BufferedReadOnlyFile (TrueZIP Kernel 7.1.3 API)

java.lang.Object
- de.schlichtherle.truezip.rof.AbstractReadOnlyFile
- - de.schlichtherle.truezip.rof.DecoratingReadOnlyFile
  - - de.schlichtherle.truezip.rof.BufferedReadOnlyFile

All Implemented Interfaces:

ReadOnlyFile, Closeable, AutoCloseable
```
@NotThreadSafe
public class BufferedReadOnlyFile
extends DecoratingReadOnlyFile
```
A ReadOnlyFile implementation which provides buffered random read only access to another ReadOnlyFile.
Note: This class implements its own virtual file pointer. Thus, if you would like to access the underlying ReadOnlyFile again after you have finished working with an instance of this class, you should synchronize their file pointers using the pattern as described in DecoratingReadOnlyFile.

Author:

Christian Schlichtherle

Field Summary

Fields
Modifier and Type	Field and Description
`private boolean`	`closed`
`private long`	`fp` The virtual file pointer in the file data.
`private long`	`length`
`private byte[]`	`window` The buffer window to the file data.
`static int`	`WINDOW_LEN` The default buffer length of the window to the file.
`private long`	`windowOff` The current offset in the read only file where the buffer window starts.

Fields inherited from class de.schlichtherle.truezip.rof.DecoratingReadOnlyFile
delegate

Constructor Summary

Constructors
Modifier	Constructor and Description
	`BufferedReadOnlyFile(File file)` Creates a new instance of `BufferedReadOnlyFile`.
	`BufferedReadOnlyFile(File file, int windowLen)` Creates a new instance of `BufferedReadOnlyFile`.
	`BufferedReadOnlyFile(ReadOnlyFile rof)` Creates a new instance of `BufferedReadOnlyFile`.
`private`	`BufferedReadOnlyFile(ReadOnlyFile rof, File file, int windowLen)`
	`BufferedReadOnlyFile(ReadOnlyFile rof, int windowLen)` Creates a new instance of `BufferedReadOnlyFile`.

Method Summary

Methods
Modifier and Type	Method and Description
`private void`	`assertOpen()` Asserts that this file is open.
`void`	`close()` Closes this read only file.
`long`	`getFilePointer()` Returns the current byte position in the file as a zero-based index.
`private void`	`invalidateWindow()` Forces the window to be reloaded on the next call to `positionWindow()`.
`long`	`length()` Returns the length of the file in bytes.
`protected static long`	`max(long a, long b)` Returns the greater parameter.
`protected static long`	`min(long a, long b)` Returns the smaller parameter.
`private void`	`positionWindow()` Positions the window so that the block containing the current virtual file pointer in the encrypted file is entirely contained in it.
`int`	`read()` Reads and returns the next byte or -1 if the end of the file has been reached.
`int`	`read(byte[] buf, int off, int len)` Reads up to `len` bytes of data from this read only file into the given array.
`void`	`seek(long fp)` Sets the current byte position in the file as a zero-based index at which the next read occurs.

Methods inherited from class de.schlichtherle.truezip.rof.DecoratingReadOnlyFile
toString

Methods inherited from class de.schlichtherle.truezip.rof.AbstractReadOnlyFile
read, readFully, readFully

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

- Field Detail
  - WINDOW_LEN
```
public static final int WINDOW_LEN
```
    The default buffer length of the window to the file.
    
    See Also:
    Constant Field Values
  - length
```
private long length
```
  - fp
```
private long fp
```
    The virtual file pointer in the file data. This is relative to the start of the file.
  - windowOff
```
private long windowOff
```
    The current offset in the read only file where the buffer window starts. This is always a multiple of the buffer window size.
  - window
```
private final byte[] window
```
    The buffer window to the file data.
  - closed
```
private boolean closed
```
- Constructor Detail
  - BufferedReadOnlyFile
```
public BufferedReadOnlyFile(File file)
                     throws NullPointerException,
                            FileNotFoundException,
                            IOException
```
    Creates a new instance of BufferedReadOnlyFile.
    
    Parameters:
    file - The file to read.
    
    Throws:
    
    NullPointerException - If any of the parameters is null.
    
    FileNotFoundException - If the file cannot get opened for reading.
    
    IOException - On any other I/O related issue.
  - BufferedReadOnlyFile
```
public BufferedReadOnlyFile(File file,
                    int windowLen)
                     throws NullPointerException,
                            FileNotFoundException,
                            IOException
```
    Creates a new instance of BufferedReadOnlyFile.
    
    Parameters:
    file - The file to read.
    windowLen - The size of the buffer window in bytes.
    
    Throws:
    
    NullPointerException - If any of the parameters is null.
    
    FileNotFoundException - If the file cannot get opened for reading.
    
    IOException - On any other I/O related issue.
  - BufferedReadOnlyFile
```
public BufferedReadOnlyFile(ReadOnlyFile rof)
                     throws NullPointerException,
                            FileNotFoundException,
                            IOException
```
    Creates a new instance of BufferedReadOnlyFile.
    
    Parameters:
    rof - The read only file to read.
    
    Throws:
    
    NullPointerException - If any of the parameters is null.
    
    FileNotFoundException - If the file cannot get opened for reading.
    
