如何快速获取文件的MD5？(300)

{******************************************************************************}{                       CnPack For Delphi/C++Builder                           }{                     中国人自己的开放源码第三方开发包                         }{                   (C)Copyright 2001-2009 CnPack 开发组                       }{                   ------------------------------------                       }{                                                                              }{            本开发包是开源的自由软件，您可以遵照 CnPack 的发布协议来修        }{        改和重新发布这一程序。                                                }{                                                                              }{            发布这一开发包的目的是希望它有用，但没有任何担保。甚至没有        }{        适合特定目的而隐含的担保。更详细的情况请参阅 CnPack 发布协议。        }{                                                                              }{            您应该已经和开发包一起收到一份 CnPack 发布协议的副本。如果        }{        还没有，可访问我们的网站：                                            }{                                                                              }{            网站地址：http://www.cnpack.org                                   }{            电子邮件：master@cnpack.org                                       }{                                                                              }{******************************************************************************}{******************************************************************************}{        该单元基于Ronald L. Rivest的MD5.pas改写，以下是MD5.pas的声明：        }{ -----------------------------------------------------------------------------}{                                                                              }{                                 MD5 Message-Digest for Delphi 4              }{                                                                              }{                                 Delphi 4 Unit implementing the               }{                      RSA Data Security, Inc. MD5 Message-Digest Algorithm    }{                                                                              }{                          Implementation of Ronald L. Rivest's RFC 1321       }{                                                                              }{                      Copyright ?1997-1999 Medienagentur Fichtner & Meyer     }{                                  Written by Matthias Fichtner                }{                                                                              }{ -----------------------------------------------------------------------------}{        See RFC 1321 for RSA Data Security's copyright and license notice!    }{ -----------------------------------------------------------------------------}{        The latest release of md5.pas will always be available from           }{        the distribution site at: http://www.fichtner.net/delphi/md5/         }{ -----------------------------------------------------------------------------}{                       Please send questions, bug reports and suggestions     }{                      regarding this code to: mfichtner@fichtner-meyer.com    }{ -----------------------------------------------------------------------------}{                        This code is provided "as is" without express or      }{                     implied warranty of any kind. Use it at your own risk.   }{******************************************************************************}unit CnMD5;{* |<PRE>================================================================================* 软件名称：开发包基础库* 单元名称：MD5算法单元* 单元作者：何清（QSoft） hq.com@263.net; http://qsoft.51.net* 备    注：* 开发平台：PWin2000Pro + Delphi 5.0* 兼容测试：PWin9X/2000/XP + Delphi 5/6* 本 地 化：该单元中的字符串均符合本地化处理方式* 单元标识：$Id: CnMD5.pas,v 1.16 2009/05/03 08:51:54 liuxiao Exp $* 修改记录：2003.09.18 V1.1*               好不容易找到了该单元原作者的版权声明*           2003.09.18 V1.0*               创建单元================================================================================|</PRE>}interface{$I CnPack.inc}{$OVERFLOWCHECKS OFF}{$RANGECHECKS OFF}uses  Classes, SysUtils, Windows;type  TMD5Count = array[0..1] of DWORD;  TMD5State = array[0..3] of DWORD;  TMD5Block = array[0..15] of DWORD;  TMD5CBits = array[0..7] of byte;  TMD5Digest = array[0..15] of byte;  TMD5Buffer = array[0..63] of byte;  TMD5Context = record    State   : TMD5State;    Count   : TMD5Count;    Buffer  : TMD5Buffer;  end;   TMD5CalcProgressFunc = procedure (ATotal, AProgress: Int64;    var Cancel: Boolean) of object;  {* 进度回调事件类型声明}    procedure MD5Init(var Context: TMD5Context);procedure MD5Update(var Context: TMD5Context; Input: PAnsiChar; Length: LongWord);procedure MD5UpdateW(var Context: TMD5Context; Input: PWideChar; Length: LongWord);procedure MD5Final(var Context: TMD5Context; var Digest: TMD5Digest);//----------------------------------------------------------------// 用户API函数定义//----------------------------------------------------------------function MD5Buffer(const Buffer; Count: LongWord): TMD5Digest;{* 对数据块进行MD5转换 |<PRE>   const Buffer     - 要计算的数据块   Count: LongWord  - 数据块长度 |</PRE>}function MD5String(const Str: string): TMD5Digest;{* 对String类型数据进行MD5转换，注意D2009或以上版本的string为UnicodeString，   因此对同一个字符串的计算结果，和D2007或以下版本的会不同，使用时请注意 |<PRE>   Str: string       - 要计算的字符串 |</PRE>}function MD5StringA(const Str: AnsiString): TMD5Digest;{* 对AnsiString类型数据进行MD5转换 |<PRE>   Str: AnsiString       - 要计算的字符串 |</PRE>}function MD5StringW(const Str: WideString): TMD5Digest;{* 对 WideString类型数据进行MD5转换 |<PRE>   Str: WideString       - 要计算的字符串 |</PRE>}function MD5File(const FileName: string;  CallBack: TMD5CalcProgressFunc = nil): TMD5Digest;{* 对指定文件数据进行MD5转换 |<PRE>   FileName: string  - 要计算的文件名   CallBack: TMD5CalcProgressFunc - 进度回调函数，默认为空 |</PRE>}function MD5Stream(Stream: TStream;  CallBack: TMD5CalcProgressFunc = nil): TMD5Digest;{* 对指定流数据进行MD5转换 |<PRE>   Stream: TStream  - 要计算的流内容   CallBack: TMD5CalcProgressFunc - 进度回调函数，默认为空 |</PRE>}function MD5Print(const Digest: TMD5Digest): string;{* 以十六进制格式输出MD5计算值 |<PRE>   Digest: TMD5Digest  - 指定的MD5计算值 |</PRE>}function MD5Match(const D1, D2: TMD5Digest): Boolean;{* 比较两个MD5计算值是否相等 |<PRE>   D1: TMD5Digest   - 需要比较的MD5计算值   D2: TMD5Digest   - 需要比较的MD5计算值 |</PRE>}function MD5DigestToStr(aDig: