builtin/checkout.c: complete parallel checkout support

Pathspec-limited checkouts (like `git checkout *.txt`) are performed by
a code path that doesn't yet support parallel checkout because it calls
checkout_entry() directly, instead of unpack_trees(). Let's add parallel
checkout support for this code path too.

The transient cache entries allocated in checkout_merged() are now
allocated in a mem_pool which is only discarded after parallel checkout
finishes. This is done because the entries need to be valid when
run_parallel_checkout() is called.

Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index db667d0267380924c26c4bee71fb0a636cb15cc8..99384d5c7aee7aff52fc78e89a84376a55ce4c62 100644 (file)
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -27,6 +27,7 @@
 #include "wt-status.h"
 #include "xdiff-interface.h"
 #include "entry.h"
+#include "parallel-checkout.h"
 
 static const char * const checkout_usage[] = {
        N_("git checkout [<options>] <branch>"),
@@ -230,7 +231,8 @@ static int checkout_stage(int stage, const struct cache_entry *ce, int pos,
                return error(_("path '%s' does not have their version"), ce->name);
 }
 
-static int checkout_merged(int pos, const struct checkout *state, int *nr_checkouts)
+static int checkout_merged(int pos, const struct checkout *state,
+                          int *nr_checkouts, struct mem_pool *ce_mem_pool)
 {
        struct cache_entry *ce = active_cache[pos];
        const char *path = ce->name;
@@ -291,11 +293,10 @@ static int checkout_merged(int pos, const struct checkout *state, int *nr_checko
        if (write_object_file(result_buf.ptr, result_buf.size, blob_type, &oid))
                die(_("Unable to add merge result for '%s'"), path);
        free(result_buf.ptr);
-       ce = make_transient_cache_entry(mode, &oid, path, 2, NULL);
+       ce = make_transient_cache_entry(mode, &oid, path, 2, ce_mem_pool);
        if (!ce)
                die(_("make_cache_entry failed for path '%s'"), path);
        status = checkout_entry(ce, state, NULL, nr_checkouts);
-       discard_cache_entry(ce);
        return status;
 }
 
@@ -359,16 +360,23 @@ static int checkout_worktree(const struct checkout_opts *opts,
        int nr_checkouts = 0, nr_unmerged = 0;
        int errs = 0;
        int pos;
+       int pc_workers, pc_threshold;
+       struct mem_pool ce_mem_pool;
 
        state.force = 1;
        state.refresh_cache = 1;
        state.istate = &the_index;
 
+       mem_pool_init(&ce_mem_pool, 0);
+       get_parallel_checkout_configs(&pc_workers, &pc_threshold);
        init_checkout_metadata(&state.meta, info->refname,
                               info->commit ? &info->commit->object.oid : &info->oid,
                               NULL);
 
        enable_delayed_checkout(&state);
+       if (pc_workers > 1)
+               init_parallel_checkout();
+
        for (pos = 0; pos < active_nr; pos++) {
                struct cache_entry *ce = active_cache[pos];
                if (ce->ce_flags & CE_MATCHED) {
@@ -384,10 +392,15 @@ static int checkout_worktree(const struct checkout_opts *opts,
                                                       &nr_checkouts, opts->overlay_mode);
                        else if (opts->merge)
                                errs |= checkout_merged(pos, &state,
-                                                       &nr_unmerged);
+                                                       &nr_unmerged,
+                                                       &ce_mem_pool);
                        pos = skip_same_name(ce, pos) - 1;
                }
        }
+       if (pc_workers > 1)
+               errs |= run_parallel_checkout(&state, pc_workers, pc_threshold,
+                                             NULL, NULL);
+       mem_pool_discard(&ce_mem_pool, should_validate_cache_entries());
        remove_marked_cache_entries(&the_index, 1);
        remove_scheduled_dirs();
        errs |= finish_delayed_checkout(&state, &nr_checkouts);