Modifier and Type	Class and Description
public static class	Chunk.PositionComparator<C extends Chunk<C>>

Field Summary

Modifier and Type	Field and Description
private static final String	ATTR_BLOCK
private static final String	ATTR_CHUNK
private static final String	ATTR_FLETCHER
private static final String	ATTR_LEN
private static final String	ATTR_LIVE_MAX
private static final String	ATTR_LIVE_PAGES
private static final String	ATTR_MAP
private static final String	ATTR_MAX
private static final String	ATTR_NEXT
private static final String	ATTR_OCCUPANCY
private static final String	ATTR_PAGES
private static final String	ATTR_PIN_COUNT
private static final String	ATTR_ROOT
private static final String	ATTR_TIME
private static final String	ATTR_TOC
private static final String	ATTR_UNUSED
private static final String	ATTR_UNUSED_AT_VERSION
private static final String	ATTR_VERSION
public volatile long	block The start block number within the file.
public volatile ByteBuffer	buffer ByteBuffer holding this Chunk's serialized content before it gets saved to file store.
pack-priv int	collectPriority The garbage collection priority.
pack-priv static final int	FOOTER_LENGTH The length of the chunk footer.
public final int	id The chunk id.
pack-priv long	layoutRootPos The position of the root of layout map.
public int	len The length in number of blocks.
public int	mapId The last used map id.
pack-priv static final int	MAX_HEADER_LENGTH The maximum length of a chunk header, in bytes.
public static final int	MAX_ID The maximum chunk id.
public long	maxLen The sum of the max length of all pages.
public long	maxLenLive The sum of the length of all pages that are still alive.
public long	next The predicted position of the next chunk.
pack-priv BitSet	occupancy Collection of "deleted" flags for all pages in the chunk.
pack-priv int	pageCount The total number of pages in this chunk.
pack-priv int	pageCountLive The number of pages that are still alive in the latest version of the store.
private int	pinCount Number of live pinned pages.
public long	time When this chunk was created, in milliseconds since the store was created.
pack-priv int	tocPos Byte offset (from the beginning of the chunk) for the table of content (ToC).
public long	unused When this chunk was no longer needed, in milliseconds after the store was created.
pack-priv long	unusedAtVersion Version of the store at which chunk become unused and therefore can be considered "dead" and collected after this version is no longer in use.
public long	version The version stored in this chunk.

Constructor Summary

Access	Constructor and Description
pack-priv	Chunk(String s)
pack-priv	Chunk(Map<String, String> map, boolean full)
pack-priv	Chunk(int id)

Method Summary

Modifier and Type	Method and Description
pack-priv boolean	Returns: true if all of the pages, this chunk contains, were already removed, and false otherwise accountForRemovedPage(int sequential page number within the chunk pageNo, int on disk of the removed page pageLength, boolean whether removed page was pinned pinned, long is a moment in time (since creation of the store), when removal is recorded, and retention period starts now, long at which page was removed version) Modifies internal state to reflect the fact that one the pages within this chunk was removed from the map.
pack-priv void	accountForWrittenPage(int size of the page pageLengthOnDisk, boolean indicates whether page belongs to append mode capable map (single writer map). Such pages are "pinned" to the chunk, they can't be evacuated (moved to a different chunk) while singleWriter) Modifies internal state to reflect the fact that one more page is stored within this chunk.
public final String	Returns: the string asString() Get the chunk metadata as a string to be stored in a layout map.
protected void	dump(StringBuilder buff)
public boolean	equals(Object the reference object with which to compare. o) Overrides java.lang.Object.equals. Indicates whether some other object is "equal to" this one.
pack-priv int	Returns: estimated size of the header estimateHeaderSize() Write the chunk header.
pack-priv int	Returns: the fill rate getFillRate() Calculate the fill rate in %.
pack-priv byte[]	getFooterBytes()
public String	getHeader()
private byte[]	getHeaderBytes()
pack-priv static String	Returns: the metadata key getMetaKey(int the chunk id chunkId) Get the metadata key for the given chunk id.
public int	hashCode() Overrides java.lang.Object.hashCode. Returns a hash code value for this object.
pack-priv boolean	isAllocated()
private boolean	isEvacuatable()
pack-priv boolean	isLive()
pack-priv boolean	isRewritable()
pack-priv boolean	isSaved()
pack-priv ByteBuffer	Returns: ByteBuffer containing page data. readBufferForPage(FileStore<C> to use fileStore, int of the page data offset, long page pos pos) Read a page of data into a ByteBuffer.
pack-priv static String	Returns: the chunk readChunkHeader(ByteBuffer the source buffer buff) Read the header from the byte buffer.
protected abstract ByteBuffer	readFully(FileStore<C> fileStore, long filePos, int length)
pack-priv long[]	readToC(FileStore<C> fileStore)
public String	toString() Overrides java.lang.Object.toString. Returns a string representation of the object.
pack-priv void	writeChunkHeader(WriteBuffer the target buffer buff, int length of the area reserved for the header maxLength) Write the chunk header.

