org.apache.storm.localizer

Class LocallyCachedBlob

java.lang.Object

org.apache.storm.localizer.LocallyCachedBlob

Direct Known Subclasses:

LocalizedResource, LocallyCachedTopologyBlob

public abstract class LocallyCachedBlob
extends Object

Represents a blob that is cached locally on disk by the supervisor.

Field Summary

Fields

Modifier and Type	Field and Description
static long	NOT_DOWNLOADED_VERSION

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	LocallyCachedBlob(String blobDescription, String blobKey, StormMetricsRegistry metricsRegistry) Create a new LocallyCachedBlob.

Method Summary

Modifier and Type	Method and Description
void	addReference(PortAndAssignment pna, BlobChangingCallback cb) Mark that a given port and assignment are using this.
abstract void	cleanupOrphanedData() Clean up any temporary files.
protected abstract void	commitNewVersion(long version) Commit the new version and make it available for the end user.
abstract void	completelyRemove() Completely remove anything that is cached locally for this blob and all tracking files also stored for it.
protected org.apache.storm.localizer.LocallyCachedBlob.DownloadMeta	fetch(ClientBlobStore store, String key, IOFunction<Long,Path> pathSupplier, IOFunction<File,OutputStream> outStreamSupplier) Helper function to download blob from blob store.
abstract long	fetchUnzipToTemp(ClientBlobStore store) Download the latest version to a temp location.
Collection<PortAndAssignment>	getDependencies()
String	getKey() Get the key for this blob.
long	getLastUsed() Get the last time that this used for LRU calculations.
abstract long	getLocalVersion() Get the version of the blob cached locally.
abstract long	getRemoteVersion(ClientBlobStore store) Get the version of the blob in the blob store.
abstract long	getSizeOnDisk() Get the amount of disk space that is used by this blob.
protected static long	getSizeOnDisk(Path p) Get the size of p in bytes.
void	informReferencesAndCommitNewVersion(long newVersion) Inform all of the callbacks that a change is going to happen and then wait for them to all get back that it is OK to make that change.
abstract boolean	isFullyDownloaded()
boolean	isUsed() Return true if this blob is actively being used, else false (meaning it can be deleted, but might not be).
void	removeReference(PortAndAssignment pna) Removes a reservation for this blob from a given slot and assignemnt.
protected void	touch() Updates the last updated time.

Methods inherited from class java.lang.Object

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

Field Detail

NOT_DOWNLOADED_VERSION

public static final long NOT_DOWNLOADED_VERSION

See Also:

Constant Field Values

Constructor Detail

LocallyCachedBlob

protected LocallyCachedBlob(String blobDescription,
                            String blobKey,
                            StormMetricsRegistry metricsRegistry)

Create a new LocallyCachedBlob.

Parameters:

blobDescription - a description of the blob this represents. Typically it should at least be the blob key, but ideally also include if it is an archive or not, what user or topology it is for, or if it is a storm.jar etc.

Method Detail

fetch

protected org.apache.storm.localizer.LocallyCachedBlob.DownloadMeta fetch(ClientBlobStore store,
                                                                          String key,
                                                                          IOFunction<Long,Path> pathSupplier,
                                                                          IOFunction<File,OutputStream> outStreamSupplier)
                                                                   throws KeyNotFoundException,
                                                                          AuthorizationException,
                                                                          IOException

Helper function to download blob from blob store.

Parameters:

store - Blob store to fetch blobs from

key - Key to retrieve blobs

pathSupplier - A function that supplies the download destination of a blob. It guarantees the validity of path or throws IOException

outStreamSupplier - A function that supplies the OutputStream object

Returns:

The metadata of the download session, including blob’s version and download destination

Throws:

KeyNotFoundException - Thrown if key to retrieve blob is invalid

AuthorizationException - Thrown if the retrieval is not under security authorization

IOException - Thrown if any IO error occurs

getLocalVersion

public abstract long getLocalVersion()

Get the version of the blob cached locally. If the version is unknown or it has not been downloaded NOT_DOWNLOADED_VERSION should be returned. PRECONDITION: this can only be called with a lock on this instance held.

getRemoteVersion

public abstract long getRemoteVersion(ClientBlobStore store)
                               throws KeyNotFoundException,
                                      AuthorizationException

Get the version of the blob in the blob store. PRECONDITION: this can only be called with a lock on this instance held.

Throws:

KeyNotFoundException

AuthorizationException

fetchUnzipToTemp

public abstract long fetchUnzipToTemp(ClientBlobStore store)
                               throws IOException,
                                      KeyNotFoundException,
                                      AuthorizationException

Download the latest version to a temp location. This may also include unzipping some or all of the data to a temp location. PRECONDITION: this can only be called with a lock on this instance held.

Parameters:

store - the store to us to download the data.

Returns:

the version that was downloaded.

Throws:

IOException

KeyNotFoundException

AuthorizationException

commitNewVersion

protected abstract void commitNewVersion(long version)
                                  throws IOException

Commit the new version and make it available for the end user. PRECONDITION: uncompressToTempLocationIfNeeded will have been called. PRECONDITION: this can only be called with a lock on this instance held.

Parameters:

version - the version of the blob to commit.

Throws:

IOException

cleanupOrphanedData

public abstract void cleanupOrphanedData()
                                  throws IOException

Clean up any temporary files. This will be called after updating a blob, either successfully or if an error has occured. The goal is to find any files that may be left over and remove them so space is not leaked. PRECONDITION: this can only be called with a lock on this instance held.

Throws:

IOException

completelyRemove

public abstract void completelyRemove()
                               throws IOException

Completely remove anything that is cached locally for this blob and all tracking files also stored for it. This will be called after the blob was determined to no longer be needed in the cache. PRECONDITION: this can only be called with a lock on this instance held.

Throws:

IOException

getSizeOnDisk

public abstract long getSizeOnDisk()

Get the amount of disk space that is used by this blob. If the blob is uncompressed it should be the sum of the space used by all of the uncompressed files. In general this will not be called with any locks held so it is a good idea to cache it and updated it when committing a new version.

getSizeOnDisk

protected static long getSizeOnDisk(Path p)
                             throws IOException

Get the size of p in bytes.

Parameters:

p - the path to read.

Returns:

the size of p in bytes.

Throws:

IOException

touch

protected void touch()

Updates the last updated time. This should be called when references are added or removed.

getLastUsed

public long getLastUsed()

Get the last time that this used for LRU calculations.

isUsed

public boolean isUsed()

Return true if this blob is actively being used, else false (meaning it can be deleted, but might not be).

addReference

public void addReference(PortAndAssignment pna,
                         BlobChangingCallback cb)

Mark that a given port and assignment are using this.

Parameters:

pna - the slot and assignment that are using this blob.

cb - an optional callback indicating that they want to know/synchronize when a blob is updated.

removeReference

public void removeReference(PortAndAssignment pna)

Removes a reservation for this blob from a given slot and assignemnt.

Parameters:

pna - the slot + assignment that no longer needs this blob.

informReferencesAndCommitNewVersion

public void informReferencesAndCommitNewVersion(long newVersion)
                                         throws IOException

Inform all of the callbacks that a change is going to happen and then wait for them to all get back that it is OK to make that change. Commit the new version once all callbacks are ready. Finally inform all callbacks that the commit is complete.

Throws:

IOException

getKey

public String getKey()

Get the key for this blob.

getDependencies

public Collection<PortAndAssignment> getDependencies()

isFullyDownloaded

public abstract boolean isFullyDownloaded()