http断点续传的单元

{******************************************************************************
    文件名称： uWnDownLoadHelper.pas
    文件功能： 断点续传下载线程单元
    作者    ： enli
--------------------------------------------------------------------------------}

unit uWnDownLoadHelper;

interface

uses
  IdHTTP, IdAuthentication, IdHeaderList, IniFiles, md5,
  SysUtils, IdAuthenticationSSPI, IdAuthenticationDigest, Classes, IdException,
  IdSocks, IdIOHandlerSocket, DateUtils, IdComponent, Forms,ucchttpClient;

const
  S_TMP_POSTFIX = '.tmp';
  S_INI_POSTFIX = '.sni';

type
  TWnDownloadProgress = procedure(APosition,ACount: Int64) of object;

  // 代理设置结构
  TWnProxySetting = packed record
    FIsProxyEnabled: Boolean;
    FSocksVersion: TSocksVersion;
    FProxyHost: string;
    FProxyPort: Word;
    FAuthUserName: string;
    FAuthPassword: string;
    FAuthDomain:string;
  end;
  PWnProxySetting = ^TWnProxySetting;

  TWnDownLoadThread = class(TThread)
  private
    FHttp: TCCHTTPClient;
    FProxy: TWnProxySetting;
    FTarget: string;
    FSaveFile: string;
    FTempFile: string;
    FProgress: TWnDownloadProgress;
    FCurrentFileSize,FFileSize : Int64;
    FSaveLocation: string;
    FOnLog: TDolog;
    FWarningMsg: string;
    FReLoad: Boolean;
    procedure SetProxy(const Value: PWnProxySetting);
    function GetProxy :PWnProxySetting;
    procedure SetHttpProxy;
    procedure SetTarget(const Value: string);
    procedure SetProgress(const Value: TWnDownloadProgress);
    procedure DoBeginWork(Sender: TObject;const APos,ACount: Int64);
    procedure DoWork(Sender: TObject;const AWork:Int64);
    procedure DoEndWork(Sender: TObject);
    procedure DoUpdateUI;
    procedure SetSaveLocation(const Value: string);
    procedure SaveIniFile;
    procedure DelIniFile;
    procedure DoLog(const AMsg:string);
    procedure DoSycLog;
    function GetTempFile:string;
    procedure SetOnLog(const Value: TDolog);
    procedure SetReLoad(const Value: Boolean);
  public
    procedure Execute; override;
    constructor Create;
    destructor Destroy; override;
    class procedure chunkedConvertToFile(const ASource,ADestination:string);
    property PProxy:PWnProxySetting read GetProxy write SetProxy;
    property Target:string read FTarget write SetTarget;
    property SaveLocation :string read FSaveLocation write SetSaveLocation;
    property Progress:TWnDownloadProgress read FProgress write SetProgress;
    property ReLoad:Boolean read FReLoad write SetReLoad;
    property OnLog: TDolog read FOnLog write SetOnLog;
  end;

  procedure DownLoadFile(const AUrl,ASaveFile:string;AProxy:PWnProxySetting;AProgress:TWnDownloadProgress;ALog:TDolog;AReLoad:Boolean);

implementation

procedure DownLoadFile(const AUrl,ASaveFile:string;AProxy:PWnProxySetting;AProgress:TWnDownloadProgress;ALog:TDolog;AReLoad:Boolean);
var
  LThread: TWnDownLoadThread;
begin
  LThread := TWnDownLoadThread.Create;
  LThread.ReLoad := AReLoad;
  LThread.Target := AUrl;
  LThread.SaveLocation := ASaveFile;
  LThread.PProxy := AProxy;
  LThread.Progress :=AProgress;
  LThread.OnLog := ALog;
  LThread.Resume;
end;

