Dave Jarvis' Repositories

<?php
class CompressionStream {
  private Closure $pumper;
  private Closure $finisher;
  private Closure $status;

  private function __construct(
    Closure $pumper,
    Closure $finisher,
    Closure $status
  ) {
    $this->pumper   = $pumper;
    $this->finisher = $finisher;
    $this->status   = $status;
  }

  public static function createInflater(): self {
    $context = inflate_init( ZLIB_ENCODING_DEFLATE );

    return new self(
      function( string $chunk ) use ( $context ): string {
        $data = @inflate_add( $context, $chunk );

        return $data === false ? '' : $data;
      },
      function(): string {
        return '';
      },
      function() use ( $context ): bool {
        return inflate_get_status( $context ) === ZLIB_STREAM_END;
      }
    );
  }

  public static function createDeflater(): self {
    $context = deflate_init( ZLIB_ENCODING_DEFLATE );

    return new self(
      function( string $chunk ) use ( $context ): string {
        $data = deflate_add( $context, $chunk, ZLIB_NO_FLUSH );

        return $data === false ? '' : $data;
      },
      function() use ( $context ): string {
        $data = deflate_add( $context, '', ZLIB_FINISH );

        return $data === false ? '' : $data;
      },
      function(): bool {
        return false;
      }
    );
  }

  public function pump( string $chunk ): string {
    return $chunk === '' ? '' : ($this->pumper)( $chunk );
  }

  public function finish(): string {
    return ($this->finisher)();
  }

  public function finished(): bool {
    return ($this->status)();
  }
}