diff options
| -rw-r--r-- | combine-diff.c | 89 |
1 files changed, 63 insertions, 26 deletions
diff --git a/combine-diff.c b/combine-diff.c index b0846bc09..a91cafbd9 100644 --- a/combine-diff.c +++ b/combine-diff.c @@ -271,21 +271,56 @@ static int interesting(struct sline *sline, unsigned long all_mask) return ((sline->flag & all_mask) != all_mask || sline->lost_head); } -static unsigned long line_diff_parents(struct sline *sline, unsigned long all_mask) +static unsigned long line_common_diff(struct sline *sline, unsigned long all_mask) { /* - * Look at the line and see from which parents we have difference. - * Lower bits of sline->flag records if the parent had this line, - * so XOR with all_mask gives us on-bits for parents we have - * differences with. + * Look at the line and see from which parents we have the + * same difference. */ - unsigned long parents = (sline->flag ^ all_mask); + + /* Lower bits of sline->flag records if the parent had this + * line, so XOR with all_mask gives us on-bits for parents we + * have differences with. + */ + unsigned long common_adds = (sline->flag ^ all_mask) & all_mask; + unsigned long common_removes = all_mask; + + /* If all the parents have this line, that also counts as + * having the same difference. + */ + if (!common_adds) + common_adds = all_mask; + + if (sline->lost_head) { + /* Lost head list records the lines removed from + * the parents, and parent_map records from which + * parent the line was removed. + */ + struct lline *ll; + for (ll = sline->lost_head; ll; ll = ll->next) { + common_removes &= ll->parent_map; + } + } + return common_adds & common_removes; +} + +static unsigned long line_all_diff(struct sline *sline, unsigned long all_mask) +{ + /* + * Look at the line and see from which parents we have some difference. + */ + unsigned long different = (sline->flag ^ all_mask) & all_mask; if (sline->lost_head) { + /* Lost head list records the lines removed from + * the parents, and parent_map records from which + * parent the line was removed. + */ struct lline *ll; - for (ll = sline->lost_head; ll; ll = ll->next) - parents |= ll->parent_map; + for (ll = sline->lost_head; ll; ll = ll->next) { + different |= ll->parent_map; + } } - return parents & all_mask; + return different; } static void make_hunks(struct sline *sline, unsigned long cnt, @@ -316,13 +351,14 @@ static void make_hunks(struct sline *sline, unsigned long cnt, if (!dense) return; - /* Look at each hunk, and if it contains changes from only - * one parent, mark that uninteresting. + /* Look at each hunk, and if we have changes from only one + * parent, or the changes are the same from all but one + * parent, mark that uninteresting. */ i = 0; while (i < cnt) { - int j, hunk_end, diffs; - unsigned long parents; + int j, hunk_end, same, diff; + unsigned long same_diff, all_diff, this_diff; while (i < cnt && !(sline[i].flag & mark)) i++; if (cnt <= i) @@ -330,22 +366,23 @@ static void make_hunks(struct sline *sline, unsigned long cnt, for (hunk_end = i + 1; hunk_end < cnt; hunk_end++) if (!(sline[hunk_end].flag & mark)) break; - /* [i..hunk_end) are interesting. Now is it from - * only one parent? - * If lost lines are only from one parent and - * remaining lines existed in parents other than - * that parent, then the hunk is not that interesting. + /* [i..hunk_end) are interesting. Now does it have + * the same change with all but one parent? */ - parents = 0; - diffs = 0; - for (j = i; j < hunk_end; j++) - parents |= line_diff_parents(sline + j, all_mask); - /* Now, how many bits from [0..num_parent) are on? */ + same_diff = all_mask; + all_diff = 0; + for (j = i; j < hunk_end; j++) { + same_diff &= line_common_diff(sline + j, all_mask); + all_diff |= line_all_diff(sline + j, all_mask); + } + diff = same = 0; for (j = 0; j < num_parent; j++) { - if (parents & (1UL<<j)) - diffs++; + if (same_diff & (1UL<<j)) + same++; + if (all_diff & (1UL<<j)) + diff++; } - if (diffs < 2) { + if ((num_parent - 1 <= same) || (diff == 1)) { /* This hunk is not that interesting after all */ for (j = i; j < hunk_end; j++) sline[j].flag &= ~mark; |