TMD5Digest): string;{* MD5计算值转 string |<PRE>   aDig: TMD5Digest   - 需要转换的MD5计算值 |</PRE>}implementationvar  PADDING: TMD5Buffer = (    $80, $00, $00, $00, $00, $00, $00, $00,    $00, $00, $00, $00, $00, $00, $00, $00,    $00, $00, $00, $00, $00, $00, $00, $00,    $00, $00, $00, $00, $00, $00, $00, $00,    $00, $00, $00, $00, $00, $00, $00, $00,    $00, $00, $00, $00, $00, $00, $00, $00,    $00, $00, $00, $00, $00, $00, $00, $00,    $00, $00, $00, $00, $00, $00, $00, $00  );function F(x, y, z: DWORD): DWORD;asm  // Result := (x and y) or ((not x) and z);  AND EDX, EAX  NOT EAX  AND EAX, ECX  OR EAX, EDXend;function G(x, y, z: DWORD): DWORD;asm  //Result := (x and z) or (y and (not z));  AND EAX, ECX  NOT ECX  AND EDX, ECX  OR EAX, EDXend;function H(x, y, z: DWORD): DWORD;asm  //Result := x xor y xor z;  XOR EAX, EDX  XOR EAX, ECXend;function I(x, y, z: DWORD): DWORD;asm  //Result := y xor (x or (not z));  NOT ECX  OR EAX, ECX  XOR EAX, EDXend;procedure rot(var x: DWORD; n: BYTE);asm  //x := (x shl n) or (x shr (32 - n));  PUSH EBX  MOV CL, $20  SUB CL, DL  MOV EBX, [EAX]  SHR EBX, CL  MOV ECX, EDX  MOV EDX, [EAX]  SHL EDX, CL  OR EBX, EDX  MOV [EAX], EBX  POP EBXend;procedure FF(var a: DWORD; b, c, d, x: DWORD; s: BYTE; ac: DWORD);begin  inc(a, F(b, c, d) + x + ac);  rot(a, s);  inc(a, b);end;procedure GG(var a: DWORD; b, c, d, x: DWORD; s: BYTE; ac: DWORD);begin  inc(a, G(b, c, d) + x + ac);  rot(a, s);  inc(a, b);end;procedure HH(var a: DWORD; b, c, d, x: DWORD; s: BYTE; ac: DWORD);begin  inc(a, H(b, c, d) + x + ac);  rot(a, s);  inc(a, b);end;procedure II(var a: DWORD; b, c, d, x: DWORD; s: BYTE; ac: DWORD);begin  inc(a, I(b, c, d) + x + ac);  rot(a, s);  inc(a, b);end;// Encode Count bytes at Source into (Count / 4) DWORDs at Targetprocedure Encode(Source, Target: pointer; Count: LongWord);var  S: PByte;  T: PDWORD;  I: LongWord;begin  S := Source;  T := Target;  for I := 1 to Count div 4 do  begin    T^ := S^;    inc(S);    T^ := T^ or (S^ shl 8);    inc(S);    T^ := T^ or (S^ shl 16);    inc(S);    T^ := T^ or (S^ shl 24);    inc(S);    inc(T);  end;end;// Decode Count DWORDs at Source into (Count * 4) Bytes at Targetprocedure Decode(Source, Target: pointer; Count: LongWord);var  S: PDWORD;  T: PByte;  I: LongWord;begin  S := Source;  T := Target;  for I := 1 to Count do  begin    T^ := S^ and $ff;    inc(T);    T^ := (S^ shr 8) and $ff;    inc(T);    T^ := (S^ shr 16) and $ff;    inc(T);    T^ := (S^ shr 24) and $ff;    inc(T);    inc(S);  end;end;// Transform State according to first 64 bytes at Bufferprocedure Transform(Buffer: pointer; var State: TMD5State);var  a, b, c, d: DWORD;  Block: TMD5Block;begin  Encode(Buffer, @Block, 64);  a := State[0];  b := State[1];  c := State[2];  d := State[3];  FF (a, b, c, d, Block[ 0],  7, $d76aa478);  FF (d, a, b, c, Block[ 1], 12, $e8c7b756);  FF (c, d, a, b, Block[ 2], 17, $242070db);  FF (b, c, d, a, Block[ 3], 22, $c1bdceee);  FF (a, b, c, d, Block[ 4],  7, $f57c0faf);  FF (d, a, b, c, Block[ 5], 12, $4787c62a);  FF (c, d, a, b, Block[ 6], 17, $a8304613);  FF (b, c, d, a, Block[ 7], 22, $fd469501);  FF (a, b, c, d, Block[ 