HFileBlockIndex (Apache HBase 1.2.12 API)

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

```
@InterfaceAudience.Private
public class HFileBlockIndex
extends Object
```
Provides functionality to write (HFileBlockIndex.BlockIndexWriter) and read BlockIndexReader single-level and multi-level block indexes. Examples of how to use the block index writer can be found in CompoundBloomFilterWriter and HFileWriterV2. Examples of how to use the reader can be found in HFileReaderV2 and TestHFileBlockIndex.

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`(package private) static class`	`HFileBlockIndex.BlockIndexChunk` A single chunk of the block index in the process of writing.
`static class`	`HFileBlockIndex.BlockIndexReader` The reader will always hold the root level index in the memory.
`static class`	`HFileBlockIndex.BlockIndexWriter` Writes the block index into the output stream.

Field Summary

Fields
Modifier and Type	Field and Description
`(package private) static int`	`DEFAULT_MAX_CHUNK_SIZE`
`(package private) static int`	`DEFAULT_MIN_INDEX_NUM_ENTRIES`
`private static String`	`INLINE_BLOCKS_NOT_ALLOWED` Error message when trying to use inline block API in single-level mode.
`private static org.apache.commons.logging.Log`	`LOG`
`static String`	`MAX_CHUNK_SIZE_KEY` The maximum size guideline for index blocks (both leaf, intermediate, and root).
`private static int`	`MID_KEY_METADATA_SIZE` The size of a meta-data record used for finding the mid-key in a multi-level index.
`static String`	`MIN_INDEX_NUM_ENTRIES_KEY` Minimum number of entries in a single index block.
`(package private) static int`	`SECONDARY_INDEX_ENTRY_OVERHEAD` The number of bytes stored in each "secondary index" entry in addition to key bytes in the non-root index block format.

Constructor Summary

Constructors
Constructor and Description

HFileBlockIndex()

Constructors
Constructor and Description
`HFileBlockIndex()`

Method Summary

Methods
Modifier and Type	Method and Description
`static int`	`getMaxChunkSize(org.apache.hadoop.conf.Configuration conf)`
`static int`	`getMinIndexNumEntries(org.apache.hadoop.conf.Configuration conf)`

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

- Field Detail
  - LOG
```
private static final org.apache.commons.logging.Log LOG
```
  - DEFAULT_MAX_CHUNK_SIZE
```
static final int DEFAULT_MAX_CHUNK_SIZE
```
    See Also:
    Constant Field Values
  - MAX_CHUNK_SIZE_KEY
```
public static final String MAX_CHUNK_SIZE_KEY
```
    The maximum size guideline for index blocks (both leaf, intermediate, and root). If not specified, DEFAULT_MAX_CHUNK_SIZE is used.
    
    See Also:
    Constant Field Values
  - MIN_INDEX_NUM_ENTRIES_KEY
```
public static final String MIN_INDEX_NUM_ENTRIES_KEY
```
    Minimum number of entries in a single index block. Even if we are above the hfile.index.block.max.size we will keep writing to the same block unless we have that many entries. We should have at least a few entries so that we don't have too many levels in the multi-level index. This should be at least 2 to make sure there is no infinite recursion.
    
    See Also:
    Constant Field Values
  - DEFAULT_MIN_INDEX_NUM_ENTRIES
```
static final int DEFAULT_MIN_INDEX_NUM_ENTRIES
```
    See Also:
    Constant Field Values
  - SECONDARY_INDEX_ENTRY_OVERHEAD
```
static final int SECONDARY_INDEX_ENTRY_OVERHEAD
```
    The number of bytes stored in each "secondary index" entry in addition to key bytes in the non-root index block format. The first long is the file offset of the deeper-level block the entry points to, and the int that follows is that block's on-disk size without including header.
    
    See Also:
    Constant Field Values
  - INLINE_BLOCKS_NOT_ALLOWED
```
private static final String INLINE_BLOCKS_NOT_ALLOWED
```
    Error message when trying to use inline block API in single-level mode.
    
    See Also:
    Constant Field Values
  - MID_KEY_METADATA_SIZE
```
private static final int MID_KEY_METADATA_SIZE
```
    The size of a meta-data record used for finding the mid-key in a multi-level index. Consists of the middle leaf-level index block offset (long), its on-disk size without header included (int), and the mid-key entry's zero-based index in that leaf index block.
    
    See Also:
    Constant Field Values
- Constructor Detail
  - HFileBlockIndex
```
public HFileBlockIndex()
```
- Method Detail
  - getMaxChunkSize
```
public static int getMaxChunkSize(org.apache.hadoop.conf.Configuration conf)
```
  - getMinIndexNumEntries
```
public static int getMinIndexNumEntries(org.apache.hadoop.conf.Configuration conf)
```

Class HFileBlockIndex

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

LOG

DEFAULT_MAX_CHUNK_SIZE

MAX_CHUNK_SIZE_KEY

MIN_INDEX_NUM_ENTRIES_KEY

DEFAULT_MIN_INDEX_NUM_ENTRIES

SECONDARY_INDEX_ENTRY_OVERHEAD

INLINE_BLOCKS_NOT_ALLOWED

MID_KEY_METADATA_SIZE

Constructor Detail

HFileBlockIndex

Method Detail

getMaxChunkSize

getMinIndexNumEntries