mutter/clutter/json/json-parser.c
Emmanuele Bassi 9ad1197cb2 json: Improve strictness of the JSON parser
Backport of the upstream JSON-GLib commit that improved the strictness
of JsonParser.

The original upstream commit is:

  29881f03468db08bfb404cfcd5b61b4cdc419a87
2010-03-07 20:54:33 +00:00

1127 lines
30 KiB
C

/* json-parser.c - JSON streams parser
*
* This file is part of JSON-GLib
* Copyright (C) 2007 OpenedHand Ltd.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* Author:
* Emmanuele Bassi <ebassi@openedhand.com>
*/
/**
* SECTION:json-parser
* @short_description: Parse JSON data streams
*
* #JsonParser provides an object for parsing a JSON data stream, either
* inside a file or inside a static buffer.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include "json-types-private.h"
#include "json-marshal.h"
#include "json-parser.h"
GQuark
json_parser_error_quark (void)
{
return g_quark_from_static_string ("json-parser-error");
}
#define JSON_PARSER_GET_PRIVATE(obj) \
(G_TYPE_INSTANCE_GET_PRIVATE ((obj), JSON_TYPE_PARSER, JsonParserPrivate))
struct _JsonParserPrivate
{
JsonNode *root;
JsonNode *current_node;
GScanner *scanner;
GError *last_error;
};
static const GScannerConfig json_scanner_config =
{
( " \t\r\n" ) /* cset_skip_characters */,
(
"_"
G_CSET_a_2_z
G_CSET_A_2_Z
) /* cset_identifier_first */,
(
G_CSET_DIGITS
"-_"
G_CSET_a_2_z
G_CSET_A_2_Z
) /* cset_identifier_nth */,
( "#\n" ) /* cpair_comment_single */,
TRUE /* case_sensitive */,
TRUE /* skip_comment_multi */,
TRUE /* skip_comment_single */,
FALSE /* scan_comment_multi */,
TRUE /* scan_identifier */,
TRUE /* scan_identifier_1char */,
FALSE /* scan_identifier_NULL */,
TRUE /* scan_symbols */,
TRUE /* scan_binary */,
TRUE /* scan_octal */,
TRUE /* scan_float */,
TRUE /* scan_hex */,
TRUE /* scan_hex_dollar */,
TRUE /* scan_string_sq */,
TRUE /* scan_string_dq */,
TRUE /* numbers_2_int */,
FALSE /* int_2_float */,
FALSE /* identifier_2_string */,
TRUE /* char_2_token */,
TRUE /* symbol_2_token */,
FALSE /* scope_0_fallback */,
TRUE /* store_int64 */
};
static const gchar symbol_names[] =
"true\0"
"false\0"
"null\0";
static const struct
{
guint name_offset;
guint token;
} symbols[] = {
{ 0, JSON_TOKEN_TRUE },
{ 5, JSON_TOKEN_FALSE },
{ 11, JSON_TOKEN_NULL }
};
static const guint n_symbols = G_N_ELEMENTS (symbols);
enum
{
PARSE_START,
OBJECT_START,
OBJECT_MEMBER,
OBJECT_END,
ARRAY_START,
ARRAY_ELEMENT,
ARRAY_END,
PARSE_END,
ERROR,
LAST_SIGNAL
};
static guint parser_signals[LAST_SIGNAL] = { 0, };
G_DEFINE_TYPE (JsonParser, json_parser, G_TYPE_OBJECT);
static guint json_parse_array (JsonParser *parser,
GScanner *scanner,
gboolean nested);
static guint json_parse_object (JsonParser *parser,
GScanner *scanner,
gboolean nested);
static void
json_parser_dispose (GObject *gobject)
{
JsonParserPrivate *priv = JSON_PARSER_GET_PRIVATE (gobject);
if (priv->root)
{
json_node_free (priv->root);
priv->root = NULL;
}
if (priv->last_error)
{
g_error_free (priv->last_error);
priv->last_error = NULL;
}
G_OBJECT_CLASS (json_parser_parent_class)->dispose (gobject);
}
static void
json_parser_class_init (JsonParserClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
g_type_class_add_private (klass, sizeof (JsonParserPrivate));
gobject_class->dispose = json_parser_dispose;
/**
* JsonParser::parse-start:
* @parser: the #JsonParser that received the signal
*
* The ::parse-start signal is emitted when the parser began parsing
* a JSON data stream.
