ResettableGZIPOutputStream

net.i2p.util.ResettableGZIPOutputStream

All Implemented Interfaces:: Closeable, Flushable, AutoCloseable

Direct Known Subclasses:: ReusableGZIPOutputStream

public class ResettableGZIPOutputStreamextends DeflaterOutputStream

GZIP implementation per RFC 1952, reusing java's standard CRC32 and Deflater implementations. The main difference is that this implementation allows its state to be reset to initial values, and hence reused, while the standard GZIPOutputStream writes the GZIP header to the stream on instantiation, rather than on first write.

Field Summary
Fields
Modifier and Type
Field
Description
private final CRC32
_crc32
Checksum of the bytes written.
private boolean
_footerWritten
True once the gzip footer has been written.
private boolean
_headerWritten
Has the header been written out yet?
private long
_writtenSize
How much data is in the uncompressed stream?
private static final boolean
DEBUG
True to log the stream's internals.
private static final byte[]
HEADER
The gzip header written at the start of each stream.
Fields inherited from class DeflaterOutputStream
buf, def
Fields inherited from class FilterOutputStream
out
Constructor Summary
Constructors
Constructor
Description
ResettableGZIPOutputStream(OutputStream o)
Stream writing gzip data to the given output stream.
Method Summary
Modifier and Type
Method
Description
void
close()
void
destroy()
Calls super.close().
private void
ensureHeaderIsWritten()
Obviously not threadsafe, but it's a stream, that's standard.
void
finish()
void
reset()
Reinitialize everything so we can write a brand new gzip output stream again.
void
write(byte[] buf)
void
write(byte[] buf, int off, int len)
void
write(int b)
private void
writeFooter()
Writes the checksum and size footer at the end of the stream.
Methods inherited from class DeflaterOutputStream
deflate, flush
Methods inherited from class OutputStream
nullOutputStream
Methods inherited from class Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details
- _headerWritten
  private boolean _headerWritten
  Has the header been written out yet?
- _footerWritten
  private boolean _footerWritten
  True once the gzip footer has been written.
- _writtenSize
  private long _writtenSize
  How much data is in the uncompressed stream?
- _crc32
  private final CRC32 _crc32
  Checksum of the bytes written.
- DEBUG
  private static final boolean DEBUG
  True to log the stream's internals.
  See Also:
  Constant Field Values
- HEADER
  private static final byte[] HEADER
  The gzip header written at the start of each stream.
Constructor Details
- ResettableGZIPOutputStream
  public ResettableGZIPOutputStream(OutputStream o)
  Stream writing gzip data to the given output stream.
  Parameters:
  o - the underlying output stream
Method Details
- reset
  public void reset()
  Reinitialize everything so we can write a brand new gzip output stream again.
- ensureHeaderIsWritten
  private void ensureHeaderIsWritten() throws IOException
  Obviously not threadsafe, but it's a stream, that's standard.
  Throws:
  IOException - if writing the header to the underlying stream fails
- writeFooter
  private void writeFooter() throws IOException
  Writes the checksum and size footer at the end of the stream.
  Throws:
  IOException - if the footer cannot be written
- destroy
  public void destroy() throws IOException
  Calls super.close(). May not be reused after this.
  Throws:
  IOException - if the wrapped stream cannot be written to or closed
- close
  public void close() throws IOException
  Specified by:
  close in interface AutoCloseable
  Specified by:
  close in interface Closeable
  Overrides:
  close in class DeflaterOutputStream
  Throws:
  IOException
- finish
  public void finish() throws IOException
  Overrides:
  finish in class DeflaterOutputStream
  Throws:
  IOException
- write
  public void write(int b) throws IOException
  Overrides:
  write in class DeflaterOutputStream
  Throws:
  IOException
- write
  public void write(byte[] buf) throws IOException
  Overrides:
  write in class FilterOutputStream
  Throws:
  IOException
- write
  public void write(byte[] buf, int off, int len) throws IOException
  Overrides:
  write in class DeflaterOutputStream
  Throws:
  IOException

Field Summary

Fields inherited from class DeflaterOutputStream

Fields inherited from class FilterOutputStream

Constructor Summary

Method Summary

Methods inherited from class DeflaterOutputStream

Methods inherited from class OutputStream

Methods inherited from class Object

Field Details

_headerWritten

_footerWritten

_writtenSize

_crc32

DEBUG

HEADER

Constructor Details

Method Details

reset

ensureHeaderIsWritten

writeFooter

destroy

close

finish

write

write

write