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// Protocol Buffers - Google's data interchange format
// Copyright 2023 Google LLC. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd
#ifndef UPB_MESSAGE_INTERNAL_EXTENSION_H_
#define UPB_MESSAGE_INTERNAL_EXTENSION_H_
#include <stddef.h>
#include "upb/mem/arena.h"
#include "upb/message/value.h"
#include "upb/mini_table/extension.h"
// Must be last.
#include "upb/port/def.inc"
// The internal representation of an extension is self-describing: it contains
// enough information that we can serialize it to binary format without needing
// to look it up in a upb_ExtensionRegistry.
//
// This representation allocates 16 bytes to data on 64-bit platforms.
// This is rather wasteful for scalars (in the extreme case of bool,
// it wastes 15 bytes). We accept this because we expect messages to be
// the most common extension type.
typedef struct {
const upb_MiniTableExtension* ext;
upb_MessageValue data;
} upb_Extension;
#ifdef __cplusplus
extern "C" {
#endif
// Adds the given extension data to the given message.
// |ext| is copied into the message instance.
// This logically replaces any previously-added extension with this number.
upb_Extension* UPB_PRIVATE(_upb_Message_GetOrCreateExtension)(
struct upb_Message* msg, const upb_MiniTableExtension* ext,
upb_Arena* arena);
// Returns an array of extensions for this message.
// Note: the array is ordered in reverse relative to the order of creation.
const upb_Extension* UPB_PRIVATE(_upb_Message_Getexts)(
const struct upb_Message* msg, size_t* count);
// Returns an extension for a message with a given mini table,
// or NULL if no extension exists with this mini table.
const upb_Extension* UPB_PRIVATE(_upb_Message_Getext)(
const struct upb_Message* msg, const upb_MiniTableExtension* ext);
#ifdef __cplusplus
} /* extern "C" */
#endif
#include "upb/port/undef.inc"
#endif /* UPB_MESSAGE_INTERNAL_EXTENSION_H_ */