run-command.c: don't copy *_fn to "struct parallel_processes"

The only remaining reason for copying the callbacks in the "struct
run_process_parallel_opts" over to the "struct parallel_processes" was
to avoid two if/else statements in case the "start_failure" and
"task_finished" callbacks were NULL.

Let's handle those cases in pp_start_one() and pp_collect_finished()
instead, and avoid the default_* stub functions, and the need to copy
this data around.

Organizing the code like this made more sense before the "struct
run_parallel_parallel_opts" existed, as we'd have needed to pass each
of these as a separate parameter.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/run-command.c b/run-command.c
index a72c4295adcf17ebf0af05826d4f359284f728f3..e10b1b97390a17e5bca285504291458855ab368c 100644 (file)
--- a/run-command.c
+++ b/run-command.c
@@ -1502,10 +1502,6 @@ struct parallel_processes {
        const size_t max_processes;
        size_t nr_processes;
 
-       get_next_task_fn get_next_task;
-       start_failure_fn start_failure;
-       task_finished_fn task_finished;
-
        struct {
                enum child_state state;
                struct child_process process;
@@ -1525,21 +1521,6 @@ struct parallel_processes {
        struct strbuf buffered_output; /* of finished children */
 };
 
-static int default_start_failure(struct strbuf *out,
-                                void *pp_cb,
-                                void *pp_task_cb)
-{
-       return 0;
-}
-
-static int default_task_finished(int result,
-                                struct strbuf *out,
-                                void *pp_cb,
-                                void *pp_task_cb)
-{
-       return 0;
-}
-
 static void kill_children(const struct parallel_processes *pp, int signo)
 {
        for (size_t i = 0; i < pp->max_processes; i++)
@@ -1560,9 +1541,6 @@ static void pp_init(struct parallel_processes *pp,
                    const struct run_process_parallel_opts *opts)
 {
        const size_t n = opts->processes;
-       get_next_task_fn get_next_task = opts->get_next_task;
-       start_failure_fn start_failure = opts->start_failure;
-       task_finished_fn task_finished = opts->task_finished;
 
        if (!n)
                BUG("you must provide a non-zero number of processes!");
@@ -1570,12 +1548,8 @@ static void pp_init(struct parallel_processes *pp,
        trace_printf("run_processes_parallel: preparing to run up to %"PRIuMAX" tasks",
                     (uintmax_t)n);
 
-       if (!get_next_task)
+       if (!opts->get_next_task)
                BUG("you need to specify a get_next_task function");
-       pp->get_next_task = get_next_task;
-
-       pp->start_failure = start_failure ? start_failure : default_start_failure;
-       pp->task_finished = task_finished ? task_finished : default_task_finished;
 
        CALLOC_ARRAY(pp->children, n);
        if (!pp->ungroup)
@@ -1622,7 +1596,8 @@ static void pp_cleanup(struct parallel_processes *pp)
  * <0 no new job was started, user wishes to shutdown early. Use negative code
  *    to signal the children.
  */
-static int pp_start_one(struct parallel_processes *pp)
+static int pp_start_one(struct parallel_processes *pp,
+                       const struct run_process_parallel_opts *opts)
 {
        size_t i;
        int code;
@@ -1633,10 +1608,10 @@ static int pp_start_one(struct parallel_processes *pp)
        if (i == pp->max_processes)
                BUG("bookkeeping is hard");
 
-       code = pp->get_next_task(&pp->children[i].process,
-                                pp->ungroup ? NULL : &pp->children[i].err,
-                                pp->data,
-                                &pp->children[i].data);
+       code = opts->get_next_task(&pp->children[i].process,
+                                  pp->ungroup ? NULL : &pp->children[i].err,
+                                  pp->data,
+                                  &pp->children[i].data);
        if (!code) {
                if (!pp->ungroup) {
                        strbuf_addbuf(&pp->buffered_output, &pp->children[i].err);
@@ -1651,10 +1626,14 @@ static int pp_start_one(struct parallel_processes *pp)
        pp->children[i].process.no_stdin = 1;
 
        if (start_command(&pp->children[i].process)) {
-               code = pp->start_failure(pp->ungroup ? NULL :
-                                        &pp->children[i].err,
-                                        pp->data,
-                                        pp->children[i].data);
+               if (opts->start_failure)
+                       code = opts->start_failure(pp->ungroup ? NULL :
+                                                  &pp->children[i].err,
+                                                  pp->data,
+                                                  pp->children[i].data);
+               else
+                       code = 0;
+
                if (!pp->ungroup) {
                        strbuf_addbuf(&pp->buffered_output, &pp->children[i].err);
                        strbuf_reset(&pp->children[i].err);
@@ -1709,7 +1688,8 @@ static void pp_output(const struct parallel_processes *pp)
        }
 }
 
-static int pp_collect_finished(struct parallel_processes *pp)
+static int pp_collect_finished(struct parallel_processes *pp,
+                              const struct run_process_parallel_opts *opts)
 {
        int code;
        size_t i, n = pp->max_processes;
@@ -1724,9 +1704,12 @@ static int pp_collect_finished(struct parallel_processes *pp)
 
                code = finish_command(&pp->children[i].process);
 
-               code = pp->task_finished(code, pp->ungroup ? NULL :
-                                        &pp->children[i].err, pp->data,
-                                        pp->children[i].data);
+               if (opts->task_finished)
+                       code = opts->task_finished(code, pp->ungroup ? NULL :
+                                                  &pp->children[i].err, pp->data,
+                                                  pp->children[i].data);
+               else
+                       code = 0;
 
                if (code)
                        result = code;
@@ -1795,7 +1778,7 @@ void run_processes_parallel(const struct run_process_parallel_opts *opts)
                    i < spawn_cap && !pp.shutdown &&
                    pp.nr_processes < pp.max_processes;
                    i++) {
-                       code = pp_start_one(&pp);
+                       code = pp_start_one(&pp, opts);
                        if (!code)
                                continue;
                        if (code < 0) {
@@ -1813,7 +1796,7 @@ void run_processes_parallel(const struct run_process_parallel_opts *opts)
                        pp_buffer_stderr(&pp, output_timeout);
                        pp_output(&pp);
                }
-               code = pp_collect_finished(&pp);
+               code = pp_collect_finished(&pp, opts);
                if (code) {
                        pp.shutdown = 1;
                        if (code < 0)