            return 0;
+        }
+        length = (int) Math.min(length, remainingBytes);
+        if (length == 0) {
+            return -1;
+        }
+        length = handler.readLob(lob, hmac, pos, buff, off, length);
+        remainingBytes -= length;
+        if (length == 0) {
+            return -1;
+        }
+        pos += length;
+        return length;
+    }
+
+    public long skip(long n) {
+        remainingBytes -= n;
+        pos += n;
+        return n;
+    }
+
+}
\ No newline at end of file

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

@@ -38,7 +38,8 @@ import org.h2.store.DataReader;
 import org.h2.store.FileLister;
 import org.h2.store.FileStore;
 import org.h2.store.FileStoreInputStream;
-import org.h2.store.LobStorage;
+import org.h2.store.LobStorageBackend;
+import org.h2.store.LobStorageInterface;
 import org.h2.store.Page;
 import org.h2.store.PageFreeList;
 import org.h2.store.PageLog;
@@ -192,8 +193,8 @@ public class Recover extends Tool implements DataHandler {
      */
     public static Value.ValueBlob readBlobDb(Connection conn, long lobId, long precision) {
         DataHandler h = ((JdbcConnection) conn).getSession().getDataHandler();
-        LobStorage lobStorage = h.getLobStorage();
-        return ValueLobDb.create(Value.BLOB, lobStorage, LobStorage.TABLE_TEMP, lobId, null, precision);
+        LobStorageInterface lobStorage = h.getLobStorage();
+        return ValueLobDb.create(Value.BLOB, lobStorage, LobStorageBackend.TABLE_TEMP, lobId, null, precision);
     }
 
     /**
@@ -201,8 +202,8 @@ public class Recover extends Tool implements DataHandler {
      */
     public static Value.ValueClob readClobDb(Connection conn, long lobId, long precision) {
         DataHandler h = ((JdbcConnection) conn).getSession().getDataHandler();
-        LobStorage lobStorage = h.getLobStorage();
-        return ValueLobDb.create(Value.CLOB, lobStorage, LobStorage.TABLE_TEMP, lobId, null, precision);
+        LobStorageInterface lobStorage = h.getLobStorage();
+        return ValueLobDb.create(Value.CLOB, lobStorage, LobStorageBackend.TABLE_TEMP, lobId, null, precision);
     }
 
     private void trace(String message) {
@@ -1229,7 +1230,7 @@ public class Recover extends Tool implements DataHandler {
                     writer.println("DELETE FROM " + name + ";");
                     writer.println("INSERT INTO " + name + " SELECT * FROM " + storageName + ";");
                     if (name.startsWith("INFORMATION_SCHEMA.LOBS")) {
-                        writer.println("UPDATE " + name + " SET TABLE = " + LobStorage.TABLE_TEMP + ";");
+                        writer.println("UPDATE " + name + " SET TABLE = " + LobStorageBackend.TABLE_TEMP + ";");
                         deleteLobs = true;
                     }
                 }
@@ -1255,7 +1256,7 @@ public class Recover extends Tool implements DataHandler {
         writer.println("DROP ALIAS READ_BLOB_DB;");
         writer.println("DROP ALIAS READ_CLOB_DB;");
         if (deleteLobs) {
-            writer.println("DELETE FROM INFORMATION_SCHEMA.LOBS WHERE TABLE = " + LobStorage.TABLE_TEMP + ";");
+            writer.println("DELETE FROM INFORMATION_SCHEMA.LOBS WHERE TABLE = " + LobStorageBackend.TABLE_TEMP + ";");
         }
         for (MetaRecord m : schema) {
             if (isSchemaObjectTypeDelayed(m)) {
@@ -1409,7 +1410,7 @@ public class Recover extends Tool implements DataHandler {
     /**
      * INTERNAL
      */
-    public LobStorage getLobStorage() {
+    public LobStorageBackend getLobStorage() {
         return null;
     }
 

h2/src/main/org/h2/value/DataType.java

@@ -31,7 +31,7 @@ import org.h2.jdbc.JdbcBlob;
 import org.h2.jdbc.JdbcClob;
 import org.h2.jdbc.JdbcConnection;
 import org.h2.message.DbException;
-import org.h2.store.LobStorage;
+import org.h2.store.LobStorageBackend;
 import org.h2.tools.SimpleResultSet;
 import org.h2.util.New;
 import org.h2.util.Utils;
@@ -540,7 +540,7 @@ public class DataType {
             }
             case Value.CLOB: {
                 if (session == null) {
-                    v = LobStorage.createSmallLob(Value.CLOB, rs.getString(columnIndex).getBytes(Constants.UTF8));
+                    v = LobStorageBackend.createSmallLob(Value.CLOB, rs.getString(columnIndex).getBytes(Constants.UTF8));
                 } else {
                     Reader in = rs.getCharacterStream(columnIndex);
                     if (in == null) {
@@ -553,7 +553,7 @@ public class DataType {
             }
             case Value.BLOB: {
                 if (session == null) {
-                    v = LobStorage.createSmallLob(Value.BLOB, rs.getBytes(columnIndex));
+                    v = LobStorageBackend.createSmallLob(Value.BLOB, rs.getBytes(columnIndex));
                 } else {
                     InputStream in = rs.getBinaryStream(columnIndex);
                     v = (in == null) ? (Value) ValueNull.INSTANCE : session.getDataHandler().getLobStorage().createBlob(in, -1);

