Dave Jarvis' Repositories

<?php
require_once __DIR__ . '/StreamReader.php';

interface CompressionStream {
  public function stream(
    StreamReader $stream,
    int $chunkSize = 8192
  ): Generator;
}

class ZlibExtractorStream implements CompressionStream {
  public function stream(
    StreamReader $stream,
    int $chunkSize = 8192
  ): Generator {
    $context = \inflate_init( \ZLIB_ENCODING_DEFLATE );
    $done    = false;

    while( !$done && !$stream->eof() ) {
      $chunk = $stream->read( $chunkSize );
      $done  = $chunk === '';

      if( !$done ) {
        $before = \inflate_get_read_len( $context );
        @\inflate_add( $context, $chunk );

        $data = \substr(
          $chunk,
          0,
          \inflate_get_read_len( $context ) - $before
        );

        if( $data !== '' ) {
          yield $data;
        }

        $done = \inflate_get_status( $context ) === \ZLIB_STREAM_END;
      }
    }
  }
}

class ZlibInflaterStream implements CompressionStream {
  public function stream(
    StreamReader $stream,
    int $chunkSize = 8192
  ): Generator {
    $context = \inflate_init( \ZLIB_ENCODING_DEFLATE );
    $done    = false;

    while( !$done && !$stream->eof() ) {
      $chunk = $stream->read( $chunkSize );
      $done  = $chunk === '';

      if( !$done ) {
        $data = @\inflate_add( $context, $chunk );

        if( $data !== false && $data !== '' ) {
          yield $data;
        }

        $done = \inflate_get_status( $context ) === \ZLIB_STREAM_END;
      }
    }
  }
}