AbstractHFileReader (Apache HBase 1.2.12 API)

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

All Implemented Interfaces:

Closeable, AutoCloseable, org.apache.hadoop.conf.Configurable, HFile.CachingBlockReader, HFile.Reader

Direct Known Subclasses:

HFileReaderV2
```
@InterfaceAudience.Private
public abstract class AbstractHFileReader
extends Object
implements HFile.Reader, org.apache.hadoop.conf.Configurable
```
Common functionality needed by all versions of HFile readers.

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`AbstractHFileReader.BlockIndexNotLoadedException`
`static class`	`AbstractHFileReader.NotSeekedException` An exception thrown when an operation requiring a scanner to be seeked is invoked on a scanner that is not seeked.
`protected static class`	`AbstractHFileReader.Scanner`

Field Summary

Fields
Modifier and Type	Field and Description
`protected int`	`avgKeyLen` Average key length read from file info
`protected int`	`avgValueLen` Average value length read from file info
`protected CacheConfig`	`cacheConf` Block cache configuration.
`protected KeyValue.KVComparator`	`comparator` Key comparator
`protected Compression.Algorithm`	`compressAlgo` Filled when we read in the trailer.
`protected org.apache.hadoop.conf.Configuration`	`conf`
`protected HFileDataBlockEncoder`	`dataBlockEncoder` What kind of data block encoding should be used while reading, writing, and handling cache.
`protected HFileBlockIndex.BlockIndexReader`	`dataBlockIndexReader` Data block index reader keeping the root data index in memory
`protected HFile.FileInfo`	`fileInfo`
`protected long`	`fileSize` Size of this file.
`protected HFileSystem`	`hfs` The filesystem used for accesing data
`private boolean`	`isPrimaryReplicaReader`
`protected byte[]`	`lastKey` Last key in the file.
`protected HFileBlockIndex.BlockIndexReader`	`metaBlockIndexReader` Meta block index reader -- always single level
`protected String`	`name` File name to be used for block names
`protected org.apache.hadoop.fs.Path`	`path` Path of file
`protected FixedFileTrailer`	`trailer`

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`AbstractHFileReader(org.apache.hadoop.fs.Path path, FixedFileTrailer trailer, long fileSize, CacheConfig cacheConf, HFileSystem hfs, org.apache.hadoop.conf.Configuration conf)`

Method Summary

Methods
Modifier and Type	Method and Description
`KeyValue.KVComparator`	`getComparator()`
`Compression.Algorithm`	`getCompressionAlgorithm()`
`org.apache.hadoop.conf.Configuration`	`getConf()`
`DataBlockEncoding`	`getDataBlockEncoding()`
`HFileBlockIndex.BlockIndexReader`	`getDataBlockIndexReader()`
`long`	`getEntries()`
`byte[]`	`getFirstKey()`
`byte[]`	`getFirstRowKey()` TODO left from `HFile` version 1: move this to StoreFile after Ryan's patch goes in to eliminate `KeyValue` here.
`byte[]`	`getLastRowKey()` TODO left from `HFile` version 1: move this to StoreFile after Ryan's patch goes in to eliminate `KeyValue` here.
`abstract int`	`getMajorVersion()`
`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.
`FixedFileTrailer`	`getTrailer()`
`(package private) abstract HFileBlock.FSReader`	`getUncachedBlockReader()` For testing
`long`	`indexSize()`
`abstract boolean`	`isFileInfoLoaded()`
`boolean`	`isPrimaryReplicaReader()`
`long`	`length()`
`HFile.FileInfo`	`loadFileInfo()`
`void`	`setConf(org.apache.hadoop.conf.Configuration conf)`
`void`	`setPrimaryReplicaReader(boolean isPrimaryReplicaReader)`
`String`	`toString()`
`protected String`	`toStringFirstKey()`
`protected String`	`toStringLastKey()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.hadoop.hbase.io.hfile.HFile.Reader
close, getDeleteBloomFilterMetadata, getFileContext, getGeneralBloomFilterMetadata, getLastKey, getMetaBlock, getScanner, hasMVCCInfo, midkey, unbufferStream

Methods inherited from interface java.io.Closeable
close

Methods inherited from interface org.apache.hadoop.hbase.io.hfile.HFile.CachingBlockReader
readBlock

- Field Detail
  - dataBlockIndexReader
```
protected HFileBlockIndex.BlockIndexReader dataBlockIndexReader
```
    Data block index reader keeping the root data index in memory
  - metaBlockIndexReader
```
protected HFileBlockIndex.BlockIndexReader metaBlockIndexReader
```
    Meta block index reader -- always single level
  - trailer
```
protected final FixedFileTrailer trailer
```
  - compressAlgo
```
protected final Compression.Algorithm compressAlgo
```
    Filled when we read in the trailer.
  - isPrimaryReplicaReader
```
private boolean isPrimaryReplicaReader
```
  - dataBlockEncoder
```
protected HFileDataBlockEncoder dataBlockEncoder
```
    What kind of data block encoding should be used while reading, writing, and handling cache.
  - lastKey
```
protected byte[] lastKey
```
    Last key in the file. Filled in when we read in the file info
  - avgKeyLen
```
protected int avgKeyLen
```
    Average key length read from file info
  - avgValueLen
```
protected int avgValueLen
```
    Average value length read from file info
  - comparator
```
protected KeyValue.KVComparator comparator
```
    Key comparator
  - fileSize
```
protected final long fileSize
```
    Size of this file.
  - cacheConf
```
protected final CacheConfig cacheConf
```
    Block cache configuration.
  - path
```
protected final org.apache.hadoop.fs.Path path
```
    Path of file
  - name
```
protected final String name
```
    File name to be used for block names
  - fileInfo
```
protected HFile.FileInfo fileInfo
```
  - hfs
```
protected HFileSystem hfs
```
    The filesystem used for accesing data
  - conf
```
protected org.apache.hadoop.conf.Configuration conf
```
- Constructor Detail
  - AbstractHFileReader
```
protected AbstractHFileReader(org.apache.hadoop.fs.Path path,
                   FixedFileTrailer trailer,
                   long fileSize,
                   CacheConfig cacheConf,
                   HFileSystem hfs,
                   org.apache.hadoop.conf.Configuration conf)
```
- Method Detail
  - toStringFirstKey
```
protected String toStringFirstKey()
```
  - toStringLastKey
```
protected String toStringLastKey()
```
  - isFileInfoLoaded
```
public abstract boolean isFileInfoLoaded()
```
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - length
```
public long length()
```
    Specified by:
    
