[Qemu-block] [PATCH 11/11] RFC: qemu-img: Use new JSON output formatter

[Eric Blake]

Now that we can pretty-print straight to JSON from a visitor,
we can eliminate the temporary conversion into QObject inside
qemu-img.

RFC because at least qemu-iotests 043 has changed output, not
included in this version of the patch.  Conflicts with Fam's
qemu-img edits, so one of the two of us will get to rebase on
the other:
https://lists.gnu.org/archive/html/qemu-devel/2015-12/msg01756.html

Signed-off-by: Eric Blake <address@hidden>
Cc: Fam Zheng <address@hidden>
---
 qemu-img.c | 70 ++++++++++++++++++++++++++------------------------------------
 1 file changed, 29 insertions(+), 41 deletions(-)

diff --git a/qemu-img.c b/qemu-img.c
index cb961e6..08dca98 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -22,9 +22,9 @@
  * THE SOFTWARE.
  */
 #include "qapi-visit.h"
-#include "qapi/qmp-output-visitor.h"
+#include "qapi/json-output-visitor.h"
 #include "qapi/qmp/qerror.h"
-#include "qapi/qmp/qobject-json.h"
+#include "qapi/qmp/qstring.h"
 #include "qemu-common.h"
 #include "qemu/option.h"
 #include "qemu/error-report.h"
@@ -375,19 +375,15 @@ fail:

 static void dump_json_image_check(ImageCheck *check, bool quiet)
 {
-    Error *local_err = NULL;
-    QString *str;
-    QmpOutputVisitor *ov = qmp_output_visitor_new();
-    QObject *obj;
-    visit_type_ImageCheck(qmp_output_get_visitor(ov),
-                          &check, NULL, &local_err);
-    obj = qmp_output_get_qobject(ov);
-    str = qobject_to_json_pretty(obj);
-    assert(str != NULL);
-    qprintf(quiet, "%s\n", qstring_get_str(str));
-    qobject_decref(obj);
-    qmp_output_visitor_cleanup(ov);
-    QDECREF(str);
+    char *str;
+    JsonOutputVisitor *ov = json_output_visitor_new(true);
+    visit_type_ImageCheck(json_output_get_visitor(ov),
+                          &check, NULL, &error_abort);
+    str = json_output_get_string(ov);
+    assert(str);
+    qprintf(quiet, "%s\n", str);
+    g_free(str);
+    json_output_visitor_cleanup(ov);
 }

 static void dump_human_image_check(ImageCheck *check, bool quiet)
@@ -1926,36 +1922,28 @@ static void dump_snapshots(BlockDriverState *bs)

 static void dump_json_image_info_list(ImageInfoList *list)
 {
-    Error *local_err = NULL;
-    QString *str;
-    QmpOutputVisitor *ov = qmp_output_visitor_new();
-    QObject *obj;
-    visit_type_ImageInfoList(qmp_output_get_visitor(ov),
-                             &list, NULL, &local_err);
-    obj = qmp_output_get_qobject(ov);
-    str = qobject_to_json_pretty(obj);
-    assert(str != NULL);
-    printf("%s\n", qstring_get_str(str));
-    qobject_decref(obj);
-    qmp_output_visitor_cleanup(ov);
-    QDECREF(str);
+    char *str;
+    JsonOutputVisitor *ov = json_output_visitor_new(true);
+    visit_type_ImageInfoList(json_output_get_visitor(ov),
+                             &list, NULL, &error_abort);
+    str = json_output_get_string(ov);
+    assert(str);
+    printf("%s\n", str);
+    json_output_visitor_cleanup(ov);
+    g_free(str);
 }

 static void dump_json_image_info(ImageInfo *info)
 {
-    Error *local_err = NULL;
-    QString *str;
-    QmpOutputVisitor *ov = qmp_output_visitor_new();
-    QObject *obj;
-    visit_type_ImageInfo(qmp_output_get_visitor(ov),
-                         &info, NULL, &local_err);
-    obj = qmp_output_get_qobject(ov);
-    str = qobject_to_json_pretty(obj);
-    assert(str != NULL);
-    printf("%s\n", qstring_get_str(str));
-    qobject_decref(obj);
-    qmp_output_visitor_cleanup(ov);
-    QDECREF(str);
+    char *str;
+    JsonOutputVisitor *ov = json_output_visitor_new(true);
+    visit_type_ImageInfo(json_output_get_visitor(ov),
+                         &info, NULL, &error_abort);
+    str = json_output_get_string(ov);
+    assert(str);
+    printf("%s\n", str);
+    json_output_visitor_cleanup(ov);
+    g_free(str);
 }

 static void dump_human_image_info_list(ImageInfoList *list)
-- 
2.4.3