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/*
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* JSON streaming support
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*
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* Copyright IBM, Corp. 2009
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*
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* Authors:
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* Anthony Liguori <aliguori@us.ibm.com>
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*
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* This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
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* See the COPYING.LIB file in the top-level directory.
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*
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*/
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#include "qlist.h" |
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#include "qint.h" |
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#include "qdict.h" |
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#include "qemu-common.h" |
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#include "json-lexer.h" |
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#include "json-streamer.h" |
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#define MAX_TOKEN_SIZE (64ULL << 20) |
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#define MAX_NESTING (1ULL << 10) |
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static void json_message_process_token(JSONLexer *lexer, QString *token, JSONTokenType type, int x, int y) |
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{ |
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JSONMessageParser *parser = container_of(lexer, JSONMessageParser, lexer); |
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QDict *dict; |
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if (type == JSON_OPERATOR) {
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switch (qstring_get_str(token)[0]) { |
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case '{': |
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parser->brace_count++; |
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break;
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case '}': |
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parser->brace_count--; |
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break;
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case '[': |
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parser->bracket_count++; |
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break;
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case ']': |
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parser->bracket_count--; |
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break;
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default:
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break;
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} |
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} |
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dict = qdict_new(); |
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qdict_put(dict, "type", qint_from_int(type));
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QINCREF(token); |
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qdict_put(dict, "token", token);
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qdict_put(dict, "x", qint_from_int(x));
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qdict_put(dict, "y", qint_from_int(y));
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parser->token_size += token->length; |
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qlist_append(parser->tokens, dict); |
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if (type == JSON_ERROR) {
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goto out_emit_bad;
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} else if (parser->brace_count < 0 || |
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parser->bracket_count < 0 ||
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(parser->brace_count == 0 &&
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parser->bracket_count == 0)) {
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goto out_emit;
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} else if (parser->token_size > MAX_TOKEN_SIZE || |
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parser->bracket_count > MAX_NESTING || |
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parser->brace_count > MAX_NESTING) { |
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/* Security consideration, we limit total memory allocated per object
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* and the maximum recursion depth that a message can force.
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*/
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goto out_emit;
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} |
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return;
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out_emit_bad:
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/* clear out token list and tell the parser to emit and error
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* indication by passing it a NULL list
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*/
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QDECREF(parser->tokens); |
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parser->tokens = NULL;
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out_emit:
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/* send current list of tokens to parser and reset tokenizer */
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parser->brace_count = 0;
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parser->bracket_count = 0;
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parser->emit(parser, parser->tokens); |
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if (parser->tokens) {
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QDECREF(parser->tokens); |
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} |
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parser->tokens = qlist_new(); |
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parser->token_size = 0;
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} |
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void json_message_parser_init(JSONMessageParser *parser,
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void (*func)(JSONMessageParser *, QList *))
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{ |
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parser->emit = func; |
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parser->brace_count = 0;
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parser->bracket_count = 0;
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parser->tokens = qlist_new(); |
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parser->token_size = 0;
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json_lexer_init(&parser->lexer, json_message_process_token); |
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} |
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int json_message_parser_feed(JSONMessageParser *parser,
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const char *buffer, size_t size) |
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{ |
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return json_lexer_feed(&parser->lexer, buffer, size);
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} |
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int json_message_parser_flush(JSONMessageParser *parser)
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{ |
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return json_lexer_flush(&parser->lexer);
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} |
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void json_message_parser_destroy(JSONMessageParser *parser)
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{ |
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json_lexer_destroy(&parser->lexer); |
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QDECREF(parser->tokens); |
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} |