Merge branch 'rc/histogram-diff' into HEAD

[git.git] / xdiff / xutils.c

diff --git a/xdiff/xutils.c b/xdiff/xutils.c
index ab6503460f760356a393a3c7b3b8438213e1ee94..0de084e53f5144153373cc66cae7b523b4ae2812 100644 (file)
--- a/xdiff/xutils.c
+++ b/xdiff/xutils.c
@@ -24,10 +24,6 @@
 
 
 
-#define XDL_GUESS_NLINES 256
-
-
-
 
 long xdl_bogosqrt(long n) {
        long i;
@@ -71,12 +67,6 @@ void *xdl_mmfile_first(mmfile_t *mmf, long *size)
 }
 
 
-void *xdl_mmfile_next(mmfile_t *mmf, long *size)
-{
-       return NULL;
-}
-
-
 long xdl_mmfile_size(mmfile_t *mmf)
 {
        return mmf->size;
@@ -159,18 +149,12 @@ void *xdl_cha_next(chastore_t *cha) {
 }
 
 
-long xdl_guess_lines(mmfile_t *mf) {
+long xdl_guess_lines(mmfile_t *mf, long sample) {
        long nl = 0, size, tsize = 0;
        char const *data, *cur, *top;
 
        if ((cur = data = xdl_mmfile_first(mf, &size)) != NULL) {
-               for (top = data + size; nl < XDL_GUESS_NLINES;) {
-                       if (cur >= top) {
-                               tsize += (long) (cur - data);
-                               if (!(cur = data = xdl_mmfile_next(mf, &size)))
-                                       break;
-                               top = data + size;
-                       }
+               for (top = data + size; nl < sample && cur < top; ) {
                        nl++;
                        if (!(cur = memchr(cur, '\n', top - cur)))
                                cur = top;
@@ -402,3 +386,34 @@ 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;
+}