8],  7, $698098d8);  FF (d, a, b, c, Block[ 9], 12, $8b44f7af);  FF (c, d, a, b, Block[10], 17, $ffff5bb1);  FF (b, c, d, a, Block[11], 22, $895cd7be);  FF (a, b, c, d, Block[12],  7, $6b901122);  FF (d, a, b, c, Block[13], 12, $fd987193);  FF (c, d, a, b, Block[14], 17, $a679438e);  FF (b, c, d, a, Block[15], 22, $49b40821);  GG (a, b, c, d, Block[ 1],  5, $f61e2562);  GG (d, a, b, c, Block[ 6],  9, $c040b340);  GG (c, d, a, b, Block[11], 14, $265e5a51);  GG (b, c, d, a, Block[ 0], 20, $e9b6c7aa);  GG (a, b, c, d, Block[ 5],  5, $d62f105d);  GG (d, a, b, c, Block[10],  9,  $2441453);  GG (c, d, a, b, Block[15], 14, $d8a1e681);  GG (b, c, d, a, Block[ 4], 20, $e7d3fbc8);  GG (a, b, c, d, Block[ 9],  5, $21e1cde6);  GG (d, a, b, c, Block[14],  9, $c33707d6);  GG (c, d, a, b, Block[ 3], 14, $f4d50d87);  GG (b, c, d, a, Block[ 8], 20, $455a14ed);  GG (a, b, c, d, Block[13],  5, $a9e3e905);  GG (d, a, b, c, Block[ 2],  9, $fcefa3f8);  GG (c, d, a, b, Block[ 7], 14, $676f02d9);  GG (b, c, d, a, Block[12], 20, $8d2a4c8a);  HH (a, b, c, d, Block[ 5],  4, $fffa3942);  HH (d, a, b, c, Block[ 8], 11, $8771f681);  HH (c, d, a, b, Block[11], 16, $6d9d6122);  HH (b, c, d, a, Block[14], 23, $fde5380c);  HH (a, b, c, d, Block[ 1],  4, $a4beea44);  HH (d, a, b, c, Block[ 4], 11, $4bdecfa9);  HH (c, d, a, b, Block[ 7], 16, $f6bb4b60);  HH (b, c, d, a, Block[10], 23, $bebfbc70);  HH (a, b, c, d, Block[13],  4, $289b7ec6);  HH (d, a, b, c, Block[ 0], 11, $eaa127fa);  HH (c, d, a, b, Block[ 3], 16, $d4ef3085);  HH (b, c, d, a, Block[ 6], 23,  $4881d05);  HH (a, b, c, d, Block[ 9],  4, $d9d4d039);  HH (d, a, b, c, Block[12], 11, $e6db99e5);  HH (c, d, a, b, Block[15], 16, $1fa27cf8);  HH (b, c, d, a, Block[ 2], 23, $c4ac5665);  II (a, b, c, d, Block[ 0],  6, $f4292244);  II (d, a, b, c, Block[ 7], 10, $432aff97);  II (c, d, a, b, Block[14], 15, $ab9423a7);  II (b, c, d, a, Block[ 5], 21, $fc93a039);  II (a, b, c, d, Block[12],  6, $655b59c3);  II (d, a, b, c, Block[ 3], 10, $8f0ccc92);  II (c, d, a, b, Block[10], 15, $ffeff47d);  II (b, c, d, a, Block[ 1], 21, $85845dd1);  II (a, b, c, d, Block[ 8],  6, $6fa87e4f);  II (d, a, b, c, Block[15], 10, $fe2ce6e0);  II (c, d, a, b, Block[ 6], 15, $a3014314);  II (b, c, d, a, Block[13], 21, $4e0811a1);  II (a, b, c, d, Block[ 4],  6, $f7537e82);  II (d, a, b, c, Block[11], 10, $bd3af235);  II (c, d, a, b, Block[ 2], 15, $2ad7d2bb);  II (b, c, d, a, Block[ 9], 21, $eb86d391);  inc(State[0], a);  inc(State[1], b);  inc(State[2], c);  inc(State[3], d);end;// Initialize given Contextprocedure MD5Init(var Context: TMD5Context);begin  with Context do  begin    State[0] := $67452301;    State[1] := $efcdab89;    State[2] := $98badcfe;    State[3] := $10325476;    Count[0] := 0;    Count[1] := 0;    ZeroMemory(@Buffer, SizeOf(TMD5Buffer));  end;end;// Update given Context to include Length bytes of Inputprocedure MD5Update(var Context: TMD5Context; Input: PAnsiChar; Length: LongWord);var  Index: LongWord;  PartLen: LongWord;  I: LongWord;begin  with Context do  begin    Index := (Count[0] shr 3) and $3f;    inc(Count[0], Length shl 3);    