Package com.exasol.bucketfs.uploadnecessity

Class ChecksumUploadNecessityCheckStrategy

java.lang.Object

com.exasol.bucketfs.uploadnecessity.ChecksumUploadNecessityCheckStrategy

All Implemented Interfaces:

UploadNecessityCheckStrategy

public class ChecksumUploadNecessityCheckStrategy
extends Object
implements UploadNecessityCheckStrategy

This UploadNecessityCheckStrategy compares the checksum of the local file and the file on BucketFS and only uploads the file if the checksums differ or if the file does not exist in BucketFS. For performance reasons this strategy always uploads files with a size less or equal 1 MB.

Constructor Summary

Constructors

Constructor	Description
ChecksumUploadNecessityCheckStrategy(Connection sqlConnection)	Create a new instance of ChecksumUploadNecessityCheckStrategy.

Method Summary

Modifier and Type	Method	Description
String	getSha512Checksum(String fileInBucketFs, ReadOnlyBucket bucket)	Get the SHA-512-checksum of a file in BucketFS.
boolean	isUploadNecessary(Path file, String fullFileNameInBucketFs, ReadOnlyBucket bucket)	Decide if it is necessary to upload a file to BucketFS.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ChecksumUploadNecessityCheckStrategy

public ChecksumUploadNecessityCheckStrategy(Connection sqlConnection)

Create a new instance of ChecksumUploadNecessityCheckStrategy.

This strategy uses a User Defined Function (UDF) to create the checksum of the file in BucketFS. Therefore it requires a database connection.

Parameters:

sqlConnection - SQL connection to the Exasol database

Method Detail

isUploadNecessary

public boolean isUploadNecessary(Path file,
                                 String fullFileNameInBucketFs,
                                 ReadOnlyBucket bucket)
                          throws BucketAccessException

Description copied from interface: UploadNecessityCheckStrategy

Decide if it is necessary to upload a file to BucketFS.

Specified by:

isUploadNecessary in interface UploadNecessityCheckStrategy

Parameters:

file - local file

fullFileNameInBucketFs - path to the file in BucketFS

bucket - bucket the file is uploaded to

Returns:

true if the file should get uploaded

Throws:

BucketAccessException - if the necessity check cannot be executed

getSha512Checksum

public String getSha512Checksum(String fileInBucketFs,
                                ReadOnlyBucket bucket)
                         throws BucketAccessException

Get the SHA-512-checksum of a file in BucketFS.

Parameters:

fileInBucketFs - path to a file in bucketFs

bucket - bucket the file is stored in

Returns:

sha 512 checksum

Throws:

BucketAccessException - if checksum calculation failed