qemu/qobject/qjson.c

345 lines
8.5 KiB
C

/*
* QObject JSON integration
*
* Copyright IBM, Corp. 2009
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
* See the COPYING.LIB file in the top-level directory.
*
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qapi/qmp/json-parser.h"
#include "qapi/qmp/qjson.h"
#include "qapi/qmp/qbool.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qmp/qlist.h"
#include "qapi/qmp/qnum.h"
#include "qapi/qmp/qstring.h"
#include "qemu/unicode.h"
typedef struct JSONParsingState
{
JSONMessageParser parser;
QObject *result;
Error *err;
} JSONParsingState;
static void consume_json(void *opaque, QObject *json, Error *err)
{
JSONParsingState *s = opaque;
assert(!json != !err);
assert(!s->result || !s->err);
if (s->result) {
qobject_unref(s->result);
s->result = NULL;
error_setg(&s->err, "Expecting at most one JSON value");
}
if (s->err) {
qobject_unref(json);
error_free(err);
return;
}
s->result = json;
s->err = err;
}
/*
* Parse @string as JSON value.
* If @ap is non-null, interpolate %-escapes.
* Takes ownership of %p arguments.
* On success, return the JSON value.
* On failure, store an error through @errp and return NULL.
* Ownership of %p arguments becomes indeterminate then. To avoid
* leaks, callers passing %p must terminate on error, e.g. by passing
* &error_abort.
*/
static QObject *qobject_from_jsonv(const char *string, va_list *ap,
Error **errp)
{
JSONParsingState state = {};
json_message_parser_init(&state.parser, consume_json, &state, ap);
json_message_parser_feed(&state.parser, string, strlen(string));
json_message_parser_flush(&state.parser);
json_message_parser_destroy(&state.parser);
if (!state.result && !state.err) {
error_setg(&state.err, "Expecting a JSON value");
}
error_propagate(errp, state.err);
return state.result;
}
QObject *qobject_from_json(const char *string, Error **errp)
{
return qobject_from_jsonv(string, NULL, errp);
}
/*
* Parse @string as JSON value with %-escapes interpolated.
* Abort on error. Do not use with untrusted @string.
* Return the resulting QObject. It is never null.
*/
QObject *qobject_from_vjsonf_nofail(const char *string, va_list ap)
{
va_list ap_copy;
QObject *obj;
/* va_copy() is needed when va_list is an array type */
va_copy(ap_copy, ap);
obj = qobject_from_jsonv(string, &ap_copy, &error_abort);
va_end(ap_copy);
assert(obj);
return obj;
}
/*
* Parse @string as JSON value with %-escapes interpolated.
* Abort on error. Do not use with untrusted @string.
* Return the resulting QObject. It is never null.
*/
QObject *qobject_from_jsonf_nofail(const char *string, ...)
{
QObject *obj;
va_list ap;
va_start(ap, string);
obj = qobject_from_vjsonf_nofail(string, ap);
va_end(ap);
return obj;
}
/*
* Parse @string as JSON object with %-escapes interpolated.
* Abort on error. Do not use with untrusted @string.
* Return the resulting QDict. It is never null.
*/
QDict *qdict_from_vjsonf_nofail(const char *string, va_list ap)
{
QDict *qdict;
qdict = qobject_to(QDict, qobject_from_vjsonf_nofail(string, ap));
assert(qdict);
return qdict;
}
/*
* Parse @string as JSON object with %-escapes interpolated.
* Abort on error. Do not use with untrusted @string.
* Return the resulting QDict. It is never null.
*/
QDict *qdict_from_jsonf_nofail(const char *string, ...)