    length in interface HFile.Reader
  - 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(byte[]) 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.
    
    Specified by:
    
    getScanner in interface HFile.Reader
    
    Parameters:
    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).
    
    Returns:
    Scanner on this file.
  - getFirstKey
```
public byte[] getFirstKey()
```
    Specified by:
    
    getFirstKey in interface HFile.Reader
    
    Returns:
    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 byte[] getFirstRowKey()
```
    TODO left from HFile version 1: move this to StoreFile after Ryan's patch goes in to eliminate KeyValue here.
    
    Specified by:
    
    getFirstRowKey in interface HFile.Reader
    
    Returns:
    the first row key, or null if the file is empty.
  - getLastRowKey
```
public byte[] getLastRowKey()
```
    TODO left from HFile version 1: move this to StoreFile after Ryan's patch goes in to eliminate KeyValue here.
    
    Specified by:
    
    getLastRowKey in interface HFile.Reader
    
    Returns:
    the last row key, or null if the file is empty.
  - getEntries
```
public long getEntries()
```
    Specified by:
    
    getEntries in interface HFile.Reader
    
    Returns:
    number of KV entries in this HFile
  - getComparator
```
public KeyValue.KVComparator getComparator()
```
    Specified by:
    
    getComparator in interface HFile.Reader
    
    Returns:
    comparator
  - getCompressionAlgorithm
```
public Compression.Algorithm getCompressionAlgorithm()
```
    Specified by:
    
    getCompressionAlgorithm in interface HFile.Reader
    
    Returns:
    compression algorithm
  - indexSize
```
public long indexSize()
```
    Specified by:
    
    indexSize in interface HFile.Reader
    
    Returns:
    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()
```
    Description copied from interface: 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.
    
    Specified by:
    
    getName in interface HFile.Reader
  - getDataBlockIndexReader
```
public HFileBlockIndex.BlockIndexReader getDataBlockIndexReader()
```
    Specified by:
    
    getDataBlockIndexReader in interface HFile.Reader
  - getTrailer
```
public FixedFileTrailer getTrailer()
```
    Specified by:
    
    getTrailer in interface HFile.Reader
  - isPrimaryReplicaReader
```
public boolean isPrimaryReplicaReader()
```
    Specified by:
    
    isPrimaryReplicaReader in interface HFile.Reader
  - setPrimaryReplicaReader
```
public void setPrimaryReplicaReader(boolean isPrimaryReplicaReader)
```
    Specified by:
    
    setPrimaryReplicaReader in interface HFile.Reader
  - loadFileInfo
```
public HFile.FileInfo loadFileInfo()
                            throws IOException
```
    Specified by:
    
    loadFileInfo in interface HFile.Reader
    
    Throws:
    
    IOException
  - getUncachedBlockReader
```
abstract HFileBlock.FSReader getUncachedBlockReader()
```
    For testing
  - getPath
```
public org.apache.hadoop.fs.Path getPath()
```
    Specified by:
    
    getPath in interface HFile.Reader
  - getDataBlockEncoding
```
public DataBlockEncoding getDataBlockEncoding()
```
    Specified by:
    
    getDataBlockEncoding in interface HFile.Reader
  - getMajorVersion
```
public abstract int getMajorVersion()
```
  - getConf
```
public org.apache.hadoop.conf.Configuration getConf()
```
    Specified by:
    
    getConf in interface org.apache.hadoop.conf.Configurable
  - setConf
```
public void setConf(org.apache.hadoop.conf.Configuration conf)
```
    Specified by:
    
    setConf in interface org.apache.hadoop.conf.Configurable

Class AbstractHFileReader

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface org.apache.hadoop.hbase.io.hfile.HFile.Reader

Methods inherited from interface java.io.Closeable

Methods inherited from interface org.apache.hadoop.hbase.io.hfile.HFile.CachingBlockReader

Field Detail

dataBlockIndexReader

metaBlockIndexReader

trailer

compressAlgo

isPrimaryReplicaReader

dataBlockEncoder

lastKey

avgKeyLen

avgValueLen

comparator

fileSize

cacheConf

path

name

fileInfo

hfs

conf

Constructor Detail

AbstractHFileReader

Method Detail

toStringFirstKey

toStringLastKey

isFileInfoLoaded

toString

length

getScanner

getFirstKey

getFirstRowKey

getLastRowKey

getEntries

getComparator

getCompressionAlgorithm

indexSize

getName

getDataBlockIndexReader

getTrailer

isPrimaryReplicaReader

setPrimaryReplicaReader

loadFileInfo

getUncachedBlockReader

getPath

getDataBlockEncoding

getMajorVersion

getConf

setConf