    IOException - On any other I/O related issue.
  - BufferedReadOnlyFile
```
public BufferedReadOnlyFile(ReadOnlyFile rof,
                    int windowLen)
                     throws NullPointerException,
                            FileNotFoundException,
                            IOException
```
    Creates a new instance of BufferedReadOnlyFile.
    
    Parameters:
    rof - The read only file to read.
    windowLen - The size of the buffer window in bytes.
    
    Throws:
    
    NullPointerException - If any of the parameters is null.
    
    FileNotFoundException - If the file cannot get opened for reading.
    
    IOException - On any other I/O related issue.
  - BufferedReadOnlyFile
```
private BufferedReadOnlyFile(ReadOnlyFile rof,
                    File file,
                    int windowLen)
                      throws NullPointerException,
                             FileNotFoundException,
                             IOException
```
    Throws:
    
    NullPointerException
    
    FileNotFoundException
    
    IOException
- Method Detail
  - min
```
protected static long min(long a,
       long b)
```
    Returns the smaller parameter.
  - max
```
protected static long max(long a,
       long b)
```
    Returns the greater parameter.
  - length
```
public long length()
            throws IOException
```
    Description copied from interface: ReadOnlyFile
    
    Returns the length of the file in bytes.
    
    Specified by:
    
    length in interface ReadOnlyFile
    
    Overrides:
    
    length in class DecoratingReadOnlyFile
    
    Throws:
    
    IOException
  - getFilePointer
```
public long getFilePointer()
                    throws IOException
```
    Description copied from interface: ReadOnlyFile
    
    Returns the current byte position in the file as a zero-based index.
    
    Specified by:
    
    getFilePointer in interface ReadOnlyFile
    
    Overrides:
    
    getFilePointer in class DecoratingReadOnlyFile
    
    Throws:
    
    IOException
  - seek
```
public void seek(long fp)
          throws IOException
```
    Description copied from interface: ReadOnlyFile
    
    Sets the current byte position in the file as a zero-based index at which the next read occurs. Whether the offset may be set beyond the end of the file is up to the implementor. For example, the DefaultReadOnlyFile subclass RandomAccessFile passes "r" as a parameter to the superclass constructor. With Sun's JSE implementation, on the Windows platform this implementation allows to seek past the end of file, but on the Linux platform it doesn't.
    
    Specified by:
    
    seek in interface ReadOnlyFile
    
    Overrides:
    
    seek in class DecoratingReadOnlyFile
    
    Parameters:
    fp - The current byte position as a zero-based index.
    
    Throws:
    
    IOException - If pos is less than 0 or if an I/O error occurs.
  - read
```
public int read()
         throws IOException
```
    Description copied from interface: ReadOnlyFile
    
    Reads and returns the next byte or -1 if the end of the file has been reached.
    
    Specified by:
    
    read in interface ReadOnlyFile
    
    Overrides:
    
    read in class DecoratingReadOnlyFile
    
    Throws:
    
    IOException
  - read
```
public int read(byte[] buf,
       int off,
       int len)
         throws IOException
```
    Description copied from interface: ReadOnlyFile
    
    Reads up to len bytes of data from this read only file into the given array. This method blocks until at least one byte of input is available.
    
    Specified by:
    
    read in interface ReadOnlyFile
    
    Overrides:
    
    read in class DecoratingReadOnlyFile
    
    Parameters:
    buf - The buffer to fill with data.
    off - The start offset of the data.
    len - The maximum number of bytes to read.
    
    Returns:
    The total number of bytes read, or -1 if there is no more data because the end of the file has been reached.
    
    Throws:
    
    IOException - On any I/O related issue.
  - close
```
public void close()
           throws IOException
```
    Closes this read only file. As a side effect, this will set the reference to the underlying read only file (DecoratingReadOnlyFile.delegate to null.
    
    Specified by:
    
    close in interface ReadOnlyFile
    
    Specified by:
    
    close in interface Closeable
    
    Specified by:
    
    close in interface AutoCloseable
    
    Overrides:
    
    close in class DecoratingReadOnlyFile
    
    Throws:
    
    IOException
  - assertOpen
```
private void assertOpen()
                 throws IOException
```
    Asserts that this file is open.
    
    Throws:
    
    IOException - If the preconditions do not hold.
  - positionWindow
```
private void positionWindow()
                     throws IOException
```
    Positions the window so that the block containing the current virtual file pointer in the encrypted file is entirely contained in it.
    
    Throws:
    
    IOException - On any I/O related issue. The window is invalidated in this case.
  - invalidateWindow
```
private void invalidateWindow()
```
    Forces the window to be reloaded on the next call to positionWindow().

Class BufferedReadOnlyFile

Field Summary

Fields inherited from class de.schlichtherle.truezip.rof.DecoratingReadOnlyFile

Constructor Summary

Method Summary

Methods inherited from class de.schlichtherle.truezip.rof.DecoratingReadOnlyFile

Methods inherited from class de.schlichtherle.truezip.rof.AbstractReadOnlyFile

Methods inherited from class java.lang.Object

Field Detail

WINDOW_LEN

length

fp

windowOff

window

closed

Constructor Detail

BufferedReadOnlyFile

BufferedReadOnlyFile

BufferedReadOnlyFile

BufferedReadOnlyFile

BufferedReadOnlyFile

Method Detail

min

max

length

getFilePointer

seek

read

read

close

assertOpen

positionWindow

invalidateWindow