com.google.cloud.hadoop.gcsio

Class PrefixMappedItemCache

java.lang.Object

com.google.cloud.hadoop.gcsio.PrefixMappedItemCache

public class PrefixMappedItemCache
extends Object

A semi-persistent storage for GoogleCloudStorageItemInfo that maintains indexes based on the item's bucket and object name. In addition to caching StorageResourceId to item mappings, it provides options for storing groups of items under similar bucket and object name prefixes.

Constructor Summary

Constructors

Constructor and Description
PrefixMappedItemCache(Duration maxEntryAge) Creates a new PrefixMappedItemCache.

Method Summary

Modifier and Type	Method and Description
GoogleCloudStorageItemInfo	getItem(StorageResourceId id) Gets the cached item associated with the given resource id.
void	invalidateAll() Invalidates all entries in the cache.
void	invalidateBucket(String bucket) Invalidates all cached items and lists associated with the given bucket.
boolean	isPrefixCached(StorageResourceId id) Checks whether any items with specified prefix are in the cache.
GoogleCloudStorageItemInfo	putItem(GoogleCloudStorageItemInfo item) Inserts an item into the cache.
GoogleCloudStorageItemInfo	removeItem(StorageResourceId id) Removes the item from the cache.

Methods inherited from class java.lang.Object

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

Constructor Detail

PrefixMappedItemCache

public PrefixMappedItemCache(Duration maxEntryAge)

Creates a new PrefixMappedItemCache.

Parameters:

maxEntryAge - time after which entries in cache expire.

Method Detail

getItem

public GoogleCloudStorageItemInfo getItem(StorageResourceId id)

Gets the cached item associated with the given resource id.

Parameters:

id - the resource id of the item to get.

Returns:

the cached item associated with the given resource id, null if the item isn't cached or it has expired in the cache.

putItem

public GoogleCloudStorageItemInfo putItem(GoogleCloudStorageItemInfo item)

Inserts an item into the cache. If an item with the same resource id is present, it is overwritten by the new item.

Parameters:

item - the item to insert. The item must have a valid resource id.

Returns:

the overwritten item, null if no item was overwritten.

removeItem

public GoogleCloudStorageItemInfo removeItem(StorageResourceId id)

Removes the item from the cache. If the item has expired, associated lists are invalidated.

Parameters:

id - the resource id of the item to remove.

Returns:

the removed item, null if no item was removed.

isPrefixCached

public boolean isPrefixCached(StorageResourceId id)

Checks whether any items with specified prefix are in the cache.

Parameters:

id - the prefix resource id of the cached items to check.

Returns:

true if items with provided prefix are cached, false otherwise.

invalidateBucket

public void invalidateBucket(String bucket)

Invalidates all cached items and lists associated with the given bucket.

Parameters:

bucket - the bucket to invalidate. This must not be null.

invalidateAll

public void invalidateAll()

Invalidates all entries in the cache.