*/
parser_signals[PARSE_START] =
g_signal_new ("parse-start",
G_OBJECT_CLASS_TYPE (gobject_class),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (JsonParserClass, parse_start),
NULL, NULL,
_json_marshal_VOID__VOID,
G_TYPE_NONE, 0);
/**
* JsonParser::parse-end:
* @parser: the #JsonParser that received the signal
*
* The ::parse-end signal is emitted when the parser successfully
* finished parsing a JSON data stream
*/
parser_signals[PARSE_END] =
g_signal_new ("parse-end",
G_OBJECT_CLASS_TYPE (gobject_class),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (JsonParserClass, parse_end),
NULL, NULL,
_json_marshal_VOID__VOID,
G_TYPE_NONE, 0);
/**
* JsonParser::object-start:
* @parser: the #JsonParser that received the signal
*
* The ::object-start signal is emitted each time the #JsonParser
* starts parsing a #JsonObject.
*/
parser_signals[OBJECT_START] =
g_signal_new ("object-start",
G_OBJECT_CLASS_TYPE (gobject_class),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (JsonParserClass, object_start),
NULL, NULL,
_json_marshal_VOID__VOID,
G_TYPE_NONE, 0);
/**
* JsonParser::object-member:
* @parser: the #JsonParser that received the signal
* @object: a #JsonObject
* @member_name: the name of the newly parsed member
*
* The ::object-member signal is emitted each time the #JsonParser
* has successfully parsed a single member of a #JsonObject. The
* object and member are passed to the signal handlers.
*/
parser_signals[OBJECT_MEMBER] =
g_signal_new ("object-member",
G_OBJECT_CLASS_TYPE (gobject_class),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (JsonParserClass, object_member),
NULL, NULL,
_json_marshal_VOID__BOXED_STRING,
G_TYPE_NONE, 2,
JSON_TYPE_OBJECT,
G_TYPE_STRING);
/**
* JsonParser::object-end:
* @parser: the #JsonParser that received the signal
* @object: the parsed #JsonObject
*
* The ::object-end signal is emitted each time the #JsonParser
* has successfully parsed an entire #JsonObject.
*/
parser_signals[OBJECT_END] =
g_signal_new ("object-end",
G_OBJECT_CLASS_TYPE (gobject_class),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (JsonParserClass, object_end),
NULL, NULL,
_json_marshal_VOID__BOXED,
G_TYPE_NONE, 1,
JSON_TYPE_OBJECT);
/**
* JsonParser::array-start:
* @parser: the #JsonParser that received the signal
*
* The ::array-start signal is emitted each time the #JsonParser
* starts parsing a #JsonArray
*/
parser_signals[ARRAY_START] =
g_signal_new ("array-start",
G_OBJECT_CLASS_TYPE (gobject_class),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (JsonParserClass, array_start),
NULL, NULL,
_json_marshal_VOID__VOID,
G_TYPE_NONE, 0);
/**
* JsonParser::array-element:
* @parser: the #JsonParser that received the signal
* @array: a #JsonArray
* @index_: the index of the newly parsed element
*
* The ::array-element signal is emitted each time the #JsonParser
* has successfully parsed a single element of a #JsonArray. The
* array and element index are passed to the signal handlers.