h2/src/main/org/h2/value/Value.java

@@ -25,7 +25,7 @@ import org.h2.constant.SysProperties;
 import org.h2.engine.Constants;
 import org.h2.message.DbException;
 import org.h2.store.DataHandler;
-import org.h2.store.LobStorage;
+import org.h2.store.LobStorageBackend;
 import org.h2.tools.SimpleResultSet;
 import org.h2.util.DateTimeUtils;
 import org.h2.util.MathUtils;
@@ -771,7 +771,7 @@ public abstract class Value {
                 switch(getType()) {
                 case BYTES:
 
-                    return LobStorage.createSmallLob(Value.BLOB, getBytesNoCopy());
+                    return LobStorageBackend.createSmallLob(Value.BLOB, getBytesNoCopy());
                 }
                 break;
             }
@@ -834,9 +834,9 @@ public abstract class Value {
             case FLOAT:
                 return ValueFloat.get(Float.parseFloat(s.trim()));
             case CLOB:
-                return LobStorage.createSmallLob(CLOB, s.getBytes(Constants.UTF8));
+                return LobStorageBackend.createSmallLob(CLOB, s.getBytes(Constants.UTF8));
             case BLOB:
-                return LobStorage.createSmallLob(BLOB, StringUtils.convertHexToBytes(s.trim()));
+                return LobStorageBackend.createSmallLob(BLOB, StringUtils.convertHexToBytes(s.trim()));
             case ARRAY:
                 return ValueArray.get(new Value[]{ValueString.get(s)});
             case RESULT_SET: {

h2/src/main/org/h2/value/ValueLobDb.java

@@ -21,7 +21,8 @@ import org.h2.store.DataHandler;
 import org.h2.store.FileStore;
 import org.h2.store.FileStoreInputStream;
 import org.h2.store.FileStoreOutputStream;
-import org.h2.store.LobStorage;
+import org.h2.store.LobStorageBackend;
+import org.h2.store.LobStorageInterface;
 import org.h2.store.fs.FileUtils;
 import org.h2.util.IOUtils;
 import org.h2.util.MathUtils;
@@ -38,7 +39,7 @@ public class ValueLobDb extends Value implements Value.ValueClob, Value.ValueBlo
     private int tableId;
     private int hash;
 
-    private LobStorage lobStorage;
+    private LobStorageInterface lobStorage;
     private final long lobId;
     private final byte[] hmac;
 
@@ -48,7 +49,7 @@ public class ValueLobDb extends Value implements Value.ValueClob, Value.ValueBlo
     private FileStore tempFile;
     private String fileName;
 
-    private ValueLobDb(int type, LobStorage lobStorage, int tableId, long lobId, byte[] hmac, long precision) {
+    private ValueLobDb(int type, LobStorageInterface lobStorage, int tableId, long lobId, byte[] hmac, long precision) {
         this.type = type;
         this.lobStorage = lobStorage;
         this.tableId = tableId;
@@ -76,7 +77,7 @@ public class ValueLobDb extends Value implements Value.ValueClob, Value.ValueBlo
      * @param precision the precision (number of bytes / characters)
      * @return the value
      */
-    public static ValueLobDb create(int type, LobStorage lobStorage,
+    public static ValueLobDb create(int type, LobStorageInterface lobStorage,
             int tableId, long id, byte[] hmac, long precision) {
         return new ValueLobDb(type, lobStorage, tableId, id, hmac, precision);
     }
@@ -108,21 +109,21 @@ public class ValueLobDb extends Value implements Value.ValueClob, Value.ValueBlo
                 Value copy = lobStorage.createClob(getReader(), -1);
                 return copy;
             } else if (small != null) {
-                return LobStorage.createSmallLob(t, small);
+                return LobStorageBackend.createSmallLob(t, small);
             }
         } else if (t == Value.BLOB) {
             if (lobStorage != null) {
                 Value copy = lobStorage.createBlob(getInputStream(), -1);
                 return copy;
             } else if (small != null) {
-                return LobStorage.createSmallLob(t, small);
+                return LobStorageBackend.createSmallLob(t, small);
             }
         }
         return super.convertTo(t);
     }
 
     public boolean isLinked() {
-        return tableId != LobStorage.TABLE_ID_SESSION_VARIABLE && small == null;
+        return tableId != LobStorageBackend.TABLE_ID_SESSION_VARIABLE && small == null;
     }
 
