HFileReaderImpl (Apache HBase - Server 2.1.3 API)

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

所有已实现的接口:

Closeable, AutoCloseable, org.apache.hadoop.conf.Configurable, HFile.CachingBlockReader, HFile.Reader
```
@InterfaceAudience.Private
public class HFileReaderImpl
extends Object
implements HFile.Reader, org.apache.hadoop.conf.Configurable
```
Implementation that can handle all hfile versions of HFile.Reader.

嵌套类概要

嵌套类
限定符和类型	类和说明
`static class`	`HFileReaderImpl.BlockIndexNotLoadedException`
`protected static class`	`HFileReaderImpl.EncodedScanner` Scanner that operates on encoded data blocks.
`protected static class`	`HFileReaderImpl.HFileScannerImpl`
`static class`	`HFileReaderImpl.NotSeekedException` An exception thrown when an operation requiring a scanner to be seeked is invoked on a scanner that is not seeked.

字段概要

字段
限定符和类型	字段和说明
`protected boolean`	`decodeMemstoreTS`
`static int`	`KEY_VALUE_LEN_SIZE` The size of a (key length, value length) tuple that prefixes each entry in a data block.
`static int`	`MINOR_VERSION_NO_CHECKSUM` In HFile minor version that does not support checksums
`static int`	`MINOR_VERSION_WITH_CHECKSUM` Minor versions in HFile starting with this number have hbase checksums
`static int`	`PBUF_TRAILER_MINOR_VERSION` HFile minor version that introduced pbuf filetrailer

构造器概要

构造器
构造器和说明
`HFileReaderImpl(org.apache.hadoop.fs.Path path, FixedFileTrailer trailer, FSDataInputStreamWrapper fsdis, long fileSize, CacheConfig cacheConf, HFileSystem hfs, boolean primaryReplicaReader, org.apache.hadoop.conf.Configuration conf)` Opens a HFile.
`HFileReaderImpl(org.apache.hadoop.fs.Path path, FixedFileTrailer trailer, FSDataInputStreamWrapper fsdis, long fileSize, CacheConfig cacheConf, HFileSystem hfs, org.apache.hadoop.conf.Configuration conf)` 已过时。

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`	`close()`
`void`	`close(boolean evictOnClose)` Close method with optional evictOnClose
`protected HFileContext`	`createHFileContext(FSDataInputStreamWrapper fsdis, long fileSize, HFileSystem hfs, org.apache.hadoop.fs.Path path, FixedFileTrailer trailer)`
`CellComparator`	`getComparator()`
`Compression.Algorithm`	`getCompressionAlgorithm()`
`org.apache.hadoop.conf.Configuration`	`getConf()`
`DataBlockEncoding`	`getDataBlockEncoding()`
`org.apache.hadoop.hbase.io.hfile.HFileBlockIndex.BlockIndexReader`	`getDataBlockIndexReader()`
`DataInput`	`getDeleteBloomFilterMetadata()` Retrieves delete family Bloom filter metadata as appropriate for each `HFile` version.
`DataBlockEncoding`	`getEffectiveEncodingInCache(boolean isCompaction)`
`long`	`getEntries()`
`HFileContext`	`getFileContext()` Return the file context of the HFile this reader belongs to
`Optional<Cell>`	`getFirstKey()`
`Optional<byte[]>`	`getFirstRowKey()` TODO left from `HFile` version 1: move this to StoreFile after Ryan's patch goes in to eliminate `KeyValue` here.
`DataInput`	`getGeneralBloomFilterMetadata()` Returns a buffer with the Bloom filter metadata.
`Optional<Cell>`	`getLastKey()`
`Optional<byte[]>`	`getLastRowKey()` TODO left from `HFile` version 1: move this to StoreFile after Ryan's patch goes in to eliminate `KeyValue` here.
`int`	`getMajorVersion()`
`HFileBlock`	`getMetaBlock(String metaBlockName, boolean cacheBlock)`
`String`	`getName()` Returns this reader's "name".
`org.apache.hadoop.fs.Path`	`getPath()`
`HFileScanner`	`getScanner(boolean cacheBlocks, boolean pread)` Create a Scanner on this file.
`HFileScanner`	`getScanner(boolean cacheBlocks, boolean pread, boolean isCompaction)` Create a Scanner on this file.
`FixedFileTrailer`	`getTrailer()`
`org.apache.hadoop.hbase.io.hfile.HFileBlock.FSReader`	`getUncachedBlockReader()` For testing
`boolean`	`hasMVCCInfo()`
`long`	`indexSize()`
`boolean`	`isDecodeMemStoreTS()`
`boolean`	`isFileInfoLoaded()`
`boolean`	`isPrimaryReplicaReader()`
`long`	`length()`
`HFile.FileInfo`	`loadFileInfo()`
`Optional<Cell>`	`midKey()`
`boolean`	`prefetchComplete()` Returns false if block prefetching was requested for this file and has not completed, true otherwise
`HFileBlock`	`readBlock(long dataBlockOffset, long onDiskBlockSize, boolean cacheBlock, boolean pread, boolean isCompaction, boolean updateCacheMetrics, BlockType expectedBlockType, DataBlockEncoding expectedDataBlockEncoding)` Read in a file block.
`void`	`returnBlock(HFileBlock block)` Return the given block back to the cache, if it was obtained from cache.
`void`	`setConf(org.apache.hadoop.conf.Configuration conf)`
`boolean`	`shouldIncludeMemStoreTS()`
`String`	`toString()`
`void`	`unbufferStream()` To close the stream's socket.

