/* Write the contents of *src as JSON, and append the JSON string to *dst.
* This will use strlen() to determine the start offset, and ta_get_size()
* and ta_realloc() to extend the memory allocation of *dst.
* Returns: 0 on success, <0 on failure.
*/
int json_write(char **dst, struct mpv_node *src)
{
bstr buffer = bstr0(*dst);
int r = json_append(&buffer, src);
*dst = buffer.start;
return r;
}
static int json_append_str(char **dst, struct mpv_node *src, int indent)
{
bstr buffer = bstr0(*dst);
int r = json_append(&buffer, src, indent);
*dst = buffer.start;
return r;
}
static int json_append(bstr *b, const struct mpv_node *src, int indent)
{
switch (src->format) {
case MPV_FORMAT_NONE:
APPEND(b, "null");
return 0;
case MPV_FORMAT_FLAG:
APPEND(b, src->u.flag ? "true" : "false");
return 0;
case MPV_FORMAT_INT64:
bstr_xappend_asprintf(NULL, b, "%"PRId64, src->u.int64);
return 0;
case MPV_FORMAT_DOUBLE:
bstr_xappend_asprintf(NULL, b, "%f", src->u.double_);
return 0;
case MPV_FORMAT_STRING:
write_json_str(b, src->u.string);
return 0;
case MPV_FORMAT_NODE_ARRAY:
case MPV_FORMAT_NODE_MAP: {
struct mpv_node_list *list = src->u.list;
bool is_obj = src->format == MPV_FORMAT_NODE_MAP;
APPEND(b, is_obj ? "{" : "[");
int next_indent = indent >= 0 ? indent + 1 : -1;
for (int n = 0; n < list->num; n++) {
if (n)
APPEND(b, ",");
add_indent(b, next_indent);
if (is_obj) {
write_json_str(b, list->keys[n]);
APPEND(b, ":");
}
json_append(b, &list->values[n], next_indent);
}
add_indent(b, indent);
APPEND(b, is_obj ? "}" : "]");
return 0;
}
}
return -1; // unknown format
}
json_value *json_parse(char *source, char **error_pos, int *error_line, block_allocator *allocator)
{
json_value *root = 0;
json_value *top = 0;
char *name = 0;
char *it = source;
int escaped_newlines = 0;
while (*it)
{
switch (*it)
{
case '{':
case '[':
{
// create new value
json_value *object = json_alloc(allocator);
// name
object->name = name;
name = 0;
// type
object->type = (*it == '{') ? JSON_OBJECT : JSON_ARRAY;
// skip open character
++it;
// set top and root
if (top)
{
json_append(top, object);
}
else if (!root)
{
root = object;
}
else
{
ERROR(it, "Second root. Only one root allowed");
}
top = object;
}
break;
case '}':
case ']':
{
if (!top || top->type != ((*it == '}') ? JSON_OBJECT : JSON_ARRAY))
{
ERROR(it, "Mismatch closing brace/bracket");
}
// skip close character
++it;
// set top
top = top->parent;
}
break;
case ':':
if (!top || top->type != JSON_OBJECT)
{
ERROR(it, "Unexpected character");
}
++it;
break;
case ',':
CHECK_TOP();
++it;
break;
case '"':
{
CHECK_TOP();
// skip '"' character
++it;
char *first = it;
char *last = it;
while (*it)
{
if ((unsigned char)*it < '\x20')
{
ERROR(first, "Control characters not allowed in strings");
}
else if (*it == '\\')
{
switch (it[1])
{
case '"':
*last = '"';
break;
case '\\':
*last = '\\';
break;
case '/':
*last = '/';
break;
case 'b':
*last = '\b';
break;
case 'f':
*last = '\f';
break;
case 'n':
*last = '\n';
++escaped_newlines;
break;
case 'r':
*last = '\r';
break;
case 't':
*last = '\t';
break;
case 'u':
{
unsigned int codepoint;
if (hatoui(it + 2, it + 6, &codepoint) != it + 6)
{
ERROR(it, "Bad unicode codepoint");
}
if (codepoint <= 0x7F)
{
*last = (char)codepoint;
}
else if (codepoint <= 0x7FF)
{
*last++ = (char)(0xC0 | (codepoint >> 6));
*last = (char)(0x80 | (codepoint & 0x3F));
}
else if (codepoint <= 0xFFFF)
{
*last++ = (char)(0xE0 | (codepoint >> 12));
*last++ = (char)(0x80 | ((codepoint >> 6) & 0x3F));
*last = (char)(0x80 | (codepoint & 0x3F));
}
}
it += 4;
break;
default:
ERROR(first, "Unrecognized escape sequence");
}
++last;
it += 2;
}
else if (*it == '"')
{
*last = 0;
++it;
break;
}
else
{
*last++ = *it++;
}
}
int json_parse_object( json_task_t *task, json_object_t *parent ) {
char ch;
json_object_t node, * append = NULL;
node.next = parent;
node.key = NULL;
node.key_len = 0;
if( !task->callback ) {
if( !task->root ) {
append = task->root = json_create_object();
} else {
append = parent->value.p = json_create_object();
}
}
task->status = STS_OBJECT_START;
