btrfs-progs: list-chunks: Workarounds for replacing qsort_r when targeting Android

Android NDK does not support `qsort_r`, this workaround first add a list of `id` to struct `compare`, and then reverse the list, and finally do the sorting stuffs using `qsort`.
This helps preserve the sorting order without `qsort_r`

Signed-off-by: Shadichy <[email protected]>

Author: shadichy

cmds/inspect.c

@@ -878,9 +878,27 @@ static int print_list_chunks(struct list_chunks_ctx *ctx, const char *sortmode,
 	}
 
 	/* Skip additional sort if nothing defined by user. */
-	if (comp.count > 0)
+	if (comp.count > 0) {
+#ifdef __ANDROID__
+		for (i = comp.count - 1; i >= 0; i--) {
+			if (comp.id[i] == CHUNK_SORT_PSTART) {
+				qsort(ctx->stats, ctx->length, sizeof(ctx->stats[0]), (sort_cmp_t)cmp_cse_pstart);
+			}
+			else if (comp.id[i] == CHUNK_SORT_LSTART) {
+				qsort(ctx->stats, ctx->length, sizeof(ctx->stats[0]), (sort_cmp_t)cmp_cse_lstart);
+			}
+			else if (comp.id[i] == CHUNK_SORT_USAGE) {
+				qsort(ctx->stats, ctx->length, sizeof(ctx->stats[0]), (sort_cmp_t)cmp_cse_usage);
+			}
+			else if (comp.id[i] == CHUNK_SORT_LENGTH) {
+				qsort(ctx->stats, ctx->length, sizeof(ctx->stats[0]), (sort_cmp_t)cmp_cse_length);
+			}
+		}
+#else
 		qsort_r(ctx->stats, ctx->length, sizeof(ctx->stats[0]),
 			(sort_r_cmp_t)compare_cmp_multi, &comp);
+#endif
+	}
 
 	col_count = 9;
 	/* Two rows for header and separator. */

common/sort-utils.c

@@ -78,6 +78,9 @@ int compare_add_sort_id(struct compare *comp, int id)
 		if (comp->sortdef[i].name == NULL)
 			return -1;
 		if (comp->sortdef[i].id == id) {
+#ifdef __ANDROID__
+			comp->id[comp->count] = id;
+#endif
 			comp->comp[comp->count] = comp->sortdef[i].comp;
 			comp->count++;
 			break;

common/sort-utils.h

@@ -89,6 +89,9 @@ struct compare {
 	unsigned long invert_map;
 	int count;
 	const struct sortdef *sortdef;
+#ifdef __ANDROID__
+	int id[SORT_MAX_KEYS];
+#endif
 };
 
 int compare_init(struct compare *comp, const struct sortdef *sortdef);