(PHP Extension) Streaming Compression

Compress and decompress using a stream.

Chilkat PHP Downloads PHP Extension for Windows, Linux, MacOS, Alpine Linux, Solaris

<?php

// The version number (9_5_0) should match version of the Chilkat extension used, omitting the micro-version number.
// For example, if using Chilkat v9.5.0.48, then include as shown here:
include("chilkat_9_5_0.php");

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

$fac = new CkFileAccess();
$compress = new CkCompression();
$compress->put_Algorithm('deflate');

$streamC = new CkStream();

// 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->put_SourceFile('qa_data/hamlet.xml');
$streamC->put_SinkFile('qa_output/hamlet_compressed.dat');

// Compress from source to sink.
$success = $compress->CompressStream($streamC);
if ($success != true) {
    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
$streamD = new CkStream();
$streamD->put_SourceFile('qa_output/hamlet_compressed.dat');
$streamD->put_SinkFile('qa_output/hamlet_restored.xml');

// Decompress from source to sink.
$success = $compress->DecompressStream($streamD);
if ($success != true) {
    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 != true) {
    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.
$streamA = new CkStream();

$streamA->put_SourceFile('qa_output/hamlet_compressed.dat');

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

// Read decompressed data from streamA:

while (($streamA->get_EndOfStream() != true)) {
    if ($streamA->get_DataAvailable() == true) {
        $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->get_Finished() != true)) {
    $task->SleepMs(20);
}

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

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

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

?>