Adding UUID display transformer for optimized UUID data stored in binary(16) column. #3302

plugins/org.jkiss.dbeaver.core/plugin.xml

@@ -3363,6 +3363,16 @@
                 custom="true">
             <type kind="BINARY"/>
             <type kind="CONTENT"/>
+        </transformer>
+		<transformer
+                class="org.jkiss.dbeaver.model.impl.data.transformers.UUIDOrderedAttributeTransformer"
+                id="org.jkiss.dbeaver.core.UUIDOrderedAttributeTransformer"
+                name="UUID (Ordered)"
+                description="Represents binary(16) value as UUID if optimized storage is used."
+                applyByDefault="false"
+                custom="true">
+            <type kind="BINARY"/>
+            <type kind="CONTENT"/>
         </transformer>
         <transformer
                 class="org.jkiss.dbeaver.model.impl.data.transformers.BinaryAttributeTransformer"

plugins/org.jkiss.dbeaver.model/src/org/jkiss/dbeaver/model/impl/data/transformers/UUIDOrderedAttributeTransformer.java

+/*
+ * DBeaver - Universal Database Manager
+ * Copyright (C) 2010-2018 Serge Rider (serge@jkiss.org)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jkiss.dbeaver.model.impl.data.transformers;
+
+import org.jkiss.code.NotNull;
+import org.jkiss.code.Nullable;
+import org.jkiss.dbeaver.DBException;
+import org.jkiss.dbeaver.model.DBPDataKind;
+import org.jkiss.dbeaver.model.data.DBDAttributeBinding;
+import org.jkiss.dbeaver.model.data.DBDAttributeTransformer;
+import org.jkiss.dbeaver.model.data.DBDDisplayFormat;
+import org.jkiss.dbeaver.model.data.DBDValueHandler;
+import org.jkiss.dbeaver.model.exec.DBCSession;
+import org.jkiss.dbeaver.model.impl.data.ProxyValueHandler;
+import org.jkiss.dbeaver.model.impl.jdbc.data.JDBCContentBytes;
+import org.jkiss.dbeaver.model.struct.DBSTypedObject;
+
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+
+/**
+ * Transforms binary(16) attribute value into UUID.
+ * <p>
+ * This specific UUID storage format saves space and improves INSERT performance as described in the linked article.
+ * </p>
+ * 
+ * @see <a href="https://www.percona.com/blog/2014/12/19/store-uuid-optimized-way/">Store UUID in an optimized way</a>
+ */
+public class UUIDOrderedAttributeTransformer implements DBDAttributeTransformer {
+
+    @Override
+    public void transformAttribute(@NotNull DBCSession session, @NotNull DBDAttributeBinding attribute, @NotNull List<Object[]> rows, @NotNull Map<String, String> options) throws DBException {
+        attribute.setPresentationAttribute(
+            new TransformerPresentationAttribute(attribute, "UUID (Ordered)", 16, DBPDataKind.BINARY));
+
+        attribute.setTransformHandler(new UUIDValueHandler(attribute.getValueHandler()));
+    }
+
+    private class UUIDValueHandler extends ProxyValueHandler {
+        public UUIDValueHandler(DBDValueHandler target) {
+        	super(target);
+        }
+
+        @NotNull
+        @Override
+        public String getValueDisplayString(@NotNull DBSTypedObject column, @Nullable Object value, @NotNull DBDDisplayFormat format) {
+            byte[] bytes = null;
+            if (value instanceof byte[]) {
+                bytes = (byte[]) value;
+            } else if (value instanceof JDBCContentBytes) {
+                bytes = ((JDBCContentBytes) value).getRawValue();
+            }
+            if (bytes != null) {
+            	// byte shift operations from Ebean ORM project pull request #1308 
+            	long mostSigBits = ((long)bytes[4] << 56) // XXXXXXXX-____-____-...
+        			+ ((long)(bytes[5] & 255) << 48)
+        			+ ((long)(bytes[6] & 255) << 40)
+        			+ ((long)(bytes[7] & 255) << 32)
+        			+ ((long)(bytes[2] & 255) << 24)      // ________-XXXX-____-...
+        			+ ((bytes[3] & 255) << 16)
+        			+ ((bytes[0] & 255) <<  8)            // ________-____-XXXX-...
+        			+ ((bytes[1] & 255) <<  0);
+            	long leastSigBits = ((long)bytes[8] << 56)// ________-____-____-XXXX-...
+        			+ ((long)(bytes[9] & 255) << 48)
+        			+ ((long)(bytes[10] & 255) << 40)     // ________-____-____-____-XXXXXXXXXXXX
+        			+ ((long)(bytes[11] & 255) << 32)
+        			+ ((long)(bytes[12] & 255) << 24)
+        			+ ((bytes[13] & 255) << 16)
+        			+ ((bytes[14] & 255) <<  8)
+        			+ ((bytes[15] & 255) <<  0);
+            	return new UUID(mostSigBits, leastSigBits).toString();
+            }
+            return super.getValueDisplayString(column, value, format);
+        }
+    }
+
+}