diff: futureproof "stop feeding the backend early" logic

Refactor the "do not stop feeding the backend early" logic into a small
helper function and use it in both run_diff_files() and diff_tree() that
has the stop-early optimization. We may later add other types of diffcore
transformation that require to look at the whole result like diff-filter
does, and having the logic in a single place is essential for longer term
maintainability.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/diff-lib.c b/diff-lib.c
index bfa65033734452faae0d5f4365a817f9e35b3e01..869d8f0e77832385c6047dce48e28dcc91171fb3 100644 (file)
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -73,9 +73,7 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
                struct cache_entry *ce = active_cache[i];
                int changed;
 
-               if (DIFF_OPT_TST(&revs->diffopt, QUICK) &&
-                   !revs->diffopt.filter &&
-                   DIFF_OPT_TST(&revs->diffopt, HAS_CHANGES))
+               if (diff_can_quit_early(&revs->diffopt))
                        break;
 
                if (!ce_path_match(ce, revs->prune_data))

diff --git a/diff.c b/diff.c
index 91d6ea21a9d3575ea940e3d71e42609e800bed6b..ae6853fcf1ea1e10c1d8f6750f69b71a7a5e73b4 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -3513,6 +3513,13 @@ int diff_result_code(struct diff_options *opt, int status)
        return result;
 }
 
+int diff_can_quit_early(struct diff_options *opt)
+{
+       return (DIFF_OPT_TST(opt, QUICK) &&
+               !opt->filter &&
+               DIFF_OPT_TST(opt, HAS_CHANGES));
+}
+
 void diff_addremove(struct diff_options *options,
                    int addremove, unsigned mode,
                    const unsigned char *sha1,

diff --git a/diff.h b/diff.h
index a7e7ccbd4230ca5cc65ea7e9255ecc345eb8f169..b412ffb9705c64e19841f89d6f9580afd51a1c7d 100644 (file)
--- a/diff.h
+++ b/diff.h
@@ -170,6 +170,8 @@ extern void diff_tree_combined_merge(const unsigned char *sha1, int, struct rev_
 
 void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b);
 
+extern int diff_can_quit_early(struct diff_options *);
+
 extern void diff_addremove(struct diff_options *,
                           int addremove,
                           unsigned mode,

diff --git a/tree-diff.c b/tree-diff.c
index 70bdb896562a6480c49efdb51151ba00f7e11d5b..33881d1ad0b7381db4bd39c97e160d93f62a1cdb 100644 (file)
--- a/tree-diff.c
+++ b/tree-diff.c
@@ -286,9 +286,7 @@ int diff_tree(struct tree_desc *t1, struct tree_desc *t2, const char *base, stru
        int baselen = strlen(base);
 
        for (;;) {
-               if (DIFF_OPT_TST(opt, QUICK) &&
-                   !opt->filter &&
-                   DIFF_OPT_TST(opt, HAS_CHANGES))
+               if (diff_can_quit_early(opt))
                        break;
                if (opt->nr_paths) {
                        skip_uninteresting(t1, base, baselen, opt);