Inherited from java.lang.Object:: clone finalize getClass notify notifyAll wait wait wait

Field Detail

ATTR_BLOCK	back to summary
private static final String ATTR_BLOCK

ATTR_CHUNK	back to summary
private static final String ATTR_CHUNK

ATTR_FLETCHER	back to summary
private static final String ATTR_FLETCHER

ATTR_LEN	back to summary
private static final String ATTR_LEN

ATTR_LIVE_MAX	back to summary
private static final String ATTR_LIVE_MAX

ATTR_LIVE_PAGES	back to summary
private static final String ATTR_LIVE_PAGES

ATTR_MAP	back to summary
private static final String ATTR_MAP

ATTR_MAX	back to summary
private static final String ATTR_MAX

ATTR_NEXT	back to summary
private static final String ATTR_NEXT

ATTR_OCCUPANCY	back to summary
private static final String ATTR_OCCUPANCY

ATTR_PAGES	back to summary
private static final String ATTR_PAGES

ATTR_PIN_COUNT	back to summary
private static final String ATTR_PIN_COUNT

ATTR_ROOT	back to summary
private static final String ATTR_ROOT

ATTR_TIME	back to summary
private static final String ATTR_TIME

ATTR_TOC	back to summary
private static final String ATTR_TOC

ATTR_UNUSED	back to summary
private static final String ATTR_UNUSED

ATTR_UNUSED_AT_VERSION	back to summary
private static final String ATTR_UNUSED_AT_VERSION

ATTR_VERSION	back to summary
private static final String ATTR_VERSION

block	back to summary
public volatile long block The start block number within the file.

buffer	back to summary
public volatile ByteBuffer buffer ByteBuffer holding this Chunk's serialized content before it gets saved to file store. This allows to release pages of this Chunk earlier, allowing them to be garbage collected.

collectPriority	back to summary
pack-priv int collectPriority The garbage collection priority. Priority 0 means it needs to be collected, a high value means low priority.

FOOTER_LENGTH	back to summary
pack-priv static final int FOOTER_LENGTH The length of the chunk footer. The longest footer is: chunk:ffffffff,len:ffffffff,version:ffffffffffffffff,fletcher:ffffffff

id	back to summary
public final int id The chunk id.

layoutRootPos	back to summary
pack-priv long layoutRootPos The position of the root of layout map.

len	back to summary
public int len The length in number of blocks.

mapId	back to summary
public int mapId The last used map id.

MAX_HEADER_LENGTH	back to summary
pack-priv static final int MAX_HEADER_LENGTH The maximum length of a chunk header, in bytes. chunk:ffffffff,len:ffffffff,pages:ffffffff,pinCount:ffffffff,max:ffffffffffffffff,map:ffffffff, root:ffffffffffffffff,time:ffffffffffffffff,version:ffffffffffffffff,next:ffffffffffffffff,toc:ffffffff

MAX_ID	back to summary
public static final int MAX_ID The maximum chunk id.

maxLen	back to summary
public long maxLen The sum of the max length of all pages.

maxLenLive	back to summary
public long maxLenLive The sum of the length of all pages that are still alive.

next	back to summary
public long next The predicted position of the next chunk.

occupancy	back to summary
pack-priv BitSet occupancy Collection of "deleted" flags for all pages in the chunk.

pageCount	back to summary
pack-priv int pageCount The total number of pages in this chunk.

pageCountLive	back to summary
pack-priv int pageCountLive The number of pages that are still alive in the latest version of the store.

pinCount	back to summary
private int pinCount Number of live pinned pages.

time	back to summary
public long time When this chunk was created, in milliseconds since the store was created.

tocPos back to summary

tocPos	back to summary
pack-priv int tocPos Byte offset (from the beginning of the chunk) for the table of content (ToC). Table of content is holding a value of type "long" for each page in the chunk. This value consists of map id, page offset, page length and page type. Format is the same as page's position id, but with map id replacing chunk id. See Also `for field format details`

pack-priv int tocPos

Byte offset (from the beginning of the chunk) for the table of content (ToC). Table of content is holding a value of type "long" for each page in the chunk. This value consists of map id, page offset, page length and page type. Format is the same as page's position id, but with map id replacing chunk id.

