com.google.cloud.hadoop.gcsio

Class PrefixMappedItemCache

java.lang.Object

com.google.cloud.hadoop.gcsio.PrefixMappedItemCache

public class PrefixMappedItemCache
extends java.lang.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.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	PrefixMappedItemCache.Config Container for various cache-configuration parameters used by a PrefixMappedItemCache when managing expiration/retention policies, etc.

Constructor Summary

Constructors

Constructor and Description
PrefixMappedItemCache(PrefixMappedItemCache.Config config) 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.
java.util.List<GoogleCloudStorageItemInfo>	getList(java.lang.String bucket, java.lang.String objectNamePrefix) Gets the cached list associated with the given bucket and object name prefix.
void	invalidateAll() Invalidates all entries in the cache.
void	invalidateBucket(java.lang.String bucket) Invalidates all cached items and lists associated with the given bucket.
GoogleCloudStorageItemInfo	putItem(GoogleCloudStorageItemInfo item) Inserts an item into the cache.
void	putList(java.lang.String bucket, java.lang.String objectNamePrefix, java.util.List<GoogleCloudStorageItemInfo> items) Inserts a list entry and the given items 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(PrefixMappedItemCache.Config config)

Creates a new PrefixMappedItemCache.

Parameters:

config - the configuration parameters to initialize the cache with. The configuration parameters are copied during construction, future modifications to the configuration will not be reflected in the cache.

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.

getList

public java.util.List<GoogleCloudStorageItemInfo> getList(java.lang.String bucket,
                                                          @Nullable
                                                          java.lang.String objectNamePrefix)

Gets the cached list associated with the given bucket and object name prefix.

Parameters:

bucket - the bucket where the entries are being retrieved from.

objectNamePrefix - the object name prefix to match against. If this is empty string or null, it will match everything in the bucket.

Returns:

a list of items matching in the given bucket matching the given object name prefix, null if a list isn't found or the is expired.

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.

putList

public void putList(java.lang.String bucket,
                    @Nullable
                    java.lang.String objectNamePrefix,
                    java.util.List<GoogleCloudStorageItemInfo> items)

Inserts a list entry and the given items into the cache. If a list entry under the same bucket/objectNamePrefix is present, its expiration time is reset. If an item with the same resource id is present, it is overwritten by the new item.

Parameters:

bucket - the bucket to index the items by.

objectNamePrefix - the object name prefix to index the items by. If this is null, it will be converted to empty string.

items - the list of items to insert.

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.

invalidateBucket

public void invalidateBucket(java.lang.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.