| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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.apache.drill.exec.expr.fn.impl; |
| |
| import io.netty.buffer.DrillBuf; |
| import org.apache.drill.exec.expr.DrillSimpleFunc; |
| import org.apache.drill.exec.expr.annotations.FunctionTemplate; |
| import org.apache.drill.exec.expr.annotations.Output; |
| import org.apache.drill.exec.expr.annotations.Workspace; |
| import org.apache.drill.exec.expr.holders.VarCharHolder; |
| import org.apache.drill.exec.ops.ContextInformation; |
| import org.apache.drill.exec.physical.impl.project.OutputSizeEstimateConstants; |
| |
| import javax.inject.Inject; |
| |
| public class ContextFunctions { |
| |
| /** |
| * Implement "user", "session_user" or "system_user" function. Returns the username of the user connected to Drillbit. |
| */ |
| @FunctionTemplate(names = {"user", "session_user", "system_user"}, scope = FunctionTemplate.FunctionScope.SIMPLE, |
| isNiladic = true, outputSizeEstimate = OutputSizeEstimateConstants.USER_NAME_LENGTH) |
| public static class User implements DrillSimpleFunc { |
| @Output VarCharHolder out; |
| @Inject ContextInformation contextInfo; |
| @Inject DrillBuf buffer; |
| @Workspace int queryUserBytesLength; |
| |
| @Override |
| public void setup() { |
| final byte[] queryUserNameBytes = contextInfo.getQueryUser().getBytes(java.nio.charset.StandardCharsets.UTF_8); |
| buffer = buffer.reallocIfNeeded(queryUserNameBytes.length); |
| queryUserBytesLength = queryUserNameBytes.length; |
| buffer.setBytes(0, queryUserNameBytes); |
| } |
| |
| @Override |
| public void eval() { |
| out.start = 0; |
| out.end = queryUserBytesLength; |
| out.buffer = buffer; |
| } |
| } |
| |
| /** |
| * Implement "current_schema" function. Returns the default schema in current session. |
| */ |
| @FunctionTemplate(name = "current_schema", scope = FunctionTemplate.FunctionScope.SIMPLE, isNiladic = true, |
| outputSizeEstimate = OutputSizeEstimateConstants.SCHEMA_LENGTH) |
| public static class CurrentSchema implements DrillSimpleFunc { |
| @Output VarCharHolder out; |
| @Inject ContextInformation contextInfo; |
| @Inject DrillBuf buffer; |
| @Workspace int currentSchemaBytesLength; |
| |
| @Override |
| public void setup() { |
| final byte[] currentSchemaBytes = contextInfo.getCurrentDefaultSchema().getBytes(java.nio.charset.StandardCharsets.UTF_8); |
| buffer = buffer.reallocIfNeeded(currentSchemaBytes.length); |
| currentSchemaBytesLength= currentSchemaBytes.length; |
| buffer.setBytes(0, currentSchemaBytes); |
| } |
| |
| @Override |
| public void eval() { |
| out.start = 0; |
| out.end = currentSchemaBytesLength; |
| out.buffer = buffer; |
| } |
| } |
| |
| /** |
| * Implement "session_id" function. Returns the unique id of the current session. |
| */ |
| @FunctionTemplate(name = "session_id", scope = FunctionTemplate.FunctionScope.SIMPLE, isNiladic = true, |
| outputSizeEstimate = OutputSizeEstimateConstants.USER_ID_LENGTH) |
| public static class SessionId implements DrillSimpleFunc { |
| @Output VarCharHolder out; |
| @Inject ContextInformation contextInfo; |
| @Inject DrillBuf buffer; |
| @Workspace int sessionIdBytesLength; |
| |
| @Override |
| public void setup() { |
| final byte[] sessionIdBytes = contextInfo.getSessionId().getBytes(java.nio.charset.StandardCharsets.UTF_8); |
| buffer = buffer.reallocIfNeeded(sessionIdBytes.length); |
| sessionIdBytesLength = sessionIdBytes.length; |
| buffer.setBytes(0, sessionIdBytes); |
| } |
| |
| @Override |
| public void eval() { |
| out.start = 0; |
| out.end = sessionIdBytesLength; |
| out.buffer = buffer; |
| } |
| } |
| } |