*/
parser_signals[ARRAY_ELEMENT] =
g_signal_new ("array-element",
G_OBJECT_CLASS_TYPE (gobject_class),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (JsonParserClass, array_element),
NULL, NULL,
_json_marshal_VOID__BOXED_INT,
G_TYPE_NONE, 2,
JSON_TYPE_ARRAY,
G_TYPE_INT);
/**
* JsonParser::array-end:
* @parser: the #JsonParser that received the signal
* @array: the parsed #JsonArrary
*
* The ::array-end signal is emitted each time the #JsonParser
* has successfully parsed an entire #JsonArray
*/
parser_signals[ARRAY_END] =
g_signal_new ("array-end",
G_OBJECT_CLASS_TYPE (gobject_class),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (JsonParserClass, array_end),
NULL, NULL,
_json_marshal_VOID__BOXED,
G_TYPE_NONE, 1,
JSON_TYPE_ARRAY);
/**
* JsonParser::error:
* @parser: the parser instance that received the signal
* @error: a pointer to the #GError
*
* The ::error signal is emitted each time a #JsonParser encounters
* an error in a JSON stream.
*/
parser_signals[ERROR] =
g_signal_new ("error",
G_OBJECT_CLASS_TYPE (gobject_class),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (JsonParserClass, error),
NULL, NULL,
_json_marshal_VOID__POINTER,
G_TYPE_NONE, 1,
G_TYPE_POINTER);
}
static void
json_parser_init (JsonParser *parser)
{
JsonParserPrivate *priv;
parser->priv = priv = JSON_PARSER_GET_PRIVATE (parser);
priv->root = NULL;
priv->current_node = NULL;
}
static guint
json_parse_array (JsonParser *parser,
GScanner *scanner,
gboolean nested)
{
JsonParserPrivate *priv = parser->priv;
JsonArray *array;
guint token;
if (!nested)
{
/* the caller already swallowed the opening '[' */
token = g_scanner_get_next_token (scanner);
if (token != G_TOKEN_LEFT_BRACE)
return G_TOKEN_LEFT_BRACE;
}
g_signal_emit (parser, parser_signals[ARRAY_START], 0);
array = json_array_new ();
token = g_scanner_get_next_token (scanner);
while (token != G_TOKEN_RIGHT_BRACE)
{
JsonNode *node = NULL;
gboolean negative = FALSE;
/* nested object */
if (token == G_TOKEN_LEFT_CURLY)
{
JsonNode *old_node = priv->current_node;
priv->current_node = json_node_new (JSON_NODE_OBJECT);
token = json_parse_object (parser, scanner, TRUE);
node = priv->current_node;
priv->current_node = old_node;
if (token != G_TOKEN_NONE)
{
json_node_free (node);
json_array_unref (array);
return token;
}
json_array_add_element (array, node);
node->parent = priv->current_node;
g_signal_emit (parser, parser_signals[ARRAY_ELEMENT], 0,
array,
json_array_get_length (array));
token = g_scanner_get_next_token (scanner);
if (token == G_TOKEN_RIGHT_BRACE)
break;
if (token == G_TOKEN_COMMA)
{
token = g_scanner_get_next_token (scanner);
if (token == G_TOKEN_RIGHT_BRACE)
return G_TOKEN_SYMBOL;
continue;
}
json_array_unref (array);
return G_TOKEN_RIGHT_BRACE;
}
/* nested array */
if (token == G_TOKEN_LEFT_BRACE)
{
JsonNode *old_node = priv->current_node;
priv->current_node = json_node_new (JSON_NODE_ARRAY);
token = json_parse_array (parser, scanner, TRUE);
node = priv->current_node;
priv->current_node = old_node;
if (token != G_TOKEN_NONE)
{
json_node_free (node);
json_array_unref (array);
return token;
}
json_array_add_element (array, node);
node->parent = priv->current_node;
g_signal_emit (parser, parser_signals[ARRAY_ELEMENT], 0,
array,
json_array_get_length (array));
token = g_scanner_get_next_token (scanner);
if (token == G_TOKEN_RIGHT_BRACE)
break;
if (token == G_TOKEN_COMMA)
{
