com.streamsets.pipeline.api.ProtoConfigurableEntity Maven / Gradle / Ivy
/*
* Copyright 2017 StreamSets Inc.
*
* 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 com.streamsets.pipeline.api;
import com.streamsets.pipeline.api.el.ELEval;
import com.streamsets.pipeline.api.el.ELEvalException;
import com.streamsets.pipeline.api.el.ELVars;
import java.util.Map;
/**
* Shared interface for all active configurable objects - such as Stage or Service.
*
* This interface is used to share methods and contexts between applicable stages. It should not be used otherwise.
*/
public interface ProtoConfigurableEntity {
/**
* Context to create and use Java Expression Language (EL) evaluators.
*/
public interface ELContext {
/**
* Validates an EL is syntactically correct.
*
* @param el EL to validate.
* @throws ELEvalException if the EL is not syntactically valid.
*/
public void parseEL(String el) throws ELEvalException;
/**
* Creates an {@link ELVars} instance to provide variables to {@link ELEval} when evaluating ELs.
*
* @return an empty ELVar instance.
*/
public ELVars createELVars();
/**
* Creates an {@link ELEval} configured with the EL functions and constants defined by the indicated stage
* configuration.
*
* @param configName stage configuration name.
* @return the configured ELEval instance.
* @see ConfigDef#elDefs()
*/
public ELEval createELEval(String configName);
/**
* Creates an {@link ELEval} configured with the EL functions and constants defined by the indicated stage
* configuration plus the additional EL functions and constants specified.
*
* @param configName stage configuration name.
* @param elDefClasses class defining additional EL functions and constants to configure the ELEval
* instance with.
* @return the configured ELEval instance.
* @see ConfigDef#elDefs()
*/
public ELEval createELEval(String configName, Class... elDefClasses);
}
/**
* Context that provides runtime information and services to the stage.
*/
public interface Context extends ConfigIssueContext, ELContext, MetricContext {
/**
* Return value for given configuration option from data collector main configuration.
*
* Stages have their own namespace, so method won't be able to return generic SDC configuration.
*
* @param configName Configuration option name
* @return String representation of the value or null if it's not defined.
* @deprecated Use getConfiguration() instead.
*/
@Deprecated
public String getConfig(String configName);
/**
* Return configuration relevant to stages from the data collector main configuration files.
*
* Stages have their own namespace, so method won't be able to return generic SDC configuration.
*/
public Configuration getConfiguration();
/**
* Get integer representing runner id - a value that doesn't change for given stage as it's executed in different
* threads. This value can be used to create temporary resources on remote system to make sure that different
* instances of the same stage in multi threaded pipeline won't step on each other's toes.
*
* @return Returns 0..N representing the runner id. 0 is used for inherent singletons (Error stage, Origin, ...)
*/
public int getRunnerId();
/**
* Get the number of runners that were created for this pipeline. This method will not return proper value during
* origin's init() method as origins init is called before number of runners is known.
*/
public int getRunnerCount();
/**
* Returns the absolute path to the SDC resources directory.
*
* @return the absolute path to the SDC resources directory.
*/
public String getResourcesDirectory();
/**
* Return pipeline constants.
*
* @return Immutable Map with pipeline constants.
*/
public Map getPipelineConstants();
/**
* Creates an empty record.
*
* @param recordSourceId the ID to identify the record. It should include enough information to track down
* the record source.
* @return an empty record with the specified ID.
*/
Record createRecord(String recordSourceId);
/**
* Creates an empty record including the original raw data of the record.
*
* @param recordSourceId the ID to identify the record. It should include enough information to track down
* the record source.
* @param raw the record raw data.
* @param rawMime the MIME type of the raw data.
* @return an empty record with the specified ID and raw data.
*/
Record createRecord(String recordSourceId, byte[] raw, String rawMime);
}
}