BaseNcodingPascal下載 - BaseNcodingPascal源代碼下載

BaseNcodingPascal

Delphi源碼

1.0.0

下載

Basencodingpascal

這是帕斯卡爾的底座編碼的港口。

有二進制數據的算法眾所周知，用於字符串編碼，例如具有2（base32，base64）的電源的算法和無功率為2（base85，base91）的算法。

該庫實現了一般情況的算法，即可以使用自定義字母（具有自定義長度的字母）。

開發算法的概念基於Base85編碼，除了塊大小不是恆定的，而是根據字母長度計算的。

###算法的步驟

計算位和字符中的塊大小。
將輸入字符串轉換為字節數組（使用UTF8編碼）。
在n位組上分裂字節陣列。
每個小組與radix n的對話。
尾部處理。

對於最佳塊大小計算，已使用以下考慮：

在此系統中：

A - 字母長度a 。
K - 編碼字符的計數。
b - 一個數字radix基座（大多數情況下為2個）。
n - radix b中的位用於表示字母a的k字符a。
R - 壓縮比（更大的比較更好）。
MBC-最大塊位計數。
⌊x⌋-最大的整數不大於x（地板）。
⌈x⌉-最小的整數不小於x（天花板）。

最佳塊大小和字母長度依賴性的圖是在上述系統的幫助下計算的：

可以看到已知的基本64，base85，base91編碼已經以優點開發（最小的塊大小具有良好的壓縮比）。

對於BITS塊到Chars塊，我的Biginteger庫中的BigInteger實現使用了一些微小的修改。

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.

###代碼示例

     // 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 ;

單位測試。

要運行單元測試，

對於FPC 3.0.0及以上

 Simply compile and run "BaseNcoding.Tests" project in "FreePascal.Tests" Folder.

對於Delphi 2010及以上

方法一（使用Dunit測試跑者）

 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.

方法兩個（使用TestInsight）（首選）。

 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.

＃＃＃執照

此“軟件”是根據MIT License (MIT)許可的。