Package org.apache.druid.storage.local

Class LocalFileStorageConnector

java.lang.Object

org.apache.druid.storage.local.LocalFileStorageConnector

All Implemented Interfaces:

StorageConnector

public class LocalFileStorageConnector
extends Object
implements StorageConnector

Implementation that uses local filesystem. All paths are appended with the base path, in such a way that it is not visible to the users of this class.

Constructor Summary

Constructors

Constructor	Description
LocalFileStorageConnector(File basePath)

Method Summary

Modifier and Type	Method	Description
void	deleteFile(String path)	Deletes the file present at the location basePath + path.
void	deleteFiles(Iterable<String> paths)	Deletes the files present at each basePath + path.
void	deleteRecursively(String dirName)	Deletes the files and sub dirs present at the basePath + dirName.
File	getBasePath()
Iterator<String>	listDir(String dirName)	Returns a lazy iterator containing all the files present in the path.
boolean	pathExists(String path)	Check if the path exists in the underlying storage layer.
InputStream	read(String path)	Reads the data present at the path in the underlying storage system.
InputStream	readRange(String path, long from, long size)	Reads the data present for a given range at the path in the underlying storage system.
OutputStream	write(String path)	Writes the file present with the materialized location as basePath + path.

Methods inherited from class java.lang.Object

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

Constructor Details

LocalFileStorageConnector

public LocalFileStorageConnector(File basePath)
                          throws IOException

Throws:

IOException

Method Details

pathExists

public boolean pathExists(String path)

Description copied from interface: StorageConnector

Check if the path exists in the underlying storage layer. Most implementations prepend the input path with a basePath.

Specified by:

pathExists in interface StorageConnector

Parameters:

path -

Returns:

true if path exists else false.

read

public InputStream read(String path)
                 throws IOException

Description copied from interface: StorageConnector

Reads the data present at the path in the underlying storage system. Most implementations prepend the input path with a basePath. The caller should take care of closing the stream when done or in case of error.

Specified by:

read in interface StorageConnector

Parameters:

path -

Returns:

InputStream

Throws:

IOException - if the path is not present or the unable to read the data present on the path.

readRange

public InputStream readRange(String path,
 long from,
 long size)
                      throws IOException

Description copied from interface: StorageConnector

Reads the data present for a given range at the path in the underlying storage system. Most implementations prepend the input path with a basePath. The caller should take care of closing the stream when done or in case of error. Further, the caller must ensure that the start offset and the size of the read are valid parameters for the given path for correct behavior.

Specified by:

readRange in interface StorageConnector

Parameters:

path - The path to read data from

from - Start offset of the read in the path

size - Length of the read to be done

Returns:

InputStream starting from the given offset limited by the given size

Throws:

IOException - if the path is not present or the unable to read the data present on the path

write

public OutputStream write(String path)
                   throws IOException

Writes the file present with the materialized location as basePath + path. In case the parent directory does not exist, we create the parent dir recursively. Closing of the stream is the responsibility of the caller.

Specified by:

write in interface StorageConnector

Parameters:

path - path to write contents to.

Returns:

OutputStream which can be used by callers to write contents.

Throws:

IOException - thrown in case of errors.

deleteFile

public void deleteFile(String path)
                throws IOException

Deletes the file present at the location basePath + path. Throws an exception in case a dir is encountered.

Specified by:

deleteFile in interface StorageConnector

Parameters:

path - input path

Throws:

IOException - thrown in case of errors.

deleteFiles

public void deleteFiles(Iterable<String> paths)
                 throws IOException

Deletes the files present at each basePath + path. Throws an exception in case a dir is encountered.

Specified by:

deleteFiles in interface StorageConnector

Parameters:

paths - list of path to delete

Throws:

IOException - thrown in case of errors.

deleteRecursively

public void deleteRecursively(String dirName)
                       throws IOException

Deletes the files and sub dirs present at the basePath + dirName. Also removes the dirName

Specified by:

deleteRecursively in interface StorageConnector

Parameters:

dirName - path

Throws:

IOException - thrown in case of errors.

listDir

public Iterator<String> listDir(String dirName)

Description copied from interface: StorageConnector

Returns a lazy iterator containing all the files present in the path. The returned filenames should be such that joining the dirName and the file name form the full path that can be used as the arguments for other methods of the storage connector. For example, for a S3 path such as s3://bucket/parent1/parent2/child, the filename returned for the input path "parent1/parent2" should be "child" and for input "parent1" should be "parent2/child"

Specified by:

listDir in interface StorageConnector

getBasePath

public File getBasePath()