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

- 字段详细资料
  - MINOR_VERSION_WITH_CHECKSUM
```
public static final int MINOR_VERSION_WITH_CHECKSUM
```
    Minor versions in HFile starting with this number have hbase checksums
    
    另请参阅:
    
    常量字段值
  - MINOR_VERSION_NO_CHECKSUM
```
public static final int MINOR_VERSION_NO_CHECKSUM
```
    In HFile minor version that does not support checksums
    
    另请参阅:
    
    常量字段值
  - PBUF_TRAILER_MINOR_VERSION
```
public static final int PBUF_TRAILER_MINOR_VERSION
```
    HFile minor version that introduced pbuf filetrailer
    
    另请参阅:
    
    常量字段值
  - KEY_VALUE_LEN_SIZE
```
public static final int KEY_VALUE_LEN_SIZE
```
    The size of a (key length, value length) tuple that prefixes each entry in a data block.
    
    另请参阅:
    
    常量字段值
  - decodeMemstoreTS
```
protected boolean decodeMemstoreTS
```
- 构造器详细资料
  - HFileReaderImpl
```
@Deprecated
public HFileReaderImpl(org.apache.hadoop.fs.Path path,
                                   FixedFileTrailer trailer,
                                   FSDataInputStreamWrapper fsdis,
                                   long fileSize,
                                   CacheConfig cacheConf,
                                   HFileSystem hfs,
                                   org.apache.hadoop.conf.Configuration conf)
                            throws IOException
```
    已过时。
    
    抛出:
    
    IOException
  - HFileReaderImpl
```
public HFileReaderImpl(org.apache.hadoop.fs.Path path,
                       FixedFileTrailer trailer,
                       FSDataInputStreamWrapper fsdis,
                       long fileSize,
                       CacheConfig cacheConf,
                       HFileSystem hfs,
                       boolean primaryReplicaReader,
                       org.apache.hadoop.conf.Configuration conf)
                throws IOException
```
    Opens a HFile. You must load the index before you can use it by calling loadFileInfo().
    
    参数:
    
    path - Path to HFile.
    
    trailer - File trailer.
    
    fsdis - input stream.
    
    fileSize - Length of the stream.
    
    cacheConf - Cache configuration.
    
    hfs - The file system.
    
    conf - Configuration
    
    抛出:
    
    IOException
- 方法详细资料
  - toString
```
public String toString()
```
    覆盖:
    
    toString 在类中 Object
  - length
```
public long length()
```
    指定者:
    
    length 在接口中 HFile.Reader
  - returnBlock
```
public void returnBlock(HFileBlock block)
```
    从接口复制的说明: HFile.CachingBlockReader
    
    Return the given block back to the cache, if it was obtained from cache.
    
