voldemort.store.readonly
Class ReadOnlyStorageEngine

java.lang.Object
  voldemort.store.readonly.ReadOnlyStorageEngine

All Implemented Interfaces:

StorageEngine<ByteArray,byte[],byte[]>, Store<ByteArray,byte[],byte[]>

public class ReadOnlyStorageEngine
extends java.lang.Object
implements StorageEngine<ByteArray,byte[],byte[]>

A read-only store that fronts a big file

Constructor Summary

ReadOnlyStorageEngine(java.lang.String name, SearchStrategy searchStrategy, RoutingStrategy routingStrategy, int nodeId, java.io.File storeDir, int numBackups)
Create an instance of the store

ReadOnlyStorageEngine(java.lang.String name, SearchStrategy searchStrategy, RoutingStrategy routingStrategy, int nodeId, java.io.File storeDir, int numBackups, int deleteBackupMs)
Create an instance of the store

ReadOnlyStorageEngine(java.lang.String name, SearchStrategy searchStrategy, RoutingStrategy routingStrategy, int nodeId, java.io.File storeDir, int numBackups, int deleteBackupMs, boolean enforceMlock)

Method Summary

boolean	beginBatchModifications() A lot of storage engines support efficient methods for performing large number of writes (puts/deletes) against the data source.
void	close() Close the store.
boolean	delete(ByteArray key, Version version) Not supported, throws UnsupportedOperationException if called
boolean	endBatchModifications()
ClosableIterator<Pair<ByteArray,Versioned<byte[]>>>	entries() Get an iterator over pairs of entries in the store.
ClosableIterator<Pair<ByteArray,Versioned<byte[]>>>	entries(int partition) Get an iterator over pairs of entries in a store's partition.
java.util.List<Versioned<byte[]>>	get(ByteArray key, byte[] transforms) Get the value associated with the given key
java.util.Map<ByteArray,java.util.List<Versioned<byte[]>>>	getAll(java.lang.Iterable<ByteArray> keys, java.util.Map<ByteArray,byte[]> transforms) Get the values associated with the given keys and returns them in a Map of keys to a list of versioned values.
java.lang.Object	getCapability(StoreCapabilityType capability) Get some capability of the store.
ChunkedFileSet	getChunkedFileSet() Returns the internal chunked file set
java.lang.String	getChunkIdToNumChunks() Returns a string representation of map of chunk id to number of chunks
java.lang.String	getCurrentDirPath() Retrieve the absolute path of the current version
long	getCurrentVersionId() Retrieve the version id of the current directory
long	getLastSwapped() Time since last time the store was swapped
java.lang.String	getName()
ReadOnlyStorageFormat	getReadOnlyStorageFormat() Retrieve the storage format of RO
java.lang.String	getStoreDirPath() Retrieves the path of the store
java.util.List<Version>	getVersions(ByteArray key)
boolean	isPartitionAware() Is the data persistence aware of partitions? In other words is the data internally stored on a per partition basis or together
boolean	isPartitionScanSupported() Does the storage engine support efficient scanning of a single partition
ClosableIterator<ByteArray>	keys() Get an iterator over keys in the store.
ClosableIterator<ByteArray>	keys(int partition) Get an iterator over keys in the store's partition Note that the iterator need not be threadsafe, and that it must be manually closed after use.
void	open(java.io.File versionDir) Open the store with the version directory specified.
void	put(ByteArray key, Versioned<byte[]> value, byte[] transforms) Not supported, throws UnsupportedOperationException if called
void	rollback(java.io.File rollbackToDir) Rollback to the specified push version
void	rollback(java.lang.String rollbackToDir) Rollback to the specified push version
void	setRoutingStrategy(RoutingStrategy routingStrategy) Set the routing strategy required to find which partition the key belongs to
void	swapFiles(java.lang.String newStoreDirectory) Swap the current version folder for a new one
void	truncate() Truncate all entries in the store

Methods inherited from class java.lang.Object

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

Constructor Detail

ReadOnlyStorageEngine

public ReadOnlyStorageEngine(java.lang.String name,
                             SearchStrategy searchStrategy,
                             RoutingStrategy routingStrategy,
                             int nodeId,
                             java.io.File storeDir,
                             int numBackups,
                             int deleteBackupMs)

