protobuf/upb/reflection/message.h

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 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
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 *       derived from this software without specific prior written permission.
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#ifndef UPB_REFLECTION_MESSAGE_H_
#define UPB_REFLECTION_MESSAGE_H_

#include "upb/collections/map.h"
#include "upb/reflection/common.h"

// Must be last.
#include "upb/port/def.inc"

#ifdef __cplusplus
extern "C" {
#endif

// Returns a mutable pointer to a map, array, or submessage value. If the given
// arena is non-NULL this will construct a new object if it was not previously
// present. May not be called for primitive fields.
upb_MutableMessageValue upb_Message_Mutable(upb_Message* msg,
                                            const upb_FieldDef* f,
                                            upb_Arena* a);

// Returns the field that is set in the oneof, or NULL if none are set.
const upb_FieldDef* upb_Message_WhichOneof(const upb_Message* msg,
                                           const upb_OneofDef* o);

// Clear all data and unknown fields.
void upb_Message_ClearByDef(upb_Message* msg, const upb_MessageDef* m);

// Clears any field presence and sets the value back to its default.
void upb_Message_ClearFieldByDef(upb_Message* msg, const upb_FieldDef* f);

// May only be called for fields where upb_FieldDef_HasPresence(f) == true.
bool upb_Message_HasFieldByDef(const upb_Message* msg, const upb_FieldDef* f);

// Returns the value in the message associated with this field def.
upb_MessageValue upb_Message_GetFieldByDef(const upb_Message* msg,
                                           const upb_FieldDef* f);

// Sets the given field to the given value. For a msg/array/map/string, the
// caller must ensure that the target data outlives |msg| (by living either in
// the same arena or a different arena that outlives it).
//
// Returns false if allocation fails.
bool upb_Message_SetFieldByDef(upb_Message* msg, const upb_FieldDef* f,
                               upb_MessageValue val, upb_Arena* a);

// Iterate over present fields.
//
// size_t iter = kUpb_Message_Begin;
// const upb_FieldDef *f;
// upb_MessageValue val;
// while (upb_Message_Next(msg, m, ext_pool, &f, &val, &iter)) {
//   process_field(f, val);
// }
//
// If ext_pool is NULL, no extensions will be returned.  If the given symtab
// returns extensions that don't match what is in this message, those extensions
// will be skipped.

#define kUpb_Message_Begin -1

bool upb_Message_Next(const upb_Message* msg, const upb_MessageDef* m,
                      const upb_DefPool* ext_pool, const upb_FieldDef** f,
                      upb_MessageValue* val, size_t* iter);

// Clears all unknown field data from this message and all submessages.
bool upb_Message_DiscardUnknown(upb_Message* msg, const upb_MessageDef* m,
                                int maxdepth);

#ifdef __cplusplus
} /* extern "C" */
#endif

#include "upb/port/undef.inc"

#endif /* UPB_REFLECTION_MESSAGE_H_ */