qemu/qjson.c
Daniel P. Berrange 212b600868 Add support for JSON pretty printing
The monitor does not pretty-print JSON output, so that everything
will be on a single line reply. When JSON docs get large this is
quite unpleasant to read. For the future command line capabilities
query ability, huge JSON docs will be available. This needs the
ability to pretty-print.

This introduces a new API qobject_to_json_pretty() that does
a minimal indentation of list and dict members. As an example,
this makes

  {"QMP": {"version": {"micro": 50, "minor": 12, "package": "", "major": 0}, "capabilities": []}}

Output as

  {
      "QMP": {
          "version": {
              "micro": 50,
              "minor": 12,
              "package": "",
              "major": 0
          },
          "capabilities": [
          ]
      }
  }

NB: this is not turned on for the QMP monitor.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2010-10-01 10:12:43 -03:00

295 lines
7.3 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 "json-lexer.h"
#include "json-parser.h"
#include "json-streamer.h"
#include "qjson.h"
#include "qint.h"
#include "qlist.h"
#include "qbool.h"
#include "qfloat.h"
#include "qdict.h"
typedef struct JSONParsingState
{
JSONMessageParser parser;
va_list *ap;
QObject *result;
} JSONParsingState;
static void parse_json(JSONMessageParser *parser, QList *tokens)
{
JSONParsingState *s = container_of(parser, JSONParsingState, parser);
s->result = json_parser_parse(tokens, s->ap);
}
QObject *qobject_from_jsonv(const char *string, va_list *ap)
{
JSONParsingState state = {};
state.ap = ap;
json_message_parser_init(&state.parser, parse_json);
json_message_parser_feed(&state.parser, string, strlen(string));
json_message_parser_flush(&state.parser);
json_message_parser_destroy(&state.parser);
return state.result;
}
QObject *qobject_from_json(const char *string)
{
return qobject_from_jsonv(string, NULL);
}
/*
* IMPORTANT: This function aborts on error, thus it must not
* be used with untrusted arguments.
*/
QObject *qobject_from_jsonf(const char *string, ...)
{
QObject *obj;
va_list ap;
va_start(ap, string);
obj = qobject_from_jsonv(string, &ap);
va_end(ap);
assert(obj != NULL);
return obj;
}
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, ", ");
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);
QDECREF(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, ", ");
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_QINT: {
QInt *val = qobject_to_qint(obj);
char buffer[1024];
snprintf(buffer, sizeof(buffer), "%" PRId64, qint_get_int(val));
qstring_append(str, buffer);
break;
}
case QTYPE_QSTRING: {
QString *val = qobject_to_qstring(obj);
const char *ptr;
ptr = qstring_get_str(val);
qstring_append(str, "\"");
while (*ptr) {
if ((ptr[0] & 0xE0) == 0xE0 &&
(ptr[1] & 0x80) && (ptr[2] & 0x80)) {
uint16_t wchar;
char escape[7];
wchar = (ptr[0] & 0x0F) << 12;
wchar |= (ptr[1] & 0x3F) << 6;
wchar |= (ptr[2] & 0x3F);
ptr += 2;
snprintf(escape, sizeof(escape), "\\u%04X", wchar);
qstring_append(str, escape);
} else if ((ptr[0] & 0xE0) == 0xC0 && (ptr[1] & 0x80)) {
uint16_t wchar;
char escape[7];
wchar = (ptr[0] & 0x1F) << 6;
wchar |= (ptr[1] & 0x3F);
ptr++;
snprintf(escape, sizeof(escape), "\\u%04X", wchar);
qstring_append(str, escape);
} else switch (ptr[0]) {
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 (ptr[0] <= 0x1F) {
char escape[7];
snprintf(escape, sizeof(escape), "\\u%04X", ptr[0]);
qstring_append(str, escape);
} else {
char buf[2] = { ptr[0], 0 };
qstring_append(str, buf);
}
break;
}
}
ptr++;
}
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_QFLOAT: {
QFloat *val = qobject_to_qfloat(obj);
char buffer[1024];
int len;
len = snprintf(buffer, sizeof(buffer), "%f", qfloat_get_double(val));
while (len > 0 && buffer[len - 1] == '0') {
len--;
}
if (len && buffer[len - 1] == '.') {
buffer[len - 1] = 0;
} else {
buffer[len] = 0;
}
qstring_append(str, buffer);
break;
}
case QTYPE_QBOOL: {
QBool *val = qobject_to_qbool(obj);
if (qbool_get_int(val)) {
qstring_append(str, "true");
} else {
qstring_append(str, "false");
}
break;
}
case QTYPE_QERROR:
/* XXX: should QError be emitted? */
case QTYPE_NONE:
break;
}
}
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;
}