merge-one-file: fix "expr: non-numeric argument"
[gitweb.git] / bisect.c
index 2c14f4d61669582da51013ceddc260eec9a134ec..6dc27ee7a6090e56d5b0f2072a72553d3b3e3b87 100644 (file)
--- a/bisect.c
+++ b/bisect.c
@@ -454,14 +454,14 @@ static int read_bisect_refs(void)
        return for_each_ref_in("refs/bisect/", register_ref, NULL);
 }
 
-void read_bisect_paths(struct argv_array *array)
+static void read_bisect_paths(struct argv_array *array)
 {
        struct strbuf str = STRBUF_INIT;
        const char *filename = git_path("BISECT_NAMES");
        FILE *fp = fopen(filename, "r");
 
        if (!fp)
-               die("Could not open file '%s': %s", filename, strerror(errno));
+               die_errno("Could not open file '%s'", filename);
 
        while (strbuf_getline(&str, fp, '\n') != EOF) {
                char *quoted;
@@ -521,14 +521,34 @@ static char *join_sha1_array_hex(struct sha1_array *array, char delim)
        return strbuf_detach(&joined_hexs, NULL);
 }
 
+/*
+ * In this function, passing a not NULL skipped_first is very special.
+ * It means that we want to know if the first commit in the list is
+ * skipped because we will want to test a commit away from it if it is
+ * indeed skipped.
+ * So if the first commit is skipped, we cannot take the shortcut to
+ * just "return list" when we find the first non skipped commit, we
+ * have to return a fully filtered list.
+ *
+ * We use (*skipped_first == -1) to mean "it has been found that the
+ * first commit is not skipped". In this case *skipped_first is set back
+ * to 0 just before the function returns.
+ */
 struct commit_list *filter_skipped(struct commit_list *list,
                                   struct commit_list **tried,
-                                  int show_all)
+                                  int show_all,
+                                  int *count,
+                                  int *skipped_first)
 {
        struct commit_list *filtered = NULL, **f = &filtered;
 
        *tried = NULL;
 
+       if (skipped_first)
+               *skipped_first = 0;
+       if (count)
+               *count = 0;
+
        if (!skipped_revs.sha1_nr)
                return list;
 
@@ -537,22 +557,110 @@ struct commit_list *filter_skipped(struct commit_list *list,
                list->next = NULL;
                if (0 <= lookup_sha1_array(&skipped_revs,
                                           list->item->object.sha1)) {
+                       if (skipped_first && !*skipped_first)
+                               *skipped_first = 1;
                        /* Move current to tried list */
                        *tried = list;
                        tried = &list->next;
                } else {
-                       if (!show_all)
-                               return list;
+                       if (!show_all) {
+                               if (!skipped_first || !*skipped_first)
+                                       return list;
+                       } else if (skipped_first && !*skipped_first) {
+                               /* This means we know it's not skipped */
+                               *skipped_first = -1;
+                       }
                        /* Move current to filtered list */
                        *f = list;
                        f = &list->next;
+                       if (count)
+                               (*count)++;
                }
                list = next;
        }
 
+       if (skipped_first && *skipped_first == -1)
+               *skipped_first = 0;
+
        return filtered;
 }
 
