On Mon, Jun 6, 2011 at 3:17 AM, Johan Corveleyn <jcor...@gmail.com> wrote:
> On Wed, Jun 1, 2011 at 5:56 PM, Morten Kloster <mor...@gmail.com> wrote:
[]
> Hi Morten,
>
> Sorry, it took me a little while longer than expected, but I finally
> got around to it.
>
> I did some more tests, and upon further investigation, I too can't
> really find a significant performance decrease because of the token
> counting. So that looks good.
>
> I've reviewed it all, and it looks fine. I just have one small
> question about the changes in lcs.c:
>
> [[[
> @@ -218,11 +228,17 @@ prepend_lcs(svn_diff__lcs_t *lcs, apr_off_t lines,
> svn_diff__lcs_t *
> svn_diff__lcs(svn_diff__position_t *position_list1, /* pointer to
> tail (ring) */
> svn_diff__position_t *position_list2, /* pointer to
> tail (ring) */
> + svn_diff__token_index_t *token_counts_list1, /* array
> of counts */
> + svn_diff__token_index_t *token_counts_list2, /* array
> of counts */
> + svn_diff__token_index_t num_tokens,
> apr_off_t prefix_lines,
> apr_off_t suffix_lines,
> apr_pool_t *pool)
> {
> apr_off_t length[2];
> + svn_diff__token_index_t *token_counts[2];
> + svn_diff__token_index_t unique_count[2];
> + svn_diff__token_index_t token_index;
>
> ...
>
> @@ -281,16 +310,17 @@ svn_diff__lcs(svn_diff__position_t *position_list1
> sentinel_position[0].next = position_list1->next;
> position_list1->next = &sentinel_position[0];
> sentinel_position[0].offset = position_list1->offset + 1;
> + token_counts[0] = token_counts_list1;
>
> sentinel_position[1].next = position_list2->next;
> position_list2->next = &sentinel_position[1];
> sentinel_position[1].offset = position_list2->offset + 1;
> + token_counts[1] = token_counts_list2;
>
> ...
>
> @@ -310,12 +340,12 @@ svn_diff__lcs(svn_diff__position_t *position_list1
> /* For k < 0, insertions are free */
> for (k = (d < 0 ? d : 0) - p; k < 0; k++)
> {
> - svn_diff__snake(fp + k, &lcs_freelist, pool);
> + svn_diff__snake(fp + k, token_counts, &lcs_freelist, pool);
> }
> /* for k > 0, deletions are free */
> for (k = (d > 0 ? d : 0) + p; k >= 0; k--)
> {
> - svn_diff__snake(fp + k, &lcs_freelist, pool);
> + svn_diff__snake(fp + k, token_counts, &lcs_freelist, pool);
> }
>
> p++;
> ]]]
>
> Why do you copy the token_counts_list parameters into the array
> token_counts[]? Is that to simplify the passing of data to __snake
> (keeping number of arguments to a minimum)?
>
> Can't you just pass the token_counts_list parameters 'as is' to
> __snake as two extra arguments, and lose the token_counts[] variable?
>
> But maybe you have a reason for this, because of compiler optimization
> or inlining or something like that?
>
> Apart from that I have no more remarks, so I think I'll be able to
> commit this soon.
>
> Thanks for your work.
> --
> Johan
>
I made the token_counts array when idx was still in, and then its
values depended on the value of idx. Now it it no longer required as
such, although I find it somewhat tidier to use arrays for "everything"
in svn_diff__snake. I get no easily detectable difference in speed on
my system from removing it, but if you want to remove it, feel free.
Thanks for the review. :-)
Morten
