galileo.fs

Class GeospatialFileSystem

java.lang.Object

galileo.fs.FileSystem

galileo.fs.GeospatialFileSystem

All Implemented Interfaces:

PhysicalGraph

public class GeospatialFileSystem
extends FileSystem

Implements a FileSystem for Geospatial data. This file system manager assumes that the information being stored has both space and time properties.

Relevant system properties include galileo.fs.GeospatialFileSystem.timeFormat and galileo.fs.GeospatialFileSystem.geohashPrecision to modify how the hierarchy is created.

Field Summary

Fields inherited from class galileo.fs.FileSystem

BLOCK_EXTENSION, storageDirectory

Constructor Summary

Constructors

Constructor and Description
GeospatialFileSystem(java.lang.String storageDirectory)

Method Summary

Modifier and Type	Method and Description
protected FeaturePath<java.lang.String>	createPath(java.lang.String physicalPath, Metadata meta) Using the Feature attributes found in the provided Metadata, a path is created for insertion into the Metadata Graph.
MetadataGraph	getMetadataGraph()
java.util.List<Path<Feature,java.lang.String>>	query(Query query)
void	shutdown() Performs a clean shutdown of the FileSystem instance.
java.lang.String	storeBlock(Block block) Stores a Block on disk.
void	storeMetadata(Metadata metadata, java.lang.String blockPath) Inserts Metadata into the file system.

Methods inherited from class galileo.fs.FileSystem

fullRecovery, getFreeSpace, initialize, isReadOnly, loadBlock, loadMetadata, rebuildPaths, recover, scanDirectory

Methods inherited from class java.lang.Object

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

Constructor Detail

GeospatialFileSystem

public GeospatialFileSystem(java.lang.String storageDirectory)
                     throws FileSystemException,
                            java.io.IOException,
                            galileo.serialization.SerializationException

Throws:

FileSystemException

java.io.IOException

galileo.serialization.SerializationException

Method Detail

storeBlock

public java.lang.String storeBlock(Block block)
                            throws FileSystemException,
                                   java.io.IOException

Description copied from interface: PhysicalGraph

Stores a Block on disk. The location of the Block will be determined by the particular FileSystem implementation being used rather than as a method parameter, so only the Block itself is provided.

Specified by:

storeBlock in interface PhysicalGraph

Overrides:

storeBlock in class FileSystem

Parameters:

block - the Block instance to persist to disk.

Returns:

String representation of the Block path on disk.

Throws:

FileSystemException

java.io.IOException

createPath

protected FeaturePath<java.lang.String> createPath(java.lang.String physicalPath,
                                                   Metadata meta)

Using the Feature attributes found in the provided Metadata, a path is created for insertion into the Metadata Graph.

storeMetadata

public void storeMetadata(Metadata metadata,
                          java.lang.String blockPath)
                   throws FileSystemException,
                          java.io.IOException

Description copied from interface: PhysicalGraph

Inserts Metadata into the file system. In many cases, Metadata is not stored individually on disk but placed in an index instead. This method is useful during a full recovery operation for re-linking indexed Metadata with its associated files on disk, or could be used in situations where information should only be indexed and not stored.

Specified by:

storeMetadata in interface PhysicalGraph

Specified by:

storeMetadata in class FileSystem

Parameters:

metadata - the Metadata to 'store,' which may just involve updating index structures.

blockPath - the on-disk path of the Block the Metadata being stored belongs to.

Throws:

FileSystemException

java.io.IOException

getMetadataGraph

public MetadataGraph getMetadataGraph()

query

public java.util.List<Path<Feature,java.lang.String>> query(Query query)

shutdown

public void shutdown()

Description copied from class: FileSystem

Performs a clean shutdown of the FileSystem instance. This includes flushing buffers, writing changes out to disk, persisting index structures, etc.

Note that this method may be called during a signal handling operation, which may mean that the logging subsystem has already shut down, so critical errors/information should be printed to stdout or stderr. Furthermore, there is no guarantee all the shutdown operations will be executed, so time is of the essence here.

Specified by:

shutdown in class FileSystem