Re: [PATCH 1/2] separate quoting and relative path generation

From: Junio C Hamano <gitster@pobox.com>
Date: Jun 3, 2010, 22:16 UTC
Message-ID: <7vocfr7oe6.fsf@alter.siamese.dyndns.org>
In-Reply-To: <20100603133631.GA31565@localhost>

Clemens Buchacher <drizzd@aon.at> writes:

Show 32 quoted lines

> +/* give path as relative to prefix */
> +char *path_relative(const char *in, int len,
> +		    struct strbuf *out, const char *prefix, int prefix_len)
> +{
>  	if (len < 0)
>  		len = strlen(in);
> +	if (prefix && prefix_len < 0)
> +		prefix_len = strlen(prefix);
>  
>  	strbuf_setlen(out, 0);
>  	strbuf_grow(out, len);
>  
> +	if (prefix_len > 0) {
> +		int off = 0, i = 0;
> +		while (i < prefix_len && i < len && prefix[i] == in[i]) {
> +			if (prefix[i] == '/')
> +				off = i + 1;
> +			i++;
> +		}
> +		in += off;
> +		len -= off;
> +
> +		while (i < prefix_len) {
> +			if (prefix[i] == '/')
>  				strbuf_addstr(out, "../");
> +			i++;
> +		}
>  	}
> +	strbuf_add(out, in, len);
> +
> +	return out->buf;
> +}

Hmm... I wonder if we really want to always make a copy of the string in the majority of the case where there is no need to add ../ and the path does not have any funny characters that needs quoting. In such a case, shouldn't write_name() be just moving the pointers into the original string to skip the $(cwd) part and writing the remainder of the string out, without any extra allocation nor copy? IIUC, that is what the original did using write_name_quoted().