token = g_scanner_get_next_token (scanner);
if (token == G_TOKEN_RIGHT_BRACE)
return G_TOKEN_SYMBOL;
continue;
}
json_array_unref (array);
return G_TOKEN_RIGHT_BRACE;
}
if (token == '-')
{
guint next_token = g_scanner_peek_next_token (scanner);
if (next_token == G_TOKEN_INT ||
next_token == G_TOKEN_FLOAT)
{
negative = TRUE;
token = g_scanner_get_next_token (scanner);
}
else
{
json_array_unref (array);
return G_TOKEN_INT;
}
}
switch (token)
{
case G_TOKEN_INT:
node = json_node_new (JSON_NODE_VALUE);
json_node_set_int (node, negative ? scanner->value.v_int64 * -1
: scanner->value.v_int64);
break;
case G_TOKEN_FLOAT:
node = json_node_new (JSON_NODE_VALUE);
json_node_set_double (node, negative ? scanner->value.v_float * -1.0
: scanner->value.v_float);
break;
case G_TOKEN_STRING:
node = json_node_new (JSON_NODE_VALUE);
json_node_set_string (node, scanner->value.v_string);
break;
case JSON_TOKEN_TRUE:
case JSON_TOKEN_FALSE:
node = json_node_new (JSON_NODE_VALUE);
json_node_set_boolean (node, token == JSON_TOKEN_TRUE ? TRUE
: FALSE);
break;
case JSON_TOKEN_NULL:
node = json_node_new (JSON_NODE_NULL);
break;
default:
json_array_unref (array);
return G_TOKEN_RIGHT_BRACE;
}
if (node)
{
json_array_add_element (array, node);
node->parent = priv->current_node;
g_signal_emit (parser, parser_signals[ARRAY_ELEMENT], 0,
array,
json_array_get_length (array));
}
token = g_scanner_get_next_token (scanner);
if (token == G_TOKEN_RIGHT_BRACE)
break;
if (token == G_TOKEN_COMMA)
{
token = g_scanner_get_next_token (scanner);
if (token == G_TOKEN_RIGHT_BRACE)
return G_TOKEN_SYMBOL;
continue;
}
json_array_unref (array);
return G_TOKEN_RIGHT_BRACE;
}
json_node_take_array (priv->current_node, array);
g_signal_emit (parser, parser_signals[ARRAY_END], 0, array);
return G_TOKEN_NONE;
}
static guint
json_parse_object (JsonParser *parser,
GScanner *scanner,
gboolean nested)
{
JsonParserPrivate *priv = parser->priv;
JsonObject *object;
guint token;
if (!nested)
{
/* the caller already swallowed the opening '{' */
token = g_scanner_get_next_token (scanner);
if (token != G_TOKEN_LEFT_CURLY)
return G_TOKEN_LEFT_CURLY;
}
g_signal_emit (parser, parser_signals[OBJECT_START], 0);
object = json_object_new ();
token = g_scanner_get_next_token (scanner);
while (token != G_TOKEN_RIGHT_CURLY)
{
JsonNode *node = NULL;
gchar *name = NULL;
gboolean negative = FALSE;
if (token == G_TOKEN_STRING)
{
name = g_strdup (scanner->value.v_string);
token = g_scanner_get_next_token (scanner);
if (token != ':')
{
g_free (name);
json_object_unref (object);
return ':';
}
else
{
/* swallow the colon */
token = g_scanner_get_next_token (scanner);
}
}
if (!name)
{
json_object_unref (object);
return G_TOKEN_STRING;
}
if (token == G_TOKEN_LEFT_CURLY)
{
JsonNode *old_node = priv->current_node;
priv->current_node = json_node_new (JSON_NODE_OBJECT);
token = json_parse_object (parser, scanner, TRUE);
node = priv->current_node;
priv->current_node = old_node;
if (token != G_TOKEN_NONE)
{
g_free (name);
if (node)
json_node_free (node);
json_object_unref (object);
return token;
}
json_object_set_member (object, name, node);
node->parent = priv->current_node;
g_signal_emit (parser, parser_signals[OBJECT_MEMBER], 0,
object,
name);
g_free (name);
token = g_scanner_get_next_token (scanner);
if (token == G_TOKEN_RIGHT_CURLY)
break;
if (token == G_TOKEN_COMMA)
{
token = g_scanner_get_next_token (scanner);