See Also: for field format details

unused	back to summary
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).

unusedAtVersion	back to summary
pack-priv long unusedAtVersion Version of the store at which chunk become unused and therefore can be considered "dead" and collected after this version is no longer in use.

version	back to summary
public long version The version stored in this chunk.

Constructor Detail

Chunk	back to summary
pack-priv Chunk(String s)

Chunk	back to summary
pack-priv Chunk(Map<String, String> map, boolean full)

Chunk	back to summary
pack-priv Chunk(int id)

Method Detail

accountForRemovedPage	back to summary
pack-priv boolean accountForRemovedPage(int pageNo, int pageLength, boolean pinned, long now, long version) Modifies internal state to reflect the fact that one the pages within this chunk was removed from the map. Parameters pageNo:int sequential page number within the chunk pageLength:int on disk of the removed page pinned:boolean whether removed page was pinned now:long is a moment in time (since creation of the store), when removal is recorded, and retention period starts version:long at which page was removed Returns:boolean true if all of the pages, this chunk contains, were already removed, and false otherwise

accountForRemovedPage

back to summary

pack-priv boolean accountForRemovedPage(int pageNo, int pageLength, boolean pinned, long now, long version)

Modifies internal state to reflect the fact that one the pages within this chunk was removed from the map.

Parameters

pageNo:int: sequential page number within the chunk
pageLength:int: on disk of the removed page
pinned:boolean: whether removed page was pinned
now:long: is a moment in time (since creation of the store), when removal is recorded, and retention period starts
version:long: at which page was removed

Returns:boolean

true if all of the pages, this chunk contains, were already removed, and false otherwise

accountForWrittenPage	back to summary
pack-priv void accountForWrittenPage(int pageLengthOnDisk, boolean singleWriter) Modifies internal state to reflect the fact that one more page is stored within this chunk. Parameters pageLengthOnDisk:int size of the page singleWriter:boolean indicates whether page belongs to append mode capable map (single writer map). Such pages are "pinned" to the chunk, they can't be evacuated (moved to a different chunk) while

accountForWrittenPage

back to summary

pack-priv void accountForWrittenPage(int pageLengthOnDisk, boolean singleWriter)

Modifies internal state to reflect the fact that one more page is stored within this chunk.

Parameters

pageLengthOnDisk:int: size of the page
singleWriter:boolean: indicates whether page belongs to append mode capable map (single writer map). Such pages are "pinned" to the chunk, they can't be evacuated (moved to a different chunk) while

asString	back to summary
public final String asString() Get the chunk metadata as a string to be stored in a layout map. Returns:String the string

asString

back to summary

public final String asString()

Get the chunk metadata as a string to be stored in a layout map.

Returns:String: the string

dump	back to summary
protected void dump(StringBuilder buff)

equals back to summary

public boolean equals(Object o)

Overrides java.lang.Object.equals.

Doc from java.lang.Object.equals.

Indicates whether some other object is "equal to" this one.

The equals method implements an equivalence relation on non-null object references:

It is reflexive: for any non-null reference value x, x.equals(x) should return true.
It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
For any non-null reference value x, x.equals(null) should return false.

An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes.

Parameters

o:Object: the reference object with which to compare.

Returns:boolean

true if this object is the same as the obj argument; false otherwise.

Annotations

@SuppressWarnings:unchecked
@Override

estimateHeaderSize

back to summary

pack-priv int estimateHeaderSize()

Write the chunk header.

Returns:int: estimated size of the header

getFillRate

back to summary

pack-priv int getFillRate()

Calculate the fill rate in %. 0 means empty, 100 means full.

