[Qemu-devel] [PATCH 07/10] monitor: Convert do_info_migrate() to QObject

[Luiz Capitulino <lcapitulino@redhat.com>]

Return a QDict, which may contain another QDict if the migration
process is active.

The main QDict contains the following:

- "status": migration status
- "ram": only present if "status" is "active", it is a QDict with the
   following information (in bytes):
        - "transferred": amount of RAM transferred
        - "remaining": amount of RAM remaining
        - "total": total RAM

IMPORTANT: as a QInt stores a int64_t integer, those RAM values
are going to stored as int64_t and not as uint64_t as they are
today. If this is a problem QInt will have to be changed.

This commit should not change user output, the following is an
example of the returned QDict:

{ "status": "active", "ram":
   { "transferred": 885030912, "remaining": 198529024, "total": 1082392576 } }

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 migration.c |   69 +++++++++++++++++++++++++++++++++++++++++++++++++++-------
 migration.h |    3 +-
 monitor.c   |    3 +-
 3 files changed, 64 insertions(+), 11 deletions(-)

diff --git a/migration.c b/migration.c
index 112a5b6..b3bf00f 100644
--- a/migration.c
+++ b/migration.c
@@ -18,6 +18,7 @@
 #include "sysemu.h"
 #include "block.h"
 #include "qemu_socket.h"
+#include "qmisc.h"
 
 //#define DEBUG_MIGRATION
 
@@ -158,29 +159,79 @@ void do_migrate_set_downtime(Monitor *mon, const QDict *qdict)
     max_downtime = (uint64_t)d;
 }
 
-void do_info_migrate(Monitor *mon)
+void migration_user_print(Monitor *mon, const QObject *data)
+{
+    QDict *qdict;
+
+    assert(qobject_type(data) == QTYPE_QDICT);
+    qdict = qobject_to_qdict(data);
+
+    monitor_printf(mon, "Migration status: %s\n",
+                   qdict_get_str(qdict, "status"));
+
+    if (qdict_haskey(qdict, "ram")) {
+        QDict *qdict_ram = qobject_to_qdict(qdict_get(qdict, "ram"));
+        monitor_printf(mon, "transferred ram: %" PRIu64 " kbytes\n",
+                       qdict_get_int(qdict_ram, "transferred") >> 10);
+        monitor_printf(mon, "remaining ram: %" PRIu64 " kbytes\n",
+                       qdict_get_int(qdict_ram, "remaining") >> 10);
+        monitor_printf(mon, "total ram: %" PRIu64 " kbytes\n",
+                       qdict_get_int(qdict_ram, "total") >> 10);
+    }
+}
+
+/**
+ * do_info_migrate(): Show migration status
+ *
+ * Return a QDict. If migration is active there will be another
+ * QDict with RAM information.
+ *
+ * The main QDict contains the following:
+ *
+ * - "status": migration status
+ * - "ram": only present if "status" is "active", it is a QDict with the
+ *   following information (in bytes):
+ *          - "transferred": amount of RAM transferred
+ *          - "remaining": amount of RAM remaining
+ *          - "total": total RAM
+ *
+ * Examples:
+ *
+ * 1. If migration is "completed", "error" or "cancelled":
+ *
+ * { "status": "completed" }
+ *
+ * 2. If migration is "active":
+ *
+ * { "status": "active", "ram":
+ *             { "transferred": 123, "remaining": 123, "total": 246 } }
+ */
+void do_info_migrate(Monitor *mon, QObject **ret_data)
 {
     MigrationState *s = current_migration;
 
     if (s) {
-        monitor_printf(mon, "Migration status: ");
         switch (s->get_status(s)) {
         case MIG_STATE_ACTIVE:
-            monitor_printf(mon, "active\n");
-            monitor_printf(mon, "transferred ram: %" PRIu64 " kbytes\n", ram_bytes_transferred() >> 10);
-            monitor_printf(mon, "remaining ram: %" PRIu64 " kbytes\n", ram_bytes_remaining() >> 10);
-            monitor_printf(mon, "total ram: %" PRIu64 " kbytes\n", ram_bytes_total() >> 10);
+            *ret_data = qobject_from_fmt("{ s: s, s: { s: i, s: i, s: i } }",
+                                         "status", "active",
+                                         "ram",
+                                         "transferred", ram_bytes_transferred(),
+                                         "remaining", ram_bytes_remaining(),
+                                         "total", ram_bytes_total());
             break;
         case MIG_STATE_COMPLETED:
-            monitor_printf(mon, "completed\n");
+            *ret_data = qobject_from_fmt("{ s: s }", "status", "completed");
             break;
         case MIG_STATE_ERROR:
-            monitor_printf(mon, "failed\n");
+            *ret_data = qobject_from_fmt("{ s: s }", "status", "failed");
             break;
         case MIG_STATE_CANCELLED:
-            monitor_printf(mon, "cancelled\n");
+            *ret_data = qobject_from_fmt("{ s: s }", "status", "cancelled");
             break;
         }
+        if (*ret_data == NULL)
+            monitor_printf(mon, "Migration: could not build QObject\n");
     }
 }
 
diff --git a/migration.h b/migration.h
index 2d28b8f..7666c4b 100644
--- a/migration.h
+++ b/migration.h
@@ -60,7 +60,8 @@ uint64_t migrate_max_downtime(void);
 
 void do_migrate_set_downtime(Monitor *mon, const QDict *qdict);
 
-void do_info_migrate(Monitor *mon);
+void migration_user_print(Monitor *mon, const QObject *data);
+void do_info_migrate(Monitor *mon, QObject **ret_data);
 
 int exec_start_incoming_migration(const char *host_port);
 
diff --git a/monitor.c b/monitor.c
index a095971..7e5c07d 100644
--- a/monitor.c
+++ b/monitor.c
@@ -2177,7 +2177,8 @@ static const mon_cmd_t info_cmds[] = {
         .args_type  = "",
         .params     = "",
         .help       = "show migration status",
-        .mhandler.info = do_info_migrate,
+        .user_print = migration_user_print,
+        .mhandler.info_new = do_info_migrate,
     },
     {
         .name       = "balloon",
-- 
1.6.5.rc2.17.gdbc1b