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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 implementing upb_src and getting its data from a
* upb_bytesrc.
*
* The decoder does not currently support non-blocking I/O, in the sense that
* if the bytesrc returns UPB_STATUS_TRYAGAIN it is not possible to resume the
* decoder when data becomes available again. Support for this could be added,
* but it would add complexity and perhaps cost efficiency also.
*/
#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;
struct _upb_decoder {
// Bytesrc from which we pull serialized data.
upb_bytesrc *bytesrc;
// String to hold our input buffer; is only active if d->buf != NULL.
upb_string *bufstr;
// Temporary string for passing string data to callbacks.
upb_string *tmp;
// The offset within the overall stream represented by the *beginning* of buf.
size_t buf_stream_offset;
// Pointer to the beginning of our current data buffer, or NULL if none.
const char *buf;
// End of this buffer, relative to *ptr.
const char *end;
const char *jit_end;
// Members which may also be written by the JIT:
// Our current position in the data buffer.
const char *ptr;
// End of this submessage, relative to *ptr.
const char *submsg_end;
// MIN(end, submsg_end)
const char *effective_end;
upb_fhandlers *f;
// Where we will store any errors that occur.
upb_status *status;
// Dispatcher to which we push parsed data.
upb_dispatcher dispatcher;
// JIT-generated machine code (else NULL).
char *jit_code;
size_t jit_size;
char *debug_info;
struct dasm_State *dynasm;
sigjmp_buf exitjmp;
};
// For use in the upb_dispatcher's stack.
typedef struct {
// Relative to the beginning of this buffer.
// For groups and the top-level: UINT32_MAX.
uint32_t end_offset;
bool is_packed; // == !upb_issubmsg(f) && end_offset != UPB_REPATEDEND
} upb_decoder_srcdata;
// A upb_decoder decodes the binary protocol buffer format, writing the data it
// decodes to a upb_sink.
struct _upb_decoder;
typedef struct _upb_decoder upb_decoder;
// 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 or msgdef.
void upb_decoder_initforhandlers(upb_decoder *d, upb_handlers *h);
// Equivalent to:
// upb_accessors_reghandlers(m, h);
// upb_decoder_initforhandlers(d, h);
// except possibly more efficient, by using cached state in the msgdef.
void upb_decoder_initformsgdef(upb_decoder *d, upb_msgdef *m);
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.
void upb_decoder_reset(upb_decoder *d, upb_bytesrc *bytesrc, void *closure);
void upb_decoder_decode(upb_decoder *d, upb_status *status);
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif /* UPB_DECODER_H_ */
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