protobuf/upb/message/internal/map_entry.h

// Protocol Buffers - Google's data interchange format
// Copyright 2023 Google LLC.  All rights reserved.
// https://developers.google.com/protocol-buffers/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google LLC nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#ifndef UPB_COLLECTIONS_INTERNAL_MAP_ENTRY_H_
#define UPB_COLLECTIONS_INTERNAL_MAP_ENTRY_H_

#include "upb/base/string_view.h"
#include "upb/hash/common.h"
#include "upb/message/internal/types.h"

// Map entries aren't actually stored for map fields, they are only used during
// parsing. For parsing, it helps a lot if all map entry messages have the same
// layout. The layout code in mini_table/decode.c will ensure that all map
// entries have this layout.
//
// Note that users can and do create map entries directly, which will also use
// this layout.
//
// NOTE: sync with wire/decode.c.
typedef struct {
  // We only need 2 hasbits max, but due to alignment we'll use 8 bytes here,
  // and the uint64_t helps make this clear.
  uint64_t hasbits;
  union {
    upb_StringView str;  // For str/bytes.
    upb_value val;       // For all other types.
  } k;
  union {
    upb_StringView str;  // For str/bytes.
    upb_value val;       // For all other types.
  } v;
} upb_MapEntryData;

typedef struct {
  upb_Message_Internal internal;
  upb_MapEntryData data;
} upb_MapEntry;

#endif  // UPB_COLLECTIONS_INTERNAL_MAP_ENTRY_H_