org.apache.bookkeeper.mledger.impl

Interface EntryCache

All Superinterfaces:

Comparable<EntryCache>

All Known Implementing Classes:

EntryCacheImpl, EntryCacheManager.EntryCacheDisabled

public interface EntryCache
extends Comparable<EntryCache>

Cache of entries used by a single ManagedLedger. An EntryCache is compared to other EntryCache instances using their size (the memory that is occupied by each of them).

Method Summary

Modifier and Type	Method and Description
void	asyncReadEntry(org.apache.bookkeeper.client.api.ReadHandle lh, long firstEntry, long lastEntry, boolean isSlowestReader, AsyncCallbacks.ReadEntriesCallback callback, Object ctx) Read entries from the cache or from bookkeeper.
void	asyncReadEntry(org.apache.bookkeeper.client.api.ReadHandle lh, PositionImpl position, AsyncCallbacks.ReadEntryCallback callback, Object ctx) Read entry at given position from the cache or from bookkeeper.
void	clear() Remove all the entries from the cache.
org.apache.commons.lang3.tuple.Pair<Integer,Long>	evictEntries(long sizeToFree) Force the cache to drop entries to free space.
String	getName()
long	getSize() Get the total size in bytes of all the entries stored in this cache.
boolean	insert(EntryImpl entry) Insert an entry in the cache.
void	invalidateAllEntries(long ledgerId) Remove from the cache all the entries belonging to a specific ledger.
void	invalidateEntries(PositionImpl lastPosition) Remove from cache all the entries related to a ledger up to lastPosition included.
void	invalidateEntriesBeforeTimestamp(long timestamp)

Methods inherited from interface java.lang.Comparable

compareTo

Method Detail

getName

String getName()

Returns:

the name of the cache

insert

boolean insert(EntryImpl entry)

Insert an entry in the cache.

If the overall limit have been reached, this will triggered the eviction of other entries, possibly from other EntryCache instances

Parameters:

entry - the entry to be cached

Returns:

whether the entry was inserted in cache

invalidateEntries

void invalidateEntries(PositionImpl lastPosition)

Remove from cache all the entries related to a ledger up to lastPosition included.

Parameters:

lastPosition - the position of the last entry to be invalidated (non-inclusive)

invalidateEntriesBeforeTimestamp

void invalidateEntriesBeforeTimestamp(long timestamp)

invalidateAllEntries

void invalidateAllEntries(long ledgerId)

Remove from the cache all the entries belonging to a specific ledger.

Parameters:

ledgerId - the ledger id

clear

void clear()

Remove all the entries from the cache.

evictEntries

org.apache.commons.lang3.tuple.Pair<Integer,Long> evictEntries(long sizeToFree)

Force the cache to drop entries to free space.

Parameters:

sizeToFree - the total memory size to free

Returns:

a pair containing the number of entries evicted and their total size

asyncReadEntry

void asyncReadEntry(org.apache.bookkeeper.client.api.ReadHandle lh,
                    long firstEntry,
                    long lastEntry,
                    boolean isSlowestReader,
                    AsyncCallbacks.ReadEntriesCallback callback,
                    Object ctx)

Read entries from the cache or from bookkeeper.

Get the entry data either from cache or bookkeeper and mixes up the results in a single list.

Parameters:

lh - the ledger handle

firstEntry - the first entry to read (inclusive)

lastEntry - the last entry to read (inclusive)

isSlowestReader - whether the reader cursor is the most far behind in the stream

callback - the callback object that will be notified when read is done

ctx - the context object

asyncReadEntry

void asyncReadEntry(org.apache.bookkeeper.client.api.ReadHandle lh,
                    PositionImpl position,
                    AsyncCallbacks.ReadEntryCallback callback,
                    Object ctx)

Read entry at given position from the cache or from bookkeeper.

Get the entry data either from cache or bookkeeper and mixes up the results in a single list.

Parameters:

lh - the ledger handle

position - position to read the entry from

callback - the callback object that will be notified when read is done

ctx - the context object

getSize

long getSize()

Get the total size in bytes of all the entries stored in this cache.

Returns:

the size of the entry cache