java.lang.Object
- com.mckoi.store.ScatteringStoreDataAccessor

All Implemented Interfaces:

StoreDataAccessor
```
public class ScatteringStoreDataAccessor
extends java.lang.Object
implements StoreDataAccessor
```
An implementation of StoreDataAccessor that scatters the addressible data resource across multiple files in the file system. When one store data resource reaches a certain threshold size, the content 'flows' over to the next file.

Nested Class Summary

Nested Classes
Modifier and Type Class Description

private static class ScatteringStoreDataAccessor.FileSlice
An object that contains information about a file slice.

Field Summary

Fields
Modifier and Type	Field	Description
`private java.lang.String`	`file_name`	The name of the file in the file system minus the extension.
`private java.lang.String`	`first_ext`	The extension of the first file in the sliced set.
`private java.lang.Object`	`lock`	A lock when modifying the true_data_size, and slice_list.
`private long`	`max_slice_size`	The maximum size a file slice can grow too before a new slice is created.
`private boolean`	`open`	Set when the store is openned.
`private java.io.File`	`path`	The path of this store in the file system.
`private java.util.ArrayList`	`slice_list`	The list of RandomAccessFile objects for each file that represents a slice of the store.
`private long`	`true_file_length`	The current actual physical size of the store data on disk.

Constructor Summary

Constructors
Constructor	Description
`ScatteringStoreDataAccessor(java.io.File path, java.lang.String file_name, java.lang.String first_ext, long max_slice_size)`	Constructs the store data accessor.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`close()`	Closes the underlying data area representation.
`void`	`convertToScatteringStore(java.io.File f)`	Given a file, this will convert to a scattering file store with files no larger than the maximum slice size.
`private int`	`countStoreFiles()`	Counts the number of files in the file store that represent this store.
`private StoreDataAccessor`	`createSliceDataAccessor(java.io.File file)`	Creates a StoreDataAccessor object for accessing a given slice.
`boolean`	`delete()`	Deletes the data area resource.
`private long`	`discoverSize()`	Discovers the size of the data resource (doesn't require the file to be open).
`boolean`	`exists()`	Returns true if the resource exists.
`long`	`getSize()`	Returns the current size of the underlying data area.
`void`	`open(boolean read_only)`	Opens the underlying data area representation.
`void`	`read(long position, byte[] buf, int off, int len)`	Reads a block of data from the underlying data area at the given position into the byte array at the given offset.
`void`	`setSize(long length)`	Sets the size of the underlying data area to the given size.
`private java.io.File`	`slicePartFile(int i)`	Given an index value, this will return a File object for the nth slice in the file system.
`void`	`synch()`	Synchronizes the data area by forcing any data out of the OS buffers onto the disk.
`void`	`write(long position, byte[] buf, int off, int len)`	Writes a block of data to the underlying data area from the byte array at the given offset.

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

- Field Detail
  - path
```
private final java.io.File path
```
    The path of this store in the file system.
  - file_name
```
private final java.lang.String file_name
```
    The name of the file in the file system minus the extension.
  - first_ext
```
private final java.lang.String first_ext
```
    The extension of the first file in the sliced set.
  - max_slice_size
```
private final long max_slice_size
```
    The maximum size a file slice can grow too before a new slice is created.
  - slice_list
```
private java.util.ArrayList slice_list
```
    The list of RandomAccessFile objects for each file that represents a slice of the store. (FileSlice objects)
  - true_file_length
```
private long true_file_length
```
    The current actual physical size of the store data on disk.
  - lock
```
private final java.lang.Object lock
```
    A lock when modifying the true_data_size, and slice_list.
  - open
```
private boolean open
```
    Set when the store is openned.
- Constructor Detail
  - ScatteringStoreDataAccessor
```
public ScatteringStoreDataAccessor(java.io.File path,
                                   java.lang.String file_name,
                                   java.lang.String first_ext,
                                   long max_slice_size)
```
    Constructs the store data accessor.
- Method Detail
  - convertToScatteringStore
```
public void convertToScatteringStore(java.io.File f)
                              throws java.io.IOException
```
    Given a file, this will convert to a scattering file store with files no larger than the maximum slice size.
    
