sequencer: refactor rearrange_squash() to work on a todo_list

This refactors rearrange_squash() to work on a todo_list to avoid
redundant reads and writes.  The function is renamed
todo_list_rearrange_squash().

The old version created a new buffer, which was directly written to the
disk.  This new version creates a new item list by just copying items
from the old item list, without creating a new buffer.  This eliminates
the need to reparse the todo list, but this also means its buffer cannot
be directly written to the disk.

As rebase -p still need to check the todo list from the disk, a new
function is introduced, rearrange_squash_in_todo_file().

complete_action() still uses rearrange_squash_in_todo_file() for now.
This will be changed in a future commit.

Signed-off-by: Alban Gruin <alban.gruin@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/rebase--interactive.c b/builtin/rebase--interactive.c
index 813bc34140e3c0da2839fde98d1175b24c488a35..60b15f9693c3c962d034abca1db12b1379832e26 100644 (file)
--- a/builtin/rebase--interactive.c
+++ b/builtin/rebase--interactive.c
@@ -268,7 +268,7 @@ int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
                ret = check_todo_list_from_file(the_repository);
                break;
        case REARRANGE_SQUASH:
-               ret = rearrange_squash(the_repository);
+               ret = rearrange_squash_in_todo_file(the_repository);
                break;
        case ADD_EXEC:
                ret = sequencer_add_exec_commands(the_repository, &commands);

diff --git a/sequencer.c b/sequencer.c
index 4c076bd18359298185a4f486b20eefbcb9adee53..7798f93b23f2250e61564951b6a467ae19746b36 100644 (file)
--- a/sequencer.c
+++ b/sequencer.c
@@ -4840,7 +4840,7 @@ int complete_action(struct repository *r, struct replay_opts *opts, unsigned fla
            write_message("noop\n", 5, todo_file, 0))
                return -1;
 
-       if (autosquash && rearrange_squash(r))
+       if (autosquash && rearrange_squash_in_todo_file(r))
                return -1;
 
        if (commands->nr)
@@ -4946,21 +4946,13 @@ define_commit_slab(commit_todo_item, struct todo_item *);
  * message will have to be retrieved from the commit (as the oneline in the
  * script cannot be trusted) in order to normalize the autosquash arrangement.
  */
-int rearrange_squash(struct repository *r)
+static int todo_list_rearrange_squash(struct todo_list *todo_list)
 {
-       const char *todo_file = rebase_path_todo();
-       struct todo_list todo_list = TODO_LIST_INIT;
        struct hashmap subject2item;
-       int res = 0, rearranged = 0, *next, *tail, i;
+       int rearranged = 0, *next, *tail, i, nr = 0, alloc = 0;
        char **subjects;
        struct commit_todo_item commit_todo;
-
-       if (strbuf_read_file_or_whine(&todo_list.buf, todo_file) < 0)
-               return -1;
-       if (todo_list_parse_insn_buffer(r, todo_list.buf.buf, &todo_list) < 0) {
-               todo_list_release(&todo_list);
-               return -1;
-       }
+       struct todo_item *items = NULL;
 
        init_commit_todo_item(&commit_todo);
        /*
@@ -4973,13 +4965,13 @@ int rearrange_squash(struct repository *r)
         * be moved to appear after the i'th.
         */
        hashmap_init(&subject2item, (hashmap_cmp_fn) subject2item_cmp,
-                    NULL, todo_list.nr);
-       ALLOC_ARRAY(next, todo_list.nr);
-       ALLOC_ARRAY(tail, todo_list.nr);
-       ALLOC_ARRAY(subjects, todo_list.nr);
-       for (i = 0; i < todo_list.nr; i++) {
+                    NULL, todo_list->nr);
+       ALLOC_ARRAY(next, todo_list->nr);
+       ALLOC_ARRAY(tail, todo_list->nr);
+       ALLOC_ARRAY(subjects, todo_list->nr);
+       for (i = 0; i < todo_list->nr; i++) {
                struct strbuf buf = STRBUF_INIT;
-               struct todo_item *item = todo_list.items + i;
+               struct todo_item *item = todo_list->items + i;
                const char *commit_buffer, *subject, *p;
                size_t subject_len;
                int i2 = -1;
@@ -4992,7 +4984,6 @@ int rearrange_squash(struct repository *r)
                }
 
