MO::import_from_reader( POMO_FileReader $reader )

	function import_from_reader($reader) {
		$endian_string = MO::get_byteorder($reader->readint32());
		if (false === $endian_string) {
			return false;
		}
		$reader->setEndian($endian_string);

		$endian = ('big' == $endian_string)? 'N' : 'V';

		$header = $reader->read(24);
		if ($reader->strlen($header) != 24)
			return false;

		// parse header
		$header = unpack("{$endian}revision/{$endian}total/{$endian}originals_lenghts_addr/{$endian}translations_lenghts_addr/{$endian}hash_length/{$endian}hash_addr", $header);
		if (!is_array($header))
			return false;

		// support revision 0 of MO format specs, only
		if ( $header['revision'] != 0 ) {
			return false;
		}

		// seek to data blocks
		$reader->seekto( $header['originals_lenghts_addr'] );

		// read originals' indices
		$originals_lengths_length = $header['translations_lenghts_addr'] - $header['originals_lenghts_addr'];
		if ( $originals_lengths_length != $header['total'] * 8 ) {
			return false;
		}

		$originals = $reader->read($originals_lengths_length);
		if ( $reader->strlen( $originals ) != $originals_lengths_length ) {
			return false;
		}

		// read translations' indices
		$translations_lenghts_length = $header['hash_addr'] - $header['translations_lenghts_addr'];
		if ( $translations_lenghts_length != $header['total'] * 8 ) {
			return false;
		}

		$translations = $reader->read($translations_lenghts_length);
		if ( $reader->strlen( $translations ) != $translations_lenghts_length ) {
			return false;
		}

		// transform raw data into set of indices
		$originals    = $reader->str_split( $originals, 8 );
		$translations = $reader->str_split( $translations, 8 );

		// skip hash table
		$strings_addr = $header['hash_addr'] + $header['hash_length'] * 4;

		$reader->seekto($strings_addr);

		$strings = $reader->read_all();
		$reader->close();

		for ( $i = 0; $i < $header['total']; $i++ ) {
			$o = unpack( "{$endian}length/{$endian}pos", $originals[$i] );
			$t = unpack( "{$endian}length/{$endian}pos", $translations[$i] );
			if ( !$o || !$t ) return false;

			// adjust offset due to reading strings to separate space before
			$o['pos'] -= $strings_addr;
			$t['pos'] -= $strings_addr;

			$original    = $reader->substr( $strings, $o['pos'], $o['length'] );
			$translation = $reader->substr( $strings, $t['pos'], $t['length'] );

			if ('' === $original) {
				$this->set_headers($this->make_headers($translation));
			} else {
				$entry = &$this->make_entry($original, $translation);
				$this->entries[$entry->key()] = &$entry;
			}
		}
		return true;
	}