Chunk

java.lang.Object
- org.h2.mvstore.Chunk

```
public final class Chunk
extends java.lang.Object
```
A chunk of data, containing one or multiple pages.
Minimum chunk size is usually 4096 bytes, and it grows in those fixed increments (blocks). Chunk's length and it's position in the underlying filestore are multiples of that increment (block size), therefore they both are measured in blocks, instead of bytes. There are at most 67 million (2^26) chunks, and each chunk is at most 2 GB large.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class Chunk.PositionComparator

Nested Classes
Modifier and Type	Class and Description
`static class`	`Chunk.PositionComparator`

Field Summary

Fields
Modifier and Type	Field and Description
`long`	`block` The start block number within the file.
`int`	`id` The chunk id.
`int`	`len` The length in number of blocks.
`int`	`mapId` The last used map id.
`static int`	`MAX_ID` The maximum chunk id.
`long`	`maxLen` The sum of the max length of all pages.
`long`	`maxLenLive` The sum of the length of all pages that are still alive.
`long`	`next` The predicted position of the next chunk.
`long`	`time` When this chunk was created, in milliseconds after the store was created.
`long`	`unused` When this chunk was no longer needed, in milliseconds after the store was created.
`long`	`version` The version stored in this chunk.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`java.lang.String`	`asString()` Get the chunk data as a string.
`boolean`	`equals(java.lang.Object o)`
`static Chunk`	`fromString(java.lang.String s)` Build a block from the given string.
`int`	`hashCode()`
`java.lang.String`	`toString()`

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

- Field Detail
  - MAX_ID
```
public static final int MAX_ID
```
    The maximum chunk id.
    
    See Also:
    
    Constant Field Values
  - id
```
public final int id
```
    The chunk id.
  - block
```
public volatile long block
```
    The start block number within the file.
  - len
```
public int len
```
    The length in number of blocks.
  - maxLen
```
public long maxLen
```
    The sum of the max length of all pages.
  - maxLenLive
```
public long maxLenLive
```
    The sum of the length of all pages that are still alive.
  - version
```
public long version
```
    The version stored in this chunk.
  - time
```
public long time
```
    When this chunk was created, in milliseconds after the store was created.
  - unused
```
public long unused
```
    When this chunk was no longer needed, in milliseconds after the store was created. After this, the chunk is kept alive a bit longer (in case it is referenced in older versions).
  - mapId
```
public int mapId
```
    The last used map id.
  - next
```
public long next
```
    The predicted position of the next chunk.
- Method Detail
  - fromString
```
public static Chunk fromString(java.lang.String s)
```
    Build a block from the given string.
    
    Parameters:
    
    s - the string
    
    Returns:
    
    the block
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class java.lang.Object
  - equals
```
public boolean equals(java.lang.Object o)
```
    Overrides:
    
    equals in class java.lang.Object
  - asString
```
public java.lang.String asString()
```
    Get the chunk data as a string.
    
    Returns:
    
    the string
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object

Class Chunk

Nested Class Summary

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

MAX_ID

id

block

len

maxLen

maxLenLive

version

time

unused

mapId

next

Method Detail

fromString

hashCode

equals

asString

toString