From 1d26b252f1128f7b31885811d7f481b6b7612bd7 Mon Sep 17 00:00:00 2001 From: Tay Ray Chuan Date: Thu, 7 Jul 2011 12:23:57 +0800 Subject: xdiff/xpatience: factor out fall-back-diff function This is in preparation for the histogram diff algorithm, which will also re-use much of the code to call the default Meyers diff algorithm. Signed-off-by: Tay Ray Chuan Signed-off-by: Junio C Hamano --- xdiff/xutils.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) (limited to 'xdiff/xutils.c') diff --git a/xdiff/xutils.c b/xdiff/xutils.c index ab6503460f..ded7c327dc 100644 --- a/xdiff/xutils.c +++ b/xdiff/xutils.c @@ -402,3 +402,34 @@ int xdl_emit_hunk_hdr(long s1, long c1, long s2, long c2, return 0; } + +int xdl_fall_back_diff(xdfenv_t *diff_env, xpparam_t const *xpp, + int line1, int count1, int line2, int count2) +{ + /* + * This probably does not work outside Git, since + * we have a very simple mmfile structure. + * + * Note: ideally, we would reuse the prepared environment, but + * the libxdiff interface does not (yet) allow for diffing only + * ranges of lines instead of the whole files. + */ + mmfile_t subfile1, subfile2; + xdfenv_t env; + + subfile1.ptr = (char *)diff_env->xdf1.recs[line1 - 1]->ptr; + subfile1.size = diff_env->xdf1.recs[line1 + count1 - 2]->ptr + + diff_env->xdf1.recs[line1 + count1 - 2]->size - subfile1.ptr; + subfile2.ptr = (char *)diff_env->xdf2.recs[line2 - 1]->ptr; + subfile2.size = diff_env->xdf2.recs[line2 + count2 - 2]->ptr + + diff_env->xdf2.recs[line2 + count2 - 2]->size - subfile2.ptr; + if (xdl_do_diff(&subfile1, &subfile2, xpp, &env) < 0) + return -1; + + memcpy(diff_env->xdf1.rchg + line1 - 1, env.xdf1.rchg, count1); + memcpy(diff_env->xdf2.rchg + line2 - 1, env.xdf2.rchg, count2); + + xdl_free_env(&env); + + return 0; +} -- cgit v1.2.3