if (token == G_TOKEN_RIGHT_CURLY)
return G_TOKEN_SYMBOL;
continue;
}
json_object_unref (object);
return G_TOKEN_RIGHT_CURLY;
}
if (token == G_TOKEN_LEFT_BRACE)
{
JsonNode *old_node = priv->current_node;
priv->current_node = json_node_new (JSON_NODE_ARRAY);
token = json_parse_array (parser, scanner, TRUE);
node = priv->current_node;
priv->current_node = old_node;
if (token != G_TOKEN_NONE)
{
g_free (name);
json_node_free (node);
json_object_unref (object);
return token;
}
json_object_set_member (object, name, node);
node->parent = priv->current_node;
g_signal_emit (parser, parser_signals[OBJECT_MEMBER], 0,
object,
name);
g_free (name);
token = g_scanner_get_next_token (scanner);
if (token == G_TOKEN_RIGHT_CURLY)
break;
if (token == G_TOKEN_COMMA)
{
token = g_scanner_get_next_token (scanner);
if (token == G_TOKEN_RIGHT_CURLY)
return G_TOKEN_SYMBOL;
continue;
}
json_object_unref (object);
return G_TOKEN_RIGHT_CURLY;
}
if (token == '-')
{
guint next_token = g_scanner_peek_next_token (scanner);
if (next_token == G_TOKEN_INT || next_token == G_TOKEN_FLOAT)
{
negative = TRUE;
token = g_scanner_get_next_token (scanner);
}
else
{
json_object_unref (object);
return G_TOKEN_INT;
}
}
switch (token)
{
case G_TOKEN_INT:
node = json_node_new (JSON_NODE_VALUE);
json_node_set_int (node, negative ? scanner->value.v_int64 * -1
: scanner->value.v_int64);
break;
case G_TOKEN_FLOAT:
node = json_node_new (JSON_NODE_VALUE);
json_node_set_double (node, negative ? scanner->value.v_float * -1.0
: scanner->value.v_float);
break;
case G_TOKEN_STRING:
node = json_node_new (JSON_NODE_VALUE);
json_node_set_string (node, scanner->value.v_string);
break;
case JSON_TOKEN_TRUE:
case JSON_TOKEN_FALSE:
node = json_node_new (JSON_NODE_VALUE);
json_node_set_boolean (node, token == JSON_TOKEN_TRUE ? TRUE
: FALSE);
break;
case JSON_TOKEN_NULL:
node = json_node_new (JSON_NODE_NULL);
break;
default:
json_object_unref (object);
return G_TOKEN_SYMBOL;
}
if (node)
{
json_object_set_member (object, name, node);
node->parent = priv->current_node;
g_signal_emit (parser, parser_signals[OBJECT_MEMBER], 0,
object,
name);
}
g_free (name);
token = g_scanner_get_next_token (scanner);
if (token == G_TOKEN_RIGHT_CURLY)
break;
if (token == G_TOKEN_COMMA)
{
token = g_scanner_get_next_token (scanner);
if (token == G_TOKEN_RIGHT_CURLY)
return G_TOKEN_SYMBOL;
continue;
}
json_object_unref (object);
return G_TOKEN_RIGHT_CURLY;
}
json_node_take_object (priv->current_node, object);
g_signal_emit (parser, parser_signals[OBJECT_END], 0, object);
return G_TOKEN_NONE;
}
static guint
json_parse_statement (JsonParser *parser,
GScanner *scanner)
{
JsonParserPrivate *priv = parser->priv;
guint token;
token = g_scanner_peek_next_token (scanner);
switch (token)
{
case G_TOKEN_LEFT_CURLY:
priv->root = priv->current_node = json_node_new (JSON_NODE_OBJECT);
return json_parse_object (parser, scanner, FALSE);
case G_TOKEN_LEFT_BRACE:
priv->root = priv->current_node = json_node_new (JSON_NODE_ARRAY);
return json_parse_array (parser, scanner, FALSE);
case JSON_TOKEN_NULL:
priv->root = priv->current_node = json_node_new (JSON_NODE_NULL);
return G_TOKEN_NONE;
case JSON_TOKEN_TRUE:
case JSON_TOKEN_FALSE:
priv->root = priv->current_node = json_node_new (JSON_NODE_VALUE);
json_node_set_boolean (priv->current_node,
token == JSON_TOKEN_TRUE ? TRUE : FALSE);
return G_TOKEN_NONE;
case '-':
{
guint next_token = g_scanner_peek_next_token (scanner);
