com.db4o.io

Class CachedIoAdapter

java.lang.Object

com.db4o.io.IoAdapter

com.db4o.io.CachedIoAdapter

Deprecated.

Use CachingStorage instead.

public class CachedIoAdapter
extends IoAdapter

CachedIoAdapter is an IOAdapter for random access files, which caches data for IO access. Its functionality is similar to OS cache.
Example:
delegateAdapter = new RandomAccessFileAdapter();
Db4o.configure().io(new CachedIoAdapter(delegateAdapter));

Constructor Summary

Constructors

Constructor and Description
CachedIoAdapter(IoAdapter ioAdapter) Deprecated. Creates an instance of CachedIoAdapter with the default page size and page count.
CachedIoAdapter(IoAdapter ioAdapter, int pageSize, int pageCount) Deprecated. Creates an instance of CachedIoAdapter with a custom page size and page count.
CachedIoAdapter(java.lang.String path, boolean lockFile, long initialLength, boolean readOnly, IoAdapter io, int pageSize, int pageCount) Deprecated. Creates an instance of CachedIoAdapter with extended parameters.

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Deprecated. Flushes and closes the file
IoAdapter	delegatedIoAdapter() Deprecated. Delegated IO Adapter
void	delete(java.lang.String path) Deprecated. Deletes the database file
boolean	exists(java.lang.String path) Deprecated. Checks if the file exists
long	getLength() Deprecated. Returns the file length
IoAdapter	open(java.lang.String path, boolean lockFile, long initialLength, boolean readOnly) Deprecated. Creates and returns a new CachedIoAdapter
int	read(byte[] buffer, int length) Deprecated. Reads the file into the buffer using pages from cache.
void	seek(long pos) Deprecated. Moves the pointer to the specified file position
void	sync() Deprecated. Flushes cache to a physical storage
void	write(byte[] buffer, int length) Deprecated. Writes the buffer to cache using pages

Methods inherited from class com.db4o.io.IoAdapter

blockCopy, blockSeek, blockSeek, blockSize, blockSize, copy, read, regularAddress, write

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CachedIoAdapter

public CachedIoAdapter(IoAdapter ioAdapter)

Deprecated.

Creates an instance of CachedIoAdapter with the default page size and page count.

Parameters:

ioAdapter - delegate IO adapter (RandomAccessFileAdapter by default)

CachedIoAdapter

public CachedIoAdapter(IoAdapter ioAdapter,
               int pageSize,
               int pageCount)

Deprecated.

Creates an instance of CachedIoAdapter with a custom page size and page count.

Parameters:

ioAdapter - delegate IO adapter (RandomAccessFileAdapter by default)

pageSize - cache page size

pageCount - allocated amount of pages

CachedIoAdapter

public CachedIoAdapter(java.lang.String path,
               boolean lockFile,
               long initialLength,
               boolean readOnly,
               IoAdapter io,
               int pageSize,
               int pageCount)
                throws Db4oIOException

Deprecated.

Creates an instance of CachedIoAdapter with extended parameters.

Parameters:

path - database file path

lockFile - determines if the file should be locked

initialLength - initial file length, new writes will start from this point

readOnly - if the file should be used in read-onlyt mode.

io - delegate IO adapter (RandomAccessFileAdapter by default)

pageSize - cache page size

pageCount - allocated amount of pages

Throws:

Db4oIOException

Method Detail

open

public IoAdapter open(java.lang.String path,
             boolean lockFile,
             long initialLength,
             boolean readOnly)
               throws Db4oIOException

Deprecated.

Creates and returns a new CachedIoAdapter

Specified by:

open in class IoAdapter

Parameters:

path - database file path

lockFile - determines if the file should be locked

initialLength - initial file length, new writes will start from this point

Throws:

Db4oIOException

delete

public void delete(java.lang.String path)

Deprecated.

Deletes the database file

Specified by:

delete in class IoAdapter

Parameters:

path - file path

exists

public boolean exists(java.lang.String path)

Deprecated.

Checks if the file exists

Specified by:

exists in class IoAdapter

Parameters:

path - file path

read

public int read(byte[] buffer,
       int length)
         throws Db4oIOException

Deprecated.

Reads the file into the buffer using pages from cache. If the next page is not cached it will be read from the file.

Specified by:

read in class IoAdapter

Parameters:

buffer - destination buffer

length - how many bytes to read

Throws:

Db4oIOException

write

public void write(byte[] buffer,
         int length)
           throws Db4oIOException

Deprecated.

Writes the buffer to cache using pages

Specified by:

write in class IoAdapter

Parameters:

buffer - source buffer

length - how many bytes to write

Throws:

Db4oIOException

sync

public void sync()
          throws Db4oIOException

Deprecated.

Flushes cache to a physical storage

Specified by:

sync in class IoAdapter

Throws:

Db4oIOException

getLength

public long getLength()
               throws Db4oIOException

Deprecated.

Returns the file length

Specified by:

getLength in class IoAdapter

Throws:

Db4oIOException

close

public void close()
           throws Db4oIOException

Deprecated.

Flushes and closes the file

Specified by:

close in class IoAdapter

Throws:

Db4oIOException

delegatedIoAdapter

public IoAdapter delegatedIoAdapter()

Deprecated.

Description copied from class: IoAdapter

Delegated IO Adapter

Overrides:

delegatedIoAdapter in class IoAdapter

Returns:

reference to itself

seek

public void seek(long pos)
          throws Db4oIOException

Deprecated.

Moves the pointer to the specified file position

Specified by:

seek in class IoAdapter

Parameters:

pos - position within the file

Throws:

Db4oIOException