protobuf/upb/mini_table/decode.h

/*
 * Copyright (c) 2009-2022, Google LLC
 * All rights reserved.
 *
 * 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 Google LLC 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_MINI_TABLE_DECODE_H_
#define UPB_MINI_TABLE_DECODE_H_

#include "upb/base/status.h"
#include "upb/mem/arena.h"
#include "upb/mini_table/common.h"

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

typedef enum {
  kUpb_MiniTablePlatform_32Bit,
  kUpb_MiniTablePlatform_64Bit,
  kUpb_MiniTablePlatform_Native =
      UPB_SIZE(kUpb_MiniTablePlatform_32Bit, kUpb_MiniTablePlatform_64Bit),
} upb_MiniTablePlatform;

#ifdef __cplusplus
extern "C" {
#endif

// Builds a mini table from the data encoded in the buffer [data, len]. If any
// errors occur, returns NULL and sets a status message. In the success case,
// the caller must call upb_MiniTable_SetSub*() for all message or proto2 enum
// fields to link the table to the appropriate sub-tables.
upb_MiniTable* _upb_MiniTable_Build(const char* data, size_t len,
                                    upb_MiniTablePlatform platform,
                                    upb_Arena* arena, upb_Status* status);

UPB_API_INLINE upb_MiniTable* upb_MiniTable_Build(const char* data, size_t len,
                                                  upb_Arena* arena,
                                                  upb_Status* status) {
  return _upb_MiniTable_Build(data, len, kUpb_MiniTablePlatform_Native, arena,
                              status);
}

// Links a sub-message field to a MiniTable for that sub-message. If a
// sub-message field is not linked, it will be treated as an unknown field
// during parsing, and setting the field will not be allowed. It is possible
// to link the message field later, at which point it will no longer be treated
// as unknown. However there is no synchronization for this operation, which
// means parallel mutation requires external synchronization.
// Returns success/failure.
UPB_API bool upb_MiniTable_SetSubMessage(upb_MiniTable* table,
                                         upb_MiniTableField* field,
                                         const upb_MiniTable* sub);

// Links an enum field to a MiniTable for that enum.
// All enum fields must be linked prior to parsing.
// Returns success/failure.
UPB_API bool upb_MiniTable_SetSubEnum(upb_MiniTable* table,
                                      upb_MiniTableField* field,
                                      const upb_MiniTableEnum* sub);

// Initializes a MiniTableExtension buffer that has already been allocated.
// This is needed by upb_FileDef and upb_MessageDef, which allocate all of the
// extensions together in a single contiguous array.
const char* _upb_MiniTableExtension_Init(const char* data, size_t len,
                                         upb_MiniTableExtension* ext,
                                         const upb_MiniTable* extendee,
                                         upb_MiniTableSub sub,
                                         upb_MiniTablePlatform platform,
                                         upb_Status* status);

UPB_API_INLINE const char* upb_MiniTableExtension_Init(
    const char* data, size_t len, upb_MiniTableExtension* ext,
    const upb_MiniTable* extendee, upb_MiniTableSub sub, upb_Status* status) {
  return _upb_MiniTableExtension_Init(data, len, ext, extendee, sub,
                                      kUpb_MiniTablePlatform_Native, status);
}

UPB_API upb_MiniTableExtension* _upb_MiniTableExtension_Build(
    const char* data, size_t len, const upb_MiniTable* extendee,
    upb_MiniTableSub sub, upb_MiniTablePlatform platform, upb_Arena* arena,
    upb_Status* status);

UPB_API_INLINE upb_MiniTableExtension* upb_MiniTableExtension_Build(
    const char* data, size_t len, const upb_MiniTable* extendee,
    upb_Arena* arena, upb_Status* status) {
  upb_MiniTableSub sub;
  sub.submsg = NULL;
  return _upb_MiniTableExtension_Build(
      data, len, extendee, sub, kUpb_MiniTablePlatform_Native, arena, status);
}

UPB_API_INLINE upb_MiniTableExtension* upb_MiniTableExtension_BuildMessage(
    const char* data, size_t len, const upb_MiniTable* extendee,
    upb_MiniTable* submsg, upb_Arena* arena, upb_Status* status) {
  upb_MiniTableSub sub;
  sub.submsg = submsg;
  return _upb_MiniTableExtension_Build(
      data, len, extendee, sub, kUpb_MiniTablePlatform_Native, arena, status);
}

UPB_API_INLINE upb_MiniTableExtension* upb_MiniTableExtension_BuildEnum(
    const char* data, size_t len, const upb_MiniTable* extendee,
    upb_MiniTableEnum* subenum, upb_Arena* arena, upb_Status* status) {
  upb_MiniTableSub sub;
  sub.subenum = subenum;
  return _upb_MiniTableExtension_Build(
      data, len, extendee, sub, kUpb_MiniTablePlatform_Native, arena, status);
}

UPB_API upb_MiniTableEnum* upb_MiniTableEnum_Build(const char* data, size_t len,
                                                   upb_Arena* arena,
                                                   upb_Status* status);

// Like upb_MiniTable_Build(), but the user provides a buffer of layout data so
// it can be reused from call to call, avoiding repeated realloc()/free().
//
// The caller owns `*buf` both before and after the call, and must free() it
// when it is no longer in use.  The function will realloc() `*buf` as
// necessary, updating `*size` accordingly.
upb_MiniTable* upb_MiniTable_BuildWithBuf(const char* data, size_t len,
                                          upb_MiniTablePlatform platform,
                                          upb_Arena* arena, void** buf,
                                          size_t* buf_size, upb_Status* status);

// Returns a list of fields that require linking at runtime, to connect the
// MiniTable to its sub-messages and sub-enums.  The list of fields will be
// written to the `subs` array, which must have been allocated by the caller
// and must be large enough to hold a list of all fields in the message.
//
// The order of the fields returned by this function is significant: it matches
// the order expected by upb_MiniTable_Link() below.
//
// The return value packs the sub-message count and sub-enum count into a single
// integer like so:
//  return (msg_count << 16) | enum_count;
UPB_API uint32_t upb_MiniTable_GetSubList(const upb_MiniTable* mt,
                                          const upb_MiniTableField** subs);

// Links a message to its sub-messages and sub-enums.  The caller must pass
// arrays of sub-tables and sub-enums, in the same length and order as is
// returned by upb_MiniTable_GetSubList() above.  However, individual elements
// of the sub_tables may be NULL if those sub-messages were tree shaken.
//
// Returns false if either array is too short, or if any of the tables fails
// to link.
UPB_API bool upb_MiniTable_Link(upb_MiniTable* mt,
                                const upb_MiniTable** sub_tables,
                                size_t sub_table_count,
                                const upb_MiniTableEnum** sub_enums,
                                size_t sub_enum_count);

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

#include "upb/port/undef.inc"

#endif /* UPB_MINI_TABLE_DECODE_H_ */