if Count[0] < (Length shl 3) then inc(Count[1]);    inc(Count[1], Length shr 29);  end;  PartLen := 64 - Index;  if Length >= PartLen then  begin    CopyMemory(@Context.Buffer[Index], Input, PartLen);    Transform(@Context.Buffer, Context.State);    I := PartLen;    while I + 63 < Length do    begin      Transform(@Input[I], Context.State);      inc(I, 64);    end;    Index := 0;  end  else I := 0;  CopyMemory(@Context.Buffer[Index], @Input[I], Length - I);end;procedure MD5UpdateW(var Context: TMD5Context; Input: PWideChar; Length: LongWord);var  pContent: PAnsiChar;  iLen: Cardinal;begin  GetMem(pContent, Length * SizeOf(WideChar));  try    iLen := WideCharToMultiByte(0, 0, Input, Length, // 代码页默认用 0      PAnsiChar(pContent), Length * SizeOf(WideChar), nil, nil);    MD5Update(Context, pContent, iLen);  finally    FreeMem(pContent);  end;end;// Finalize given Context, create Digest and zeroize Contextprocedure MD5Final(var Context: TMD5Context; var Digest: TMD5Digest);var  Bits: TMD5CBits;  Index: LongWord;  PadLen: LongWord;begin  Decode(@Context.Count, @Bits, 2);  Index := (Context.Count[0] shr 3) and $3f;  if Index < 56 then    PadLen := 56 - Index  else    PadLen := 120 - Index;  MD5Update(Context, @PADDING, PadLen);  MD5Update(Context, @Bits, 8);  Decode(@Context.State, @Digest, 4);  ZeroMemory(@Context, SizeOf(TMD5Context));end;function InternalMD5Stream(Stream: TStream; const BufSize: Cardinal; var D:  TMD5Digest; CallBack: TMD5CalcProgressFunc = nil): Boolean;var  Context: TMD5Context;  Buf: PAnsiChar;  BufLen: Cardinal;  Size: Int64;  ReadBytes: Cardinal;  TotalBytes: Int64;  SavePos: Int64;  CancelCalc: Boolean;begin  Result := False;  Size := Stream.Size;  SavePos := Stream.Position;  TotalBytes := 0;  if Size = 0 then Exit;  if Size < BufSize then BufLen := Size  else BufLen := BufSize;  CancelCalc := False;  MD5Init(Context);  GetMem(Buf, BufLen);  try    Stream.Seek(0, soFromBeginning);    repeat      ReadBytes := Stream.Read(Buf^, BufLen);      if ReadBytes <> 0 then      begin        Inc(TotalBytes, ReadBytes);        MD5Update(Context, Buf, ReadBytes);        if Assigned(CallBack) then        begin          CallBack(Size, TotalBytes, CancelCalc);          if CancelCalc then Exit;        end;      end;    until (ReadBytes = 0) or (TotalBytes = Size);    MD5Final(Context, D);    Result := True;  finally    FreeMem(Buf, BufLen);    Stream.Position := SavePos;  end;end;//----------------------------------------------------------------// 用户API函数实现//----------------------------------------------------------------// 对数据块进行MD5转换function MD5Buffer(const Buffer; Count: Longword): TMD5Digest;var  Context: TMD5Context;begin  MD5Init(Context);  MD5Update(Context, PAnsiChar(Buffer), Count);  MD5Final(Context, Result);end;// 对String类型数据进行MD5转换function MD5String(const Str: string): TMD5Digest;var  Context: TMD5Context;begin  MD5Init(Context);  MD5Update(Context, PAnsiChar(Str), Length(Str) * SizeOf(Char));  MD5Final(Context, Result);end;// 对AnsiString类型数据进行MD5转换function MD5StringA(const Str: AnsiString): TMD5Digest;var  Context: TMD5Context;begin  MD5Init(Context);  