while(( ch = *(task->str + task->count) )) {
task->count ++;
if( ch == ' ' || ch == '\n' || ch == '\t' ) {
continue;
}
switch( task->status ) {
case STS_OBJECT_START:
if( ch == '"' ) {
node.key = task->str + task->count;
if( json_parse_string( task ) != 0 ) {
return -1;
}
// WARNING: key_len 可能发生溢出
node.key_len = task->str + task->count - node.key - 1;
task->status = STS_OBJECT_COLON;
} else if( ch == '}' ) {
// 空对象 {}，忽略
return 0;
} else {
task->err_msg = "expect '\"' or '}'";
return -1;
}
break;
case STS_OBJECT_COLON:
if( ch == ':' ) {
task->status = STS_OBJECT_VALUE;
} else {
task->err_msg = "expect ':'";
return -1;
}
break;
case STS_OBJECT_VALUE:
/* 这里需要将计数减一，因为 json_parse_value 需要根据这一个字符判断 value 类型 */
task->count --;
node.value.s = task->str + task->count;
if( json_parse_value( task, &node ) != 0 ) {
if( node.value_type == JSON_OBJECT ||
node.value_type == JSON_ARRAY ) {
json_delete_object(node.value.p);
}
return -1;
}
// WARNING: value_len 可能发生溢出
node.value_len = task->str + task->count - node.value.s;
task->status = STS_OBJECT_COMMA;
break;
case STS_OBJECT_COMMA:
if( ( ch == ',' || ch == '}' ) ) {
// 对 value 进行处理
switch(node.value_type) {
case JSON_STRING:
// 去除字符串两端的引号
node.value.s += 1;
node.value_len -= 2;
break;
case JSON_DOUBLE:
node.value.d = atof(node.value.s);
break;
case JSON_LONGLONG:
node.value.l = atoll(node.value.s);
break;
case JSON_ARRAY:
case JSON_OBJECT:
break;
}
if( task->callback ) {
task->callback( task, &node );
}
if( !task->callback ) {
switch( node.value_type ) {
case JSON_ARRAY:
case JSON_OBJECT:
case JSON_STRING:
append = json_append(append, node.key, node.key_len,
node.value_type, node.value.p, node.value_len);
break;
default:
append = json_append(append, node.key, node.key_len,
node.value_type, &node.value, node.value_len);
}
}
}
if( ch == ',' ) {
task->status = STS_OBJECT_START;
} else if( ch == '}' ) {
return 0;
} else {
task->err_msg = "expect ',' or '}'";
return -1;
}
break;
default:
task->err_msg = "unknown status";
return -1;
}
}
task->err_msg = "unexpect EOF";
return -1;
}
int json_parse_array( json_task_t *task, json_object_t *parent ) {
char ch;
json_object_t node, * append = NULL;
node.next = parent;
node.key = NULL;
node.key_len = 0;
if( !task->callback ) {
if( !task->root ) {
append = task->root = json_create_array();
} else {
append = parent->value.p = json_create_array();
}
}
task->status = STS_ARRAY_START;
while(( ch = *(task->str + task->count) )) {
task->count ++;
if( ch == ' ' || ch == '\n' || ch == '\t' ) {
continue;
}
switch( task->status ) {
case STS_ARRAY_START:
if( ch == ']' ) {
return 0;
} else {
/* 这里需要将计数减一，因为 json_parse_value 需要根据这一个字符判断 value 类型 */
task->count --;
node.value.s = task->str + task->count;
if( json_parse_value( task, &node ) != 0 ) {
if( node.value_type == JSON_OBJECT ||
node.value_type == JSON_ARRAY ) {
json_delete_object(node.value.p);
}
return -1;
}
// WARNING: value_len 可能发生溢出
node.value_len = task->str + task->count - node.value.s;
// 对 value 进行处理
switch(node.value_type) {
case JSON_STRING:
// 去除字符串两端的引号
node.value.s += 1;
node.value_len -= 2;
break;
case JSON_DOUBLE:
// TODO 在解析测试用例时，atof 与 atoll 使解析时间延长了几乎一半
// 移除对数值的默认解析可以显著提升性能
node.value.d = atof(node.value.s);
break;
case JSON_LONGLONG:
node.value.l = atoll(node.value.s);
break;
case JSON_ARRAY:
case JSON_OBJECT:
break;
}
// 需要放在 node.key_len ++ 之前以便正确输出数组下标
if( task->callback ) {
task->callback( task, &node );
}
if( !task->callback ) {
switch( node.value_type ) {
case JSON_ARRAY:
case JSON_OBJECT:
case JSON_STRING:
append = json_append(append, node.key, node.key_len,
node.value_type, node.value.p, node.value_len);
break;
default:
append = json_append(append, node.key, node.key_len,
node.value_type, &node.value, node.value_len);
}
}
node.key_len ++;
task->status = STS_ARRAY_COMMA;
}
break;
case STS_ARRAY_COMMA:
if( ch == ',' ) {
task->status = STS_ARRAY_START;
} else if( ch == ']' ) {
return 0;
} else {
task->err_msg = "expect ',' or ']'";
return -1;
}
break;
default:
task->err_msg = "unknown status";
return -1;
}
}
task->err_msg = "unexpect EOF";
return -1;
}
