com.mesosphere.sdk.storage

Class MemPersister

java.lang.Object

com.mesosphere.sdk.storage.MemPersister

All Implemented Interfaces:

Persister

public class MemPersister
extends java.lang.Object
implements Persister

Implementation of Persister which stores the data in local memory. Mirrors the behavior of CuratorPersister.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	MemPersister.LockMode Whether to enable or disable thread-safe locking.

Constructor Summary

Constructors

Constructor and Description
MemPersister() Creates a new instance with locking enabled and without any initial data.
MemPersister(MemPersister.LockMode mode, java.util.Map<java.lang.String,byte[]> data) Creates a new instance with the provided options.

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.lang.String	getDebugString() Returns a summary of this instance in a newline-separated string.
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	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

MemPersister

public MemPersister()

Creates a new instance with locking enabled and without any initial data.

MemPersister

public MemPersister(MemPersister.LockMode mode,
                    java.util.Map<java.lang.String,byte[]> data)

Creates a new instance with the provided options.

Parameters:

mode - Allows enabling or disabling internal thread-safe locking. Disable in cases where the caller is already performing their own locking

data - The initial data to be stored in the instance, or an empty map if none is applicable

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

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)

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)

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

getDebugString

public java.lang.String getDebugString()

Returns a summary of this instance in a newline-separated string.