pack-bitmap: introduce bitmap_writer_free()

Now that there is clearer memory ownership around the bitmap_writer
structure, introduce a bitmap_writer_free() function that callers may
use to free any memory associated with their instance of the
bitmap_writer structure.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/pack-objects.c

@@ -1245,7 +1245,6 @@ static void write_pack_file(void)
 	uint32_t nr_remaining = nr_result;
 	time_t last_mtime = 0;
 	struct object_entry **write_order;
-	struct bitmap_writer bitmap_writer;
 
 	if (progress > pack_to_stdout)
 		progress_state = start_progress(_("Writing objects"), nr_result);
@@ -1315,6 +1314,7 @@ static void write_pack_file(void)
 		if (!pack_to_stdout) {
 			struct stat st;
 			struct strbuf tmpname = STRBUF_INIT;
+			struct bitmap_writer bitmap_writer;
 			char *idx_tmp_name = NULL;
 
 			/*
@@ -1370,6 +1370,7 @@ static void write_pack_file(void)
 				bitmap_writer_finish(&bitmap_writer,
 						     written_list, nr_written,
 						     tmpname.buf, write_bitmap_options);
+				bitmap_writer_free(&bitmap_writer);
 				write_bitmap_index = 0;
 				strbuf_setlen(&tmpname, tmpname_len);
 			}

midx-write.c

@@ -853,6 +853,7 @@ static int write_midx_bitmap(const char *midx_name,
 cleanup:
 	free(index);
 	free(bitmap_name);
+	bitmap_writer_free(&writer);
 
 	trace2_region_leave("midx", "write_midx_bitmap", the_repository);
 

pack-bitmap-write.c

@@ -32,6 +32,29 @@ void bitmap_writer_init(struct bitmap_writer *writer)
 	memset(writer, 0, sizeof(struct bitmap_writer));
 }
 
+void bitmap_writer_free(struct bitmap_writer *writer)
+{
+	uint32_t i;
+
+	if (!writer)
+		return;
+
+	ewah_free(writer->commits);
+	ewah_free(writer->trees);
+	ewah_free(writer->blobs);
+	ewah_free(writer->tags);
+
+	kh_destroy_oid_map(writer->bitmaps);
+
+	for (i = 0; i < writer->selected_nr; i++) {
+		struct bitmapped_commit *bc = &writer->selected[i];
+		if (bc->write_as != bc->bitmap)
+			ewah_free(bc->write_as);
+		ewah_free(bc->bitmap);
+	}
+	free(writer->selected);
+}
+
 void bitmap_writer_show_progress(struct bitmap_writer *writer, int show)
 {
 	writer->show_progress = show;

pack-bitmap.h

@@ -139,6 +139,7 @@ void bitmap_writer_finish(struct bitmap_writer *writer,
 			  uint32_t index_nr,
 			  const char *filename,
 			  uint16_t options);
+void bitmap_writer_free(struct bitmap_writer *writer);
 char *midx_bitmap_filename(struct multi_pack_index *midx);
 char *pack_bitmap_filename(struct packed_git *p);