Add a JSON message boundary identifier

The second stage of our JSON parser is a simple state machine that identifies
individual JSON values by counting the levels of nesting of tokens.  It does
not perform grammar validation.  We use this to emit a full JSON value to the
parser.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Anthony Liguori 2009-11-11 10:38:59 -06:00
parent 5ab8558d9b
commit d7ff3acbb4
3 changed files with 128 additions and 0 deletions

View File

@ -138,6 +138,7 @@ obj-y += qemu-char.o aio.o savevm.o
obj-y += msmouse.o ps2.o
obj-y += qdev.o qdev-properties.o
obj-y += qint.o qstring.o qdict.o qlist.o qfloat.o qbool.o json-lexer.o
obj-y += json-streamer.o
obj-y += qemu-config.o block-migration.o
obj-$(CONFIG_BRLAPI) += baum.o

88
json-streamer.c Normal file
View File

@ -0,0 +1,88 @@
/*
* JSON streaming support
*
* Copyright IBM, Corp. 2009
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
* See the COPYING.LIB file in the top-level directory.
*
*/
#include "qlist.h"
#include "qint.h"
#include "qdict.h"
#include "qemu-common.h"
#include "json-lexer.h"
#include "json-streamer.h"
static void json_message_process_token(JSONLexer *lexer, QString *token, JSONTokenType type, int x, int y)
{
JSONMessageParser *parser = container_of(lexer, JSONMessageParser, lexer);
QDict *dict;
if (type == JSON_OPERATOR) {
switch (qstring_get_str(token)[0]) {
case '{':
parser->brace_count++;
break;
case '}':
parser->brace_count--;
break;
case '[':
parser->bracket_count++;
break;
case ']':
parser->bracket_count--;
break;
default:
break;
}
}
dict = qdict_new();
qdict_put_obj(dict, "type", QOBJECT(qint_from_int(type)));
QINCREF(token);
qdict_put_obj(dict, "token", QOBJECT(token));
qdict_put_obj(dict, "x", QOBJECT(qint_from_int(x)));
qdict_put_obj(dict, "y", QOBJECT(qint_from_int(y)));
qlist_append(parser->tokens, dict);
if (parser->brace_count == 0 &&
parser->bracket_count == 0) {
parser->emit(parser, parser->tokens);
QDECREF(parser->tokens);
parser->tokens = qlist_new();
}
}
void json_message_parser_init(JSONMessageParser *parser,
void (*func)(JSONMessageParser *, QList *))
{
parser->emit = func;
parser->brace_count = 0;
parser->bracket_count = 0;
parser->tokens = qlist_new();
json_lexer_init(&parser->lexer, json_message_process_token);
}
int json_message_parser_feed(JSONMessageParser *parser,
const char *buffer, size_t size)
{
return json_lexer_feed(&parser->lexer, buffer, size);
}
int json_message_parser_flush(JSONMessageParser *parser)
{
return json_lexer_flush(&parser->lexer);
}
void json_message_parser_destroy(JSONMessageParser *parser)
{
json_lexer_destroy(&parser->lexer);
QDECREF(parser->tokens);
}

39
json-streamer.h Normal file
View File

@ -0,0 +1,39 @@
/*
* JSON streaming support
*
* Copyright IBM, Corp. 2009
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
* See the COPYING.LIB file in the top-level directory.
*
*/
#ifndef QEMU_JSON_STREAMER_H
#define QEMU_JSON_STREAMER_H
#include "qlist.h"
#include "json-lexer.h"
typedef struct JSONMessageParser
{
void (*emit)(struct JSONMessageParser *parser, QList *tokens);
JSONLexer lexer;
int brace_count;
int bracket_count;
QList *tokens;
} JSONMessageParser;
void json_message_parser_init(JSONMessageParser *parser,
void (*func)(JSONMessageParser *, QList *));
int json_message_parser_feed(JSONMessageParser *parser,
const char *buffer, size_t size);
int json_message_parser_flush(JSONMessageParser *parser);
void json_message_parser_destroy(JSONMessageParser *parser);
#endif