    指定者:
    
    returnBlock 在接口中 HFile.CachingBlockReader
    
    参数:
    
    block - Block to be returned.
  - getFirstKey
```
public Optional<Cell> getFirstKey()
```
    指定者:
    
    getFirstKey 在接口中 HFile.Reader
    
    返回:
    
    the first key in the file. May be null if file has no entries. Note that this is not the first row key, but rather the byte form of the first KeyValue.
  - getFirstRowKey
```
public Optional<byte[]> getFirstRowKey()
```
    TODO left from HFile version 1: move this to StoreFile after Ryan's patch goes in to eliminate KeyValue here.
    
    指定者:
    
    getFirstRowKey 在接口中 HFile.Reader
    
    返回:
    
    the first row key, or null if the file is empty.
  - getLastRowKey
```
public Optional<byte[]> getLastRowKey()
```
    TODO left from HFile version 1: move this to StoreFile after Ryan's patch goes in to eliminate KeyValue here.
    
    指定者:
    
    getLastRowKey 在接口中 HFile.Reader
    
    返回:
    
    the last row key, or null if the file is empty.
  - getEntries
```
public long getEntries()
```
    指定者:
    
    getEntries 在接口中 HFile.Reader
    
    返回:
    
    number of KV entries in this HFile
  - getComparator
```
public CellComparator getComparator()
```
    指定者:
    
    getComparator 在接口中 HFile.Reader
    
    返回:
    
    comparator
  - getCompressionAlgorithm
```
public Compression.Algorithm getCompressionAlgorithm()
```
    指定者:
    
    getCompressionAlgorithm 在接口中 HFile.Reader
    
    返回:
    
    compression algorithm
  - indexSize
```
public long indexSize()
```
    指定者:
    
    indexSize 在接口中 HFile.Reader
    
    返回:
    
    the total heap size of data and meta block indexes in bytes. Does not take into account non-root blocks of a multilevel data index.
  - getName
```
public String getName()
```
    从接口复制的说明: HFile.Reader
    
    Returns this reader's "name". Usually the last component of the path. Needs to be constant as the file is being moved to support caching on write.
    
    指定者:
    
    getName 在接口中 HFile.Reader
  - getDataBlockIndexReader
```
public org.apache.hadoop.hbase.io.hfile.HFileBlockIndex.BlockIndexReader getDataBlockIndexReader()
```
    指定者:
    
    getDataBlockIndexReader 在接口中 HFile.Reader
  - getTrailer
```
public FixedFileTrailer getTrailer()
```
    指定者:
    
    getTrailer 在接口中 HFile.Reader
  - isPrimaryReplicaReader
```
public boolean isPrimaryReplicaReader()
```
    指定者:
    
    isPrimaryReplicaReader 在接口中 HFile.Reader
  - loadFileInfo
```
public HFile.FileInfo loadFileInfo()
                            throws IOException
```
    指定者:
    
    loadFileInfo 在接口中 HFile.Reader
    
    抛出:
    
    IOException
  - getPath
```
public org.apache.hadoop.fs.Path getPath()
```
    指定者:
    
    getPath 在接口中 HFile.Reader
  - getDataBlockEncoding
```
public DataBlockEncoding getDataBlockEncoding()
```
    指定者:
    
    getDataBlockEncoding 在接口中 HFile.Reader
  - getConf
```
public org.apache.hadoop.conf.Configuration getConf()
```
    指定者:
    
    getConf 在接口中 org.apache.hadoop.conf.Configurable
  - setConf
```
public void setConf(org.apache.hadoop.conf.Configuration conf)
```
    指定者:
    
    setConf 在接口中 org.apache.hadoop.conf.Configurable
  - isDecodeMemStoreTS
```
public boolean isDecodeMemStoreTS()
```
    指定者:
    
    isDecodeMemStoreTS 在接口中 HFile.Reader
  - shouldIncludeMemStoreTS
```
public boolean shouldIncludeMemStoreTS()
```
    指定者:
    
    shouldIncludeMemStoreTS 在接口中 HFile.Reader
  - getMetaBlock
```
public HFileBlock getMetaBlock(String metaBlockName,
                               boolean cacheBlock)
                        throws IOException
```
    指定者:
    
    getMetaBlock 在接口中 HFile.Reader
    
    参数:
    
    metaBlockName -
    
    cacheBlock - Add block to cache, if found
    
    返回:
    
    block wrapped in a ByteBuffer, with header skipped
    
    抛出:
    