{ TWnDownLoadThread }

class procedure TWnDownLoadThread.chunkedConvertToFile(const ASource,
  ADestination: string);
var
  LSStream,LDStream: TFileStream;
  LBuff: Byte;
  LFlag: Boolean;
  LTemp : string;
  I,LCount : Integer;
begin
  if not FileExists(ASource) then Exit;
  if FileExists(ADestination) then Exit;
  LSStream := TFileStream.Create(ASource,fmOpenRead    );
  LDStream := TFileStream.Create(ADestination,fmCreate);
  try
    LSStream.Seek(0,0);
    LFlag := True;
    I := 0;
    while LFlag do
    begin
      LSStream.Read(LBuff,SizeOf(Byte));
      Inc(I);
      if (LBuff = $0A) and (I>2) and (LTemp[I-1] = #$0D) then begin
        LCount := StrToIntDef('$'+trim(LTemp),1);
        if LCount = 1 then
        begin
          LCount := 0;
          Break;
          //raise 异常
        end;
        if LCount = 0 then
          LFlag := False
        else
        begin
          LDStream.CopyFrom(LSStream,LCount);
          I := 0;
          LTemp := '';
        end;
      end
      else
        LTemp := LTemp + Char(LBuff);
    end;

  finally
    FreeAndNil(LSStream);
    FreeAndNil(LDStream);
  end;

end;

constructor TWnDownLoadThread.Create;
begin
  inherited Create(True);
  FreeOnTerminate := True;
  FTarget := '';
  FSaveFile := '';
  //New(FProxy);
end;

procedure TWnDownLoadThread.DelIniFile;
begin
  DeleteFile(FSaveLocation + FTempFile+S_INI_POSTFIX);
end;

destructor TWnDownLoadThread.Destroy;
begin
  //Dispose(FProxy);
  inherited;
end;

procedure TWnDownLoadThread.DoBeginWork(Sender: TObject;
  const APos,ACount: Int64);
begin
  FFileSize := ACount;
  FCurrentFileSize := APos ;
  SaveIniFile;
  Synchronize(DoUpdateUI);
end;

procedure TWnDownLoadThread.DoEndWork(Sender: TObject);
begin
  FCurrentFileSize := FFileSize;
  Synchronize(DoUpdateUI);
end;

procedure TWnDownLoadThread.DoLog(const AMsg: string);
begin
  if Assigned(FOnlog) then
  begin
    ///DoDownLoadLog(AMsg);
    FWarningMsg:= AMsg;
    Synchronize(DoSycLog);
  end;
end;

procedure TWnDownLoadThread.DoSycLog;
begin
  FOnlog(FWarningMsg);
end;

procedure TWnDownLoadThread.DoUpdateUI;
begin
  if Assigned(FProgress) then
    FProgress(FCurrentFileSize,FFileSize);
end;

procedure TWnDownLoadThread.DoWork(Sender: TObject; const AWork: Int64);
begin
  FCurrentFileSize := FCurrentFileSize+ AWork;
  Synchronize(DoUpdateUI);
end;

procedure TWnDownLoadThread.Execute;
var
  LDoc,
  LHost,
  LPath,
  LProto,
  LPort,
  LBookmark: string;
begin
  if Length(FTarget) = 0 then Exit;
  if Length(FSaveLocation) = 0 then Exit;
  FHttp := TCCHTTPClient.Create(nil);
  try
    FHttp.IOHandler := TIdIOHandlerSocket.Create(FHttp);
    FHttp.Socket.SocksInfo := TIdSocksInfo.Create(FHttp);
    FHttp.ProtocolVersion := uCCHTTPClient.pv1_1;    
    SetHttpProxy;
    FHttp.OnDownloadBegin :=  DoBeginWork;
    FHttp.OnDownload :=  DoWork;
    FHttp.OnDownloadEnd := DoEndWork;
    FHttp.OnLog := DoLog;

    FHttp.ParseURI(FTarget, LProto, LHost, LPath, LDoc, LPort, LBookmark);
    FSaveFile := LDoc;
    FTempFile := GetTempFile+'.'+LDoc;
    if FReLoad and FileExists(FSaveLocation + FTempFile+S_TMP_POSTFIX) then
      DeleteFile(FSaveLocation + FTempFile+S_TMP_POSTFIX);
    DoLog('下载开始请求');
    try
      FHttp.DownLoad(FTarget,FSaveLocation + FTempFile+S_TMP_POSTFIX);
    except
      on E:Exception do
        DoLog(e.Message);
    end;
    if FileExists(FSaveLocation + FTempFile+S_INI_POSTFIX) then
    begin