Create an instance of the store

Parameters:

name - The name of the store

searchStrategy - The algorithm to use for searching for keys

routingStrategy - The routing strategy used to route keys

nodeId - Node id

storeDir - The directory in which the .data and .index files reside

numBackups - The number of backups of these files to retain

deleteBackupMs - The time in ms for which we'll wait before we delete a backup

ReadOnlyStorageEngine

public ReadOnlyStorageEngine(java.lang.String name,
                             SearchStrategy searchStrategy,
                             RoutingStrategy routingStrategy,
                             int nodeId,
                             java.io.File storeDir,
                             int numBackups)

Create an instance of the store

Parameters:

name - The name of the store

searchStrategy - The algorithm to use for searching for keys

routingStrategy - The routing strategy used to route keys

nodeId - Node id

storeDir - The directory in which the .data and .index files reside

numBackups - The number of backups of these files to retain

ReadOnlyStorageEngine

public ReadOnlyStorageEngine(java.lang.String name,
                             SearchStrategy searchStrategy,
                             RoutingStrategy routingStrategy,
                             int nodeId,
                             java.io.File storeDir,
                             int numBackups,
                             int deleteBackupMs,
                             boolean enforceMlock)

Method Detail

getChunkedFileSet

public ChunkedFileSet getChunkedFileSet()

Returns the internal chunked file set

Returns:

The chunked file set

getChunkIdToNumChunks

public java.lang.String getChunkIdToNumChunks()

Returns a string representation of map of chunk id to number of chunks

Returns:

String of map of chunk id to number of chunks

open

public void open(java.io.File versionDir)

Open the store with the version directory specified. If null is specified we open the directory with the maximum version

Parameters:

versionDir - Version Directory to open. If null, we open the max versioned / latest directory

setRoutingStrategy

public void setRoutingStrategy(RoutingStrategy routingStrategy)

Set the routing strategy required to find which partition the key belongs to

getCurrentDirPath

public java.lang.String getCurrentDirPath()

Retrieve the absolute path of the current version

Returns:

Returns the absolute path of the current dir

getCurrentVersionId

public long getCurrentVersionId()

Retrieve the version id of the current directory

Returns:

Returns a long indicating the version number

getStoreDirPath

public java.lang.String getStoreDirPath()

Retrieves the path of the store

Returns:

The absolute path of the store

getReadOnlyStorageFormat

public ReadOnlyStorageFormat getReadOnlyStorageFormat()

Retrieve the storage format of RO

Returns:

The type of the storage format

getLastSwapped

public long getLastSwapped()

Time since last time the store was swapped

Returns:

Time in milliseconds since the store was swapped

close

public void close()
           throws VoldemortException

Close the store.

Specified by:

close in interface Store<ByteArray,byte[],byte[]>

Throws:

VoldemortException - If closing fails.

swapFiles

public void swapFiles(java.lang.String newStoreDirectory)

Swap the current version folder for a new one

Parameters:

newStoreDirectory - The path to the new version directory

rollback

public void rollback(java.lang.String rollbackToDir)

Rollback to the specified push version

Parameters:

rollbackToDir - The full path of the version directory to rollback to

rollback

public void rollback(java.io.File rollbackToDir)

Rollback to the specified push version

Parameters:

rollbackToDir - The version directory to rollback to

keys

public ClosableIterator<ByteArray> keys()

Description copied from interface: StorageEngine

Get an iterator over keys in the store. Note that the iterator need not be threadsafe, and that it must be manually closed after use.

Specified by:

keys in interface StorageEngine<ByteArray,byte[],byte[]>

Returns:

An iterator over the keys in this StorageEngine.

entries

public ClosableIterator<Pair<ByteArray,Versioned<byte[]>>> entries()

Description copied from interface: StorageEngine

Get an iterator over pairs of entries in the store. The key is the first element in the pair and the versioned value is the second element. Note that the iterator need not be threadsafe, and that it must be manually closed after use.

Specified by:

entries in interface StorageEngine<ByteArray,byte[],byte[]>

Returns:

An iterator over the entries in this StorageEngine.

entries

public ClosableIterator<Pair<ByteArray,Versioned<byte[]>>> entries(int partition)

Description copied from interface: StorageEngine

Get an iterator over pairs of entries in a store's partition. The key is the first element in the pair and the versioned value is the second element. Note that the iterator need not be threadsafe, and that it must be manually closed after use.