    IOException
  - readBlock
```
public HFileBlock readBlock(long dataBlockOffset,
                            long onDiskBlockSize,
                            boolean cacheBlock,
                            boolean pread,
                            boolean isCompaction,
                            boolean updateCacheMetrics,
                            BlockType expectedBlockType,
                            DataBlockEncoding expectedDataBlockEncoding)
                     throws IOException
```
    从接口复制的说明: HFile.CachingBlockReader
    
    Read in a file block.
    
    指定者:
    
    readBlock 在接口中 HFile.CachingBlockReader
    
    参数:
    
    dataBlockOffset - offset to read.
    
    onDiskBlockSize - size of the block
    
    isCompaction - is this block being read as part of a compaction
    
    expectedBlockType - the block type we are expecting to read with this read operation, or null to read whatever block type is available and avoid checking (that might reduce caching efficiency of encoded data blocks)
    
    expectedDataBlockEncoding - the data block encoding the caller is expecting data blocks to be in, or null to not perform this check and return the block irrespective of the encoding. This check only applies to data blocks and can be set to null when the caller is expecting to read a non-data block and has set expectedBlockType accordingly.
    
    返回:
    
    Block wrapped in a ByteBuffer.
    
    抛出:
    
    IOException
  - hasMVCCInfo
```
public boolean hasMVCCInfo()
```
    指定者:
    
    hasMVCCInfo 在接口中 HFile.Reader
  - getLastKey
```
public Optional<Cell> getLastKey()
```
    指定者:
    
    getLastKey 在接口中 HFile.Reader
    
    返回:
    
    Last key as cell in the file. May be null if file has no entries. Note that this is not the last row key, but it is the Cell representation of the last key
  - midKey
```
public Optional<Cell> midKey()
                      throws IOException
```
    指定者:
    
    midKey 在接口中 HFile.Reader
    
    返回:
    
    Midkey for this file. We work with block boundaries only so returned midkey is an approximation only.
    
    抛出:
    
    IOException
  - close
```
public void close()
           throws IOException
```
    指定者:
    
    close 在接口中 Closeable
    
    指定者:
    
    close 在接口中 AutoCloseable
    
    抛出:
    
    IOException
  - close
```
public void close(boolean evictOnClose)
           throws IOException
```
    从接口复制的说明: HFile.Reader
    
    Close method with optional evictOnClose
    
    指定者:
    
    close 在接口中 HFile.Reader
    
    抛出:
    
    IOException
  - getEffectiveEncodingInCache
```
public DataBlockEncoding getEffectiveEncodingInCache(boolean isCompaction)
```
    指定者:
    
    getEffectiveEncodingInCache 在接口中 HFile.Reader
  - getUncachedBlockReader
```
public org.apache.hadoop.hbase.io.hfile.HFileBlock.FSReader getUncachedBlockReader()
```
    For testing
    
    指定者:
    
    getUncachedBlockReader 在接口中 HFile.Reader
  - getGeneralBloomFilterMetadata
```
public DataInput getGeneralBloomFilterMetadata()
                                        throws IOException
```
    Returns a buffer with the Bloom filter metadata. The caller takes ownership of the buffer.
    
    指定者:
    
    getGeneralBloomFilterMetadata 在接口中 HFile.Reader
    
    抛出:
    
    IOException
  - getDeleteBloomFilterMetadata
```
public DataInput getDeleteBloomFilterMetadata()
                                       throws IOException
```
    从接口复制的说明: HFile.Reader
    
    Retrieves delete family Bloom filter metadata as appropriate for each HFile version. Knows nothing about how that metadata is structured.
    
