com.mesosphere.sdk.storage

Class PersisterCache

java.lang.Object

com.mesosphere.sdk.storage.PersisterCache

All Implemented Interfaces:

Persister

public class PersisterCache
extends java.lang.Object
implements Persister

A transparent write-through cache for an underlying Persister instance. Each cache instance is thread-safe, but there is no guarantee of consistent behavior across multiple cache instances.

Constructor Summary

Constructors

Constructor and Description
PersisterCache(Persister persister)

Method Summary

Modifier and Type	Method and Description
void	close() Closes this storage and cleans up any local client resources.
byte[]	get(java.lang.String path) Retrieves the previously stored data at the specified path, or throws an exception if the path doesn't exist.
java.util.Collection<java.lang.String>	getChildren(java.lang.String path) Returns the names of child nodes at the provided path.
java.util.Map<java.lang.String,byte[]>	getMany(java.util.Collection<java.lang.String> paths) Atomically reads many values from storage at once, returning a mapping of paths to values.
void	recursiveDelete(java.lang.String path) Recursively deletes the data at the specified path, or throws an exception if no data existed at that location.
void	recursiveDeleteMany(java.util.Collection<java.lang.String> paths) Atomically deletes many values from storage at once, with each path entry being treated as a call to Persister.recursiveDelete(String) for those paths.
void	refresh() Refreshes the cache with the underlying persister's data.
void	set(java.lang.String path, byte[] bytes) Writes a single value to storage at the specified path, replacing any existing data at the path or creating the path if it doesn't exist yet.
void	setMany(java.util.Map<java.lang.String,byte[]> pathBytesMap) Atomically writes many values to storage at once.

Methods inherited from class java.lang.Object

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

Constructor Detail

PersisterCache

public PersisterCache(Persister persister)
               throws PersisterException

Throws:

PersisterException

Method Detail

get

public byte[] get(java.lang.String path)
           throws PersisterException

Description copied from interface: Persister

Retrieves the previously stored data at the specified path, or throws an exception if the path doesn't exist. If the path is valid but has no data (i.e. is a parent of another path), this returns null.

Specified by:

get in interface Persister

Throws:

PersisterException - if the requested path doesn't exist, or for other access errors

getChildren

public java.util.Collection<java.lang.String> getChildren(java.lang.String path)
                                                   throws PersisterException

Description copied from interface: Persister

Returns the names of child nodes at the provided path. Some returned nodes may have null data when retrieved via Persister.get(String), indicating that these are stub parent entries to other nodes.

To translate the returned values to full absolute paths, they may be joined with the provided path input using PersisterUtils.join(String, String).

To get the list of nodes at the root, use "" or "/" as the input path.

Specified by:

getChildren in interface Persister

Throws:

PersisterException - if the requested path doesn't exist, or for other access errors

set

public void set(java.lang.String path,
                byte[] bytes)
         throws PersisterException

Description copied from interface: Persister

Writes a single value to storage at the specified path, replacing any existing data at the path or creating the path if it doesn't exist yet.

Specified by:

set in interface Persister

Throws:

PersisterException - in the event of an access error

getMany

public java.util.Map<java.lang.String,byte[]> getMany(java.util.Collection<java.lang.String> paths)
                                               throws PersisterException

Description copied from interface: Persister

Atomically reads many values from storage at once, returning a mapping of paths to values. Values which are missing will be unset in the returned Map.

Specified by:

getMany in interface Persister

Throws:

PersisterException - in the event of an access error

See Also:

Persister.get(String)

setMany

public void setMany(java.util.Map<java.lang.String,byte[]> pathBytesMap)
             throws PersisterException

Description copied from interface: Persister

Atomically writes many values to storage at once.

Specified by:

setMany in interface Persister

Throws:

PersisterException - in the event of an access error, in which case no changes should have been made

See Also:

Persister.set(String, byte[])

recursiveDeleteMany

public void recursiveDeleteMany(java.util.Collection<java.lang.String> paths)
                         throws PersisterException

Description copied from interface: Persister

Atomically deletes many values from storage at once, with each path entry being treated as a call to Persister.recursiveDelete(String) for those paths.

Specified by:

recursiveDeleteMany in interface Persister

Throws:

PersisterException - in the event of an access error, in which case no changes should have been made

See Also:

Persister.recursiveDelete(String)

recursiveDelete

public void recursiveDelete(java.lang.String path)
                     throws PersisterException

Description copied from interface: Persister

Recursively deletes the data at the specified path, or throws an exception if no data existed at that location.

Deleting the root node (as "" or "/") will result in all nodes EXCEPT the root node being deleted.

Specified by:

recursiveDelete in interface Persister

Throws:

PersisterException - if the data at the requested path didn't exist, or for other access errors

close

public void close()

Description copied from interface: Persister

Closes this storage and cleans up any local client resources. No other operations should be performed against the instance after calling this.

Specified by:

close in interface Persister

refresh

public void refresh()
             throws PersisterException

Refreshes the cache with the underlying persister's data.

Throws:

PersisterException