(PHP ActiveX) Streaming Compression

Compress and decompress using a stream.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows Note: The php_com_dotnet.dll may need to be enabled inside of php.ini.

<?php

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

// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.FileAccess')
$fac = new COM("Chilkat.FileAccess");
// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.Compression')
$compress = new COM("Chilkat.Compression");
$compress->Algorithm = 'deflate';

// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.Stream')
$streamC = new COM("Chilkat.Stream");

// 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..)
$streamC->SourceFile = 'qa_data/hamlet.xml';
$streamC->SinkFile = 'qa_output/hamlet_compressed.dat';

// Compress from source to sink.
$success = $compress->CompressStream($streamC);
if ($success != 1) {
    print $compress->LastErrorText . "\n";
    exit;
}

print 'File-to-file deflate compression successful.' . "\n";
// Note: The FileSize method returns a signed 32-bit integer.  If the file is potentially larger than 2GB, call FileSizeStr instead to return
// the size of the file as a string, then convert to an integer value.
print 'Original size = ' . $fac->FileSize($streamC->SourceFile) . "\n";
print 'Compressed size = ' . $fac->FileSize($streamC->SinkFile) . "\n";

// Now do file-to-file decompression
// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.Stream')
$streamD = new COM("Chilkat.Stream");
$streamD->SourceFile = 'qa_output/hamlet_compressed.dat';
$streamD->SinkFile = 'qa_output/hamlet_restored.xml';

// Decompress from source to sink.
$success = $compress->DecompressStream($streamD);
if ($success != 1) {
    print $compress->LastErrorText . "\n";
    exit;
}

print 'File-to-file deflate decompression successful.' . "\n";

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

$bFilesEqual = $fac->FileContentsEqual($streamC->SourceFile,$streamD->SinkFile);
if ($bFilesEqual != 1) {
    print 'The output file is not equal to the input file!' . "\n";
}
else {
    print 'The file was successfully compressed and decompressed.' . "\n";
}

// ---------------------------------------------------------------------
// Now let's decompress again, but this time w/ the application reading
// the decompressed data directly from a stream.
// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.Stream')
$streamA = new COM("Chilkat.Stream");

$streamA->SourceFile = 'qa_output/hamlet_compressed.dat';

// Start decompressing in a background thread.
// task is a Chilkat.Task
$task = $compress->DecompressStreamAsync($streamA);
$success = $task->Run();

// Read decompressed data from streamA:

while (($streamA->EndOfStream != 1)) {
    if ($streamA->DataAvailable == 1) {
        $decompressedText = $streamA->readString();
        print $decompressedText . "\n";
    }

}

// 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 (($task->Finished != 1)) {
    $task->SleepMs(20);
}

// The decompressor may have finished, but it is possible that data
// remains to be flushed.  
if ($streamA->DataAvailable == 1) {
    $decompressedText = $streamA->readString();
    print $decompressedText . "\n";
}

// Did streamA succeed in reading the entire file?
if ($task->TaskSuccess != 1) {
    print 'async decompress failed:' . "\n";
    print $task->ResultErrorText . "\n";
    $success = 0;
}

print 'The async decompress was successful.' . "\n";

?>