summaryrefslogtreecommitdiff
path: root/xdiff
diff options
context:
space:
mode:
Diffstat (limited to 'xdiff')
-rw-r--r--xdiff/xhistogram.c96
1 files changed, 53 insertions, 43 deletions
diff --git a/xdiff/xhistogram.c b/xdiff/xhistogram.c
index 5098b6c..fc2d3cd 100644
--- a/xdiff/xhistogram.c
+++ b/xdiff/xhistogram.c
@@ -251,44 +251,13 @@ static inline void free_index(struct histindex *index)
xdl_cha_free(&index->rcha);
}
-static int find_lcs(struct histindex *index, struct region *lcs,
- int line1, int count1, int line2, int count2) {
- int b_ptr;
-
- if (scanA(index, line1, count1))
- return -1;
-
- index->cnt = index->max_chain_length + 1;
-
- for (b_ptr = line2; b_ptr <= LINE_END(2); )
- b_ptr = try_lcs(index, lcs, b_ptr, line1, count1, line2, count2);
-
- return index->has_common && index->max_chain_length < index->cnt;
-}
-
-static int histogram_diff(xpparam_t const *xpp, xdfenv_t *env,
- int line1, int count1, int line2, int count2)
+static int find_lcs(xpparam_t const *xpp, xdfenv_t *env,
+ struct region *lcs,
+ int line1, int count1, int line2, int count2)
{
+ int b_ptr;
+ int sz, ret = -1;
struct histindex index;
- struct region lcs;
- int sz;
- int result = -1;
-
- if (count1 <= 0 && count2 <= 0)
- return 0;
-
- if (LINE_END(1) >= MAX_PTR)
- return -1;
-
- if (!count1) {
- while(count2--)
- env->xdf2.rchg[line2++ - 1] = 1;
- return 0;
- } else if (!count2) {
- while(count1--)
- env->xdf1.rchg[line1++ - 1] = 1;
- return 0;
- }
memset(&index, 0, sizeof(index));
@@ -326,8 +295,52 @@ static int histogram_diff(xpparam_t const *xpp, xdfenv_t *env,
index.ptr_shift = line1;
index.max_chain_length = 64;
+ if (scanA(&index, line1, count1))
+ goto cleanup;
+
+ index.cnt = index.max_chain_length + 1;
+
+ for (b_ptr = line2; b_ptr <= LINE_END(2); )
+ b_ptr = try_lcs(&index, lcs, b_ptr, line1, count1, line2, count2);
+
+ if (index.has_common && index.max_chain_length < index.cnt)
+ ret = 1;
+ else
+ ret = 0;
+
+cleanup:
+ free_index(&index);
+ return ret;
+}
+
+static int histogram_diff(xpparam_t const *xpp, xdfenv_t *env,
+ int line1, int count1, int line2, int count2)
+{
+ struct region lcs;
+ int lcs_found;
+ int result = -1;
+
+ if (count1 <= 0 && count2 <= 0)
+ return 0;
+
+ if (LINE_END(1) >= MAX_PTR)
+ return -1;
+
+ if (!count1) {
+ while(count2--)
+ env->xdf2.rchg[line2++ - 1] = 1;
+ return 0;
+ } else if (!count2) {
+ while(count1--)
+ env->xdf1.rchg[line1++ - 1] = 1;
+ return 0;
+ }
+
memset(&lcs, 0, sizeof(lcs));
- if (find_lcs(&index, &lcs, line1, count1, line2, count2))
+ lcs_found = find_lcs(xpp, env, &lcs, line1, count1, line2, count2);
+ if (lcs_found < 0)
+ goto out;
+ else if (lcs_found)
result = fall_back_to_classic_diff(xpp, env, line1, count1, line2, count2);
else {
if (lcs.begin1 == 0 && lcs.begin2 == 0) {
@@ -341,18 +354,15 @@ static int histogram_diff(xpparam_t const *xpp, xdfenv_t *env,
line1, lcs.begin1 - line1,
line2, lcs.begin2 - line2);
if (result)
- goto cleanup;
+ goto out;
result = histogram_diff(xpp, env,
lcs.end1 + 1, LINE_END(1) - lcs.end1,
lcs.end2 + 1, LINE_END(2) - lcs.end2);
if (result)
- goto cleanup;
+ goto out;
}
}
-
-cleanup:
- free_index(&index);
-
+out:
return result;
}