Provide marshalling mechanism for json

This introduces qobject_to_json which will convert a QObject to a JSON string
representation.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Anthony Liguori 2009-11-11 12:01:22 -06:00
parent 21f800d340
commit 1fd825f785
2 changed files with 181 additions and 0 deletions

178
qjson.c
View File

@ -15,6 +15,11 @@
#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
{
@ -58,3 +63,176 @@ QObject *qobject_from_jsonf(const char *string, ...)
return state.result;
}
typedef struct ToJsonIterState
{
int count;
QString *str;
} ToJsonIterState;
static void to_json(const QObject *obj, QString *str);
static void to_json_dict_iter(const char *key, QObject *obj, void *opaque)
{
ToJsonIterState *s = opaque;
QString *qkey;
if (s->count) {
qstring_append(s->str, ", ");
}
qkey = qstring_from_str(key);
to_json(QOBJECT(qkey), s->str);
QDECREF(qkey);
qstring_append(s->str, ": ");
to_json(obj, s->str);
s->count++;
}
static void to_json_list_iter(QObject *obj, void *opaque)
{
ToJsonIterState *s = opaque;
if (s->count) {
qstring_append(s->str, ", ");
}
to_json(obj, s->str);
s->count++;
}
static void to_json(const QObject *obj, QString *str)
{
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 '\n':
qstring_append(str, "\\n");
break;
case '\r':
qstring_append(str, "\\r");
break;
case '\t':
qstring_append(str, "\\t");
break;
default: {
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;
qstring_append(str, "{");
qdict_iter(val, to_json_dict_iter, &s);
qstring_append(str, "}");
break;
}
case QTYPE_QLIST: {
ToJsonIterState s;
QList *val = qobject_to_qlist(obj);
s.count = 0;
s.str = str;
qstring_append(str, "[");
qlist_iter(val, (void *)to_json_list_iter, &s);
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_NONE:
break;
}
}
QString *qobject_to_json(const QObject *obj)
{
QString *str = qstring_new();
to_json(obj, str);
return str;
}

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@ -15,9 +15,12 @@
#define QJSON_H
#include "qobject.h"
#include "qstring.h"
QObject *qobject_from_json(const char *string);
QObject *qobject_from_jsonf(const char *string, ...)
__attribute__((__format__ (__printf__, 1, 2)));
QString *qobject_to_json(const QObject *obj);
#endif /* QJSON_H */