    指定者:
    
    getDeleteBloomFilterMetadata 在接口中 HFile.Reader
    
    抛出:
    
    IOException
  - isFileInfoLoaded
```
public boolean isFileInfoLoaded()
```
  - getFileContext
```
public HFileContext getFileContext()
```
    从接口复制的说明: HFile.Reader
    
    Return the file context of the HFile this reader belongs to
    
    指定者:
    
    getFileContext 在接口中 HFile.Reader
  - prefetchComplete
```
public boolean prefetchComplete()
```
    Returns false if block prefetching was requested for this file and has not completed, true otherwise
    
    指定者:
    
    prefetchComplete 在接口中 HFile.Reader
  - createHFileContext
```
protected HFileContext createHFileContext(FSDataInputStreamWrapper fsdis,
                                          long fileSize,
                                          HFileSystem hfs,
                                          org.apache.hadoop.fs.Path path,
                                          FixedFileTrailer trailer)
                                   throws IOException
```
    抛出:
    
    IOException
  - getScanner
```
public HFileScanner getScanner(boolean cacheBlocks,
                               boolean pread)
```
    Create a Scanner on this file. No seeks or reads are done on creation. Call HFileScanner.seekTo(Cell) to position an start the read. There is nothing to clean up in a Scanner. Letting go of your references to the scanner is sufficient. NOTE: Do not use this overload of getScanner for compactions. See getScanner(boolean, boolean, boolean)
    
    指定者:
    
    getScanner 在接口中 HFile.Reader
    
    参数:
    
    cacheBlocks - True if we should cache blocks read in by this scanner.
    
    pread - Use positional read rather than seek+read if true (pread is better for random reads, seek+read is better scanning).
    
    返回:
    
    Scanner on this file.
  - getScanner
```
public HFileScanner getScanner(boolean cacheBlocks,
                               boolean pread,
                               boolean isCompaction)
```
    Create a Scanner on this file. No seeks or reads are done on creation. Call HFileScanner.seekTo(Cell) to position an start the read. There is nothing to clean up in a Scanner. Letting go of your references to the scanner is sufficient.
    
    指定者:
    
    getScanner 在接口中 HFile.Reader
    
    参数:
    
    cacheBlocks - True if we should cache blocks read in by this scanner.
    
    pread - Use positional read rather than seek+read if true (pread is better for random reads, seek+read is better scanning).
    
    isCompaction - is scanner being used for a compaction?
    
    返回:
    
    Scanner on this file.
  - getMajorVersion
```
public int getMajorVersion()
```
  - unbufferStream
```
public void unbufferStream()
```
    从接口复制的说明: HFile.Reader
    
    To close the stream's socket. Note: This can be concurrently called from multiple threads and implementation should take care of thread safety.
    
    指定者:
    
    unbufferStream 在接口中 HFile.Reader

类 HFileReaderImpl

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

字段详细资料

MINOR_VERSION_WITH_CHECKSUM

MINOR_VERSION_NO_CHECKSUM

PBUF_TRAILER_MINOR_VERSION

KEY_VALUE_LEN_SIZE

decodeMemstoreTS

构造器详细资料

HFileReaderImpl

HFileReaderImpl

方法详细资料

toString

length

returnBlock

getFirstKey

getFirstRowKey

getLastRowKey

getEntries

getComparator

getCompressionAlgorithm

indexSize

getName

getDataBlockIndexReader

getTrailer

isPrimaryReplicaReader

loadFileInfo

getPath

getDataBlockEncoding

getConf

setConf

isDecodeMemStoreTS

shouldIncludeMemStoreTS

getMetaBlock

readBlock

hasMVCCInfo

getLastKey

midKey

close

close

getEffectiveEncodingInCache

getUncachedBlockReader

getGeneralBloomFilterMetadata

getDeleteBloomFilterMetadata

isFileInfoLoaded

getFileContext

prefetchComplete

createHFileContext

getScanner

getScanner

getMajorVersion

unbufferStream