CombinedBlockCache (Apache HBase

java.lang.Object
- org.apache.hadoop.hbase.io.hfile.CombinedBlockCache

所有已实现的接口:

Iterable<CachedBlock>, HeapSize, BlockCache, ResizableBlockCache

直接已知子类:

InclusiveCombinedBlockCache
```
@InterfaceAudience.Private
public class CombinedBlockCache
extends Object
implements ResizableBlockCache, HeapSize
```
CombinedBlockCache is an abstraction layer that combines LruBlockCache and BucketCache. The smaller lruCache is used to cache bloom blocks and index blocks. The larger Cache is used to cache data blocks. getBlock(BlockCacheKey, boolean, boolean, boolean) reads first from the smaller lruCache before looking for the block in the l2Cache. Metrics are the combined size and hits and misses of both caches.

嵌套类概要

嵌套类
限定符和类型类和说明

static class CombinedBlockCache.CombinedCacheStats

嵌套类
限定符和类型	类和说明
`static class`	`CombinedBlockCache.CombinedCacheStats`

字段概要

字段
限定符和类型字段和说明

protected CombinedBlockCache.CombinedCacheStats combinedCacheStats

protected BlockCache l2Cache

protected LruBlockCache onHeapCache

字段
限定符和类型	字段和说明
`protected CombinedBlockCache.CombinedCacheStats`	`combinedCacheStats`
`protected BlockCache`	`l2Cache`
`protected LruBlockCache`	`onHeapCache`

构造器概要

构造器
构造器和说明

CombinedBlockCache(LruBlockCache onHeapCache, BlockCache l2Cache)

构造器
构造器和说明
`CombinedBlockCache(LruBlockCache onHeapCache, BlockCache l2Cache)`

方法概要

所有方法实例方法具体方法
限定符和类型	方法和说明
`void`	`cacheBlock(BlockCacheKey cacheKey, Cacheable buf)` Add block to cache (defaults to not in-memory).
`void`	`cacheBlock(BlockCacheKey cacheKey, Cacheable buf, boolean inMemory)` Add block to cache.
`boolean`	`evictBlock(BlockCacheKey cacheKey)` Evict block from cache.
`int`	`evictBlocksByHfileName(String hfileName)` Evicts all blocks for the given HFile.
`Cacheable`	`getBlock(BlockCacheKey cacheKey, boolean caching, boolean repeat, boolean updateCacheMetrics)` Fetch block from cache.
`BlockCache[]`	`getBlockCaches()`
`long`	`getBlockCount()` Returns the number of blocks currently cached in the block cache.
`long`	`getCurrentDataSize()` Returns the occupied size of data blocks, in bytes.
`long`	`getCurrentSize()` Returns the occupied size of the block cache, in bytes.
`long`	`getDataBlockCount()` Returns the number of data blocks currently cached in the block cache.
`long`	`getFreeSize()` Returns the free size of the block cache, in bytes.
`long`	`getMaxSize()` Returns the Max size of the block cache, in bytes.
`int`	`getRefCount(BlockCacheKey cacheKey)`
`CacheStats`	`getStats()` Get the statistics for this block cache.
`long`	`heapSize()`
`Iterator<CachedBlock>`	`iterator()`
`void`	`returnBlock(BlockCacheKey cacheKey, Cacheable block)` Called when the scanner using the block decides to return the block once its usage is over.
`void`	`setMaxSize(long size)` Sets the max heap size that can be used by the BlockCache.
`void`	`shutdown()` Shutdown the cache.
`long`	`size()` Returns the total size of the block cache, in bytes.

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

从接口继承的方法 java.lang.Iterable
forEach, spliterator

- 字段详细资料
  - onHeapCache
```
protected final LruBlockCache onHeapCache
```
  - l2Cache
```
protected final BlockCache l2Cache
```
  - combinedCacheStats
```
protected final CombinedBlockCache.CombinedCacheStats combinedCacheStats
```
- 构造器详细资料
  - CombinedBlockCache
```
public CombinedBlockCache(LruBlockCache onHeapCache,
                          BlockCache l2Cache)
```
- 方法详细资料
  - heapSize
```
public long heapSize()
```
    指定者:
    
    heapSize 在接口中 HeapSize
  - cacheBlock
```
public void cacheBlock(BlockCacheKey cacheKey,
                       Cacheable buf,
                       boolean inMemory)
```
    从接口复制的说明: BlockCache
    
    Add block to cache.
    
    指定者:
    
    cacheBlock 在接口中 BlockCache
    
    参数:
    
    cacheKey - The block's cache key.
    
    buf - The block contents wrapped in a ByteBuffer.
    
    inMemory - Whether block should be treated as in-memory
  - cacheBlock
```
public void cacheBlock(BlockCacheKey cacheKey,
                       Cacheable buf)
```
    从接口复制的说明: BlockCache
    
    Add block to cache (defaults to not in-memory).
    
    指定者:
    
    cacheBlock 在接口中 BlockCache
    
    参数:
    
    cacheKey - The block's cache key.
    
    buf - The object to cache.
  - getBlock
```
public Cacheable getBlock(BlockCacheKey cacheKey,
                          boolean caching,
                          boolean repeat,
                          boolean updateCacheMetrics)
```
    从接口复制的说明: BlockCache
    
    Fetch block from cache.
    