      if FileExists(FSaveLocation + LDoc) then
        DeleteFile(FSaveLocation + LDoc);
      if FHttp.Response.TransferEncoding = 'chunked' then
      begin
        chunkedConvertToFile(FSaveLocation + FTempFile+S_TMP_POSTFIX,FSaveLocation + LDoc);
        DeleteFile(FSaveLocation + FTempFile+S_TMP_POSTFIX);
      end
      else
        RenameFile(FSaveLocation + FTempFile+S_TMP_POSTFIX,FSaveLocation + LDoc);
      DelIniFile;
    end
    else
      DeleteFile(FSaveLocation + FTempFile+S_TMP_POSTFIX);
  finally
    FreeAndNil(FHttp);
    DoLog('下载结束');
  end;
end;

function TWnDownLoadThread.GetProxy: PWnProxySetting;
begin
  Result := @FProxy
end;

function TWnDownLoadThread.GetTempFile: string;
var
  Ltemp: string;
begin
  Ltemp := MD5Print(MD5String(FTarget));
  //Ltemp := copy(Ltemp, 2, length(Ltemp) - 2);
  Result := StringReplace(Ltemp,'-','.',[rfReplaceAll]    );
end;

procedure TWnDownLoadThread.SaveIniFile;
var
  LIni:TIniFile;
begin
  LIni := TIniFile.Create(FSaveLocation + FTempFile+S_INI_POSTFIX);
  try
    LIni.WriteString('Setup','URL',FTarget);
    LIni.WriteString('Setup','SaveLocation',FSaveLocation);
    LIni.WriteString('Setup','SaveFile',FSaveFile);
    LIni.WriteString('Setup','TempFile',FTempFile);
    LIni.WriteString('Setup','FileSize',FloatToStr(FFileSize));
  finally
    LIni.Free;
  end;

end;

procedure TWnDownLoadThread.SetHttpProxy;
begin
  if not Assigned(FHttp) then Exit;
  with FProxy do
  if FIsProxyEnabled then
  begin
    FHttp.Socket.SocksInfo.Version := FSocksVersion;
    FHttp.Socket.SocksInfo.Host := FProxyHost;
    FHttp.Socket.SocksInfo.Port := FProxyPort;

    if FHttp.Socket.SocksInfo.Username <> '' then
      FHttp.Socket.SocksInfo.Authentication := saUsernamePassword
    else
      FHttp.Socket.SocksInfo.Authentication := saNoAuthentication;
    FHttp.AuthUsername := FAuthUserName;
    FHttp.AuthPassword := FAuthPassword;
    FHttp.AuthDomain   := FAuthDomain;
    FHttp.ProxyHost    := FProxyHost;
    FHttp.ProxyPort    := FProxyPort;
  end;
end;

procedure TWnDownLoadThread.SetOnLog(const Value: TDolog);
begin
  FOnLog := Value;
end;

procedure TWnDownLoadThread.SetProgress(const Value: TWnDownloadProgress);
begin
  FProgress := Value;
end;

procedure TWnDownLoadThread.SetProxy(const Value: PWnProxySetting);
begin
    //New(FProxy);
    FProxy.FIsProxyEnabled :=Value^.FIsProxyEnabled;
    FProxy.FSocksVersion := Value^.FSocksVersion;
    FProxy.FProxyHost := Value^.FProxyHost;
    FProxy.FProxyPort := Value^.FProxyPort;
    FProxy.FAuthUserName := Value^.FAuthUserName;
    FProxy.FAuthPassword := Value^.FAuthPassword;
    FProxy.FAuthDomain   := Value^.FAuthDomain;
    FProxy.FProxyHost   := Value^.FProxyHost;
    FProxy.FProxyPort    := Value^.FProxyPort;

end;

procedure TWnDownLoadThread.SetReLoad(const Value: Boolean);
begin
  FReLoad := Value;
end;

procedure TWnDownLoadThread.SetSaveLocation(const Value: string);
begin
  FSaveLocation := Value;
  if FSaveLocation[Length(FSaveLocation)] <> '\' then
    FSaveLocation := FSaveLocation +'\';
end;

procedure TWnDownLoadThread.SetTarget(const Value: string);
begin
  if Length(Value) = 0 then Exit;
  if UpperCase(Copy(Value,1,7)) <> 'HTTP://' then Exit;
  FTarget := Value;
end;

　　end.

  备忘：IdDownLoad