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/*
* upb - a minimalist implementation of protocol buffers.
*
* Copyright (c) 2014 Google Inc. See LICENSE for details.
* Author: Josh Haberman <jhaberman@gmail.com>
*
* upb::json::Parser can parse JSON according to a specific schema.
* Support for parsing arbitrary JSON (schema-less) will be added later.
*/
#ifndef UPB_JSON_PARSER_H_
#define UPB_JSON_PARSER_H_
#include "upb/sink.h"
#ifdef __cplusplus
namespace upb {
namespace json {
class Parser;
} // namespace json
} // namespace upb
#endif
UPB_DECLARE_TYPE(upb::json::Parser, upb_json_parser);
// Internal-only struct used by the parser. A parser frame corresponds
// one-to-one with a handler (sink) frame.
typedef struct {
UPB_PRIVATE_FOR_CPP
upb_sink sink;
// The current message in which we're parsing, and the field whose value we're
// expecting next.
const upb_msgdef *m;
const upb_fielddef *f;
// We are in a repeated-field context, ready to emit mapentries as
// submessages. This flag alters the start-of-object (open-brace) behavior to
// begin a sequence of mapentry messages rather than a single submessage.
bool is_map;
// We are in a map-entry message context. This flag is set when parsing the
// value field of a single map entry and indicates to all value-field parsers
// (subobjects, strings, numbers, and bools) that the map-entry submessage
// should end as soon as the value is parsed.
bool is_mapentry;
// If |is_map| or |is_mapentry| is true, |mapfield| refers to the parent
// message's map field that we're currently parsing. This differs from |f|
// because |f| is the field in the *current* message (i.e., the map-entry
// message itself), not the parent's field that leads to this map.
const upb_fielddef *mapfield;
} upb_jsonparser_frame;
/* upb::json::Parser **********************************************************/
#define UPB_JSON_MAX_DEPTH 64
// Parses an incoming BytesStream, pushing the results to the destination sink.
UPB_DEFINE_CLASS0(upb::json::Parser,
public:
Parser(Status* status);
~Parser();
// Resets the state of the printer, so that it will expect to begin a new
// document.
void Reset();
// Resets the output pointer which will serve as our closure. Implies
// Reset().
void ResetOutput(Sink* output);
// The input to the printer.
BytesSink* input();
,
UPB_DEFINE_STRUCT0(upb_json_parser,
upb_byteshandler input_handler_;
upb_bytessink input_;
// Stack to track the JSON scopes we are in.
upb_jsonparser_frame stack[UPB_JSON_MAX_DEPTH];
upb_jsonparser_frame *top;
upb_jsonparser_frame *limit;
upb_status *status;
// Ragel's internal parsing stack for the parsing state machine.
int current_state;
int parser_stack[UPB_JSON_MAX_DEPTH];
int parser_top;
// The handle for the current buffer.
const upb_bufhandle *handle;
// Accumulate buffer. See details in parser.rl.
const char *accumulated;
size_t accumulated_len;
char *accumulate_buf;
size_t accumulate_buf_size;
// Multi-part text data. See details in parser.rl.
int multipart_state;
upb_selector_t string_selector;
// Input capture. See details in parser.rl.
const char *capture;
// Intermediate result of parsing a unicode escape sequence.
uint32_t digit;
));
UPB_BEGIN_EXTERN_C
void upb_json_parser_init(upb_json_parser *p, upb_status *status);
void upb_json_parser_uninit(upb_json_parser *p);
void upb_json_parser_reset(upb_json_parser *p);
void upb_json_parser_resetoutput(upb_json_parser *p, upb_sink *output);
upb_bytessink *upb_json_parser_input(upb_json_parser *p);
UPB_END_EXTERN_C
#ifdef __cplusplus
namespace upb {
namespace json {
inline Parser::Parser(Status* status) { upb_json_parser_init(this, status); }
inline Parser::~Parser() { upb_json_parser_uninit(this); }
inline void Parser::Reset() { upb_json_parser_reset(this); }
inline void Parser::ResetOutput(Sink* output) {
upb_json_parser_resetoutput(this, output);
}
inline BytesSink* Parser::input() {
return upb_json_parser_input(this);
}
} // namespace json
} // namespace upb
#endif
#endif // UPB_JSON_PARSER_H_
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