Package org.apache.beam.sdk.util

Class NumberedShardedFile

java.lang.Object

org.apache.beam.sdk.util.NumberedShardedFile

All Implemented Interfaces:

java.io.Serializable, ShardedFile

@Internal
public class NumberedShardedFile
extends java.lang.Object
implements ShardedFile

Utility methods for working with sharded files. For internal use only; many parameters are just hardcoded to allow existing uses to work OK.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor	Description
NumberedShardedFile(java.lang.String filePattern)	Constructor that uses default shard template.
NumberedShardedFile(java.lang.String filePattern, java.util.regex.Pattern shardTemplate)	Constructor.

Method Summary

Modifier and Type	Method	Description
java.lang.String	getFilePattern()
java.util.List<java.lang.String>	readFilesWithRetries()	Discovers all shards of this file.
java.util.List<java.lang.String>	readFilesWithRetries(Sleeper sleeper, BackOff backOff)	Discovers all shards of this file using the provided Sleeper and BackOff.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

NumberedShardedFile

public NumberedShardedFile(java.lang.String filePattern)

Constructor that uses default shard template.

Parameters:

filePattern - path or glob of files to include

NumberedShardedFile

public NumberedShardedFile(java.lang.String filePattern,
                           java.util.regex.Pattern shardTemplate)

Constructor.

Parameters:

filePattern - path or glob of files to include

shardTemplate - template of shard name to parse out the total number of shards which is used in I/O retry to avoid inconsistency of filesystem. Customized template should assign name "numshards" to capturing group - total shard number.

Method Detail

getFilePattern

public java.lang.String getFilePattern()

readFilesWithRetries

public java.util.List<java.lang.String> readFilesWithRetries(Sleeper sleeper,
                                                             BackOff backOff)
                                                      throws java.io.IOException,
                                                             java.lang.InterruptedException

Discovers all shards of this file using the provided Sleeper and BackOff.

Because of eventual consistency, reads may discover no files or fewer files than the shard template implies. In this case, the read is considered to have failed.

Specified by:

readFilesWithRetries in interface ShardedFile

Throws:

java.io.IOException

java.lang.InterruptedException

readFilesWithRetries

public java.util.List<java.lang.String> readFilesWithRetries()
                                                      throws java.io.IOException,
                                                             java.lang.InterruptedException

Discovers all shards of this file.

Because of eventual consistency, reads may discover no files or fewer files than the shard template implies. In this case, the read is considered to have failed.

Throws:

java.io.IOException

java.lang.InterruptedException

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object