JSONzip (TotalCrossSDK 6.1.0 API)

java.lang.Object
- totalcross.json.zip.JSONzip

All Implemented Interfaces:

None, PostMortem

Direct Known Subclasses:

Unzipper, Zipper
```
public abstract class JSONzip
extends java.lang.Object
implements None, PostMortem
```
JSONzip is a binary-encoded JSON dialect. It is designed to compress the messages in a session in bandwidth constrained applications, such as mobile. JSONzip is adaptive, so with each message seen, it should improve its compression. It minimizes JSON's overhead, reducing punctuation to a small number of bits. It uses Huffman encoding to reduce the average size of characters. It uses caches (or Keeps) to keep recently seen strings and values, so repetitive content (such as object keys) can be substantially reduced. It uses a character encoding called Kim (Keep it minimal) that is smaller than UTF-8 for most East European, African, and Asian scripts. JSONzip tends to reduce most content by about half. If there is a lot of recurring information, the reduction can be much more dramatic. FOR EVALUATION PURPOSES ONLY. THIS PACKAGE HAS NOT YET BEEN TESTED ADEQUATELY FOR PRODUCTION USE.

Field Summary

Fields
Modifier and Type	Field and Description
`static byte[]`	`bcd` The characters in JSON numbers can be reduced to 4 bits each.
`static int`	`end` The end of string code.
`static int`	`endOfNumber` The end of number code.
`static long`	`int14` The first positive integer that cannot be encoded in 14 bits.
`static long`	`int4` The first positive integer that cannot be encoded in 4 bits.
`static long`	`int7` The first positive integer that cannot be encoded in 7 bits.
`protected Huff`	`namehuff` A Huffman encoder for names.
`protected Huff`	`namehuffext` A Huffman encoder for names extended bytes.
`protected totalcross.json.zip.Keep`	`namekeep` A place to keep the names (keys).
`static boolean`	`probe` The package supports tracing for debugging.
`protected Huff`	`stringhuff` A Huffman encoder for string values.
`protected Huff`	`stringhuffext` A Huffman encoder for string values extended bytes.
`protected totalcross.json.zip.Keep`	`stringkeep` A place to keep the strings.
`protected totalcross.json.zip.Keep`	`valuekeep` A place to keep the values.
`static int`	`zipArrayString` The value code for an array with a string as its first element.
`static int`	`zipArrayValue` The value code for an array with a non-string value as its first element.
`static int`	`zipEmptyArray` The value code for an empty array.
`static int`	`zipEmptyObject` The value code for an empty object.
`static int`	`zipFalse` The value code for false.
`static int`	`zipNull` The value code for null.
`static int`	`zipObject` The value code for a non-empty object.
`static int`	`zipTrue` The value code for true.

Fields inherited from interface totalcross.json.zip.None
none

Constructor Summary

Constructors
Modifier Constructor and Description

protected JSONzip()
Initialize the data structures.

Constructors
Modifier	Constructor and Description
`protected`	`JSONzip()` Initialize the data structures.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`protected void`	`generate()` Generate the Huffman tables.
`boolean`	`postMortem(PostMortem pm)` This method is used for testing the implementation of JSONzip.

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

- Field Detail
  - bcd
```
public static final byte[] bcd
```
    The characters in JSON numbers can be reduced to 4 bits each.
  - end
```
public static final int end
```
    The end of string code.
    
    See Also:
    
    Constant Field Values
  - endOfNumber
```
public static final int endOfNumber
```
    The end of number code.
  - int4
```
public static final long int4
```
    The first positive integer that cannot be encoded in 4 bits.
    
    See Also:
    
    Constant Field Values
  - int7
```
public static final long int7
```
    The first positive integer that cannot be encoded in 7 bits.
    
    See Also:
    
    Constant Field Values
  - int14
```
public static final long int14
```
    The first positive integer that cannot be encoded in 14 bits.
    
    See Also:
    
    Constant Field Values
  - probe
```
public static final boolean probe
```
    The package supports tracing for debugging.
    
    See Also:
    
    Constant Field Values
  - zipEmptyObject
```
public static final int zipEmptyObject
```
    The value code for an empty object.
    
    See Also:
    
    Constant Field Values
  - zipEmptyArray
```
public static final int zipEmptyArray
```
    The value code for an empty array.
    
    See Also:
    
    Constant Field Values
  - zipTrue
```
public static final int zipTrue
```
    The value code for true.
    
    See Also:
    
    Constant Field Values
  - zipFalse
```
public static final int zipFalse
```
    The value code for false.
    
    See Also:
    
    Constant Field Values
  - zipNull
```
public static final int zipNull
```
    The value code for null.
    
    See Also:
    
    Constant Field Values
  - zipObject
```
public static final int zipObject
```
    The value code for a non-empty object.
    
    See Also:
    
    Constant Field Values
  - zipArrayString
```
public static final int zipArrayString
```
    The value code for an array with a string as its first element.
    
    See Also:
    
    Constant Field Values
  - zipArrayValue
```
public static final int zipArrayValue
```
    The value code for an array with a non-string value as its first element.
    
    See Also:
    
    Constant Field Values
  - namehuff
```
protected final Huff namehuff
```
    A Huffman encoder for names.
  - namehuffext
```
protected final Huff namehuffext
```
    A Huffman encoder for names extended bytes.
  - namekeep
```
protected final totalcross.json.zip.Keep namekeep
```
    A place to keep the names (keys).
  - stringhuff
```
protected final Huff stringhuff
```
    A Huffman encoder for string values.
  - stringhuffext
```
protected final Huff stringhuffext
```
    A Huffman encoder for string values extended bytes.
  - stringkeep
```
protected final totalcross.json.zip.Keep stringkeep
```
    A place to keep the strings.
  - valuekeep
```
protected final totalcross.json.zip.Keep valuekeep
```
    A place to keep the values.
- Constructor Detail
  - JSONzip
```
protected JSONzip()
```
    Initialize the data structures.
- Method Detail
  - generate
```
protected void generate()
```
    Generate the Huffman tables.
  - postMortem
```
public boolean postMortem(PostMortem pm)
```
    This method is used for testing the implementation of JSONzip. It is not suitable for any other purpose. It is used to compare a Compressor and a Decompressor, verifying that the data structures that were built during zipping and unzipping were the same.
    
    Specified by:
    
    postMortem in interface PostMortem
    
    Parameters:
    
    pm - Another object of the same type.
    
    Returns:
    
    true if the structures match.

Class JSONzip

Field Summary

Fields inherited from interface totalcross.json.zip.None

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

bcd

end

endOfNumber

int4

int7

int14

probe

zipEmptyObject

zipEmptyArray

zipTrue

zipFalse

zipNull

zipObject

zipArrayString

zipArrayValue

namehuff

namehuffext

namekeep

stringhuff

stringhuffext

stringkeep

valuekeep

Constructor Detail

JSONzip

Method Detail

generate

postMortem