Add bts_filename which gets the current filename from a bt_stream.

misc/stream.c

@@ -178,3 +178,9 @@ bts_sha(struct bt_stream *bts, off_t start, off_t length, uint8_t *hash)
     SHA1_Final(hash, &ctx);
     return err;
 }
+
+const char *
+bts_filename(struct bt_stream *bts)
+{
+    return bts->files[bts->index].path;
+}

misc/stream.h

@@ -23,4 +23,6 @@ int bts_get(struct bt_stream *bts, off_t off, uint8_t *buf, size_t len);
 int bts_put(struct bt_stream *bts, off_t off, const uint8_t *buf, size_t len);
 int bts_sha(struct bt_stream *bts, off_t start, off_t length, uint8_t *hash);
 
+const char *bts_filename(struct bt_stream *bts);
+
 #endif