WP_Translation_File_MO::export()

	public function export(): string {
		// Prefix the headers as the first key.
		$headers_string = '';
		foreach ( $this->headers as $header => $value ) {
			$headers_string .= "{$header}: $value\n";
		}
		$entries     = array_merge( array( '' => $headers_string ), $this->entries );
		$entry_count = count( $entries );

		if ( false === $this->uint32 ) {
			$this->uint32 = 'V';
		}

		$bytes_for_entries = $entry_count * 4 * 2;
		// Pair of 32bit ints per entry.
		$originals_addr    = 28; /* header */
		$translations_addr = $originals_addr + $bytes_for_entries;
		$hash_addr         = $translations_addr + $bytes_for_entries;
		$entry_offsets     = $hash_addr;

		$file_header = pack( $this->uint32 . '*', self::MAGIC_MARKER, 0 /* rev */, $entry_count, $originals_addr, $translations_addr, 0 /* hash_length */, $hash_addr );

		$o_entries = '';
		$t_entries = '';
		$o_addr    = '';
		$t_addr    = '';

		foreach ( array_keys( $entries ) as $original ) {
			$o_addr        .= pack( $this->uint32 . '*', strlen( $original ), $entry_offsets );
			$entry_offsets += strlen( $original ) + 1;
			$o_entries     .= $original . "\0";
		}

		foreach ( $entries as $translations ) {
			$t_addr        .= pack( $this->uint32 . '*', strlen( $translations ), $entry_offsets );
			$entry_offsets += strlen( $translations ) + 1;
			$t_entries     .= $translations . "\0";
		}

		return $file_header . $o_addr . $t_addr . $o_entries . $t_entries;
	}