ds.granules.dataset

Interface FileDataset

All Superinterfaces:

Dataset, ds.funnel.data.format.FormatMarshaller

All Known Implementing Classes:

FileDatasetImpl

public interface FileDataset
extends Dataset

The interface for accessing a dataset comprising files.

Author:

Shrideep Pallickara

Nested Class Summary

Nested classes/interfaces inherited from interface ds.granules.dataset.Dataset

Dataset.DatasetType

Method Summary

Methods

Modifier and Type	Method and Description
void	addFile(String fileName, String mode) Adds a file with the specified permission "r", "w" or "rw" to this dataset.
Collection<String>	getFiles() Retrieves the list of files in this dataset.
long	getPosition(String fileName) Retrieves the position of filePointer for the given dataset
long	getSize(String fileName) Returns the current size of the file in question
boolean	hasFile(String fileName) Checks to see if the file is part of a given dataset
int	read(String fileName, byte[] bytesToRead) Attempts to read a set of bytes from the underlying file.
int	read(String fileName, ByteBuffer readBuffer) Attempts to read a set of bytes from the underlying file.
void	removeFile(String fileName) Removes a file from this dataset.
void	setPosition(String fileName, long newPosition) Sets the position of filePointer for one of the file in the given dataset.
int	write(String fileName, byte[] bytesToWrite) Writes a byte[] to a give file.
int	write(String fileName, ByteBuffer writeBuffer) Write the specified Buffer to the file corresponding to the specified file.

Methods inherited from interface ds.granules.dataset.Dataset

close, getDataAvailabilityNotifier, getDatasetIdentifier, getDatasetType, getDescription, getLastModificationTime, initializeDataset, isAvailable, isDataAvailable, isInitialized, supportsDataAvailabilityNotifications

Methods inherited from interface ds.funnel.data.format.FormatMarshaller

marshall

Method Detail

getSize

long getSize(String fileName)
             throws DatasetException

Returns the current size of the file in question

Parameters:

fileName - The name of the file

Returns:

The current size of the file

Throws:

DatasetException - If there are problems retrieving the FileChannel corresponding to the file

IOException - If there are IO problems in completing the operation.

getPosition

long getPosition(String fileName)
                 throws DatasetException

Retrieves the position of filePointer for the given dataset

Parameters:

fileName - The name of the file.

Returns:

The position of filePointer for the given dataset

Throws:

DatasetException - If there are problems retrieving the FileChannel corresponding to the file

IOException - If there are IO problems in performing the operation

setPosition

void setPosition(String fileName,
               long newPosition)
                 throws DatasetException

Sets the position of filePointer for one of the file in the given dataset.

Parameters:

fileName - The file

newPosition - The new position for the pointer

Throws:

DatasetException - If there are problems retrieving the FileChannel corresponding to the file

read

int read(String fileName,
       byte[] bytesToRead)
         throws DatasetException

Attempts to read a set of bytes from the underlying file.

Parameters:

fileName - The file to be read

bytesToRead - The byte[] to be read into

Returns:

The number of bytes read, possibly zero, or -1 if the channel has reached end-of-stream

Throws:

DatasetException - If there are problems retrieving the FileChannel corresponding to the file

read

int read(String fileName,
       ByteBuffer readBuffer)
         throws DatasetException

Attempts to read a set of bytes from the underlying file.

Parameters:

fileName - The file to be read

readBuffer - The buffer to be read into

Returns:

The number of bytes read, possibly zero, or -1 if the channel has reached end-of-stream

Throws:

DatasetException - If there are problems retrieving the FileChannel corresponding to the file

write

int write(String fileName,
        byte[] bytesToWrite)
          throws DatasetException

Writes a byte[] to a give file.

Parameters:

fileName - The file to be written to

bytesToWrite - The byte[] to be written.

Returns:

The number of bytes written, possibly zero

Throws:

DatasetException - If there are problems retrieving the FileChannel corresponding to the file

write

int write(String fileName,
        ByteBuffer writeBuffer)
          throws DatasetException

Write the specified Buffer to the file corresponding to the specified file.

Parameters:

fileName - The file to be written to

writeBuffer - The buffer holding the bytes to be written

Returns:

The number of bytes written, possibly zero

Throws:

DatasetException - If there are problems retrieving the FileChannel corresponding to the file

addFile

void addFile(String fileName,
           String mode)
             throws DatasetException

Adds a file with the specified permission "r", "w" or "rw" to this dataset.

Parameters:

fileName - The name of the file

mode - The permissions associated with this file

Throws:

NullPointerException - If the specified filename is NULL

DatasetException - If there are problems adding this file

removeFile

void removeFile(String fileName)
                throws DatasetException

Removes a file from this dataset.

Parameters:

fileName - The name of the file

Throws:

NullPointerException - If the specified filename is NULL

DatasetException - If there are problems removing this file

hasFile

boolean hasFile(String fileName)

Checks to see if the file is part of a given dataset

Parameters:

fileName - The name of the file

Returns:

true if the file is a part of the dataset; false otherwise.

getFiles

Collection<String> getFiles()

Retrieves the list of files in this dataset.

Returns:

An collection of the files in this dataset.