Merge pull request #871 from katzyn/clob2

Fix OOME in Transfer.readValue() with large CLOB V2

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

@@ -171,7 +171,7 @@ public class DataReader extends Reader {
         int i = 0;
         try {
             for (; i < len; i++) {
-                buff[i] = readChar();
+                buff[off + i] = readChar();
             }
             return len;
         } catch (EOFException e) {

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

@@ -14,7 +14,6 @@ import java.io.Reader;
 import java.math.BigDecimal;
 import java.net.InetAddress;
 import java.net.Socket;
-import java.nio.charset.StandardCharsets;
 import java.sql.ResultSet;
 import java.sql.ResultSetMetaData;
 import java.sql.SQLException;
@@ -463,10 +462,6 @@ public class Transfer {
                 throw DbException.get(
                         ErrorCode.CONNECTION_BROKEN_1, "length=" + length);
             }
-            if (length > Integer.MAX_VALUE) {
-                throw DbException.get(
-                        ErrorCode.CONNECTION_BROKEN_1, "length="+ length);
-            }
             writeLong(length);
             Reader reader = v.getReader();
             Data.copyString(reader, out);
@@ -652,21 +647,10 @@ public class Transfer {
                     return ValueLobDb.create(
                             Value.CLOB, session.getDataHandler(), tableId, id, hmac, precision);
                 }
-                if (length < 0 || length > Integer.MAX_VALUE) {
+                if (length < 0) {
                     throw DbException.get(
                             ErrorCode.CONNECTION_BROKEN_1, "length="+ length);
                 }
-                DataReader reader = new DataReader(in);
-                int len = (int) length;
-                char[] buff = new char[len];
-                IOUtils.readFully(reader, buff, len);
-                int magic = readInt();
-                if (magic != LOB_MAGIC) {
-                    throw DbException.get(
-                            ErrorCode.CONNECTION_BROKEN_1, "magic=" + magic);
-                }
-                byte[] small = new String(buff).getBytes(StandardCharsets.UTF_8);
-                return ValueLobDb.createSmallLob(Value.CLOB, small, length);
             }
             Value v = session.getDataHandler().getLobStorage().
                     createClob(new DataReader(in), length);

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

@@ -26,6 +26,7 @@ import org.h2.store.FileStoreInputStream;
 import org.h2.store.FileStoreOutputStream;
 import org.h2.store.LobStorageFrontend;
 import org.h2.store.LobStorageInterface;
+import org.h2.store.RangeReader;
 import org.h2.store.fs.FileUtils;
 import org.h2.util.IOUtils;
 import org.h2.util.MathUtils;
@@ -544,6 +545,15 @@ public class ValueLobDb extends Value implements Value.ValueClob,
      */
     public static ValueLobDb createTempClob(Reader in, long length,
             DataHandler handler) {
+        if (length >= 0) {
+            // Otherwise BufferedReader may try to read more data than needed and that
+            // blocks the network level
+            try {
+                in = new RangeReader(in, 0, length);
+            } catch (IOException e) {
+                throw DbException.convert(e);
+            }
+        }
         BufferedReader reader;
         if (in instanceof BufferedReader) {
             reader = (BufferedReader) in;

h2/src/test/org/h2/test/jdbc/TestLobApi.java

@@ -119,7 +119,20 @@ public class TestLobApi extends TestBase {
         prep.setString(1, "");
         prep.setBytes(2, new byte[0]);
         prep.execute();
+
         Random r = new Random(1);
+
+        char[] charsSmall = new char[20];
+        for (int i = 0; i < charsSmall.length; i++) {
+            charsSmall[i] = (char) r.nextInt(10000);
+        }
+        String dSmall = new String(charsSmall);
+        prep.setCharacterStream(1, new StringReader(dSmall), -1);
+        byte[] bytesSmall = new byte[20];
+        r.nextBytes(bytesSmall);
+        prep.setBinaryStream(2, new ByteArrayInputStream(bytesSmall), -1);
+        prep.execute();
+
         char[] chars = new char[100000];
         for (int i = 0; i < chars.length; i++) {
             chars[i] = (char) r.nextInt(10000);
@@ -130,6 +143,7 @@ public class TestLobApi extends TestBase {
         r.nextBytes(bytes);
         prep.setBinaryStream(2, new ByteArrayInputStream(bytes), -1);
         prep.execute();
+
         conn.setAutoCommit(false);
         ResultSet rs = stat.executeQuery("select * from test order by id");
         rs.next();
@@ -138,18 +152,27 @@ public class TestLobApi extends TestBase {
         rs.next();
         Clob c2 = rs.getClob(2);
         Blob b2 = rs.getBlob(3);
+        rs.next();
+        Clob c3 = rs.getClob(2);
+        Blob b3 = rs.getBlob(3);
         assertFalse(rs.next());
         // now close
         rs.close();
         // but the LOBs must stay open
         assertEquals(0, c1.length());
         assertEquals(0, b1.length());
-        assertEquals(chars.length, c2.length());
-        assertEquals(bytes.length, b2.length());
         assertEquals("", c1.getSubString(1, 0));
         assertEquals(new byte[0], b1.getBytes(1, 0));
-        assertEquals(d, c2.getSubString(1, (int) c2.length()));
-        assertEquals(bytes, b2.getBytes(1, (int) b2.length()));
+
+        assertEquals(charsSmall.length, c2.length());
+        assertEquals(bytesSmall.length, b2.length());
+        assertEquals(dSmall, c2.getSubString(1, (int) c2.length()));
+        assertEquals(bytesSmall, b2.getBytes(1, (int) b2.length()));
+
+        assertEquals(chars.length, c3.length());
+        assertEquals(bytes.length, b3.length());
+        assertEquals(d, c3.getSubString(1, (int) c3.length()));
+        assertEquals(bytes, b3.getBytes(1, (int) b3.length()));
         stat.execute("drop table test");
         conn.close();
     }