FileStore (H2 Database Engine 2.0.0 API)

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

直接已知子类:

OffHeapStore
```
public class FileStore
extends Object
```
The default storage mechanism of the MVStore. This implementation persists data to a file. The file store is responsible to persist data and for free space management.

字段概要

字段
限定符和类型	字段和说明
`protected long`	`fileSize` The file size (cached).
`protected FreeSpaceBitSet`	`freeSpace` The free spaces between the chunks.
`protected AtomicLong`	`readBytes` The number of read bytes.
`protected AtomicLong`	`readCount` The number of read operations.
`protected AtomicLong`	`writeBytes` The number of written bytes.
`protected AtomicLong`	`writeCount` The number of write operations.

构造器概要

构造器
构造器和说明

FileStore()

构造器
构造器和说明
`FileStore()`

方法概要

所有方法实例方法具体方法
限定符和类型	方法和说明
`void`	`clear()` Mark the file as empty.
`void`	`close()` Close this store.
`void`	`free(long pos, int length)` Mark the space as free.
`int`	`getDefaultRetentionTime()` Get the default retention time for this store in milliseconds.
`FileChannel`	`getEncryptedFile()` Get the encrypted file instance, if encryption is used.
`FileChannel`	`getFile()` Get the file instance in use.
`String`	`getFileName()` Get the file name.
`int`	`getFillRate()`
`int`	`getProjectedFillRate(int vacatedBlocks)` Calculates a prospective fill rate, which store would have after rewrite of sparsely populated chunk(s) and evacuation of still live data into a new chunk.
`long`	`getReadBytes()` Get the number of read bytes since this store was opened.
`long`	`getReadCount()` Get the number of read operations since this store was opened.
`long`	`getWriteBytes()` Get the number of written bytes since this store was opened.
`long`	`getWriteCount()` Get the number of write operations since this store was opened.
`boolean`	`isReadOnly()`
`void`	`markUsed(long pos, int length)` Mark the space as in use.
`FileStore`	`open(String fileName, boolean readOnly)`
`void`	`open(String fileName, boolean readOnly, char[] encryptionKey)` Try to open the file.
`ByteBuffer`	`readFully(long pos, int len)` Read from the file.
`long`	`size()` Get the file size.
`void`	`sync()` Flush all changes.
`String`	`toString()`
`void`	`truncate(long size)` Truncate the file.
`void`	`writeFully(long pos, ByteBuffer src)` Write to the file.

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- 字段详细资料
  - readCount
```
protected final AtomicLong readCount
```
    The number of read operations.
  - readBytes
```
protected final AtomicLong readBytes
```
    The number of read bytes.
  - writeCount
```
protected final AtomicLong writeCount
```
    The number of write operations.
  - writeBytes
```
protected final AtomicLong writeBytes
```
    The number of written bytes.
  - 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).
  - fileSize
```
protected long fileSize
```
    The file size (cached).
- 构造器详细资料
  - FileStore
```
public FileStore()
```
- 方法详细资料
  - toString
```
public String toString()
```
    覆盖:
    
    toString 在类中 Object
  - readFully
```
public ByteBuffer readFully(long pos,
                            int len)
```
    Read from the file.
    
    参数:
    
    pos - the write position
    
    len - the number of bytes to read
    
    返回:
    
    the byte buffer
  - writeFully
```
public void writeFully(long pos,
                       ByteBuffer src)
```
    Write to the file.
    
    参数:
    
    pos - the write position
    
    src - the source buffer
  - open
```
public void open(String fileName,
                 boolean readOnly,
                 char[] encryptionKey)
```
    Try to open the file.
    
    参数:
    
    fileName - the file name
    
    readOnly - whether the file should only be opened in read-only mode, even if the file is writable
    
    encryptionKey - the encryption key, or null if encryption is not used
  - open
```
public FileStore open(String fileName,
                      boolean readOnly)
```
  - close
```
public void close()
```
    Close this store.
  - sync
```
public void sync()
```
    Flush all changes.
  - size
```
public long size()
```
    Get the file size.
    
    返回:
    
    the file size
  - truncate
```
public void truncate(long size)
```
    Truncate the file.
    
    参数:
    
    size - the new file size
  - getFile
```
public FileChannel getFile()
```
    Get the file instance in use.
    The application may read from the file (for example for online backup), but not write to it or truncate it.
    
    返回:
    
    the file
  - getEncryptedFile
```
public FileChannel getEncryptedFile()
```
    Get the encrypted file instance, if encryption is used.
    The application may read from the file (for example for online backup), but not write to it or truncate it.
    
    返回:
    
    the encrypted file, or null if encryption is not used
  - getWriteCount
```
public long getWriteCount()
```
    Get the number of write operations since this store was opened. For file based stores, this is the number of file write operations.
    
    返回:
    
    the number of write operations
  - getWriteBytes
```
public long getWriteBytes()
```
    Get the number of written bytes since this store was opened.
    
    返回:
    
    the number of write operations
  - getReadCount
```
public long getReadCount()
```
    Get the number of read operations since this store was opened. For file based stores, this is the number of file read operations.
    
    返回:
    
    the number of read operations
  - getReadBytes
```
public long getReadBytes()
```
    Get the number of read bytes since this store was opened.
    
    返回:
    
    the number of write operations
  - isReadOnly
```
public boolean isReadOnly()
```
  - getDefaultRetentionTime
```
public int getDefaultRetentionTime()
```
    Get the default retention time for this store in milliseconds.
    
    返回:
    
    the retention time
  - markUsed
```
public void markUsed(long pos,
                     int length)
```
    Mark the space as in use.
    
    参数:
    
    pos - the position in bytes
    
    length - the number of bytes
  - free
```
public void free(long pos,
                 int length)
```
    Mark the space as free.
    
    参数:
    
    pos - the position in bytes
    
    length - the number of bytes
  - getFillRate
```
public int getFillRate()
```
  - getProjectedFillRate
```
public int getProjectedFillRate(int vacatedBlocks)
```
    Calculates a prospective fill rate, which store would have after rewrite of sparsely populated chunk(s) and evacuation of still live data into a new chunk.
    
    参数:
    
    vacatedBlocks - number of blocks vacated
    
    返回:
    
    prospective fill rate (0 - 100)
  - clear
```
public void clear()
```
    Mark the file as empty.
  - getFileName
```
public String getFileName()
```
    Get the file name.
    
    返回:
    
    the file name

类 FileStore

字段概要

构造器概要

方法概要

从类继承的方法 java.lang.Object

字段详细资料

readCount

readBytes

writeCount

writeBytes

freeSpace

fileSize

构造器详细资料

FileStore

方法详细资料

toString

readFully

writeFully

open

open

close

sync

size

truncate

getFile

getEncryptedFile

getWriteCount

getWriteBytes

getReadCount

getReadBytes

isReadOnly

getDefaultRetentionTime

markUsed

free

getFillRate

getProjectedFillRate

clear

getFileName