BaseNcodingPascal
1.0.0
Este é um porto de Basencoding para Pascal.
Existem algoritmos bem conhecidos para dados binários para codificação de cordas, como algoritmos com radix de potência de 2 (base32, base64) e algoritmos sem potência de 2 (base85, base91).
Esta biblioteca implementa o algoritmo para o caso geral, ou seja, o alfabeto personalizado pode ser usado (alfabeto com comprimento personalizado).
A idéia de algoritmo desenvolvida é baseada na codificação Base85, exceto que o tamanho do bloco não é constante, mas é calculado dependendo do comprimento do alfabeto.
### Etapas do algoritmo
Para o cálculo ideal do tamanho do bloco, foram usadas as seguintes considerações:
Neste sistema:
O diagrama de tamanho ideal do bloco e dependência do comprimento do alfabeto foi calculado com a ajuda do sistema acima:
Pode -se ver que as codificações conhecidas base64, base85 e base91 foram desenvolvidas em pontos positivos (tamanho mínimo de bloco com boa taxa de compressão).
Para o bloco de bits para chars Block, foi utilizada a implementação Biginteger na minha biblioteca BigMumber, DelphibigNumberxlib com algumas pequenas modificações.
Porting guidelines:
1. All file names (units) are the same, but with a "u" prefix.
2. Some variables were closely named.
3. Some functions were written by me because I could not find a Delphi/
FreePascal Equivalent of the C# function used, in the RTL or for Backwards
Compatibility with older Unicode versions of Delphi or FreePascal.
Hints about the code:
1. Multi-condition "for" loops and loops where iterator gets changed inside
the loop were converted to while loops.
2. Log method (Delphi/FreePascal Equivalent "LogN"), two arguments (a, newBase) needed to be
swapped in Delphi/FreePascal.
3. This Library was written with (Delphi 10 Seattle Update 1) but will
work fine with anything from Delphi 2010 and FreePascal 3.0.0 Upwards.
4. "Parallel version" was implemented using PPL (Parallel Programming Library)
but will only work in Delphi XE7 Upwards.
5. This Library was written with the Object Oriented Paradigm (Class-Based) but
implements memory management through reference counting with the help of
Interfaces (that is, created objects or class instances are "freed" once they
go out of scope).
6. If you are working with FreePascal in which the String and Char types are Mapped
to "AnsiString" and "AnsiChar" by Default, you could "remap" them to "UnicodeString"
and "UnicodeChar" by declaring "{$mode delphiunicode}" at the top of your unit
excluding the ("") symbols.
Common pitfalls during porting:
1. Calling Log methods without swapping arguments places.
2. Writing for .. to .. do loop instead of for .. downto .. do in rare cases.
3. Differences in Order of Operator Precedence between C# and Pascal.
Exemplos de código ###
// Here is a Little Snippet showing Usage for Base32 Operations.
uses
SysUtils, BcpBase32, BcpIBaseInterfaces, BcpBaseFactory;
procedure TForm1.Button1Click (Sender: TObject);
var
B32: IBase32;
EncodedString, DecodedString, BaseAlphabet: { $IFDEF FPC } UnicodeString { $ELSE } String { $ENDIF } ;
DecodedArray: TBytes;
BaseSpecial: { $IFDEF FPC } UnicodeChar { $ELSE } Char { $ENDIF } ;
begin
// Creates a Base32 Instance with Default Values. You can Specify your Desired
// Parameters During Creation of the Instance.
B32 := TBase32.Create();
// Accepts a String and Encodes it Internally using UTF8 as the Default Encoding
EncodedString := B32.EncodeString( ' TestValue ' );
// Accepts an Encoded String and Decodes it Internally using UTF8 as the Default Encoding
DecodedString := B32.DecodeToString(EncodedString);
// Accepts a Byte Array and Encodes it.
EncodedString := B32.Encode(TEncoding.ANSI.GetBytes( ' TestValue ' ));
// Accepts an Encoded String and Decodes it. (Returns a Byte Array)
DecodedArray := B32.Decode(EncodedString);
// Property that allows you to modifies The Encoding of the Created Instance.
B32.Encoding := TEncoding.Unicode;
// Property that allows you to get The Base Alphabets used to perform the Encoding.
BaseAlphabet := B32.Alphabet;
// Property that allows you to get The Base Char (Padder) used to perform the Encoding.
BaseSpecial := B32.Special;
// There are some other important properties but those are left for you to figure out. :)
// Also no need to "Free" the Created Instance Since it is Reference Counted.
// or for a simple one-liner to Base32 Encode a String
TBaseFactory.CreateBase32().EncodeString( ' Fish ' );
end ;Testes de unidade.
Para executar testes de unidade,
Para FPC 3.0.0 e acima
Simply compile and run "BaseNcoding.Tests" project in "FreePascal.Tests" Folder.
Para Delphi 2010 e acima
Método um (usando Dunit Test Runner)
To Build and Run the Unit Tests For Delphi 10 Seattle (should be similar for
other versions)
1). Open Project Options of Unit Test (BaseNcoding.Tests) in "Delphi.Tests" Folder.
2). Change Target to All Configurations (Or "Base" In Older Delphi Versions.)
3). In Output directory add ".$(Platform)$(Config)" without the quotes.
4). In Search path add "$(BDS)SourceDUnitsrc" without the quotes.
5). In Unit output directory add "." without the quotes.
6). In Unit scope names (If Available), Delete "DUnitX" from the List.
Press Ok and save, then build and run.
Método dois (usando o testInsight) (preferido).
1). Download and Install TestInsight.
2). Open Project Options of Unit Test (BaseNcoding.Tests.TestInsight) in "Delphi.Tests"
Folder.
3). Change Target to All Configurations (Or "Base" In Older Delphi Versions.)
4). In Unit scope names (If Available), Delete "DUnitX" from the List.
5). To Use TestInsight, right-click on the project, then select
"Enable for TestInsight" or "TestInsight Project".
Save Project then Build and Run Test Project through TestInsight.
###Licença
Este "software" está licenciado sob MIT License (MIT) .
1MhFfW7tDuEHQSgie65uJcAfJgCNchGeKf0x6c1DC21aeC49A822A4f1E3bf07c623C2C1978a98345367-40###Conclusão
Agradecimentos especiais a Ivan Kochurkin por esta biblioteca incrível.