MD5Update(Context, PAnsiChar(Str), Length(Str));  MD5Final(Context, Result);end;// 对WideString类型数据进行MD5转换function MD5StringW(const Str: WideString): TMD5Digest;var  Context: TMD5Context;begin  MD5Init(Context);  MD5UpdateW(Context, PWideChar(Str), Length(Str));  MD5Final(Context, Result);end;// 对指定文件数据进行MD5转换function MD5File(const FileName: string;  CallBack: TMD5CalcProgressFunc): TMD5Digest;var  FileHandle: THandle;  MapHandle: THandle;  ViewPointer: Pointer;  Context: TMD5Context;  Stream: TStream;  function FileSizeIsLargeThan2G(const AFileName: string): Boolean;  var    H: THandle;    Info: BY_HANDLE_FILE_INFORMATION;    Rec : Int64Rec;  begin    Result := False;    H := CreateFile(PChar(FileName), GENERIC_READ, FILE_SHARE_READ, nil, OPEN_EXISTING, 0, 0);    if H = INVALID_HANDLE_VALUE then Exit;    if not GetFileInformationByHandle(H, Info) then Exit;    CloseHandle(H);    Rec.Lo := Info.nFileSizeLow;    Rec.Hi := Info.nFileSizeHigh;    Result := (Rec.Hi > 0) or (Rec.Lo > Cardinal(MaxInt));  end;begin  if FileSizeIsLargeThan2G(FileName) then  begin    // 大于 2G 的文件可能 Map 失败，采用流方式循环处理    Stream := TFileStream.Create(FileName, fmOpenRead or fmShareDenyWrite);    try      InternalMD5Stream(Stream, 4096 * 1024, Result, CallBack);    finally      Stream.Free;    end;  end  else  begin    MD5Init(Context);    FileHandle := CreateFile(PChar(FileName), GENERIC_READ, FILE_SHARE_READ or                  FILE_SHARE_WRITE, nil, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL or                  FILE_FLAG_SEQUENTIAL_SCAN, 0);    if FileHandle <> INVALID_HANDLE_VALUE then      try        MapHandle := CreateFileMapping(FileHandle, nil, PAGE_READONLY, 0, 0, nil);        if MapHandle <> 0 then          try            ViewPointer := MapViewOfFile(MapHandle, FILE_MAP_READ, 0, 0, 0);            if ViewPointer <> nil then              try                MD5Update(Context, ViewPointer, GetFileSize(FileHandle, nil));              finally                UnmapViewOfFile(ViewPointer);              end;          finally            CloseHandle(MapHandle);          end;      finally        CloseHandle(FileHandle);      end;    MD5Final(Context, Result);  end;end;// 对指定流进行MD5计算function MD5Stream(Stream: TStream;  CallBack: TMD5CalcProgressFunc = nil): TMD5Digest;begin  InternalMD5Stream(Stream, 4096 * 1024, Result, CallBack);end;// 以十六进制格式输出MD5计算值function MD5Print(const Digest: TMD5Digest): string;var  I: byte;const  Digits: array[0..15] of AnsiChar = ('0', '1', '2', '3', '4', '5', '6', '7',                                  '8', '9', 'A', 'B', 'C', 'D', 'E', 'F');begin  Result := '';  for I := 0 to 15 do    Result := Result + Digits[(Digest[I] shr 4) and $0f] +              Digits[Digest[I] and $0f];end;// 比较两个MD5计算值是否相等function MD5Match(const D1, D2: TMD5Digest): Boolean;var  I: byte;begin  I := 0;  Result := TRUE;  while Result and (I < 16) do  begin    Result := D1[I] = D2[I];    inc(I);  end;end;// MD5计算值转 stringfunction MD5DigestToStr(aDig: TMD5Digest): string;var  I: Integer;begin  SetLength(Result, 16);  for I := 1 to 16 do    Result[I] := Chr(aDig[I - 1]);end;end.