json-streamer.c

   1 /*
   2  * JSON streaming support
   3  *
   4  * Copyright IBM, Corp. 2009
   5  *
   6  * Authors:
   7  *  Anthony Liguori   <aliguori@us.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
  10  * See the COPYING.LIB file in the top-level directory.
  11  *
  12  */
  13
  14 #include "qlist.h"
  15 #include "qint.h"
  16 #include "qdict.h"
  17 #include "qemu-common.h"
  18 #include "json-lexer.h"
  19 #include "json-streamer.h"
  20
  21 static void json_message_process_token(JSONLexer *lexer, QString *token, JSONTokenType type, int x, int y)
  22 {
  23     JSONMessageParser *parser = container_of(lexer, JSONMessageParser, lexer);
  24     QDict *dict;
  25
  26     if (type == JSON_OPERATOR) {
  27         switch (qstring_get_str(token)[0]) {
  28         case '{':
  29             parser->brace_count++;
  30             break;
  31         case '}':
  32             parser->brace_count--;
  33             break;
  34         case '[':
  35             parser->bracket_count++;
  36             break;
  37         case ']':
  38             parser->bracket_count--;
  39             break;
  40         default:
  41             break;
  42         }
  43     }
  44
  45     dict = qdict_new();
  46     qdict_put(dict, "type", qint_from_int(type));
  47     QINCREF(token);
  48     qdict_put(dict, "token", token);
  49     qdict_put(dict, "x", qint_from_int(x));
  50     qdict_put(dict, "y", qint_from_int(y));
  51
  52     qlist_append(parser->tokens, dict);
  53
  54     if (parser->brace_count < 0 ||
  55         parser->bracket_count < 0 ||
  56         (parser->brace_count == 0 &&
  57          parser->bracket_count == 0)) {
  58         parser->brace_count = 0;
  59         parser->bracket_count = 0;
  60         parser->emit(parser, parser->tokens);
  61         QDECREF(parser->tokens);
  62         parser->tokens = qlist_new();
  63     }
  64 }
  65
  66 void json_message_parser_init(JSONMessageParser *parser,
  67                               void (*func)(JSONMessageParser *, QList *))
  68 {
  69     parser->emit = func;
  70     parser->brace_count = 0;
  71     parser->bracket_count = 0;
  72     parser->tokens = qlist_new();
  73
  74     json_lexer_init(&parser->lexer, json_message_process_token);
  75 }
  76
  77 int json_message_parser_feed(JSONMessageParser *parser,
  78                              const char *buffer, size_t size)
  79 {
  80     return json_lexer_feed(&parser->lexer, buffer, size);
  81 }
  82
  83 int json_message_parser_flush(JSONMessageParser *parser)
  84 {
  85     return json_lexer_flush(&parser->lexer);
  86 }
  87
  88 void json_message_parser_destroy(JSONMessageParser *parser)
  89 {
  90     json_lexer_destroy(&parser->lexer);
  91     QDECREF(parser->tokens);
  92 }