Zipping/Unzipping with thread

[otomazeli]

Hello Kevin,

I'm actually working for a company that uses your zip component; it works really great, well done!

I'm designing a data transfer using ftp protocol and I'm using TVCLzip/unzip to do it. My question is ::)I have many clients connecting to my server and sending zipped files and I need receive all files at the same time and unzip them in the right place so I need to start many instances of TVCLUnzip at the same time my question TVCLUnzip can handle this by itself or I need to implement something using thread? I'm not very expert with threads can you help me with that? Do you have any example?

Thanks in advance for any information ;D

[Kevin]

Hi!

VCLZip won't handle that by itself. But it will work if you create separate instances of VCLZip. So yes, you will probably want to use threads.

My experience with threads is mostly in Java, but I believe they should be very similar so I will see if I can put together a simple example.

Kevin

[Kevin]

This has not been tested or even compiled so it likely has errors, this is only meant to be a possible example...


Here is an example of the thread class.  ==============

interface

uses
 TVCLUnZip;

type
 TVCLZipThrd = class(TThread)
 private
   unzipper: TVCLUnZip;
   FDestination: String;
   FZipFileName: String;
 protected
   procedure Execute; override;
 public
   property Destination: String write FDestination;
   property ZipFileName: String write FZipFileName;
 end;

implementation


procedure TVCLZipThrd.Execute;
begin
 unzipper := TVCLUnzip.Create(nil);
 unzipper.ZipName := FZipFileName;
 unzipper.DestDir := FDesination;
 unzipper.RecreateDirs := true;
 unzipper.Unzip;
end;

end.


Here is an example of calling the thread.  =============

procedure MainObject.SpawnUnZip(Archive: String; Dest: String);

var
 NewThread: TPrimeThrd;

begin
 NewThread := TVCLZipThrd.Create(True);
 NewThread.FreeOnTerminate := True;
 try
   NewThread.ZipFileName := Archive;
   NewThread.Destination := Dest;
   NewThread.Resume;
 except
   begin
     NewThread.Free;
     // Log errors here
   end;
 end;
end;



[otomazeli]

Thank you very much for the example, I'm going to test right now and I let you know how it work out.

Thank you very much

Regards,

[Kevin]

Let us know how it goes!!! :-)

[otomazeli]

Hi,

Here my first class using with Indy 10


unit ThreadZip;

interface

uses
 Classes, Windows, VCLUnZip, VCLZip, IdCommandHandlers, IdContext, SysUtils, ComCtrls;

type
 TDisplayStatus = procedure(Msg: string; Senderror: Boolean; ErrorType, ErrorNumb: Integer; const AClient: TIdContext = nil; Store: string = ''; AImageIndex: Integer = 12) of object;
 TUpdateListview= procedure(Sender: TObject; Client: TIdContext; oListView: TListView; AIp, AClientStore, AMessage: string; AMsgImage, APosition: Integer; const AMax: Integer = 0) of object;

 TThreadZip = class(TThread)
 private
   { Private declarations }
   FPassword:String;
   FHost:String;
   FResult:Boolean;
   FListOfFiles:TStringList;
   FFileName:String;
   FDelete:Boolean;
   FSender:TIdCommand;
   FZip:TVCLZip;
   FListView:TListView;
   FOnFilePercentDone:TFilePercentDone;
   FOnTotalPercentDone:TTotalPercentDone;
   FOnInCompleteZip:TInCompleteZip;
   FOnDisplayStatus:TDisplayStatus;
   FOnUpdateListView:TUpdateListview;
 protected
   procedure Execute; override;
 public
   constructor Create(AListOfFiles: TStringList; ATargetZIPFileName: string; ADelete: Boolean; const ASender: TIdCommand = nil; AHost:String=''; APassword:String='');
 published
     property ListView: TListView READ FListView WRITE FListView;
     property Result: Boolean READ FResult WRITE FResult;
       property OnFilePercentDone: TFilePercentDone READ FOnFilePercentDone
        WRITE FOnFilePercentDone;
     property OnTotalPercentDone: TTotalPercentDone READ FOnTotalPercentDone
        WRITE FOnTotalPercentDone;
     property OnInCompleteZip: TInCompleteZip READ FOnInCompleteZip WRITE FOnInCompleteZip;
     property OnDisplayStatus: TDisplayStatus READ FOnDisplayStatus WRITE FOnDisplayStatus;
     property OnUpdateListView: TUpdateListview READ FOnUpdateListView WRITE FOnUpdateListView;
 end;


resourcestring
   strCheckingZipFiles = 'Beginning integrity test for %s files for %s';
   strZipping = 'Zipping Files';
   strFileZipOK = 'Zip file integrity is OK.';
   strFileZipCorrupted = 'Zip file is corrupted.';
   strFileCheckOK = 'File Check OK';
   strFileCheckFailed = 'File Check FAILED.';
   strDeletingFile = 'Deleting File ';
   strErrorDeletingFile = 'Error deleting file: %s ';

implementation

{ Important: Methods and properties of objects in VCL can only be used in a
 method called using Synchronize, for example,