Specified by:

entries in interface StorageEngine<ByteArray,byte[],byte[]>

Parameters:

partition - partition whose entries are to be fetched

Returns:

An iterator over the entries in this StorageEngine.

keys

public ClosableIterator<ByteArray> keys(int partition)

Description copied from interface: StorageEngine

Get an iterator over keys in the store's partition Note that the iterator need not be threadsafe, and that it must be manually closed after use.

Specified by:

keys in interface StorageEngine<ByteArray,byte[],byte[]>

Parameters:

partition - partition whose keys are to be fetched

Returns:

An iterator over the keys in this StorageEngine.

truncate

public void truncate()

Description copied from interface: StorageEngine

Truncate all entries in the store

Specified by:

truncate in interface StorageEngine<ByteArray,byte[],byte[]>

get

public java.util.List<Versioned<byte[]>> get(ByteArray key,
                                             byte[] transforms)
                                      throws VoldemortException

Description copied from interface: Store

Get the value associated with the given key

Specified by:

get in interface Store<ByteArray,byte[],byte[]>

Parameters:

key - The key to check for

Returns:

The value associated with the key or an empty list if no values are found.

Throws:

VoldemortException

getAll

public java.util.Map<ByteArray,java.util.List<Versioned<byte[]>>> getAll(java.lang.Iterable<ByteArray> keys,
                                                                         java.util.Map<ByteArray,byte[]> transforms)
                                                                  throws VoldemortException

Description copied from interface: Store

Get the values associated with the given keys and returns them in a Map of keys to a list of versioned values. Note that the returned map will only contain entries for the keys which have a value associated with them.

Specified by:

getAll in interface Store<ByteArray,byte[],byte[]>

Parameters:

keys - The keys to check for.

Returns:

A Map of keys to a list of versioned values.

Throws:

VoldemortException

delete

public boolean delete(ByteArray key,
                      Version version)
               throws VoldemortException

Not supported, throws UnsupportedOperationException if called

Specified by:

delete in interface Store<ByteArray,byte[],byte[]>

Parameters:

key - The key to delete

version - The current value of the key

Returns:

True if anything was deleted

Throws:

VoldemortException

put

public void put(ByteArray key,
                Versioned<byte[]> value,
                byte[] transforms)
         throws VoldemortException

Not supported, throws UnsupportedOperationException if called

Specified by:

put in interface Store<ByteArray,byte[],byte[]>

Parameters:

key - The key to use

value - The value to store and its version.

Throws:

VoldemortException

getName

public java.lang.String getName()

Specified by:

getName in interface Store<ByteArray,byte[],byte[]>

Returns:

The name of the store.

getCapability

public java.lang.Object getCapability(StoreCapabilityType capability)

Description copied from interface: Store

Get some capability of the store. Examples would be the serializer used, or the routing strategy. This provides a mechanism to verify that the store hierarchy has some set of capabilities without knowing the precise layering.

Specified by:

getCapability in interface Store<ByteArray,byte[],byte[]>

Parameters:

capability - The capability type to retrieve

Returns:

The given capaiblity

getVersions

public java.util.List<Version> getVersions(ByteArray key)

Specified by:

getVersions in interface Store<ByteArray,byte[],byte[]>

isPartitionAware

public boolean isPartitionAware()

Description copied from interface: StorageEngine

Is the data persistence aware of partitions? In other words is the data internally stored on a per partition basis or together

Specified by:

isPartitionAware in interface StorageEngine<ByteArray,byte[],byte[]>

Returns:

Boolean indicating if the data persistence is partition aware

isPartitionScanSupported

public boolean isPartitionScanSupported()

Description copied from interface: StorageEngine

Does the storage engine support efficient scanning of a single partition

Specified by:

isPartitionScanSupported in interface StorageEngine<ByteArray,byte[],byte[]>

Returns:

true if the storage engine implements the capability. false otherwise

beginBatchModifications

public boolean beginBatchModifications()

Description copied from interface: StorageEngine

A lot of storage engines support efficient methods for performing large number of writes (puts/deletes) against the data source. This method puts the storage engine in this batch write mode

Specified by:

beginBatchModifications in interface StorageEngine<ByteArray,byte[],byte[]>

Returns:

true if the storage engine took successful action to switch to 'batch-write' mode

endBatchModifications

public boolean endBatchModifications()

Specified by:

endBatchModifications in interface StorageEngine<ByteArray,byte[],byte[]>

Returns:

true if the storage engine successfully returned to normal mode