Chunk

A chunk of data, containing one or multiple pages.

Chunks are page aligned (each page is usually 4096 bytes). There are at most 67 million (2^26) chunks, each chunk is at most 2 GB large.

Methods
static Chunk	fromString(String s) Build a block from the given string.
static Chunk	fromString(String s) Build a block from the given string. Parameters: s - the string Returns: the block
static String	getMetaKey(int chunkId) Get the metadata key for the given chunk id.
static String	getMetaKey(int chunkId) Get the metadata key for the given chunk id. Parameters: chunkId - the chunk id Returns: the metadata key
static Chunk	readChunkHeader(ByteBuffer buff, long start) Read the header from the byte buffer.
static Chunk	readChunkHeader(ByteBuffer buff, long start) Read the header from the byte buffer. Parameters: buff - the source buffer start - the start of the chunk in the file Returns: the chunk
String	asString() Get the chunk data as a string.
String	asString() Get the chunk data as a string. Returns: the string
boolean	equals(Object o)
boolean	equals(Object o)
int	getFillRate() Calculate the fill rate in %.
int	getFillRate() Calculate the fill rate in %. 0 means empty, 100 means full. Returns: the fill rate
byte[]	getFooterBytes()
byte[]	getFooterBytes()
int	hashCode()
int	hashCode()
String	toString()
String	toString()
void	writeChunkHeader(WriteBuffer buff, int minLength) Write the chunk header.
void	writeChunkHeader(WriteBuffer buff, int minLength) Write the chunk header. Parameters: buff - the target buffer minLength - the minimum length

Fields
static int	FOOTER_LENGTH = 128
static int	MAX_HEADER_LENGTH = 1024
static int	MAX_ID = 67108863
static long	block
static int	collectPriority
static int	id
static int	len
static int	mapId
static long	maxLen
static long	maxLenLive
static long	metaRootPos
static long	next
static int	pageCount
static int	pageCountLive
static long	time
static long	unused
static long	version

MAX_HEADER_LENGTH = 1024

The maximum length of a chunk header, in bytes.

FOOTER_LENGTH = 128

The length of the chunk footer. The longest footer is: chunk:ffffffff,block:ffffffffffffffff, version:ffffffffffffffff,fletcher:ffffffff

MAX_ID = 67108863

The maximum chunk id.

block

The start block number within the file.

collectPriority

The garbage collection priority. Priority 0 means it needs to be collected, a high value means low priority.

id

The chunk id.

len

The length in number of blocks.

mapId

The last used map id.

maxLen

The sum of the max length of all pages.

maxLenLive

The sum of the max length of all pages that are in use.

metaRootPos

The position of the meta root.

The predicted position of the next chunk.

pageCount

The total number of pages in this chunk.

pageCountLive

The number of pages still alive.

time

When this chunk was created, in milliseconds after the store was created.

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).

version

The version stored in this chunk.