org.iids.aos.kernel.ac
Class PersistentStoreFS

java.lang.Object
  org.iids.aos.kernel.ac.PersistentStore
      org.iids.aos.kernel.ac.PersistentStoreFS

public class PersistentStoreFS
extends PersistentStore

A PersistentStoreFS is a persistent store that uses files to store the data. Each data item is stored in a separate file. The key value is interpreted as a filename (including directories if any). Relative filenames are resolved against the current user directory. This directory is named by the system property user.dir, and is typically the directory in which the Java virtual machine was invoked. (See also the File interface of the Java language.) Author: Michel Oey

Constructor Summary

PersistentStoreFS(java.io.File directory)

Method Summary

void	close() Close the persistent store.
void	delete(java.lang.String key) Deletes a (key, value) pair from the persistent storage.
boolean	exists(java.lang.String key) Checks whether a key is stored in the persistent storage.
byte[]	get(java.lang.String key) Retrieves value associated with key from the persistent storage.
byte[]	get(java.lang.String key, int offset, int length) Retrieves part of the value associated with key from the persistent storage.
void	put(java.lang.String key, byte[] value) Stores (key, value) pair in the persistent storage.
void	put(java.lang.String key, byte[] value, int length) Stores (key, value) pair in the persistent storage.
void	put(java.lang.String key, int offset, byte[] value, int length) Overwrite any (key, value) pair in the persistent storage by overwriting the stored value starting at offset with the byte array given as parameter.
void	put(java.lang.String key, int offset, byte[] value, int length, boolean sync) Overwrite any (key, value) pair in the persistent storage by overwriting the stored value starting at offset with the byte array given as parameter.

Methods inherited from class org.iids.aos.kernel.ac.PersistentStore

getInstance, setup

Methods inherited from class java.lang.Object

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

Constructor Detail

PersistentStoreFS

public PersistentStoreFS(java.io.File directory)
                  throws InputOutputException

Throws:

InputOutputException

Method Detail

close

public void close()

Description copied from class: PersistentStore

Close the persistent store. Allows the implementation to do some cleanup.

Specified by:

close in class PersistentStore

put

public void put(java.lang.String key,
                byte[] value)
         throws InputOutputException

Stores (key, value) pair in the persistent storage.

Specified by:

put in class PersistentStore

Throws:

InputOutputException

put

public void put(java.lang.String key,
                byte[] value,
                int length)
         throws InputOutputException

Stores (key, value) pair in the persistent storage.

Specified by:

put in class PersistentStore

Throws:

InputOutputException

put

public void put(java.lang.String key,
                int offset,
                byte[] value,
                int length)
         throws InputOutputException

Overwrite any (key, value) pair in the persistent storage by overwriting the stored value starting at offset with the byte array given as parameter. Only length bytes are copied.

Specified by:

put in class PersistentStore

Throws:

InputOutputException

put

public void put(java.lang.String key,
                int offset,
                byte[] value,
                int length,
                boolean sync)
         throws InputOutputException

Overwrite any (key, value) pair in the persistent storage by overwriting the stored value starting at offset with the byte array given as parameter. Only length bytes are copied. Sync indicates whether the write should be made persistent immediately.

Specified by:

put in class PersistentStore

Throws:

InputOutputException

get

public byte[] get(java.lang.String key)
           throws InputOutputException

Retrieves value associated with key from the persistent storage. If the data cannot be found, null is returned.

Specified by:

get in class PersistentStore

Throws:

InputOutputException

get

public byte[] get(java.lang.String key,
                  int offset,
                  int length)
           throws InputOutputException

Retrieves part of the value associated with key from the persistent storage. Which part of the value is returned is specified by the offset and length parameters. No more bytes than are available in the value will be returned. If the data cannot be found, null is returned.

Specified by:

get in class PersistentStore

Throws:

InputOutputException

exists

public boolean exists(java.lang.String key)
               throws InputOutputException

Checks whether a key is stored in the persistent storage.

Specified by:

exists in class PersistentStore

Throws:

InputOutputException

delete

public void delete(java.lang.String key)
            throws InputOutputException

Deletes a (key, value) pair from the persistent storage.

Specified by:

delete in class PersistentStore

Throws:

InputOutputException