HashLinkedListMemTableConfig

java.lang.Object
- org.rocksdb.MemTableConfig
- - org.rocksdb.HashLinkedListMemTableConfig

```
public class HashLinkedListMemTableConfig
extends MemTableConfig
```
The config for hash linked list memtable representation Such memtable contains a fix-sized array of buckets, where each bucket points to a sorted singly-linked list (or null if the bucket is empty).
Note that since this mem-table representation relies on the key prefix, it is required to invoke one of the usePrefixExtractor functions to specify how to extract key prefix given a key. If proper prefix-extractor is not set, then RocksDB will use the default memtable representation (SkipList) instead and post a warning in the LOG.

字段概要

字段
限定符和类型	字段和说明
`static int`	`DEFAUL_THRESHOLD_USE_SKIPLIST`
`static long`	`DEFAULT_BUCKET_COUNT`
`static int`	`DEFAULT_BUCKET_ENTRIES_LOG_THRES`
`static long`	`DEFAULT_HUGE_PAGE_TLB_SIZE`
`static boolean`	`DEFAULT_IF_LOG_BUCKET_DIST_WHEN_FLUSH`

构造器概要

构造器
构造器和说明

HashLinkedListMemTableConfig()
HashLinkedListMemTableConfig constructor

构造器
构造器和说明
`HashLinkedListMemTableConfig()` HashLinkedListMemTableConfig constructor

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
`long`	`bucketCount()` Returns the number of buckets that will be used in the memtable created based on this config.
`int`	`bucketEntriesLoggingThreshold()` Returns the maximum number of entries in one bucket before logging starts.
`long`	`hugePageTlbSize()` Returns the size value of hugePageTlbSize.
`boolean`	`ifLogBucketDistWhenFlush()` Returns information about logging the distribution of number of entries on flush.
`protected long`	`newMemTableFactoryHandle()` This function should only be called by Options.setMemTableConfig(), which will create a c++ shared-pointer to the c++ MemTableRepFactory that associated with the Java MemTableConfig.
`HashLinkedListMemTableConfig`	`setBucketCount(long count)` Set the number of buckets in the fixed-size array used in the hash linked-list mem-table.
`HashLinkedListMemTableConfig`	`setBucketEntriesLoggingThreshold(int threshold)` If number of entries in one bucket exceeds that setting, log about it.
`HashLinkedListMemTableConfig`	`setHugePageTlbSize(long size)` Set the size of huge tlb or allocate the hashtable bytes from malloc if `size <= 0`.
`HashLinkedListMemTableConfig`	`setIfLogBucketDistWhenFlush(boolean logDistribution)` If true the distrubition of number of entries will be logged.
`HashLinkedListMemTableConfig`	`setThresholdUseSkiplist(int threshold)` Set maximum number of entries in one bucket.
`int`	`thresholdUseSkiplist()` Returns entries per bucket threshold before LinkedList is replaced by SkipList usage for that bucket.

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

- 字段详细资料
  - DEFAULT_BUCKET_COUNT
```
public static final long DEFAULT_BUCKET_COUNT
```
    另请参阅:
    
    常量字段值
  - DEFAULT_HUGE_PAGE_TLB_SIZE
```
public static final long DEFAULT_HUGE_PAGE_TLB_SIZE
```
    另请参阅:
    
    常量字段值
  - DEFAULT_BUCKET_ENTRIES_LOG_THRES
```
public static final int DEFAULT_BUCKET_ENTRIES_LOG_THRES
```
    另请参阅:
    
    常量字段值
  - DEFAULT_IF_LOG_BUCKET_DIST_WHEN_FLUSH
```
public static final boolean DEFAULT_IF_LOG_BUCKET_DIST_WHEN_FLUSH
```
    另请参阅:
    
    常量字段值
  - DEFAUL_THRESHOLD_USE_SKIPLIST
```
public static final int DEFAUL_THRESHOLD_USE_SKIPLIST
```
    另请参阅:
    
    常量字段值
- 构造器详细资料
  - HashLinkedListMemTableConfig
```
public HashLinkedListMemTableConfig()
```
    HashLinkedListMemTableConfig constructor
- 方法详细资料
  - setBucketCount
```
public HashLinkedListMemTableConfig setBucketCount(long count)
```
    Set the number of buckets in the fixed-size array used in the hash linked-list mem-table.
    