     Synchronize(UpdateCaption);

 and UpdateCaption could look like,

   procedure TThreadZip.UpdateCaption;
   begin
     Form1.Caption := 'Updated in a thread';
   end; }


function IFF(ACondition: Variant; ATrue: TIdCommand): TIdContext;
begin
   if ACondition then
       result := ATrue.Context
   else
       result := nil;
end;



{ TThreadZip }

constructor TThreadZip.Create(AListOfFiles: TStringList;
 ATargetZIPFileName: string; ADelete: Boolean; const ASender: TIdCommand; AHost:String; APassword:String);
begin
  FResult := False;
  FListOfFiles:= TStringList.Create;
  FListOfFiles.Assign(AListOfFiles);

  FFileName := ATargetZIPFileName;

  FDelete:=ADelete;

  FSender := ASender;
  FPassword := APassword;
  FHost := AHost;

  FreeOnTerminate := True;
  inherited Create(False);
end;

procedure TThreadZip.Execute;
var i:integer;
begin
 { Place thread code here }
   FResult := False;
   with FZip.Create(nil) do
   begin
       OnFilePercentDone  := FOnFilePercentDone;
       OnTotalPercentDone := FOnTotalPercentDone;
       OnInCompleteZip    := FOnInCompleteZip;
       if Assigned(FSender) then
           VCLComObject := FSender;
       ResetArchiveBitOnZip := False;
       ZipName := FFileName;
       FilesList.Assign(FListOfFiles);
       Recurse := False; //* Recurse directories */
       StorePaths := False; //* Keep path information */
       PackLevel := 9; //* Highest level of compression */
       if FPassword <> EmptyStr then
       Password := FPassword; ///Set security password

       Zip; //* Return value of Zip is the actual number of files zipped */

       sleep(500);  ///timer to finish and close zip file

       FOnDisplayStatus(Format(strCheckingZipFiles, [IntToStr(Count), ZipName]), false, 0, 0, IFF(Assigned(FSender), FSender));

       if Assigned(FListView) then
       begin
         if Assigned(FSender) then
             FOnUpdateListView(self, FSender.Context, FListView, EmptyStr, EmptyStr, strZipping, 7, 1, Count - 1)
         else
             FOnUpdateListView(self, nil, FListView, FHost, EmptyStr, strZipping, 7, 1, Count - 1);
       end;

       for i := 0 to Count - 1 do
       begin
           if Assigned(FListView) then
           begin
             if Assigned(FSender) then
               FOnUpdateListView(Self, FSender.Context, FListView, EmptyStr, EmptyStr, strZipping, 7, i, 0)
             else
               FOnUpdateListView(Self, nil, FListView, FHost, EmptyStr, strZipping, 7, i, 0);
           end;

           if FileIsOK[i] then
               FResult := true
           else
           begin
               FResult := false;
               break;
           end;
       end;
   end; //with


   if FResult then
   begin
       if Assigned(FListView) then
       begin
         if Assigned(FSender) then
             FOnUpdateListView(Self, FSender.Context, FListView, EmptyStr, EmptyStr, strFileZipOK, 6, i, 0)
         else
             FOnUpdateListView(Self, nil, FListView, FHost, EmptyStr, strFileZipOK, 6, i, 0);
       end;

       FOnDisplayStatus(strFileCheckOK, false, 0, 0, IFF(Assigned(FSender), FSender));
   end
   else
   begin
       if Assigned(FListView) then
       begin
         if Assigned(FSender) then
             FOnUpdateListView(Self, FSender.Context, FListView, EmptyStr, EmptyStr, strFileZipCorrupted, 9, i, 0)
         else
             FOnUpdateListView(Self, nil, FListView, FHost, EmptyStr, strFileZipCorrupted, 9, i, 0);
       end;
       FOnDisplayStatus(strFileCheckFailed, false, 0, 0, IFF(Assigned(FSender), FSender));
       FOnDisplayStatus(strDeletingFile + FFileName, false, 0, 0, IFF(Assigned(FSender), FSender));
       if not DeleteFile(FFileName) then
         FOnDisplayStatus(strErrorDeletingFile + FFileName, false, 0, 0, IFF(Assigned(FSender), FSender));
   end;
end;

end.


[Kevin]

Very cool! Good job!

You probably should download VCLZip 3.10 which is now available. There is a fix of a problem that could cause VCLZip to leave a directory open when using threads in version 3.06.

[otomazeli]

Thanks for the advice, I will download the new version.

Best regards,