upb/wire/decode_fast/dispatch.c

// Protocol Buffers - Google's data interchange format
// Copyright 2025 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

#include "upb/wire/decode_fast/dispatch.h"

#include <stdint.h>

#include "upb/mini_table/message.h"
#include "upb/wire/decode_fast/data.h"
#include "upb/wire/internal/decoder.h"
#include "upb/wire/internal/eps_copy_input_stream.h"

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

UPB_NOINLINE UPB_PRESERVE_NONE upb_FastDecoder_Return
upb_DecodeFast_MessageIsDoneFallback(UPB_PARSE_PARAMS) {
  int overrun;
  switch (UPB_PRIVATE(upb_EpsCopyInputStream_IsDoneStatus)(&d->input, ptr,
                                                           &overrun)) {
    case kUpb_IsDoneStatus_Done: {
      // We've reach end-of-message.  Sync hasbits and maybe check required
      // fields.
      d->message_is_done = true;
      upb_DecodeFast_SetHasbits(msg, hasbits);
      return (upb_FastDecoder_Return){
          .ptr = UPB_UNLIKELY(table->UPB_PRIVATE(required_count))
                     ? _upb_Decoder_CheckRequired(d, ptr, msg, table)
                     : ptr};
    }
    case kUpb_IsDoneStatus_NeedFallback:
      // We've reached end-of-buffer.  Refresh the buffer.
      ptr = UPB_PRIVATE(upb_EpsCopyInputStream_IsDoneFallback)(EPS(d), ptr,
                                                               overrun);

      // We successfully refreshed the buffer (otherwise the function above
      // would have thrown an error with longjmp()).  So continue with the
      // fast decoder.
      uint16_t tag = _upb_FastDecoder_LoadTag(ptr);
      _upb_Decoder_Trace(d, 'r');
      data2 = upb_DecodeFastData2_PackOriginalTag(data2, tag);
      UPB_MUSTTAIL return _upb_FastDecoder_TagDispatch(UPB_PARSE_ARGS);
    case kUpb_IsDoneStatus_NotDone:  // Handled by caller.
    default:
      UPB_UNREACHABLE();
  }
}

upb_FastDecoder_Return _upb_FastDecoder_ErrorJmp2(upb_Decoder* d) {
  UPB_LONGJMP(d->err->buf, 1);
  return (upb_FastDecoder_Return){.ptr = NULL};
}