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/*
* Licensed to SequoiaDB (C) under one or more contributor license agreements.
* See the NOTICE file distributed with this work for additional information
* regarding copyright ownership. The SequoiaDB (C) 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 com.sequoiadb.spark.util
/**
* Source File Name = CollectionUtil.scala
* Description = Sequoiadb Collections utilities
* Restrictions = N/A
* Change Activity:
* Date Who Description
* ======== ================== ================================================
* 20150307 Tao Wang Initial Draft
*/
import com.sequoiadb.base.SequoiadbDatasource
import com.sequoiadb.base.Sequoiadb
import com.sequoiadb.spark.SequoiadbException
import scala.collection.JavaConversions._
import org.apache.spark.sql.SaveMode
import com.sequoiadb.exception.BaseException
import com.sequoiadb.spark.SequoiadbConfig
object CollectionUtil {
/**
* Check whether collection exist, and create the collection if it doesn't exist
* Return true if not exist, return false if exist
* @param connection Sequoiadb Connection object
* @param collectionspace Collection space name
* @param colleciton Collection name
*/
private def errorIfExist (
connection: Option[Sequoiadb],
collectionspace: String,
collection: String): Boolean = {
try {
// perform collections snapshot and check if row exist
val snapcur = connection.get.getSnapshot ( Sequoiadb.SDB_SNAP_COLLECTIONS,
"{Name:\"" + collectionspace + "." + collection + "\"}",
null,
null )
// check if there's any record available
if ( snapcur.hasNext ) {
snapcur.close()
// return false if collection exist
false
}
else {
// create the collection since it's not available
createIfNotExist ( connection, collectionspace, collection )
}
}
catch {
case ex: Exception => throw SequoiadbException ( ex.getMessage, ex )
}
}
/**
* Create the collection if not exist
* Always return true
* @param connection Sequoiadb Connection object
* @param collectionspace Collection space name
* @param colleciton Collection name
*/
private def createIfNotExist (
connection: Option[Sequoiadb],
collectionspace: String,
collection: String): Boolean = {
try {
// perform catalog snapshot and check if cs exist
val cscur = connection.get.getSnapshot ( Sequoiadb.SDB_SNAP_COLLECTIONSPACES,
"{Name:\"" + collectionspace + "\"}",
null,
null )
// check if there's any record available
if ( cscur.hasNext ) {
cscur.close()
}
else {
// create collection space
connection.get.createCollectionSpace(collectionspace)
}
// perform catalog snapshot and check if collection exist
val clcur = connection.get.getSnapshot ( Sequoiadb.SDB_SNAP_COLLECTIONS,
"{Name:\"" + collectionspace + "." + collection + "\"}",
null,
null )
// check if there's any record available
if ( clcur.hasNext ) {
clcur.close()
}
else {
// get collection space
val cs = connection.get.getCollectionSpace(collectionspace)
// create collection
cs.createCollection ( collection )
}
true
}
catch {
case ex: Exception => throw SequoiadbException ( ex.getMessage, ex )
}
}
/**
* Check whether a collection is writable for the given mode
* Return true for writable, return false for non-writable, throw exception for error
* @param mode SaveMode provided by caller
* @param parameters Configuration paramters
*/
def checkCollectionWritable (
mode: SaveMode,
config: SequoiadbConfig ) : Boolean = {
var ds : Option[SequoiadbDatasource] = None
var connection : Option[Sequoiadb] = None
try {
ds = Option(new SequoiadbDatasource (
config[List[String]](SequoiadbConfig.Host),
config[String](SequoiadbConfig.Username),
config[String](SequoiadbConfig.Password),
ConnectionUtil.initConfigOptions,
ConnectionUtil.initSequoiadbOptions ))
// pickup a connection
connection = Option(ds.get.getConnection)
mode match {
case SaveMode.Append => {
// create a new collection if doesn't exist
createIfNotExist (
connection,
config[String](SequoiadbConfig.CollectionSpace),
config[String](SequoiadbConfig.Collection))
}
case SaveMode.Overwrite => {
// overwrite can't be supported without collection truncation
throw new BaseException("SDB_OPTION_NOT_SUPPORT")
}
case SaveMode.ErrorIfExists => {
// create a new collection if doens't exist
// throw error if it's already exist
if ( !errorIfExist (
connection,
config[String](SequoiadbConfig.CollectionSpace),
config[String](SequoiadbConfig.Collection)) ) {
throw new BaseException ( "SDB_DMS_EXIST" )
}
true
}
case SaveMode.Ignore => false
case _ => false
}
} catch {
case ex: Exception =>
throw SequoiadbException(ex.getMessage, ex)
} finally {
ds.fold(ifEmpty=()) { connectionpool =>
connection.fold(ifEmpty=()) { conn =>
connectionpool.close(conn)
}
// TODO: Close connection pool
} // ds.fold(ifEmpty=())
} // finally
}
}