    参数:
    
    count - the number of hash buckets.
    
    返回:
    
    the reference to the current HashLinkedListMemTableConfig.
  - bucketCount
```
public long bucketCount()
```
    Returns the number of buckets that will be used in the memtable created based on this config.
    
    返回:
    
    the number of buckets
  - setHugePageTlbSize
```
public HashLinkedListMemTableConfig setHugePageTlbSize(long size)
```
    Set the size of huge tlb or allocate the hashtable bytes from malloc if size <= 0.
    
    The user needs to reserve huge pages for it to be allocated, like: sysctl -w vm.nr_hugepages=20
    
    See linux documentation/vm/hugetlbpage.txt
    
    参数:
    
    size - if set to <= 0 hashtable bytes from malloc
    
    返回:
    
    the reference to the current HashLinkedListMemTableConfig.
  - hugePageTlbSize
```
public long hugePageTlbSize()
```
    Returns the size value of hugePageTlbSize.
    
    返回:
    
    the hugePageTlbSize.
  - setBucketEntriesLoggingThreshold
```
public HashLinkedListMemTableConfig setBucketEntriesLoggingThreshold(int threshold)
```
    If number of entries in one bucket exceeds that setting, log about it.
    
    参数:
    
    threshold - - number of entries in a single bucket before logging starts.
    
    返回:
    
    the reference to the current HashLinkedListMemTableConfig.
  - bucketEntriesLoggingThreshold
```
public int bucketEntriesLoggingThreshold()
```
    Returns the maximum number of entries in one bucket before logging starts.
    
    返回:
    
    maximum number of entries in one bucket before logging starts.
  - setIfLogBucketDistWhenFlush
```
public HashLinkedListMemTableConfig setIfLogBucketDistWhenFlush(boolean logDistribution)
```
    If true the distrubition of number of entries will be logged.
    
    参数:
    
    logDistribution - - boolean parameter indicating if number of entry distribution shall be logged.
    
    返回:
    
    the reference to the current HashLinkedListMemTableConfig.
  - ifLogBucketDistWhenFlush
```
public boolean ifLogBucketDistWhenFlush()
```
    Returns information about logging the distribution of number of entries on flush.
    
    返回:
    
    if distribution of number of entries shall be logged.
  - setThresholdUseSkiplist
```
public HashLinkedListMemTableConfig setThresholdUseSkiplist(int threshold)
```
    Set maximum number of entries in one bucket. Exceeding this val leads to a switch from LinkedList to SkipList.
    
    参数:
    
    threshold - maximum number of entries before SkipList is used.
    
    返回:
    
    the reference to the current HashLinkedListMemTableConfig.
  - thresholdUseSkiplist
```
public int thresholdUseSkiplist()
```
    Returns entries per bucket threshold before LinkedList is replaced by SkipList usage for that bucket.
    
    返回:
    
    entries per bucket threshold before SkipList is used.
  - newMemTableFactoryHandle
```
protected long newMemTableFactoryHandle()
```
    从类复制的说明: MemTableConfig
    
    This function should only be called by Options.setMemTableConfig(), which will create a c++ shared-pointer to the c++ MemTableRepFactory that associated with the Java MemTableConfig.
    
    指定者:
    
    newMemTableFactoryHandle 在类中 MemTableConfig
    
    返回:
    
    native handle address to native memory table instance.
    
    另请参阅:
    
    Options.setMemTableConfig(MemTableConfig)

类 HashLinkedListMemTableConfig

字段概要

构造器概要

方法概要

从类继承的方法 java.lang.Object

字段详细资料

DEFAULT_BUCKET_COUNT

DEFAULT_HUGE_PAGE_TLB_SIZE

DEFAULT_BUCKET_ENTRIES_LOG_THRES

DEFAULT_IF_LOG_BUCKET_DIST_WHEN_FLUSH

DEFAUL_THRESHOLD_USE_SKIPLIST

构造器详细资料

HashLinkedListMemTableConfig

方法详细资料

setBucketCount

bucketCount

setHugePageTlbSize

hugePageTlbSize

setBucketEntriesLoggingThreshold

bucketEntriesLoggingThreshold

setIfLogBucketDistWhenFlush

ifLogBucketDistWhenFlush

setThresholdUseSkiplist

thresholdUseSkiplist

newMemTableFactoryHandle