static int json_skip_string(struct json_parser *parser)
{
for (; parser->data != parser->end; parser->data++) {
if (*parser->data == '"') {
parser->data++;
json_parser_update_input_pos(parser);
return 1;
}
if (*parser->data == '\\') {
switch (*++parser->data) {
case '"':
case '\\':
case '/':
case 'b':
case 'f':
case 'n':
case 'r':
case 't':
break;
case 'u':
if (parser->end - parser->data < 4)
return -1;
parser->data += 3;
break;
default:
return -1;
}
}
}
json_parser_update_input_pos(parser);
return 0;
}
static int
json_try_parse_stream_start(struct json_parser *parser,
struct istream **input_r)
{
if (!json_parse_whitespace(parser))
return -1;
if (parser->state == JSON_STATE_OBJECT_COLON) {
if (*parser->data != ':') {
parser->error = "Expected ':' after key";
return -1;
}
parser->data++;
parser->state = JSON_STATE_OBJECT_VALUE;
if (!json_parse_whitespace(parser))
return -1;
}
if (*parser->data != '"')
return -1;
parser->data++;
json_parser_update_input_pos(parser);
parser->state = parser->state == JSON_STATE_OBJECT_VALUE ?
JSON_STATE_OBJECT_SKIP_STRING : JSON_STATE_ARRAY_SKIP_STRING;
parser->strinput = i_stream_create_jsonstr(parser->input);
i_stream_add_destroy_callback(parser->strinput,
json_strinput_destroyed, parser);
*input_r = parser->strinput;
return 1;
}
static int json_parse_denest(struct json_parser *parser)
{
const enum json_state *nested_states;
unsigned count;
parser->data++;
json_parser_update_input_pos(parser);
nested_states = array_get(&parser->nesting, &count);
if (count == 0) {
/* closing root */
parser->state = JSON_STATE_DONE;
return 0;
}
/* closing a nested object */
if (count == 1) {
/* we're back to root */
parser->state = JSON_STATE_OBJECT_NEXT;
} else {
/* back to previous nested object */
parser->state = nested_states[count-2] == JSON_STATE_OBJECT_OPEN ?
JSON_STATE_OBJECT_NEXT : JSON_STATE_ARRAY_NEXT;
}
array_delete(&parser->nesting, count-1, 1);
if (parser->nested_skip_count > 0) {
parser->nested_skip_count--;
return 0;
}
return 1;
}
static void json_parser_object_open(struct json_parser *parser)
{
parser->data++;
parser->state = JSON_STATE_OBJECT_OPEN;
array_append(&parser->nesting, &parser->state, 1);
json_parser_update_input_pos(parser);
}
static int json_parse_denest(struct json_parser *parser)
{
const enum json_state *nested_states;
unsigned count;
parser->data++;
json_parser_update_input_pos(parser);
nested_states = array_get(&parser->nesting, &count);
i_assert(count > 0);
if (count == 1) {
/* closing root */
parser->state = JSON_STATE_DONE;
if ((parser->flags & JSON_PARSER_NO_ROOT_OBJECT) == 0)
return 0;
/* we want to return the ending "]" or "}" to caller */
return 1;
}
/* closing a nested object */
parser->state = nested_states[count-2] == JSON_STATE_OBJECT_OPEN ?