                if (is_fixup(item->command)) {
-                       todo_list_release(&todo_list);
                        clear_commit_todo_item(&commit_todo);
                        return error(_("the script was already rearranged."));
                }
@@ -5027,7 +5018,7 @@ int rearrange_squash(struct repository *r)
                                 *commit_todo_item_at(&commit_todo, commit2))
                                /* found by commit name */
                                i2 = *commit_todo_item_at(&commit_todo, commit2)
-                                       - todo_list.items;
+                                       - todo_list->items;
                        else {
                                /* copy can be a prefix of the commit subject */
                                for (i2 = 0; i2 < i; i2++)
@@ -5040,7 +5031,7 @@ int rearrange_squash(struct repository *r)
                }
                if (i2 >= 0) {
                        rearranged = 1;
-                       todo_list.items[i].command =
+                       todo_list->items[i].command =
                                starts_with(subject, "fixup!") ?
                                TODO_FIXUP : TODO_SQUASH;
                        if (next[i2] < 0)
@@ -5058,10 +5049,8 @@ int rearrange_squash(struct repository *r)
        }
 
        if (rearranged) {
-               struct strbuf buf = STRBUF_INIT;
-
-               for (i = 0; i < todo_list.nr; i++) {
-                       enum todo_command command = todo_list.items[i].command;
+               for (i = 0; i < todo_list->nr; i++) {
+                       enum todo_command command = todo_list->items[i].command;
                        int cur = i;
 
                        /*
@@ -5072,37 +5061,50 @@ int rearrange_squash(struct repository *r)
                                continue;
 
                        while (cur >= 0) {
-                               const char *bol =
-                                       get_item_line(&todo_list, cur);
-                               const char *eol =
-                                       get_item_line(&todo_list, cur + 1);
-
-                               /* replace 'pick', by 'fixup' or 'squash' */
-                               command = todo_list.items[cur].command;
-                               if (is_fixup(command)) {
-                                       strbuf_addstr(&buf,
-                                               todo_command_info[command].str);
-                                       bol += strcspn(bol, " \t");
-                               }
-
-                               strbuf_add(&buf, bol, eol - bol);
-
+                               ALLOC_GROW(items, nr + 1, alloc);
+                               items[nr++] = todo_list->items[cur];
                                cur = next[cur];
                        }
                }
 
-               res = rewrite_file(todo_file, buf.buf, buf.len);
-               strbuf_release(&buf);
+               FREE_AND_NULL(todo_list->items);
+               todo_list->items = items;
+               todo_list->nr = nr;
+               todo_list->alloc = alloc;
        }
 
        free(next);
        free(tail);
-       for (i = 0; i < todo_list.nr; i++)
+       for (i = 0; i < todo_list->nr; i++)
                free(subjects[i]);
        free(subjects);
        hashmap_free(&subject2item, 1);
-       todo_list_release(&todo_list);
 
        clear_commit_todo_item(&commit_todo);
-       return res;
+
+       return 0;
+}
+
+int rearrange_squash_in_todo_file(struct repository *r)
+{
+       const char *todo_file = rebase_path_todo();
+       struct todo_list todo_list = TODO_LIST_INIT;
+       int res = 0;
+
+       if (strbuf_read_file_or_whine(&todo_list.buf, todo_file) < 0)
+               return -1;
+       if (todo_list_parse_insn_buffer(r, todo_list.buf.buf, &todo_list) < 0) {
+               todo_list_release(&todo_list);
+               return -1;
+       }
+
+       res = todo_list_rearrange_squash(&todo_list);
+       if (!res)
+               res = todo_list_write_to_file(r, &todo_list, todo_file, NULL, NULL, -1, 0);
+
+       todo_list_release(&todo_list);
+
+       if (res)
+               return error_errno(_("could not write '%s'."), todo_file);
+       return 0;
 }

diff --git a/sequencer.h b/sequencer.h
index 87d04a3b9bda8144a48adcf1c30cc6c96dcf4e6a..add50f04f1c0bd1ff0feb9c57360890a70934b78 100644 (file)
--- a/sequencer.h
+++ b/sequencer.h
@@ -154,7 +154,7 @@ int complete_action(struct repository *r, struct replay_opts *opts, unsigned fla
                    const char *shortrevisions, const char *onto_name,
                    const char *onto, const char *orig_head, struct string_list *commands,
                    unsigned autosquash);
-int rearrange_squash(struct repository *r);
+int rearrange_squash_in_todo_file(struct repository *r);
 
 extern const char sign_off_header[];