BaseNcodingPascal
1.0.0
Dies ist ein Basiskodierhafen für Pascal.
Es gibt bekannte Algorithmen für binäre Daten zur String-Codierung, wie Algorithmen mit Stromradix von 2 (Base32, Base64) und Algorithmen ohne Leistung von 2 (Base85, Base91).
Diese Bibliothek implementiert Algorithmus für den allgemeinen Fall, dh ein benutzerdefiniertes Alphabet (Alphabet mit benutzerdefinierter Länge).
Die Idee des entwickelten Algorithmus basiert auf der Base85 -Codierung, außer dass die Blockgröße nicht konstant ist, sondern je nach Alphabetlänge berechnet wird.
### Schritte des Algorithmus
Für eine optimale Berechnung der Blockgröße wurden folgende Überlegungen verwendet:
In diesem System:
Das Diagramm der optimalen Blockgröße und der Abhängigkeit von Alphabetlängen wurde mit Hilfe des oben genannten Systems berechnet:
Man kann sehen, dass bekannte Base64, Base85, Base91 -Codierungen in guten Punkten entwickelt wurden (minimale Blockgröße mit gutem Komprimierungsverhältnis).
Für Bits Block to Chars Block wurde die BiginTeger -Implementierung in meiner BIGNUMBER -Bibliothek DelphibignumberxLib mit einigen leichten Modifikationen verwendet.
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.
### Code Beispiele
// 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 { $ENDIF } ;
begin
// Creates a Base32 Instance with Default Values. You can Specify your Desired
// Parameters During Creation of the Instance.
B32 := TBase32.Create();
// Accepts a String and Encodes it Internally using UTF8 as the Default Encoding
EncodedString := B32.EncodeString( ' TestValue ' );
// Accepts an Encoded String and Decodes it Internally using UTF8 as the Default Encoding
DecodedString := B32.DecodeToString(EncodedString);
// Accepts a Byte Array and Encodes it.
EncodedString := B32.Encode(TEncoding.ANSI.GetBytes( ' TestValue ' ));
// Accepts an Encoded String and Decodes it. (Returns a Byte Array)
DecodedArray := B32.Decode(EncodedString);
// Property that allows you to modifies The Encoding of the Created Instance.
B32.Encoding := TEncoding.Unicode;
// Property that allows you to get The Base Alphabets used to perform the Encoding.
BaseAlphabet := B32.Alphabet;
// Property that allows you to get The Base Char (Padder) used to perform the Encoding.
BaseSpecial := B32.Special;
// There are some other important properties but those are left for you to figure out. :)
// Also no need to "Free" the Created Instance Since it is Reference Counted.
// or for a simple one-liner to Base32 Encode a String
TBaseFactory.CreateBase32().EncodeString( ' Fish ' );
end ;Unit -Tests.
Einheitstests ausführen,
Für FPC 3.0.0 und höher
Simply compile and run "BaseNcoding.Tests" project in "FreePascal.Tests" Folder.
Für Delphi 2010 und höher
Methode eins (mit Dunit -Testläufer)
To Build and Run the Unit Tests For Delphi 10 Seattle (should be similar for
other versions)
1). Open Project Options of Unit Test (BaseNcoding.Tests) in "Delphi.Tests" Folder.
2). Change Target to All Configurations (Or "Base" In Older Delphi Versions.)
3). In Output directory add ".$(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.
Methode zwei (unter Verwendung von TestInsight) (bevorzugt).
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.
###Lizenz
Diese "Software" ist unter MIT License (MIT) lizenziert.
1MhFfW7tDuEHQSgie65uJcAfJgCNchGeKf0x6c1DC21aeC49A822A4f1E3bf07c623C2C1978a98345367-40###Abschluss
Besonderer Dank geht an Ivan Kochurkin für diese großartige Bibliothek.
