Protocol Buffers - Google's data interchange format (grpc依赖) https://developers.google.com/protocol-buffers/
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/*
* upb - a minimalist implementation of protocol buffers.
*
* Copyright (c) 2009-2010 Google Inc. See LICENSE for details.
* Author: Josh Haberman <jhaberman@gmail.com>
*
* upb_decoder implements a high performance, streaming decoder for protobuf
* data that works by getting its input data from a upb_bytesrc and calling
* into a upb_handlers.
*/
#ifndef UPB_DECODER_H_
#define UPB_DECODER_H_
#include <setjmp.h>
#include <stdbool.h>
#include <stdint.h>
#include "upb/handlers.h"
#ifdef __cplusplus
extern "C" {
#endif
/* upb_decoder *****************************************************************/
struct dasm_State;
typedef struct _upb_decoder {
upb_bytesrc *bytesrc; // Source of our serialized data.
upb_dispatcher dispatcher; // Dispatcher to which we push parsed data.
upb_status *status; // Where we will store any errors that occur.
upb_strref strref; // For passing string data to callbacks.
// Offsets for the bytesrc region we currently have ref'd.
uint64_t refstart_ofs, refend_ofs;
// Current input buffer and its stream offset.
const char *buf, *ptr, *end;
uint64_t bufstart_ofs, bufend_ofs;
// Stream offset for the end of the top-level message, if any.
uint64_t end_ofs;
// Buf offset as of which we've delivered calbacks; needed for rollback if
// a callback returns UPB_BREAK.
const char *completed_ptr;
// End of the delimited region, relative to ptr, or NULL if not in this buf.
const char *delim_end;
bool top_is_packed;
#ifdef UPB_USE_JIT_X64
// For JIT, which doesn't do bounds checks in the middle of parsing a field.
const char *jit_end, *effective_end; // == MIN(jit_end, submsg_end)
// JIT-generated machine code (else NULL).
char *jit_code;
size_t jit_size;
char *debug_info;
struct dasm_State *dynasm;
#endif
// For exiting the decoder on error.
sigjmp_buf exitjmp;
} upb_decoder;
// Used for frames that have no specific end offset: groups, repeated primitive
// fields inside groups, and the top-level message.
#define UPB_NONDELIMITED UINT64_MAX
// Initializes/uninitializes a decoder for calling into the given handlers
// or to write into the given msgdef, given its accessors). Takes a ref
// on the handlers.
void upb_decoder_init(upb_decoder *d, upb_handlers *h);
void upb_decoder_uninit(upb_decoder *d);
// Resets the internal state of an already-allocated decoder. This puts it in a
// state where it has not seen any data, and expects the next data to be from
// the beginning of a new protobuf. Parsers must be reset before they can be
// used. A decoder can be reset multiple times.
//
// Pass UINT64_MAX for end_ofs to indicate a non-delimited top-level message.
void upb_decoder_reset(upb_decoder *d, upb_bytesrc *src, uint64_t start_ofs,
uint64_t end_ofs, void *closure);
void upb_decoder_decode(upb_decoder *d, upb_status *status);
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif /* UPB_DECODER_H_ */