org.norther.tammi.acorn.io
Class RecordAccessFile

java.lang.Object
  org.norther.tammi.acorn.io.RecordAccessFile

public class RecordAccessFile
extends Object

A record oriented RandomAccessFile.

Author:

Ilkka Priha

Nested Class Summary

protected static class

RecordAccessFile.RecordHeader A header for records.

Field Summary

static int	DEFAULT_CAPACITY The default capcacity.
static int	DEFAULT_RECORD_LENGTH The default record length.

Constructor Summary

RecordAccessFile(File file, String mode)
Constructs a record access file.

RecordAccessFile(File file, String mode, int capacity)
Constructs a record access file, initializing the appropriate headers.

RecordAccessFile(File file, String mode, int capacity, int recordLength)
Constructs a record access file, initializing the appropriate headers.

Method Summary

void	acquire() Acquires an exclusive lock to this record.
void	addRecord(String key, RecordWriter rec) Adds a new record.
void	clear() Clears the file.
void	close() Closes the file.
boolean	containsRecord(String key) Checks if there is a record with the given key.
File	getFile() Gets the file.
RecordReader	getRecord(String key) Gets a record.
boolean	getRecord(String key, RecordReader rec) Gets a record.
Set	keySet() Return the keys of all records in the file.
void	putRecord(String key, RecordWriter rec) Puts a record.
int	recordCount() Returns the number or records in the file.
void	release() Releases an exclusive lock to this record.
boolean	removeRecord(String key) Removes a record.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_CAPACITY

public static final int DEFAULT_CAPACITY

The default capcacity.

See Also:

Constant Field Values

DEFAULT_RECORD_LENGTH

public static final int DEFAULT_RECORD_LENGTH

The default record length.

See Also:

Constant Field Values

Constructor Detail

RecordAccessFile

public RecordAccessFile(File file,
                        String mode)
                 throws IOException

Constructs a record access file.

Parameters:

file - the internal file.

mode - the access mode.

Throws:

IOException - on I/O errors.

RecordAccessFile

public RecordAccessFile(File file,
                        String mode,
                        int capacity)
                 throws IOException

Constructs a record access file, initializing the appropriate headers. Enough space is allocated in the index for the specified capacity.

Parameters:

file - the internal file.

mode - the access mode.

capacity - the initial capacity (0 = use default).

Throws:

IOException - on I/O errors.

RecordAccessFile

public RecordAccessFile(File file,
                        String mode,
                        int capacity,
                        int recordLength)
                 throws IOException

Constructs a record access file, initializing the appropriate headers. Enough space is allocated in the index for the specified capacity. The default record length is set to the specified value.

Parameters:

file - the internal file.

mode - the access mode.

capacity - the initial capacity (0 = use default).

recordLength - the default record length (0 = use default).

Throws:

IOException - on I/O errors.

Method Detail

getFile

public File getFile()

Gets the file.

Returns:

the file.

getRecord

public RecordReader getRecord(String key)
                       throws IOException

Gets a record.

Parameters:

key - the record key.

Returns:

a new record reader or null.

Throws:

IOException - on I/O errors.

getRecord

public boolean getRecord(String key,
                         RecordReader rec)
                  throws IOException

Gets a record.

Parameters:

key - the record key.

rec - a record reader.

Returns:

true if the record was found, otherwise false.

Throws:

IOException - on I/O errors.

putRecord

public void putRecord(String key,
                      RecordWriter rec)
               throws IOException

Puts a record.

Parameters:

key - the record key.

rec - a record writer.

Throws:

IOException - on I/O errors.

addRecord

public void addRecord(String key,
                      RecordWriter rec)
               throws IOException

Adds a new record.

Parameters:

key - the record key.

rec - a record writer.

Throws:

IOException - on I/O errors.

removeRecord

public boolean removeRecord(String key)
                     throws IOException

Removes a record.

Parameters:

key - the record key.

Returns:

true if the record was removed, otherwise false.

Throws:

IOException - on I/O errors.

keySet

public Set keySet()

Return the keys of all records in the file.

Returns:

a set of keys or an empty set.

recordCount

public int recordCount()

Returns the number or records in the file.

Returns:

the record count.

containsRecord

public boolean containsRecord(String key)

Checks if there is a record with the given key.

Parameters:

key - the record key.

Returns:

true if the record is found, otherwise false.

clear

public void clear()
           throws IOException

Clears the file.

Throws:

IOException - on I/O errors.

close

public void close()
           throws IOException

Closes the file.

Throws:

IOException - on I/O errors.

acquire

public void acquire()

Acquires an exclusive lock to this record.

release

public void release()

Releases an exclusive lock to this record.