    Throws:
    
    java.io.IOException
  - slicePartFile
```
private java.io.File slicePartFile(int i)
```
    Given an index value, this will return a File object for the nth slice in the file system. For example, given '4' will return [file name].004, given 1004 will return [file name].1004, etc.
  - countStoreFiles
```
private int countStoreFiles()
```
    Counts the number of files in the file store that represent this store.
  - createSliceDataAccessor
```
private StoreDataAccessor createSliceDataAccessor(java.io.File file)
```
    Creates a StoreDataAccessor object for accessing a given slice.
  - discoverSize
```
private long discoverSize()
                   throws java.io.IOException
```
    Discovers the size of the data resource (doesn't require the file to be open).
    
    Throws:
    
    java.io.IOException
  - open
```
public void open(boolean read_only)
          throws java.io.IOException
```
    Description copied from interface: StoreDataAccessor
    
    Opens the underlying data area representation. If the resource doesn't exist then it is created and the size is set to 0.
    
    Specified by:
    
    open in interface StoreDataAccessor
    
    Throws:
    
    java.io.IOException
  - close
```
public void close()
           throws java.io.IOException
```
    Description copied from interface: StoreDataAccessor
    
    Closes the underlying data area representation.
    
    Specified by:
    
    close in interface StoreDataAccessor
    
    Throws:
    
    java.io.IOException
  - delete
```
public boolean delete()
```
    Description copied from interface: StoreDataAccessor
    
    Deletes the data area resource. Returns true if the delete was successful.
    
    Specified by:
    
    delete in interface StoreDataAccessor
  - exists
```
public boolean exists()
```
    Description copied from interface: StoreDataAccessor
    
    Returns true if the resource exists.
    
    Specified by:
    
    exists in interface StoreDataAccessor
  - read
```
public void read(long position,
                 byte[] buf,
                 int off,
                 int len)
          throws java.io.IOException
```
    Description copied from interface: StoreDataAccessor
    
    Reads a block of data from the underlying data area at the given position into the byte array at the given offset.
    
    Specified by:
    
    read in interface StoreDataAccessor
    
    Throws:
    
    java.io.IOException
  - write
```
public void write(long position,
                  byte[] buf,
                  int off,
                  int len)
           throws java.io.IOException
```
    Description copied from interface: StoreDataAccessor
    
    Writes a block of data to the underlying data area from the byte array at the given offset.
    
    Specified by:
    
    write in interface StoreDataAccessor
    
    Throws:
    
    java.io.IOException
  - setSize
```
public void setSize(long length)
             throws java.io.IOException
```
    Description copied from interface: StoreDataAccessor
    
    Sets the size of the underlying data area to the given size. If the size of the data area is increased, the content between the old size and the new size is implementation defined.
    
    Specified by:
    
    setSize in interface StoreDataAccessor
    
    Throws:
    
    java.io.IOException
  - getSize
```
public long getSize()
             throws java.io.IOException
```
    Description copied from interface: StoreDataAccessor
    
    Returns the current size of the underlying data area.
    
    Specified by:
    
    getSize in interface StoreDataAccessor
    
    Throws:
    
    java.io.IOException
  - synch
```
public void synch()
           throws java.io.IOException
```
    Description copied from interface: StoreDataAccessor
    
    Synchronizes the data area by forcing any data out of the OS buffers onto the disk.
    
    Specified by:
    
    synch in interface StoreDataAccessor
    
    Throws:
    
    java.io.IOException

Class ScatteringStoreDataAccessor

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

path

file_name

first_ext

max_slice_size

slice_list

true_file_length

lock

open

Constructor Detail

ScatteringStoreDataAccessor

Method Detail

convertToScatteringStore

slicePartFile

countStoreFiles

createSliceDataAccessor

discoverSize

open

close

delete

exists

read

write

setSize

getSize

synch