Expose minimal asset cache API.

PiperOrigin-RevId: 803126923
Change-Id: Iabf63802572f7cb86864b5ece85f44b3f15a4ec0

doc/APIreference/functions.rst

@@ -1289,6 +1289,12 @@ Add file to VFS. The directory argument is optional and can be NULL or empty. Re
 
 *Nullable:* ``directory``
 
+
+.. Assetcache:
+
+The asset cache is a mechanism for caching assets (e.g. textures, meshes, etc.) to avoid repeated slow recompilation.
+The following methods provide way to control the capacity of the cache or to disable it altogether.
+
 .. _mj_addBufferVFS:
 
 `mj_addBufferVFS <#mj_addBufferVFS>`__

doc/APIreference/functions_override.rst

@@ -25,6 +25,12 @@ Add file to VFS. The directory argument is optional and can be NULL or empty. Re
 
 *Nullable:* ``directory``
 
+
+.. Assetcache:
+
+The asset cache is a mechanism for caching assets (e.g. textures, meshes, etc.) to avoid repeated slow recompilation.
+The following methods provide way to control the capacity of the cache or to disable it altogether.
+
 .. _Parseandcompile:
 
 The key function here is :ref:`mj_loadXML`. It invokes the built-in parser and compiler, and either returns a pointer to

doc/includes/references.h

@@ -789,6 +789,10 @@ struct mjLROpt_ {                 // options for mj_setLengthRange()
   mjtNum tolrange;                // convergence tolerance (relative to range)
 };
 typedef struct mjLROpt_ mjLROpt;
+struct mjCache_ {                 // asset cache used by the compiler
+  void* impl_;                    // internal pointer to cache
+};
+typedef struct mjCache_ mjCache;
 struct mjVFS_ {                   // virtual file system for loading from memory
   void* impl_;                    // internal pointer to VFS memory
 };
@@ -2999,6 +3003,11 @@ int mj_addFileVFS(mjVFS* vfs, const char* directory, const char* filename);
 int mj_addBufferVFS(mjVFS* vfs, const char* name, const void* buffer, int nbuffer);
 int mj_deleteFileVFS(mjVFS* vfs, const char* filename);
 void mj_deleteVFS(mjVFS* vfs);
+size_t mj_getCacheSize(const mjCache* cache);
+size_t mj_getCacheCapacity(const mjCache* cache);
+size_t mj_setCacheCapacity(mjCache* cache, size_t size);
+mjCache* mj_getCache(void);
+void mj_clearCache(mjCache* cache);
 mjModel* mj_loadXML(const char* filename, const mjVFS* vfs, char* error, int error_sz);
 mjSpec* mj_parseXML(const char* filename, const mjVFS* vfs, char* error, int error_sz);
 mjSpec* mj_parseXMLString(const char* xml, const mjVFS* vfs, char* error, int error_sz);