     public boolean isStored() {
@@ -147,22 +148,22 @@ public class ValueLobDb extends Value implements Value.ValueClob, Value.ValueBlo
     }
 
     public void unlink() {
-        if (small == null && tableId != LobStorage.TABLE_ID_SESSION_VARIABLE) {
-            lobStorage.setTable(lobId, LobStorage.TABLE_ID_SESSION_VARIABLE);
-            tableId = LobStorage.TABLE_ID_SESSION_VARIABLE;
+        if (small == null && tableId != LobStorageBackend.TABLE_ID_SESSION_VARIABLE) {
+            lobStorage.setTable(lobId, LobStorageBackend.TABLE_ID_SESSION_VARIABLE);
+            tableId = LobStorageBackend.TABLE_ID_SESSION_VARIABLE;
         }
     }
 
     public Value link(DataHandler h, int tabId) {
         if (small == null) {
-            if (tableId == LobStorage.TABLE_TEMP) {
+            if (tableId == LobStorageBackend.TABLE_TEMP) {
                 lobStorage.setTable(lobId, tabId);
                 this.tableId = tabId;
             } else {
                 return lobStorage.copyLob(type, lobId, tabId, getPrecision());
             }
         } else if (small.length > h.getMaxLengthInplaceLob()) {
-            LobStorage s = h.getLobStorage();
+            LobStorageInterface s = h.getLobStorage();
             Value v;
             if (type == Value.BLOB) {
                 v = s.createBlob(getInputStream(), getPrecision());

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

@@ -15,7 +15,7 @@ import java.sql.Types;
 import org.h2.store.Data;
 import org.h2.store.DataHandler;
 import org.h2.store.FileStore;
-import org.h2.store.LobStorage;
+import org.h2.store.LobStorageBackend;
 import org.h2.test.TestBase;
 import org.h2.tools.SimpleResultSet;
 import org.h2.util.SmallLRUCache;
@@ -315,7 +315,7 @@ public class TestDataPage extends TestBase implements DataHandler {
         return TempFileDeleter.getInstance();
     }
 
-    public LobStorage getLobStorage() {
+    public LobStorageBackend getLobStorage() {
         return null;
     }
 

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

@@ -10,7 +10,7 @@ import java.sql.Connection;
 import java.util.Random;
 import org.h2.store.DataHandler;
 import org.h2.store.FileStore;
-import org.h2.store.LobStorage;
+import org.h2.store.LobStorageBackend;
 import org.h2.store.fs.FileUtils;
 import org.h2.test.TestBase;
 import org.h2.util.SmallLRUCache;
@@ -169,7 +169,7 @@ public class TestFile extends TestBase implements DataHandler {
         return TempFileDeleter.getInstance();
     }
 
-    public LobStorage getLobStorage() {
+    public LobStorageBackend getLobStorage() {
         return null;
     }
 

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

@@ -14,7 +14,7 @@ import java.util.HashMap;
 import java.util.Random;
 import org.h2.store.DataHandler;
 import org.h2.store.FileStore;
-import org.h2.store.LobStorage;
+import org.h2.store.LobStorageBackend;
 import org.h2.test.TestBase;
 import org.h2.util.New;
 import org.h2.util.SmallLRUCache;
@@ -145,7 +145,7 @@ public class TestValueHashMap extends TestBase implements DataHandler {
         return TempFileDeleter.getInstance();
     }
 
-    public LobStorage getLobStorage() {
+    public LobStorageBackend getLobStorage() {
         return null;
     }
 

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

@@ -17,7 +17,8 @@ import java.util.Random;
 import org.h2.engine.Constants;
 import org.h2.store.DataHandler;
 import org.h2.store.FileStore;
-import org.h2.store.LobStorage;
+import org.h2.store.LobStorageBackend;
+import org.h2.store.LobStorageFrontend;
 import org.h2.test.TestBase;
 import org.h2.test.utils.MemoryFootprint;
 import org.h2.tools.SimpleResultSet;
@@ -54,7 +55,7 @@ public class TestValueMemory extends TestBase implements DataHandler {
 
     private final Random random = new Random(1);
     private final SmallLRUCache<String, String[]> lobFileListCache = SmallLRUCache.newInstance(128);
-    private LobStorage lobStorage;
+    private LobStorageFrontend lobStorage;
 
     /**
      * Run just this test.
@@ -246,9 +247,9 @@ public class TestValueMemory extends TestBase implements DataHandler {
         return TempFileDeleter.getInstance();
     }
 
-    public LobStorage getLobStorage() {
+    public LobStorageFrontend getLobStorage() {
         if (lobStorage == null) {
-            lobStorage = new LobStorage(this);
+            lobStorage = new LobStorageFrontend(this);
         }
         return lobStorage;
     }