Expose minimal asset cache API.

PiperOrigin-RevId: 803126923
Change-Id: Iabf63802572f7cb86864b5ece85f44b3f15a4ec0

include/mujoco/mjmodel.h

@@ -450,6 +450,12 @@ struct mjLROpt_ {                 // options for mj_setLengthRange()
 };
 typedef struct mjLROpt_ mjLROpt;
 
+//---------------------------------- mjCache -------------------------------------------------------
+
+struct mjCache_ {                 // asset cache used by the compiler
+  void* impl_;                    // internal pointer to cache
+};
+typedef struct mjCache_ mjCache;
 
 //---------------------------------- mjVFS ---------------------------------------------------------
 

include/mujoco/mujoco.h

@@ -90,6 +90,22 @@ MJAPI int mj_deleteFileVFS(mjVFS* vfs, const char* filename);
 // Delete all files from VFS and deallocates VFS internal memory.
 MJAPI void mj_deleteVFS(mjVFS* vfs);
 
+//------------------------------------ Asset cache -------------------------------------------------
+
+// Get the current size of the asset cache in bytes.
+MJAPI size_t mj_getCacheSize(const mjCache* cache);
+
+// Get the capacity of the asset cache in bytes.
+MJAPI size_t mj_getCacheCapacity(const mjCache* cache);
+
+// Set the capacity of the asset cache in bytes (0 to disable); returns the new capacity.
+MJAPI size_t mj_setCacheCapacity(mjCache* cache, size_t size);
+
+// Get the internal asset cache used by the compiler.
+MJAPI mjCache* mj_getCache(void);
+
+// Clear the asset cache.
+MJAPI void mj_clearCache(mjCache* cache);
 
 //---------------------------------- Parse and compile ---------------------------------------------