Chilkat Examples

ChilkatHOMEAndroid™Classic ASPCC++C#Mono C#.NET Core C#C# UWP/WinRTDataFlexDelphi ActiveXDelphi DLLVisual FoxProJavaLianjaMFCObjective-CPerlPHP ActiveXPHP ExtensionPowerBuilderPowerShellPureBasicCkPythonChilkat2-PythonRubySQL ServerSwift 2Swift 3/4TclUnicode CUnicode C++Visual Basic 6.0VB.NETVB.NET UWP/WinRTVBScriptXojo PluginNode.jsExcelGo

Delphi DLL Examples

Web API Categories

ASN.1
Amazon Glacier
Amazon S3
Amazon S3 (new)
Amazon SES
Amazon SNS
Amazon SQS
Async
Azure Cloud Storage
Azure Service Bus
Base64
Bounced Email
Box
CAdES
CSR
CSV
Certificates
Compression
DKIM / DomainKey
DSA
Diffie-Hellman
Digital Signatures
Dropbox
Dynamics CRM
ECC
Email Object
Encryption
FTP
FileAccess
Firebase
GMail REST API
Geolocation
Google APIs
Google Calendar
Google Cloud Storage
Google Drive
Google Photos
Google Sheets
Google Tasks
Gzip
HTML-to-XML/Text

HTTP
HTTP Misc
IMAP
JSON
JSON Web Encryption (JWE)
JSON Web Signatures (JWS)
JSON Web Token (JWT)
Java KeyStore (JKS)
MHT / HTML Email
MIME
Microsoft Graph
NTLM
OAuth1
OAuth2
OneDrive
OpenSSL
Outlook
PEM
PFX/P12
POP3
PRNG
REST
REST Misc
RSA
SCP
SFTP
SMTP
SSH
SSH Key
SSH Tunnel
SharePoint
Socket/SSL/TLS
Spider
Stream
Tar Archive
Upload
WebSocket
XAdES
XML
XML Digital Signatures
XMP
Zip
curl

 

 

 

(Delphi DLL) Streaming Compression

Compress and decompress using a stream.

Chilkat for Delphi Downloads

Chilkat non-ActiveX DLL for Delphi

Chilkat ActiveX DLL for Delphi

* The examples here use the non-ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, FileAccess, Task, Stream, Compression;

...

procedure TForm1.Button1Click(Sender: TObject);
var
fac: HCkFileAccess;
compress: HCkCompression;
streamC: HCkStream;
success: Boolean;
streamD: HCkStream;
bFilesEqual: Boolean;
streamA: HCkStream;
task: HCkTask;
decompressedText: PWideChar;

begin
// This example assumes the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

fac := CkFileAccess_Create();
compress := CkCompression_Create();
CkCompression_putAlgorithm(compress,'deflate');

streamC := CkStream_Create();

// This example sets the source and sink of the stream to files.
// A stream can have use other streams as a source or sink,
// or the application can itself be the source/sink by directly
// reading or writing a stream.  (See below for an example of this..)
CkStream_putSourceFile(streamC,'qa_data/hamlet.xml');
CkStream_putSinkFile(streamC,'qa_output/hamlet_compressed.dat');

// Compress from source to sink.
success := CkCompression_CompressStream(compress,streamC);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkCompression__lastErrorText(compress));
    Exit;
  end;

Memo1.Lines.Add('File-to-file deflate compression successful.');
Memo1.Lines.Add('Original size = ' + IntToStr(CkFileAccess_FileSize(fac,CkStream__sourceFile(streamC))));
Memo1.Lines.Add('Compressed size = ' + IntToStr(CkFileAccess_FileSize(fac,CkStream__sinkFile(streamC))));

// Now do file-to-file decompression
streamD := CkStream_Create();
CkStream_putSourceFile(streamD,'qa_output/hamlet_compressed.dat');
CkStream_putSinkFile(streamD,'qa_output/hamlet_restored.xml');

// Decompress from source to sink.
success := CkCompression_DecompressStream(compress,streamD);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkCompression__lastErrorText(compress));
    Exit;
  end;

Memo1.Lines.Add('File-to-file deflate decompression successful.');

// Let's double-check to see that the files are equal in size and content:

bFilesEqual := CkFileAccess_FileContentsEqual(fac,CkStream__sourceFile(streamC),CkStream__sinkFile(streamD));
if (bFilesEqual <> True) then
  begin
    Memo1.Lines.Add('The output file is not equal to the input file!');
  end
else
  begin
    Memo1.Lines.Add('The file was successfully compressed and decompressed.');
  end;

// ---------------------------------------------------------------------
// Now let's decompress again, but this time w/ the application reading
// the decompressed data directly from a stream.
streamA := CkStream_Create();

CkStream_putSourceFile(streamA,'qa_output/hamlet_compressed.dat');

// Start decompressing in a background thread.
task := CkCompression_DecompressStreamAsync(compress,streamA);
success := CkTask_Run(task);

// Read decompressed data from streamA:

while (CkStream_getEndOfStream(streamA) <> True) do
  begin
    if (CkStream_getDataAvailable(streamA) = True) then
      begin
        decompressedText := CkStream__readString(streamA);
        Memo1.Lines.Add(decompressedText);
      end;
  end;

// Let's make sure the background task finished and that the decompress was successful.
// It should already be the case that the task is finished.
while (CkTask_getFinished(task) <> True) do
  begin
    CkTask_SleepMs(task,20);
  end;

// The decompressor may have finished, but it is possible that data
// remains to be flushed.  
if (CkStream_getDataAvailable(streamA) = True) then
  begin
    decompressedText := CkStream__readString(streamA);
    Memo1.Lines.Add(decompressedText);
  end;

// Did streamA succeed in reading the entire file?
if (CkTask_getTaskSuccess(task) <> True) then
  begin
    Memo1.Lines.Add('async decompress failed:');
    Memo1.Lines.Add(CkTask__resultErrorText(task));
    success := False;
  end;

Memo1.Lines.Add('The async decompress was successful.');

CkFileAccess_Dispose(fac);
CkCompression_Dispose(compress);
CkStream_Dispose(streamC);
CkStream_Dispose(streamD);
CkStream_Dispose(streamA);

end;

 

© 2000-2019 Chilkat Software, Inc. All Rights Reserved.