if (next_token == G_TOKEN_INT || next_token == G_TOKEN_FLOAT)
{
priv->root = priv->current_node = json_node_new (JSON_NODE_VALUE);
token = g_scanner_get_next_token (scanner);
switch (token)
{
case G_TOKEN_INT:
json_node_set_int (priv->current_node, scanner->value.v_int64);
break;
case G_TOKEN_FLOAT:
json_node_set_double (priv->current_node, scanner->value.v_float);
break;
default:
break;
}
return G_TOKEN_NONE;
}
else
return G_TOKEN_INT;
}
break;
case G_TOKEN_INT:
case G_TOKEN_FLOAT:
case G_TOKEN_STRING:
priv->root = priv->current_node = json_node_new (JSON_NODE_VALUE);
if (token == G_TOKEN_INT)
json_node_set_int (priv->current_node, scanner->value.v_int64);
else if (token == G_TOKEN_FLOAT)
json_node_set_double (priv->current_node, scanner->value.v_float);
else
json_node_set_string (priv->current_node, scanner->value.v_string);
return G_TOKEN_NONE;
default:
g_scanner_get_next_token (scanner);
return G_TOKEN_SYMBOL;
}
}
static void
json_scanner_msg_handler (GScanner *scanner,
gchar *message,
gboolean is_error)
{
JsonParser *parser = scanner->user_data;
if (is_error)
{
GError *error = NULL;
g_set_error (&error, JSON_PARSER_ERROR,
JSON_PARSER_ERROR_PARSE,
"Parse error on line %d: %s",
scanner->line,
message);
parser->priv->last_error = error;
g_signal_emit (parser, parser_signals[ERROR], 0, error);
}
else
g_warning ("Line %d: %s", scanner->line, message);
}
static GScanner *
json_scanner_new (JsonParser *parser)
{
GScanner *scanner;
scanner = g_scanner_new (&json_scanner_config);
scanner->msg_handler = json_scanner_msg_handler;
scanner->user_data = parser;
return scanner;
}
/**
* json_parser_new:
*
* Creates a new #JsonParser instance. You can use the #JsonParser to
* load a JSON stream from either a file or a buffer and then walk the
* hierarchy using the data types API.
*
* Return value: the newly created #JsonParser. Use g_object_unref()
* to release all the memory it allocates.
*/
JsonParser *
json_parser_new (void)
{
return g_object_new (JSON_TYPE_PARSER, NULL);
}
/**
* json_parser_load_from_file:
* @parser: a #JsonParser
* @filename: the path for the file to parse
* @error: return location for a #GError, or %NULL
*
* Loads a JSON stream from the content of @filename and parses it. See
* json_parser_load_from_data().
*
* Return value: %TRUE if the file was successfully loaded and parsed.
* In case of error, @error is set accordingly and %FALSE is returned
*/
gboolean
json_parser_load_from_file (JsonParser *parser,
const gchar *filename,
GError **error)
{
GError *internal_error;
gchar *data;
gsize length;
gboolean retval = TRUE;
g_return_val_if_fail (JSON_IS_PARSER (parser), FALSE);
g_return_val_if_fail (filename != NULL, FALSE);
internal_error = NULL;
if (!g_file_get_contents (filename, &data, &length, &internal_error))
{
g_propagate_error (error, internal_error);
return FALSE;
}
if (!json_parser_load_from_data (parser, data, length, &internal_error))
{
g_propagate_error (error, internal_error);
retval = FALSE;
}
g_free (data);
return retval;
}
/**
* json_parser_load_from_data:
* @parser: a #JsonParser
* @data: the buffer to parse
* @length: the length of the buffer, or -1
* @error: return location for a #GError, or %NULL
*
* Loads a JSON stream from a buffer and parses it. You can call this function
* multiple times with the same #JsonParser object, but the contents of the
* parser will be destroyed each time.
