[Qemu-devel] [PATCH v4 28/28] qemu-img: Use new JSON output formatter

[Eric Blake <eblake@redhat.com>]

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

The changes to qemu-iotests 043 expected output demonstrates
the fact that output is now done in qapi declaration order,
rather than QDict hash order.

Signed-off-by: Eric Blake <eblake@redhat.com>

---
v4: rebase to earlier changes
v3: rebase to master
v2: Drop RFC, adjust expected output of 043; rebase to 'name' motion

Overlaps with Fam's qemu-img edits, although he has expressed
interest in getting this one in first.
https://lists.gnu.org/archive/html/qemu-devel/2015-12/msg01756.html
https://lists.gnu.org/archive/html/qemu-devel/2015-12/msg01806.html
---
 qemu-img.c                 | 43 +++++++++++++++++--------------------------
 tests/qemu-iotests/043.out | 22 +++++++++++-----------
 2 files changed, 28 insertions(+), 37 deletions(-)

diff --git a/qemu-img.c b/qemu-img.c
index 086530f..d5dc19b 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -24,9 +24,9 @@
 #include "qemu/osdep.h"
 #include "qapi/error.h"
 #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/types.h"
 #include "qemu/cutils.h"
 #include "qemu/config-file.h"
 #include "qemu/option.h"
@@ -479,17 +479,14 @@ fail:

 static void dump_json_image_check(ImageCheck *check, bool quiet)
 {
-    QString *str;
-    QObject *obj;
-    Visitor *v = qmp_output_visitor_new(&obj);
+    char *str;
+    Visitor *v = json_output_visitor_new(true, &str);

     visit_type_ImageCheck(v, NULL, &check, &error_abort);
-    visit_complete(v, &obj);
-    str = qobject_to_json(obj, true);
-    qprintf(quiet, "%s\n", qstring_get_str(str));
-    qobject_decref(obj);
+    visit_complete(v, &str);
+    qprintf(quiet, "%s\n", str);
+    g_free(str);
     visit_free(v);
-    QDECREF(str);
 }

 static void dump_human_image_check(ImageCheck *check, bool quiet)
@@ -2168,32 +2165,26 @@ static void dump_snapshots(BlockDriverState *bs)

 static void dump_json_image_info_list(ImageInfoList *list)
 {
-    QString *str;
-    QObject *obj;
-    Visitor *v = qmp_output_visitor_new(&obj);
+    char *str;
+    Visitor *v = json_output_visitor_new(true, &str);

     visit_type_ImageInfoList(v, NULL, &list, &error_abort);
-    visit_complete(v, &obj);
-    str = qobject_to_json(obj, true);
-    printf("%s\n", qstring_get_str(str));
-    qobject_decref(obj);
+    visit_complete(v, &str);
+    printf("%s\n", str);
     visit_free(v);
-    QDECREF(str);
+    g_free(str);
 }

 static void dump_json_image_info(ImageInfo *info)
 {
-    QString *str;
-    QObject *obj;
-    Visitor *v = qmp_output_visitor_new(&obj);
+    char *str;
+    Visitor *v = json_output_visitor_new(true, &str);

     visit_type_ImageInfo(v, NULL, &info, &error_abort);
-    visit_complete(v, &obj);
-    str = qobject_to_json(obj, true);
-    printf("%s\n", qstring_get_str(str));
-    qobject_decref(obj);
+    visit_complete(v, &str);
+    printf("%s\n", str);
     visit_free(v);
-    QDECREF(str);
+    g_free(str);
 }

 static void dump_human_image_info_list(ImageInfoList *list)
diff --git a/tests/qemu-iotests/043.out b/tests/qemu-iotests/043.out
index b37d2a3..41697a2 100644
--- a/tests/qemu-iotests/043.out
+++ b/tests/qemu-iotests/043.out
@@ -40,29 +40,29 @@ cluster_size: 65536
 == finite chain of length 3 (json) ==
 [
     {
-        "virtual-size": 134217728,
         "filename": "TEST_DIR/t.IMGFMT",
-        "cluster-size": 65536,
         "format": "IMGFMT",
-        "full-backing-filename": "TEST_DIR/t.IMGFMT.2.base",
+        "dirty-flag": false,
+        "virtual-size": 134217728,
+        "cluster-size": 65536,
         "backing-filename": "TEST_DIR/t.IMGFMT.2.base",
-        "dirty-flag": false
+        "full-backing-filename": "TEST_DIR/t.IMGFMT.2.base",
     },
     {
-        "virtual-size": 134217728,
         "filename": "TEST_DIR/t.IMGFMT.2.base",
-        "cluster-size": 65536,
         "format": "IMGFMT",
-        "full-backing-filename": "TEST_DIR/t.IMGFMT.1.base",
+        "dirty-flag": false,
+        "virtual-size": 134217728,
+        "cluster-size": 65536,
         "backing-filename": "TEST_DIR/t.IMGFMT.1.base",
-        "dirty-flag": false
+        "full-backing-filename": "TEST_DIR/t.IMGFMT.1.base",
     },
     {
-        "virtual-size": 134217728,
         "filename": "TEST_DIR/t.IMGFMT.1.base",
-        "cluster-size": 65536,
         "format": "IMGFMT",
-        "dirty-flag": false
+        "dirty-flag": false,
+        "virtual-size": 134217728,
+        "cluster-size": 65536,
     }
 ]
 *** done
-- 
2.5.5