+#define PRN_MODULO 32768
+
+/*
+ * This is a pseudo random number generator based on "man 3 rand".
+ * It is not used properly because the seed is the argument and it
+ * is increased by one between each call, but that should not matter
+ * for this application.
+ */
+static int get_prn(int count) {
+       count = count * 1103515245 + 12345;
+       return ((unsigned)(count/65536) % PRN_MODULO);
+}
+
+/*
+ * Custom integer square root from
+ * http://en.wikipedia.org/wiki/Integer_square_root
+ */
+static int sqrti(int val)
+{
+       float d, x = val;
+
+       if (val == 0)
+               return 0;
+
+       do {
+               float y = (x + (float)val / x) / 2;
+               d = (y > x) ? y - x : x - y;
+               x = y;
+       } while (d >= 0.5);
+
+       return (int)x;
+}
+
+static struct commit_list *skip_away(struct commit_list *list, int count)
+{
+       struct commit_list *cur, *previous;
+       int prn, index, i;
+
+       prn = get_prn(count);
+       index = (count * prn / PRN_MODULO) * sqrti(prn) / sqrti(PRN_MODULO);
+
+       cur = list;
+       previous = NULL;
+
+       for (i = 0; cur; cur = cur->next, i++) {
+               if (i == index) {
+                       if (hashcmp(cur->item->object.sha1, current_bad_sha1))
+                               return cur;
+                       if (previous)
+                               return previous;
+                       return list;
+               }
+               previous = cur;
+       }
+
+       return list;
+}
+
+static struct commit_list *managed_skipped(struct commit_list *list,
+                                          struct commit_list **tried)
+{
+       int count, skipped_first;
+
+       *tried = NULL;
+
+       if (!skipped_revs.sha1_nr)
+               return list;
+
+       list = filter_skipped(list, tried, 0, &count, &skipped_first);
+
+       if (!skipped_first)
+               return list;
+
+       return skip_away(list, count);
+}
+
 static void bisect_rev_setup(struct rev_info *revs, const char *prefix,
                             const char *bad_format, const char *good_format,
                             int read_paths)
@@ -632,8 +740,7 @@ static void mark_expected_rev(char *bisect_rev_hex)
        int fd = open(filename, O_CREAT | O_TRUNC | O_WRONLY, 0600);
 
        if (fd < 0)
-               die("could not create file '%s': %s",
-                   filename, strerror(errno));
+               die_errno("could not create file '%s'", filename);
 
        bisect_rev_hex[len] = '\n';
        write_or_die(fd, bisect_rev_hex, len + 1);
@@ -700,17 +807,17 @@ static void handle_bad_merge_base(void)
        exit(1);
 }
 
-void handle_skipped_merge_base(const unsigned char *mb)
+static void handle_skipped_merge_base(const unsigned char *mb)
 {
        char *mb_hex = sha1_to_hex(mb);
        char *bad_hex = sha1_to_hex(current_bad_sha1);
        char *good_hex = join_sha1_array_hex(&good_revs, ' ');
 
-       fprintf(stderr, "Warning: the merge base between %s and [%s] "
+       warning("the merge base between %s and [%s] "
                "must be skipped.\n"
                "So we cannot be sure the first bad commit is "
                "between %s and %s.\n"
-               "We continue anyway.\n",
+               "We continue anyway.",
                bad_hex, good_hex, mb_hex, bad_hex);
        free(good_hex);
 }
@@ -849,7 +956,7 @@ int bisect_next_all(const char *prefix)
 {
        struct rev_info revs;
        struct commit_list *tried;
-       int reaches = 0, all = 0, nr;
+       int reaches = 0, all = 0, nr, steps;
        const unsigned char *bisect_rev;
        char bisect_rev_hex[41];
 
@@ -865,7 +972,7 @@ int bisect_next_all(const char *prefix)
 
        revs.commits = find_bisection(revs.commits, &reaches, &all,
                                       !!skipped_revs.sha1_nr);
-       revs.commits = filter_skipped(revs.commits, &tried, 0);
+       revs.commits = managed_skipped(revs.commits, &tried);
 
        if (!revs.commits) {
                /*
@@ -884,15 +991,17 @@ int bisect_next_all(const char *prefix)
 
        if (!hashcmp(bisect_rev, current_bad_sha1)) {
                exit_if_skipped_commits(tried, current_bad_sha1);
-               printf("%s is first bad commit\n", bisect_rev_hex);
+               printf("%s is the first bad commit\n", bisect_rev_hex);
                show_diff_tree(prefix, revs.commits->item);
                /* This means the bisection process succeeded. */
                exit(10);
        }
 
        nr = all - reaches - 1;
-       printf("Bisecting: %d revisions left to test after this "
-              "(roughly %d steps)\n", nr, estimate_bisect_steps(all));
+       steps = estimate_bisect_steps(all);
+       printf("Bisecting: %d revision%s left to test after this "
+              "(roughly %d step%s)\n", nr, (nr == 1 ? "" : "s"),
+              steps, (steps == 1 ? "" : "s"));
 
        return bisect_checkout(bisect_rev_hex);
 }