Move `load_state` and its helper functions to their own module.

1 files changed, 49 insertions, 0 deletions

diff --git a/toxcore/state.h b/toxcore/state.h
new file mode 100644
index 00000000..3f7ff043
--- /dev/null
+++ b/toxcore/state.h
@@ -0,0 +1,49 @@
+/**
+ * The state module is responsible for parsing the Tox save data format and for
+ * saving state in that format.
+ *
+ * This module provides functions for iterating over serialised data sections
+ * and reading/writing numbers in the correct format (little endian).
+ *
+ * Note that unlike the Tox network protocol, the save data stores its values in
+ * little endian, which is native to most desktop and server architectures in
+ * 2018.
+ */
+#ifndef C_TOXCORE_TOXCORE_STATE_H
+#define C_TOXCORE_TOXCORE_STATE_H
+
+#include "logger.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Returned by the state_load_cb to instruct the loader on what to do next.
+typedef enum State_Load_Status {
+    // Continue loading state data sections.
+    STATE_LOAD_STATUS_CONTINUE,
+    // An error occurred. Stop loading sections.
+    STATE_LOAD_STATUS_ERROR,
+    // We're at the end of the save data, terminate loading successfully.
+    STATE_LOAD_STATUS_END,
+} State_Load_Status;
+
+typedef State_Load_Status state_load_cb(void *outer, const uint8_t *data, uint32_t len, uint16_t type);
+
+// state load/save
+int state_load(const Logger *log, state_load_cb *state_load_callback, void *outer,
+               const uint8_t *data, uint32_t length, uint16_t cookie_inner);
+
+// Utilities for state data serialisation.
+
+uint16_t lendian_to_host16(uint16_t lendian);
+#define host_tolendian16(x) lendian_to_host16(x)
+
+void host_to_lendian32(uint8_t *dest, uint32_t num);
+void lendian_to_host32(uint32_t *dest, const uint8_t *lendian);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif // C_TOXCORE_TOXCORE_STATE_H