+/*
+ * Return the data stream that will be used
+ */
+int select_data_stream(FF_PKT *ff_pkt)
+{
+ int stream;
+
+ /*
+ * Fix all incompatible options
+ */
+
+ /* No sparse option for encrypted data */
+ if (ff_pkt->flags & FO_ENCRYPT) {
+ ff_pkt->flags &= ~FO_SPARSE;
+ }
+
+ /* Note, no sparse option for win32_data */
+ if (!is_portable_backup(&ff_pkt->bfd)) {
+ stream = STREAM_WIN32_DATA;
+ ff_pkt->flags &= ~FO_SPARSE;
+ } else if (ff_pkt->flags & FO_SPARSE) {
+ stream = STREAM_SPARSE_DATA;
+ } else {
+ stream = STREAM_FILE_DATA;
+ }
+
+ /* Encryption is only supported for file data */
+ if (stream != STREAM_FILE_DATA && stream != STREAM_WIN32_DATA &&
+ stream != STREAM_MACOS_FORK_DATA) {
+ ff_pkt->flags &= ~FO_ENCRYPT;
+ }
+
+ /* Compression is not supported for Mac fork data */
+ if (stream == STREAM_MACOS_FORK_DATA) {
+ ff_pkt->flags &= ~FO_GZIP;
+ }
+
+ /*
+ * Handle compression and encryption options
+ */
+#ifdef HAVE_LIBZ
+ if (ff_pkt->flags & FO_GZIP) {
+ switch (stream) {
+ case STREAM_WIN32_DATA:
+ stream = STREAM_WIN32_GZIP_DATA;
+ break;
+ case STREAM_SPARSE_DATA:
+ stream = STREAM_SPARSE_GZIP_DATA;
+ break;
+ case STREAM_FILE_DATA:
+ stream = STREAM_GZIP_DATA;
+ break;
+ default:
+ /* All stream types that do not support gzip should clear out
+ * FO_GZIP above, and this code block should be unreachable. */
+ ASSERT(!(ff_pkt->flags & FO_GZIP));
+ return STREAM_NONE;
+ }
+ }
+#endif
+#ifdef HAVE_CRYPTO
+ if (ff_pkt->flags & FO_ENCRYPT) {
+ switch (stream) {
+ case STREAM_WIN32_DATA:
+ stream = STREAM_ENCRYPTED_WIN32_DATA;
+ break;
+ case STREAM_WIN32_GZIP_DATA:
+ stream = STREAM_ENCRYPTED_WIN32_GZIP_DATA;
+ break;
+ case STREAM_FILE_DATA:
+ stream = STREAM_ENCRYPTED_FILE_DATA;
+ break;
+ case STREAM_GZIP_DATA:
+ stream = STREAM_ENCRYPTED_FILE_GZIP_DATA;
+ break;
+ default:
+ /* All stream types that do not support encryption should clear out
+ * FO_ENCRYPT above, and this code block should be unreachable. */
+ ASSERT(!(ff_pkt->flags & FO_ENCRYPT));
+ return STREAM_NONE;
+ }
+ }
+#endif
+
+ return stream;
+}
+