CompressorStream (PNGJ 2.1.0 API)

java.lang.Object
- java.io.OutputStream
- - java.io.FilterOutputStream
  - - ar.com.hjg.pngj.pixels.CompressorStream

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable

Direct Known Subclasses:

CompressorStreamDeflater, CompressorStreamLz4
```
public abstract class CompressorStream
extends FilterOutputStream
```
This is an OutputStream that compresses (via Deflater or a deflater-like object), and optionally passes the compressed stream to another output stream. It allows to compute in/out/ratio stats. It works as a stream (similar to DeflaterOutputStream), but it's peculiar in that it expects that each writes has a fixed length (other lenghts are accepted, but it's less efficient) and that the total amount of bytes is known (so it can close itself, but it can also be closed on demand) In PNGJ use, the block is typically a row (including filter byte). We use this to do the real compression (with Deflate) but also to compute tentative estimators If not closed, it can be recicled via reset()

Field Summary

Fields
Modifier and Type	Field and Description
`protected int`	`block`
`int`	`blockLen`
`protected long`	`bytesIn`
`protected long`	`bytesOut`
`protected boolean`	`done`
`protected OutputStream`	`os`
`protected boolean`	`storeFirstByte`
`long`	`totalbytes`

Fields inherited from class java.io.FilterOutputStream
out

Constructor Summary

Constructors
Constructor and Description

CompressorStream(OutputStream os, int blockLen, long totalbytes)

Constructors
Constructor and Description
`CompressorStream(OutputStream os, int blockLen, long totalbytes)`

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`close()` Releases resources.
`abstract void`	`done()` Will be called automatically when the number of bytes reaches the total expected Can be also be called from outside.
`void`	`flush()`
`long`	`getBytesCompressed()` compressed (out) bytes.
`long`	`getBytesRaw()` raw (input) bytes.
`double`	`getCompressionRatio()` compressed/raw.
`byte[]`	`getFirstBytes()`
`OutputStream`	`getOs()`
`boolean`	`isClosed()`
`boolean`	`isDone()`
`protected abstract void`	`mywrite(byte[] b, int off, int len)` same as write, but guarantedd to not exceed blockLen The implementation should update bytesOut and bytesInt but not check for totalBytes
`void`	`reset()`
`void`	`reset(OutputStream os)` resets and sets a new outputstream
`void`	`setStoreFirstByte(boolean storeFirstByte, int nblocks)`
`void`	`write(byte[] b)`
`void`	`write(byte[] b, int off, int len)`
`void`	`write(int b)`

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

- Field Detail
  - os
```
protected OutputStream os
```
  - blockLen
```
public final int blockLen
```
  - totalbytes
```
public final long totalbytes
```
  - done
```
protected boolean done
```
  - bytesIn
```
protected long bytesIn
```
  - bytesOut
```
protected long bytesOut
```
  - block
```
protected int block
```
  - storeFirstByte
```
protected boolean storeFirstByte
```
- Constructor Detail
  - CompressorStream
```
public CompressorStream(OutputStream os,
                int blockLen,
                long totalbytes)
```
    Parameters:
    os - Can be null (if we are only interested in compute compression ratio)
    blockLen - Estimated maximum block length. If unknown, use -1.
    totalbytes - Expected total bytes to be fed. If unknown, use -1.
- Method Detail
  - close
```
public void close()
```
    Releases resources. Does NOT close the OuputStream. Idempotent.
    
    Specified by:
    
    close in interface Closeable
    
    Specified by:
    
    close in interface AutoCloseable
    
    Overrides:
    
    close in class FilterOutputStream
  - done
```
public abstract void done()
```
    Will be called automatically when the number of bytes reaches the total expected Can be also be called from outside. This should set the flag done=true
  - write
```
public final void write(byte[] b,
         int off,
         int len)
```
    Overrides:
    
    write in class FilterOutputStream
  - mywrite
```
protected abstract void mywrite(byte[] b,
           int off,
           int len)
```
    same as write, but guarantedd to not exceed blockLen The implementation should update bytesOut and bytesInt but not check for totalBytes
  - write
```
public final void write(byte[] b)
```
    Overrides:
    
    write in class FilterOutputStream
  - write
```
public void write(int b)
           throws IOException
```
    Overrides:
    
    write in class FilterOutputStream
    
    Throws:
    
    IOException
  - reset
```
public void reset()
```
  - reset
```
public void reset(OutputStream os)
```
    resets and sets a new outputstream
    
    Parameters:
    os -
  - getCompressionRatio
```
public final double getCompressionRatio()
```
    compressed/raw. This should be called only when done
  - getBytesRaw
```
public final long getBytesRaw()
```
    raw (input) bytes. This should be called only when done
  - getBytesCompressed
```
public final long getBytesCompressed()
```
    compressed (out) bytes. This should be called only when done
  - getOs
```
public OutputStream getOs()
```
    Returns:
    the output stream : warning, it can be null
  - flush
```
public void flush()
```
    Specified by:
    
    flush in interface Flushable
    
    Overrides:
    
    flush in class FilterOutputStream
  - isClosed
```
public boolean isClosed()
```
  - isDone
```
public boolean isDone()
```
  - getFirstBytes
```
public byte[] getFirstBytes()
```
  - setStoreFirstByte
```
public void setStoreFirstByte(boolean storeFirstByte,
                     int nblocks)
```

Class CompressorStream

Field Summary

Fields inherited from class java.io.FilterOutputStream

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

os

blockLen

totalbytes

done

bytesIn

bytesOut

block

storeFirstByte

Constructor Detail

CompressorStream

Method Detail

close

done

write

mywrite

write

write

reset

reset

getCompressionRatio

getBytesRaw

getBytesCompressed

getOs

flush

isClosed

isDone

getFirstBytes

setStoreFirstByte