midx: extract bitmap write setup

The write_midx_bitmap() method is a long method that does a lot of
steps. It requires the write_midx_context struct for use in
prepare_midx_packing_data() and find_commits_for_midx_bitmap(), but
after that only needs the pack_order array.

This is a messy, but completely non-functional refactoring. The code is
only being moved around to reduce visibility of the write_midx_context
during the longest part of computing reachability bitmaps.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/midx.c b/midx.c
index 5f0dd386b0266b6549c85499ab50e964ed868f1d..e2dd808b35d449934d7b9973da52f79ba912ec64 100644 (file)
--- a/midx.c
+++ b/midx.c
@@ -1053,40 +1053,35 @@ static struct commit **find_commits_for_midx_bitmap(uint32_t *indexed_commits_nr
        return cb.commits;
 }
 
-static int write_midx_bitmap(char *midx_name, unsigned char *midx_hash,
-                            struct write_midx_context *ctx,
+static int write_midx_bitmap(const char *midx_name,
+                            const unsigned char *midx_hash,
+                            struct packing_data *pdata,
+                            struct commit **commits,
+                            uint32_t commits_nr,
+                            uint32_t *pack_order,
                             const char *refs_snapshot,
                             unsigned flags)
 {
-       struct packing_data pdata;
-       struct pack_idx_entry **index;
-       struct commit **commits = NULL;
-       uint32_t i, commits_nr;
+       int ret, i;
        uint16_t options = 0;
-       char *bitmap_name = xstrfmt("%s-%s.bitmap", midx_name, hash_to_hex(midx_hash));
-       int ret;
-
-       if (!ctx->entries_nr)
-               BUG("cannot write a bitmap without any objects");
+       struct pack_idx_entry **index;
+       char *bitmap_name = xstrfmt("%s-%s.bitmap", midx_name,
+                                       hash_to_hex(midx_hash));
 
        if (flags & MIDX_WRITE_BITMAP_HASH_CACHE)
                options |= BITMAP_OPT_HASH_CACHE;
 
-       prepare_midx_packing_data(&pdata, ctx);
-
-       commits = find_commits_for_midx_bitmap(&commits_nr, refs_snapshot, ctx);
-
        /*
         * Build the MIDX-order index based on pdata.objects (which is already
         * in MIDX order; c.f., 'midx_pack_order_cmp()' for the definition of
         * this order).
         */
-       ALLOC_ARRAY(index, pdata.nr_objects);
-       for (i = 0; i < pdata.nr_objects; i++)
-               index[i] = &pdata.objects[i].idx;
+       ALLOC_ARRAY(index, pdata->nr_objects);
+       for (i = 0; i < pdata->nr_objects; i++)
+               index[i] = &pdata->objects[i].idx;
 
        bitmap_writer_show_progress(flags & MIDX_PROGRESS);
-       bitmap_writer_build_type_index(&pdata, index, pdata.nr_objects);
+       bitmap_writer_build_type_index(pdata, index, pdata->nr_objects);
 
        /*
         * bitmap_writer_finish expects objects in lex order, but pack_order
@@ -1101,16 +1096,16 @@ static int write_midx_bitmap(char *midx_name, unsigned char *midx_hash,
         * happens between bitmap_writer_build_type_index() and
         * bitmap_writer_finish().
         */
-       for (i = 0; i < pdata.nr_objects; i++)
-               index[ctx->pack_order[i]] = &pdata.objects[i].idx;
+       for (i = 0; i < pdata->nr_objects; i++)
+               index[pack_order[i]] = &pdata->objects[i].idx;
 
        bitmap_writer_select_commits(commits, commits_nr, -1);
-       ret = bitmap_writer_build(&pdata);
+       ret = bitmap_writer_build(pdata);
        if (ret < 0)
                goto cleanup;
 
        bitmap_writer_set_checksum(midx_hash);
-       bitmap_writer_finish(index, pdata.nr_objects, bitmap_name, options);
+       bitmap_writer_finish(index, pdata->nr_objects, bitmap_name, options);
 
 cleanup:
        free(index);
@@ -1443,8 +1438,21 @@ static int write_midx_internal(const char *object_dir,
        if (flags & MIDX_WRITE_REV_INDEX &&
            git_env_bool("GIT_TEST_MIDX_WRITE_REV", 0))
                write_midx_reverse_index(midx_name.buf, midx_hash, &ctx);
+
        if (flags & MIDX_WRITE_BITMAP) {
-               if (write_midx_bitmap(midx_name.buf, midx_hash, &ctx,
+               struct packing_data pdata;
+               struct commit **commits;
+               uint32_t commits_nr;
+
+               if (!ctx.entries_nr)
+                       BUG("cannot write a bitmap without any objects");
+
+               prepare_midx_packing_data(&pdata, &ctx);
+
+               commits = find_commits_for_midx_bitmap(&commits_nr, refs_snapshot, &ctx);
+
+               if (write_midx_bitmap(midx_name.buf, midx_hash, &pdata,
+                                     commits, commits_nr, ctx.pack_order,
                                      refs_snapshot, flags) < 0) {
                        error(_("could not write multi-pack bitmap"));
                        result = 1;