Returns:int: the fill rate

getFooterBytes	back to summary
pack-priv byte[] getFooterBytes()

getHeader	back to summary
public String getHeader()

getHeaderBytes	back to summary
private byte[] getHeaderBytes()

getMetaKey

back to summary

pack-priv static String getMetaKey(int chunkId)

Get the metadata key for the given chunk id.

Parameters

chunkId:int: the chunk id

Returns:String

the metadata key

hashCode back to summary

public int hashCode()

Overrides java.lang.Object.hashCode.

Doc from java.lang.Object.hashCode.

Returns a hash code value for this object. This method is supported for the benefit of hash tables such as those provided by java.util.HashMap.

The general contract of hashCode is:

Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
If two objects are equal according to the equals method, then calling the hashCode method on each of the two objects must produce the same integer result.
It is not required that if two objects are unequal according to the equals method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

Returns:int

a hash code value for this object

Annotations

@Override

isAllocated	back to summary
pack-priv boolean isAllocated()

isEvacuatable	back to summary
private boolean isEvacuatable()

isLive	back to summary
pack-priv boolean isLive()

isRewritable	back to summary
pack-priv boolean isRewritable()

isSaved	back to summary
pack-priv boolean isSaved()

readBufferForPage

back to summary

pack-priv ByteBuffer readBufferForPage(FileStore<C> fileStore, int offset, long pos)

Read a page of data into a ByteBuffer.

Parameters

fileStore:FileStore<C>: to use
offset:int: of the page data
pos:long: page pos

Returns:ByteBuffer

ByteBuffer containing page data.

readChunkHeader back to summary

pack-priv static String readChunkHeader(ByteBuffer buff)

Read the header from the byte buffer.

Parameters

buff:ByteBuffer: the source buffer

Returns:String

the chunk

Exceptions

MVStoreException:: if buff does not contain a chunk header

readFully	back to summary
protected abstract ByteBuffer readFully(FileStore<C> fileStore, long filePos, int length)

readToC	back to summary
pack-priv long[] readToC(FileStore<C> fileStore)

toString back to summary

public String toString()

Overrides java.lang.Object.toString.

Doc from java.lang.Object.toString.

Returns a string representation of the object. Satisfying this method's contract implies a non-null result must be returned.

Returns:String

a string representation of the object

Annotations

@Override

writeChunkHeader

back to summary

pack-priv void writeChunkHeader(WriteBuffer buff, int maxLength)

Write the chunk header.

Parameters

buff:WriteBuffer: the target buffer
maxLength:int: length of the area reserved for the header

org.h2.mvstore back to summary

public final Class Chunk.PositionComparator<C extends Chunk<C>>

Class Inheritance

extends Object
implements Comparator<C extends Chunk<C>>

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

All Implemented Interfaces

java.util.Comparator

Field Summary

Modifier and Type	Field and Description
public static final Comparator<? extends Chunk<?>>	INSTANCE

Constructor Summary

Access	Constructor and Description
private	PositionComparator()

Method Summary

Modifier and Type	Method and Description
public int	compare(C the first object to be compared. one, C the second object to be compared. two) Implements java.util.Comparator.compare. Compares its two arguments for order.
public static <C extends Chunk<C>> Comparator<C>	instance()

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

INSTANCE	back to summary
public static final Comparator<? extends Chunk<?>> INSTANCE

Constructor Detail

PositionComparator	back to summary
private PositionComparator()

Method Detail

compare back to summary

public int compare(C one, C two)

Implements java.util.Comparator.compare.

Doc from java.util.Comparator.compare.

Compares its two arguments for order. Returns a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second.

The implementor must ensure that signum(compare(x, y)) == -signum(compare(y, x)) for all x and y. (This implies that compare(x, y) must throw an exception if and only if compare(y, x) throws an exception.)

The implementor must also ensure that the relation is transitive: ((compare(x, y)>0) && (compare(y, z)>0)) implies compare(x, z)>0.

Finally, the implementor must ensure that compare(x, y)==0 implies that signum(compare(x, z))==signum(compare(y, z)) for all z.

Parameters

one:C: the first object to be compared.
two:C: the second object to be compared.

Returns:int

a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second.

Annotations

@Override

instance	back to summary
public static <C extends Chunk<C>> Comparator<C> instance() Annotations @SuppressWarnings:unchecked

public abstract Class Chunk<C extends Chunk<C>>

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

public final Class Chunk.PositionComparator<C extends Chunk<C>>

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail