java.lang.Object
- org.h2.mvstore.FileStore<SFChunk>
- - org.h2.mvstore.RandomAccessStore

Direct Known Subclasses:

OffHeapStore, SingleFileStore
```
public abstract class RandomAccessStore
extends FileStore<SFChunk>
```
Class RandomAccessStore.
- 4/5/20 2:51 PM initial creation

Nested Class Summary
- Nested classes/interfaces inherited from class org.h2.mvstore.FileStore
  FileStore.PageSerializationManager

Field Summary

Fields
Modifier and Type Field Description

protected FreeSpaceBitSet freeSpace
The free spaces between the chunks.
- Fields inherited from class org.h2.mvstore.FileStore
  lastChunk, META_ID_KEY, PIPE_LENGTH, readBytes, readCount, recoveryMode, saveChunkLock, storeHeader, writeBytes, writeCount

Constructor Summary

Constructors
Constructor Description

RandomAccessStore(java.util.Map<java.lang.String,java.lang.Object> config)

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`protected void`	`adjustStoreToLastChunk()`	Make persistent changes after lastChunk was reset
`protected void`	`allocateChunkSpace(SFChunk chunk, WriteBuffer buff)`	Allocate logical space and assign position of the buffer within the store.
`void`	`clear()`	Mark the file as empty.
`void`	`compactMoveChunks(int targetFillRate, long moveSize, MVStore mvStore)`	Compact the store by moving all chunks next to each other, if there is free space between chunks.
`protected void`	`compactStore(int thresholdFillRate, long maxCompactTime, int maxWriteSize, MVStore mvStore)`	Compact store file, that is, compact blocks that have a low fill rate, and move chunks next to each other.
`protected SFChunk`	`createChunk(int newChunkId)`
`SFChunk`	`createChunk(java.lang.String s)`	Build a Chunk from the given string.
`protected SFChunk`	`createChunk(java.util.Map<java.lang.String,java.lang.String> map)`
`protected void`	`doHousekeeping(MVStore mvStore)`
`protected void`	`free(long pos, int length)`	Mark the space as free.
`protected void`	`freeChunkSpace(java.lang.Iterable<SFChunk> chunks)`	Mark the space occupied by specified chunks as free.
`int`	`getFillRate()`
`int`	`getMovePriority(int block)`	Calculates relative "priority" for chunk to be moved.
`java.util.Collection<SFChunk>`	`getRewriteCandidates()`
`protected void`	`initializeStoreHeader(long time)`
`boolean`	`isSpaceReused()`
`void`	`markUsed(long pos, int length)`	Mark the space as in use.
`protected void`	`readStoreHeader(boolean recoveryMode)`
`void`	`setReuseSpace(boolean reuseSpace)`
`boolean`	`shouldSaveNow(int unsavedMemory, int autoCommitMemory)`	Decision about autocommit is delegated to store
`protected void`	`shrinkStoreIfPossible(int minPercent)`	Shrink the store if possible, and if at least a given percentage can be saved.
`protected abstract void`	`truncate(long size)`
`protected boolean`	`validateFileLength(java.lang.String msg)`
`protected void`	`writeChunk(SFChunk chunk, WriteBuffer buffer)`	Write buffer associated with chunk into store at chunk's allocated position
`protected void`	`writeCleanShutdownMark()`	Performs final preparation before store is closed normally

Methods inherited from class org.h2.mvstore.FileStore
accountForRemovedPage, backup, bind, close, compact, compactStore, deregisterMapRoot, discoverChunk, dropUnusedChunks, executeFileStoreOperation, findLastChunkWithCompleteValidChunkSet, getAutoCommitDelay, getAutoCompactFillRate, getCacheHitRatio, getCacheSize, getCacheSizeUsed, getChunks, getChunksFillRate, getChunksFromLayoutMap, getCreationTime, getDefaultRetentionTime, getFileName, getLayoutMap, getMaxPageSize, getMetaMapId, getMvStore, getReadBytes, getReadCount, getRetentionTime, getRootPos, getStoreHeader, getTocCacheHitRatio, getWriteBuffer, getWriteCount, hasChangesSince, hasPersistentData, init, initializeCommonHeaderAttributes, isIdle, isKnownVersion, isReadOnly, isRegularMap, lastChunkVersion, open, open, populateInfo, processCommonHeaderAttributes, readChunkFooter, readChunkHeaderAndFooter, readChunkHeaderOptionally, readChunkHeaderOptionally, readFully, readFully, registerDeadChunk, releaseWriteBuffer, rewriteChunks, rollbackTo, saveChunkMetadataChanges, setAutoCommitDelay, setCacheSize, setLastChunk, setRetentionTime, setSize, size, start, stop, store, submitOrRun, sync, writeCleanShutdown, writeFully

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

- Field Detail
  - freeSpace
```
protected final FreeSpaceBitSet freeSpace
```
    The free spaces between the chunks. The first block to use is block 2 (the first two blocks are the store header). Access to this object is protected by FileStore.saveChunkLock
- Constructor Detail
  - RandomAccessStore
```
public RandomAccessStore(java.util.Map<java.lang.String,java.lang.Object> config)
```
- Method Detail
  - createChunk
```
protected final SFChunk createChunk(int newChunkId)
```
    Specified by:
    
    createChunk in class FileStore<SFChunk>
  - createChunk
```
public SFChunk createChunk(java.lang.String s)
```
    Description copied from class: FileStore
    
    Build a Chunk from the given string.
    
    Specified by:
    
    createChunk in class FileStore<SFChunk>
    
    Parameters:
    
    s - the string
    
    Returns:
    
    the Chunk created
  - createChunk
```
protected SFChunk createChunk(java.util.Map<java.lang.String,java.lang.String> map)
```
    Specified by:
    
    createChunk in class FileStore<SFChunk>
  - markUsed
```
public void markUsed(long pos,
                     int length)
```
    Mark the space as in use.
    
    Specified by:
    
    markUsed in class FileStore<SFChunk>
    
    Parameters:
    
    pos - the position in bytes
    
    length - the number of bytes
  - shouldSaveNow
```
public boolean shouldSaveNow(int unsavedMemory,
                             int autoCommitMemory)
```
    Description copied from class: FileStore
    
    Decision about autocommit is delegated to store
    
    Specified by:
    
    shouldSaveNow in class FileStore<SFChunk>
    
    Parameters:
    
    unsavedMemory - amount of unsaved memory, so far
    
    autoCommitMemory - configured limit on amount of unsaved memory
    
    Returns:
    
    true if commit should happen now
  - isSpaceReused
```
public boolean isSpaceReused()
```
    Overrides:
    
    isSpaceReused in class FileStore<SFChunk>
  - setReuseSpace
```
public void setReuseSpace(boolean reuseSpace)
```
    Overrides:
    
    setReuseSpace in class FileStore<SFChunk>
  - freeChunkSpace
```
protected void freeChunkSpace(java.lang.Iterable<SFChunk> chunks)
```
    Description copied from class: FileStore
    
    Mark the space occupied by specified chunks as free.
    
    Specified by:
    
    freeChunkSpace in class FileStore<SFChunk>
    
    Parameters:
    
    chunks - chunks to be processed
  - free
```
protected void free(long pos,
                    int length)
```
    Mark the space as free.
    
    Parameters:
    
    pos - the position in bytes
    
    length - the number of bytes
  - getFillRate
```
public int getFillRate()
```
    Specified by:
    
    getFillRate in class FileStore<SFChunk>
  - validateFileLength
```
protected final boolean validateFileLength(java.lang.String msg)
```
    Specified by:
    
    validateFileLength in class FileStore<SFChunk>
  - readStoreHeader
```
protected void readStoreHeader(boolean recoveryMode)
```
    Specified by:
    
    readStoreHeader in class FileStore<SFChunk>
  - initializeStoreHeader
```
protected void initializeStoreHeader(long time)
```
    Specified by:
    
    initializeStoreHeader in class FileStore<SFChunk>
  - allocateChunkSpace
```
protected final void allocateChunkSpace(SFChunk chunk,
                                        WriteBuffer buff)
```
    Description copied from class: FileStore
    
    Allocate logical space and assign position of the buffer within the store.
    
    Specified by:
    
    allocateChunkSpace in class FileStore<SFChunk>
    
    Parameters:
    
    chunk - to allocate space for
    
    buff - to allocate space for
  - writeChunk
```
protected final void writeChunk(SFChunk chunk,
                                WriteBuffer buffer)
```
    Description copied from class: FileStore
    
    Write buffer associated with chunk into store at chunk's allocated position
    
    Specified by:
    
    writeChunk in class FileStore<SFChunk>
    
    Parameters:
    
    chunk - chunk to write
    
    buffer - to write
  - writeCleanShutdownMark
```
protected final void writeCleanShutdownMark()
```
    Description copied from class: FileStore
    
    Performs final preparation before store is closed normally
    
    Specified by:
    
    writeCleanShutdownMark in class FileStore<SFChunk>
  - adjustStoreToLastChunk
```
protected final void adjustStoreToLastChunk()
```
    Description copied from class: FileStore
    
    Make persistent changes after lastChunk was reset
    
    Specified by:
    
    adjustStoreToLastChunk in class FileStore<SFChunk>
  - compactStore
```
protected void compactStore(int thresholdFillRate,
                            long maxCompactTime,
                            int maxWriteSize,
                            MVStore mvStore)
```
    Compact store file, that is, compact blocks that have a low fill rate, and move chunks next to each other. This will typically shrink the file. Changes are flushed to the file, and old chunks are overwritten.
    
    Specified by:
    
    compactStore in class FileStore<SFChunk>
    
    Parameters:
    
    thresholdFillRate - do not compact if store fill rate above this value (0-100)
    
    maxCompactTime - the maximum time in milliseconds to compact
    
    maxWriteSize - the maximum amount of data to be written as part of this call
    
    mvStore - that owns this FileStore
  - compactMoveChunks
```
public void compactMoveChunks(int targetFillRate,
                              long moveSize,
                              MVStore mvStore)
```
    Compact the store by moving all chunks next to each other, if there is free space between chunks. This might temporarily increase the file size. Chunks are overwritten irrespective of the current retention time. Before overwriting chunks and before resizing the file, syncFile() is called.
    
    Parameters:
    
    targetFillRate - do nothing if the file store fill rate is higher than this
    
    moveSize - the number of bytes to move
    
    mvStore - owner of this store
  - shrinkStoreIfPossible
```
protected void shrinkStoreIfPossible(int minPercent)
```
    Shrink the store if possible, and if at least a given percentage can be saved.
    
    Specified by:
    
    shrinkStoreIfPossible in class FileStore<SFChunk>
    
    Parameters:
    
    minPercent - the minimum percentage to save
  - doHousekeeping
```
protected void doHousekeeping(MVStore mvStore)
                       throws java.lang.InterruptedException
```
    Specified by:
    
    doHousekeeping in class FileStore<SFChunk>
    
    Throws:
    
    java.lang.InterruptedException
  - truncate
```
protected abstract void truncate(long size)
```
  - clear
```
public void clear()
```
    Mark the file as empty.
    
    Overrides:
    
    clear in class FileStore<SFChunk>
  - getMovePriority
```
public int getMovePriority(int block)
```
    Calculates relative "priority" for chunk to be moved.
    
    Parameters:
    
    block - where chunk starts
    
    Returns:
    
    priority, bigger number indicate that chunk need to be moved sooner
  - getRewriteCandidates
```
public java.util.Collection<SFChunk> getRewriteCandidates()
```
    Overrides:
    
    getRewriteCandidates in class FileStore<SFChunk>

Class RandomAccessStore

Nested Class Summary

Nested classes/interfaces inherited from class org.h2.mvstore.FileStore

Field Summary

Fields inherited from class org.h2.mvstore.FileStore

Constructor Summary

Method Summary

Methods inherited from class org.h2.mvstore.FileStore

Methods inherited from class java.lang.Object

Field Detail

freeSpace

Constructor Detail

RandomAccessStore

Method Detail

createChunk

createChunk

createChunk

markUsed

shouldSaveNow

isSpaceReused

setReuseSpace

freeChunkSpace

free

getFillRate

validateFileLength

readStoreHeader

initializeStoreHeader

allocateChunkSpace

writeChunk

writeCleanShutdownMark

adjustStoreToLastChunk

compactStore

compactMoveChunks

shrinkStoreIfPossible

doHousekeeping

truncate

clear

getMovePriority

getRewriteCandidates