--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/truffle/com.oracle.truffle.tck/src/com/oracle/truffle/tck/Schema.java	Fri Dec 11 15:20:27 2015 +0100
@@ -0,0 +1,134 @@
+/*
+ * Copyright (c) 2015, 2015, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.truffle.tck;
+
+import java.nio.ByteBuffer;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+public final class Schema {
+
+    public enum Type {
+        DOUBLE(Double.SIZE / Byte.SIZE),
+        INT(Integer.SIZE / Byte.SIZE);
+
+        private final int size;
+
+        private Type(int size) {
+            this.size = size;
+        }
+    }
+
+    private final int size;
+    private final boolean rowBased;
+    private final List<String> names;
+    private final List<Type> types;
+
+    public Schema(int size, boolean rowBased, List<String> names, List<Type> types) {
+        this.size = size;
+        this.rowBased = rowBased;
+        this.names = names;
+        this.types = types;
+    }
+
+    public int length() {
+        return size;
+    }
+
+    // for simplicity: structured data is read-only
+
+    public Map<String, Object> getEntry(byte[] buffer, int index) {
+        Map<String, Object> entry = new HashMap<>();
+        for (int i = 0; i < names.size(); i++) {
+            String name = names.get(i);
+            Object value = get(buffer, index, name);
+            entry.put(name, value);
+        }
+        return entry;
+    }
+
+    private Object get(byte[] buffer, int index, String name) {
+        assert names.contains(name);
+        int offset = rowBased ? getRowOffset(name, index) : getColumnOffset(name, index);
+        if (types.get(names.indexOf(name)) == Type.DOUBLE) {
+            byte[] b = new byte[Type.DOUBLE.size];
+            for (int i = 0; i < Type.DOUBLE.size; i++) {
+                b[i] = buffer[offset + i];
+            }
+            return ByteBuffer.wrap(b).getDouble();
+        } else if (types.get(names.indexOf(name)) == Type.INT) {
+            byte[] b = new byte[Type.INT.size];
+            for (int i = 0; i < Type.INT.size; i++) {
+                b[i] = buffer[offset + i];
+            }
+            return ByteBuffer.wrap(b).getInt();
+        }
+        throw new IllegalStateException();
+    }
+
+    private int getRowSize() {
+        assert rowBased;
+        int rowSize = 0;
+        for (Type t : types) {
+            rowSize += t.size;
+        }
+        return rowSize;
+    }
+
+    private int getRowOffset(String name, int index) {
+        assert rowBased;
+        if (names.contains(name)) {
+            int offset = 0;
+            for (int i = 0; i < names.size(); i++) {
+                if (names.get(i).equals(name)) {
+                    return index * getRowSize() + offset;
+                } else {
+                    offset += types.get(i).size;
+                }
+            }
+        } else {
+            throw new IllegalArgumentException();
+        }
+        throw new IllegalStateException();
+    }
+
+    private int getColumnOffset(String name, int index) {
+        assert !rowBased;
+        if (names.contains(name)) {
+            int offset = 0;
+            for (int i = 0; i < names.size(); i++) {
+                if (names.get(i).equals(name)) {
+                    return offset + index * types.get(i).size;
+                } else {
+                    offset += types.get(i).size * size;
+                }
+            }
+        } else {
+            throw new IllegalArgumentException();
+        }
+        throw new IllegalStateException();
+    }
+}