    指定者:
    
    getBlock 在接口中 BlockCache
    
    参数:
    
    cacheKey - Block to fetch.
    
    caching - Whether this request has caching enabled (used for stats)
    
    repeat - Whether this is a repeat lookup for the same block (used to avoid double counting cache misses when doing double-check locking)
    
    updateCacheMetrics - Whether to update cache metrics or not
    
    返回:
    
    Block or null if block is not in 2 cache.
  - evictBlock
```
public boolean evictBlock(BlockCacheKey cacheKey)
```
    从接口复制的说明: BlockCache
    
    Evict block from cache.
    
    指定者:
    
    evictBlock 在接口中 BlockCache
    
    参数:
    
    cacheKey - Block to evict
    
    返回:
    
    true if block existed and was evicted, false if not
  - evictBlocksByHfileName
```
public int evictBlocksByHfileName(String hfileName)
```
    从接口复制的说明: BlockCache
    
    Evicts all blocks for the given HFile.
    
    指定者:
    
    evictBlocksByHfileName 在接口中 BlockCache
    
    返回:
    
    the number of blocks evicted
  - getStats
```
public CacheStats getStats()
```
    从接口复制的说明: BlockCache
    
    Get the statistics for this block cache.
    
    指定者:
    
    getStats 在接口中 BlockCache
    
    返回:
    
    Stats
  - shutdown
```
public void shutdown()
```
    从接口复制的说明: BlockCache
    
    Shutdown the cache.
    
    指定者:
    
    shutdown 在接口中 BlockCache
  - size
```
public long size()
```
    从接口复制的说明: BlockCache
    
    Returns the total size of the block cache, in bytes.
    
    指定者:
    
    size 在接口中 BlockCache
    
    返回:
    
    size of cache, in bytes
  - getMaxSize
```
public long getMaxSize()
```
    从接口复制的说明: BlockCache
    
    Returns the Max size of the block cache, in bytes.
    
    指定者:
    
    getMaxSize 在接口中 BlockCache
    
    返回:
    
    size of cache, in bytes
  - getCurrentDataSize
```
public long getCurrentDataSize()
```
    从接口复制的说明: BlockCache
    
    Returns the occupied size of data blocks, in bytes.
    
    指定者:
    
    getCurrentDataSize 在接口中 BlockCache
    
    返回:
    
    occupied space in cache, in bytes
  - getFreeSize
```
public long getFreeSize()
```
    从接口复制的说明: BlockCache
    
    Returns the free size of the block cache, in bytes.
    
    指定者:
    
    getFreeSize 在接口中 BlockCache
    
    返回:
    
    free space in cache, in bytes
  - getCurrentSize
```
public long getCurrentSize()
```
    从接口复制的说明: BlockCache
    
    Returns the occupied size of the block cache, in bytes.
    
    指定者:
    
    getCurrentSize 在接口中 BlockCache
    
    返回:
    
    occupied space in cache, in bytes
  - getBlockCount
```
public long getBlockCount()
```
    从接口复制的说明: BlockCache
    
    Returns the number of blocks currently cached in the block cache.
    
    指定者:
    
    getBlockCount 在接口中 BlockCache
    
    返回:
    
    number of blocks in the cache
  - getDataBlockCount
```
public long getDataBlockCount()
```
    从接口复制的说明: BlockCache
    
    Returns the number of data blocks currently cached in the block cache.
    
    指定者:
    
    getDataBlockCount 在接口中 BlockCache
    
    返回:
    
    number of blocks in the cache
  - iterator
```
public Iterator<CachedBlock> iterator()
```
    指定者:
    
    iterator 在接口中 Iterable<CachedBlock>
    
    指定者:
    
    iterator 在接口中 BlockCache
    
    返回:
    
    Iterator over the blocks in the cache.
  - getBlockCaches
```
public BlockCache[] getBlockCaches()
```
    指定者:
    
    getBlockCaches 在接口中 BlockCache
    
    返回:
    
    The list of sub blockcaches that make up this one; returns null if no sub caches.
  - setMaxSize
```
public void setMaxSize(long size)
```
    从接口复制的说明: ResizableBlockCache
    
    Sets the max heap size that can be used by the BlockCache.
    
    指定者:
    
    setMaxSize 在接口中 ResizableBlockCache
    
    参数:
    
    size - The max heap size.
  - returnBlock
```
public void returnBlock(BlockCacheKey cacheKey,
                        Cacheable block)
```
    从接口复制的说明: BlockCache
    
    Called when the scanner using the block decides to return the block once its usage is over. This API should be called after the block is used, failing to do so may have adverse effects by preventing the blocks from being evicted because of which it will prevent new hot blocks from getting added to the block cache. The implementation of the BlockCache will decide on what to be done with the block based on the memory type of the block's Cacheable.MemoryType.
    
    指定者:
    
    returnBlock 在接口中 BlockCache
    
    参数:
    
    cacheKey - the cache key of the block
    
    block - the hfileblock to be returned
  - getRefCount
```
public int getRefCount(BlockCacheKey cacheKey)
```

类 CombinedBlockCache

嵌套类概要

字段概要

构造器概要

方法概要

从类继承的方法 java.lang.Object

从接口继承的方法 java.lang.Iterable

字段详细资料

onHeapCache

l2Cache

combinedCacheStats

构造器详细资料

CombinedBlockCache

方法详细资料

heapSize

cacheBlock

cacheBlock

getBlock

evictBlock

evictBlocksByHfileName

getStats

shutdown

size

getMaxSize

getCurrentDataSize

getFreeSize

getCurrentSize

getBlockCount

getDataBlockCount

iterator

getBlockCaches

setMaxSize

returnBlock

getRefCount