JSON_STATE_OBJECT_NEXT : JSON_STATE_ARRAY_NEXT;
array_delete(&parser->nesting, count-1, 1);
if (parser->nested_skip_count > 0) {
parser->nested_skip_count--;
return 0;
}
return 1;
}
static bool json_parse_whitespace(struct json_parser *parser)
{
for (; parser->data != parser->end; parser->data++) {
switch (*parser->data) {
case ' ':
case '\t':
case '\r':
case '\n':
break;
default:
json_parser_update_input_pos(parser);
return TRUE;
}
}
json_parser_update_input_pos(parser);
return FALSE;
}
static int
json_try_parse_next(struct json_parser *parser, enum json_type *type_r,
const char **value_r)
{
bool skipping = parser->skipping;
int ret;
if (!json_parse_whitespace(parser))
return -1;
switch (parser->state) {
case JSON_STATE_ROOT:
if (*parser->data != '{') {
parser->error = "Object doesn't begin with '{'";
return -1;
}
parser->data++;
parser->state = JSON_STATE_OBJECT_OPEN;
json_parser_update_input_pos(parser);
return 0;
case JSON_STATE_OBJECT_VALUE:
case JSON_STATE_ARRAY_VALUE:
if (*parser->data == '{') {
parser->data++;
parser->state = JSON_STATE_OBJECT_OPEN;
array_append(&parser->nesting, &parser->state, 1);
json_parser_update_input_pos(parser);
if (parser->skipping) {
parser->nested_skip_count++;
return 0;
}
*type_r = JSON_TYPE_OBJECT;
return 1;
} else if (*parser->data == '[') {
parser->data++;
parser->state = JSON_STATE_ARRAY_OPEN;
array_append(&parser->nesting, &parser->state, 1);
json_parser_update_input_pos(parser);
if (parser->skipping) {
parser->nested_skip_count++;
return 0;
}
*type_r = JSON_TYPE_ARRAY;
return 1;
}
if ((ret = json_parse_string(parser, TRUE, value_r)) >= 0) {
*type_r = JSON_TYPE_STRING;
} else if ((ret = json_parse_number(parser, value_r)) >= 0) {
*type_r = JSON_TYPE_NUMBER;
} else if ((ret = json_parse_atom(parser, "true")) >= 0) {
*type_r = JSON_TYPE_TRUE;
*value_r = "true";
} else if ((ret = json_parse_atom(parser, "false")) >= 0) {
*type_r = JSON_TYPE_FALSE;
*value_r = "false";
} else if ((ret = json_parse_atom(parser, "null")) >= 0) {
*type_r = JSON_TYPE_NULL;
*value_r = NULL;
} else {
parser->error = "Invalid data as value";
return -1;
}
if (ret == 0) {
i_assert(parser->data == parser->end);
if (parser->skipping && *type_r == JSON_TYPE_STRING) {
/* a large string that we want to skip over. */
json_parser_update_input_pos(parser);
parser->state = parser->state == JSON_STATE_OBJECT_VALUE ?
JSON_STATE_OBJECT_SKIP_STRING :
JSON_STATE_ARRAY_SKIP_STRING;
return 0;
}
return -1;
}
parser->state = parser->state == JSON_STATE_OBJECT_VALUE ?
JSON_STATE_OBJECT_NEXT : JSON_STATE_ARRAY_NEXT;
break;
case JSON_STATE_OBJECT_OPEN:
if (*parser->data == '}')
return json_parse_close_object(parser, type_r);
parser->state = JSON_STATE_OBJECT_KEY;
/* fall through */
case JSON_STATE_OBJECT_KEY:
if (json_parse_string(parser, FALSE, value_r) <= 0) {
parser->error = "Expected string as object key";
return -1;
}
*type_r = JSON_TYPE_OBJECT_KEY;
parser->state = JSON_STATE_OBJECT_COLON;
break;
case JSON_STATE_OBJECT_COLON:
if (*parser->data != ':') {
parser->error = "Expected ':' after key";
return -1;
}
parser->data++;
parser->state = JSON_STATE_OBJECT_VALUE;
json_parser_update_input_pos(parser);
return 0;
case JSON_STATE_OBJECT_NEXT:
if (parser->skipping && parser->nested_skip_count == 0) {
/* we skipped over the previous value */
parser->skipping = FALSE;
}
if (*parser->data == '}')
return json_parse_close_object(parser, type_r);
if (*parser->data != ',') {
parser->error = "Expected ',' or '}' after object value";
return -1;
}
parser->state = JSON_STATE_OBJECT_KEY;
parser->data++;
json_parser_update_input_pos(parser);
return 0;
case JSON_STATE_ARRAY_OPEN:
if (*parser->data == ']')
return json_parse_close_array(parser, type_r);
parser->state = JSON_STATE_ARRAY_VALUE;
return 0;
case JSON_STATE_ARRAY_NEXT:
if (parser->skipping && parser->nested_skip_count == 0) {
/* we skipped over the previous value */
parser->skipping = FALSE;
}
if (*parser->data == ']')
return json_parse_close_array(parser, type_r);
if (*parser->data != ',') {
parser->error = "Expected ',' or '}' after array value";
return -1;
}
parser->state = JSON_STATE_ARRAY_VALUE;
parser->data++;
json_parser_update_input_pos(parser);
return 0;
case JSON_STATE_OBJECT_SKIP_STRING:
case JSON_STATE_ARRAY_SKIP_STRING:
if (json_skip_string(parser) <= 0)
return -1;
parser->state = parser->state == JSON_STATE_OBJECT_SKIP_STRING ?
JSON_STATE_OBJECT_NEXT : JSON_STATE_ARRAY_NEXT;
return 0;
case JSON_STATE_DONE:
parser->error = "Unexpected data at the end";
return -1;
}
json_parser_update_input_pos(parser);
return skipping ? 0 : 1;
}
