On 27/10/2018 22:29, Alban Gruin wrote:
This refactors sequencer_add_exec_commands() to work on a todo_list to
avoid redundant reads and writes to the disk.
An obvious way to do this would be to insert the `exec' command between
the other commands, and reparse it once this is done. This is not what
is done here. Instead, the command is appended to the buffer once, and
a new list of items is created. Items from the old list are copied to
it, and new `exec' items are appended when necessary. This eliminates
the need to reparse the todo list, but this also means its buffer cannot
be directly written to the disk, hence todo_list_write_to_disk().
I'd reword this slightly, maybe
Instead of just inserting the `exec' command between the other commands,
and re-parsing the buffer at the end the exec command is appended to the
buffer once, and a new list of items is created. Items from the old
list are copied across and new `exec' items are appended when necessary.
This eliminates the need to reparse the buffer, but this also means we
have to use todo_list_write_to_disk() to write the file.
sequencer_add_exec_commands() still reads the todo list from the disk,
as it is needed by rebase -p. todo_list_add_exec_commands() works on a
todo_list structure, and reparses it at the end.
I think the saying 'reparses' is confusing as that is what we're trying
to avoid.
complete_action() still uses sequencer_add_exec_commands() for now.
This will be changed in a future commit.
Signed-off-by: Alban Gruin <alban.gruin@xxxxxxxxx>
---
sequencer.c | 69 +++++++++++++++++++++++++++++++++++++----------------
1 file changed, 49 insertions(+), 20 deletions(-)
diff --git a/sequencer.c b/sequencer.c
index e12860c047..12a3efeca8 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -4216,6 +4216,50 @@ int sequencer_make_script(FILE *out, int argc, const char **argv,
return 0;
}
+static void todo_list_add_exec_commands(struct todo_list *todo_list,
+ const char *commands)
+{
+ struct strbuf *buf = &todo_list->buf;
+ const char *old_buf = buf->buf;
+ size_t commands_len = strlen(commands + strlen("exec ")) - 1;
+ int i, first = 1, nr = 0, alloc = 0;
Minor nit pick, I think it is clearer if first is initialized just
before the loop as it is in the deleted code below.
+ struct todo_item *items = NULL,
+ base_item = {TODO_EXEC, NULL, 0, 0, commands_len, 0};
+
+ strbuf_addstr(buf, commands);
+ base_item.offset_in_buf = buf->len - commands_len - 1;
+ base_item.arg = buf->buf + base_item.offset_in_buf;
I think if the user gives --exec more than once on the command line then
commands will contain more than one exec command so this needs to parse
commands and create one todo_item for each command.
+
+ /*
+ * Insert <commands> after every pick. Here, fixup/squash chains
+ * are considered part of the pick, so we insert the commands *after*
+ * those chains if there are any.
+ */
+ for (i = 0; i < todo_list->nr; i++) {
+ enum todo_command command = todo_list->items[i].command;
+ if (todo_list->items[i].arg)
+ todo_list->items[i].arg = todo_list->items[i].arg - old_buf + buf->buf;
+
+ if (command == TODO_PICK && !first) {
+ ALLOC_GROW(items, nr + 1, alloc);
+ memcpy(items + nr++, &base_item, sizeof(struct todo_item));
I think it would be clearer to say
items[nr++] = base_item;
rather than using memcpy. This applies below and to some of the other
patches as well. Also this needs to loop over all the base_items if the
user gave --exec more than once on the command line.
Best Wishes
Phillip
+ }
+
+ ALLOC_GROW(items, nr + 1, alloc);
+ memcpy(items + nr++, todo_list->items + i, sizeof(struct todo_item));
+ first = 0;
+ }
+
+ /* insert or append final <commands> */
+ ALLOC_GROW(items, nr + 1, alloc);
+ memcpy(items + nr++, &base_item, sizeof(struct todo_item));
+
+ FREE_AND_NULL(todo_list->items);
+ todo_list->items = items;
+ todo_list->nr = nr;
+ todo_list->alloc = alloc;
+}
+
/*
* Add commands after pick and (series of) squash/fixup commands
* in the todo list.
@@ -4224,10 +4268,7 @@ int sequencer_add_exec_commands(const char *commands)
{
const char *todo_file = rebase_path_todo();
struct todo_list todo_list = TODO_LIST_INIT;
- struct todo_item *item;
- struct strbuf *buf = &todo_list.buf;
- size_t offset = 0, commands_len = strlen(commands);
- int i, first;
+ int res;
if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
return error(_("could not read '%s'."), todo_file);
@@ -4237,23 +4278,11 @@ int sequencer_add_exec_commands(const char *commands)
return error(_("unusable todo list: '%s'"), todo_file);
}
- first = 1;
- /* insert <commands> before every pick except the first one */
- for (item = todo_list.items, i = 0; i < todo_list.nr; i++, item++) {
- if (item->command == TODO_PICK && !first) {
- strbuf_insert(buf, item->offset_in_buf + offset,
- commands, commands_len);
- offset += commands_len;
- }
- first = 0;
- }
-
- /* append final <commands> */
- strbuf_add(buf, commands, commands_len);
-
- i = write_message(buf->buf, buf->len, todo_file, 0);
+ todo_list_add_exec_commands(&todo_list, commands);
+ res = todo_list_write_to_file(&todo_list, todo_file, NULL, NULL, 0, 0, -1, 0);
todo_list_release(&todo_list);
- return i;
+
+ return res;
}
static void todo_list_to_strbuf(struct todo_list *todo_list, struct strbuf *buf,