{
QDict *qdict;
va_list ap;
va_start(ap, string);
qdict = qdict_from_vjsonf_nofail(string, ap);
va_end(ap);
return qdict;
}
typedef struct ToJsonIterState
{
int indent;
int pretty;
int count;
QString *str;
} ToJsonIterState;
static void to_json(const QObject *obj, QString *str, int pretty, int indent);
static void to_json_dict_iter(const char *key, QObject *obj, void *opaque)
{
ToJsonIterState *s = opaque;
QString *qkey;
int j;
if (s->count) {
qstring_append(s->str, s->pretty ? "," : ", ");
}
if (s->pretty) {
qstring_append(s->str, "\n");
for (j = 0 ; j < s->indent ; j++)
qstring_append(s->str, " ");
}
qkey = qstring_from_str(key);
to_json(QOBJECT(qkey), s->str, s->pretty, s->indent);
qobject_unref(qkey);
qstring_append(s->str, ": ");
to_json(obj, s->str, s->pretty, s->indent);
s->count++;
}
static void to_json_list_iter(QObject *obj, void *opaque)
{
ToJsonIterState *s = opaque;
int j;
if (s->count) {
qstring_append(s->str, s->pretty ? "," : ", ");
}
if (s->pretty) {
qstring_append(s->str, "\n");
for (j = 0 ; j < s->indent ; j++)
qstring_append(s->str, " ");
}
to_json(obj, s->str, s->pretty, s->indent);
s->count++;
}
static void to_json(const QObject *obj, QString *str, int pretty, int indent)
{
switch (qobject_type(obj)) {
case QTYPE_QNULL:
qstring_append(str, "null");
break;
case QTYPE_QNUM: {
QNum *val = qobject_to(QNum, obj);
char *buffer = qnum_to_string(val);
qstring_append(str, buffer);
g_free(buffer);
break;
}
case QTYPE_QSTRING: {
QString *val = qobject_to(QString, obj);
const char *ptr;
int cp;
char buf[16];
char *end;
ptr = qstring_get_str(val);
qstring_append(str, "\"");
for (; *ptr; ptr = end) {
cp = mod_utf8_codepoint(ptr, 6, &end);
switch (cp) {
case '\"':
qstring_append(str, "\\\"");
break;
case '\\':
qstring_append(str, "\\\\");
break;
case '\b':
qstring_append(str, "\\b");
break;
case '\f':
qstring_append(str, "\\f");
break;
case '\n':
qstring_append(str, "\\n");
break;
case '\r':
qstring_append(str, "\\r");
break;
case '\t':
qstring_append(str, "\\t");
break;
default:
if (cp < 0) {
cp = 0xFFFD; /* replacement character */
}
if (cp > 0xFFFF) {
/* beyond BMP; need a surrogate pair */
snprintf(buf, sizeof(buf), "\\u%04X\\u%04X",
0xD800 + ((cp - 0x10000) >> 10),
0xDC00 + ((cp - 0x10000) & 0x3FF));
} else if (cp < 0x20 || cp >= 0x7F) {
snprintf(buf, sizeof(buf), "\\u%04X", cp);
} else {
buf[0] = cp;
buf[1] = 0;
}
qstring_append(str, buf);
}
};
qstring_append(str, "\"");
break;
}
case QTYPE_QDICT: {
ToJsonIterState s;
QDict *val = qobject_to(QDict, obj);
s.count = 0;
s.str = str;
s.indent = indent + 1;
s.pretty = pretty;
qstring_append(str, "{");
qdict_iter(val, to_json_dict_iter, &s);
if (pretty) {
int j;
qstring_append(str, "\n");
for (j = 0 ; j < indent ; j++)
qstring_append(str, " ");
}
qstring_append(str, "}");
break;
}
case QTYPE_QLIST: {
ToJsonIterState s;
QList *val = qobject_to(QList, obj);
s.count = 0;
s.str = str;
s.indent = indent + 1;
s.pretty = pretty;
qstring_append(str, "[");
qlist_iter(val, (void *)to_json_list_iter, &s);
if (pretty) {
int j;
qstring_append(str, "\n");
for (j = 0 ; j < indent ; j++)
qstring_append(str, " ");
}
qstring_append(str, "]");
break;
}
case QTYPE_QBOOL: {
QBool *val = qobject_to(QBool, obj);
if (qbool_get_bool(val)) {
qstring_append(str, "true");
} else {
qstring_append(str, "false");
}
break;
}
default:
abort();
}
}
QString *qobject_to_json(const QObject *obj)
{
QString *str = qstring_new();
to_json(obj, str, 0, 0);
return str;
}
QString *qobject_to_json_pretty(const QObject *obj)
{
QString *str = qstring_new();
to_json(obj, str, 1, 0);
return str;
}