*
* Return value: %TRUE if the buffer was succesfully parser. In case
* of error, @error is set accordingly and %FALSE is returned
*/
gboolean
json_parser_load_from_data (JsonParser *parser,
const gchar *data,
gssize length,
GError **error)
{
GScanner *scanner;
gboolean done;
gboolean retval = TRUE;
gint i;
g_return_val_if_fail (JSON_IS_PARSER (parser), FALSE);
g_return_val_if_fail (data != NULL, FALSE);
if (length < 0)
length = strlen (data);
if (parser->priv->root)
{
json_node_free (parser->priv->root);
parser->priv->root = NULL;
}
scanner = json_scanner_new (parser);
g_scanner_input_text (scanner, data, length);
for (i = 0; i < n_symbols; i++)
{
g_scanner_scope_add_symbol (scanner, 0,
symbol_names + symbols[i].name_offset,
GINT_TO_POINTER (symbols[i].token));
}
parser->priv->scanner = scanner;
g_signal_emit (parser, parser_signals[PARSE_START], 0);
done = FALSE;
while (!done)
{
if (g_scanner_peek_next_token (scanner) == G_TOKEN_EOF)
done = TRUE;
else
{
guint expected_token;
expected_token = json_parse_statement (parser, scanner);
if (expected_token != G_TOKEN_NONE)
{
const gchar *symbol_name;
gchar *msg;
msg = NULL;
symbol_name = NULL;
if (scanner->scope_id == 0)
{
if (expected_token > JSON_TOKEN_INVALID &&
expected_token < JSON_TOKEN_LAST)
{
for (i = 0; i < n_symbols; i++)
if (symbols[i].token == expected_token)
symbol_name = symbol_names + symbols[i].name_offset;
if (!msg)
msg = g_strconcat ("e.g. '", symbol_name, "'", NULL);
}
if (scanner->token > JSON_TOKEN_INVALID &&
scanner->token < JSON_TOKEN_LAST)
{
symbol_name = "???";
for (i = 0; i < n_symbols; i++)
if (symbols[i].token == scanner->token)
symbol_name = symbol_names + symbols[i].name_offset;
}
}
/* this will emit the ::error signal via the custom
* message handler we install
*/
g_scanner_unexp_token (scanner, expected_token,
NULL, "keyword",
symbol_name, msg,
TRUE);
if (parser->priv->last_error)
{
g_propagate_error (error, parser->priv->last_error);
parser->priv->last_error = NULL;
}
retval = FALSE;
g_free (msg);
done = TRUE;
}
}
}
g_scanner_destroy (scanner);
parser->priv->scanner = NULL;
parser->priv->current_node = NULL;
g_signal_emit (parser, parser_signals[PARSE_END], 0);
return retval;
}
/**
* json_parser_get_root:
* @parser: a #JsonParser
*
* Retrieves the top level node from the parsed JSON stream.
*
* Return value: (transfer none): the root #JsonNode . The returned node
* is owned by the #JsonParser and should never be modified or freed.
*/
JsonNode *
json_parser_get_root (JsonParser *parser)
{
g_return_val_if_fail (JSON_IS_PARSER (parser), NULL);
return parser->priv->root;
}
/**
* json_parser_get_current_line:
* @parser: a #JsonParser
*
* Retrieves the line currently parsed, starting from 1.
*
* Return value: the currently parsed line.
*/
guint
json_parser_get_current_line (JsonParser *parser)
{
g_return_val_if_fail (JSON_IS_PARSER (parser), 0);
if (parser->priv->scanner)
return g_scanner_cur_line (parser->priv->scanner);
return 0;
}
/**
* json_parser_get_current_pos:
* @parser: a #JsonParser
*
* Retrieves the current position inside the current line, starting
* from 0.
*
* Return value: the position in the current line
*/
guint
json_parser_get_current_pos (JsonParser *parser)
{
g_return_val_if_fail (JSON_IS_PARSER (parser), 0);
if (parser->priv->scanner)
return g_scanner_cur_line (parser->priv->scanner);
return 0;
}