[PATCH v3 2/4] qemu: Create common code for JSON "query-block" call

[John Ferlan <jferlan@xxxxxxxxxx>]

Reduce some cut-n-paste code by creating common helper. Make use of the
recently added virJSONValueObjectStealArray to grab the devices list as
part of the common code (we we can Free the reply) and return devices for
each of the callers to continue to parse.

NB: This also adds error checking to qemuMonitorJSONDiskNameLookup

Signed-off-by: John Ferlan <jferlan@xxxxxxxxxx>
---
 src/qemu/qemu_monitor_json.c | 91 ++++++++++++++++++++------------------------
 1 file changed, 41 insertions(+), 50 deletions(-)

diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
index e1494df..a5e7ddc 100644
--- a/src/qemu/qemu_monitor_json.c
+++ b/src/qemu/qemu_monitor_json.c
@@ -1772,32 +1772,52 @@ qemuMonitorJSONSetMemoryStatsPeriod(qemuMonitorPtr mon,
 }
 
 
-int qemuMonitorJSONGetBlockInfo(qemuMonitorPtr mon,
-                                virHashTablePtr table)
+/* qemuMonitorJSONQueryBlock:
+ * @mon: Monitor pointer
+ *
+ * This helper will attempt to make a "query-block" call and check for
+ * errors before returning with the reply.
+ *
+ * Returns: NULL on error, reply on success
+ */
+static virJSONValuePtr
+qemuMonitorJSONQueryBlock(qemuMonitorPtr mon)
 {
-    int ret = -1;
-    size_t i;
-
-    virJSONValuePtr cmd = qemuMonitorJSONMakeCommand("query-block",
-                                                     NULL);
+    virJSONValuePtr cmd;
     virJSONValuePtr reply = NULL;
-    virJSONValuePtr devices;
+    virJSONValuePtr devices = NULL;
 
-    if (!cmd)
-        return -1;
-
-    if (qemuMonitorJSONCommand(mon, cmd, &reply) < 0)
-        goto cleanup;
+    if (!(cmd = qemuMonitorJSONMakeCommand("query-block", NULL)))
+        return NULL;
 
-    if (qemuMonitorJSONCheckError(cmd, reply) < 0)
+    if (qemuMonitorJSONCommand(mon, cmd, &reply) < 0 ||
+        qemuMonitorJSONCheckError(cmd, reply) < 0)
         goto cleanup;
 
-    if (!(devices = virJSONValueObjectGetArray(reply, "return"))) {
+    if (!(devices = virJSONValueObjectStealArray(reply, "return"))) {
         virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
-                       _("block info reply was missing device list"));
+                       _("query-block reply was missing device list"));
         goto cleanup;
     }
 
+ cleanup:
+    virJSONValueFree(cmd);
+    virJSONValueFree(reply);
+    return devices;
+}
+
+
+int qemuMonitorJSONGetBlockInfo(qemuMonitorPtr mon,
+                                virHashTablePtr table)
+{
+    int ret = -1;
+    size_t i;
+
+    virJSONValuePtr devices;
+
+    if (!(devices = qemuMonitorJSONQueryBlock(mon)))
+        return -1;
+
     for (i = 0; i < virJSONValueArraySize(devices); i++) {
         virJSONValuePtr dev = virJSONValueArrayGet(devices, i);
         struct qemuDomainDiskInfo *info;
@@ -1858,8 +1878,7 @@ int qemuMonitorJSONGetBlockInfo(qemuMonitorPtr mon,
 
     ret = 0;
  cleanup:
-    virJSONValueFree(cmd);
-    virJSONValueFree(reply);
+    virJSONValueFree(devices);
     return ret;
 }
 
@@ -2056,27 +2075,12 @@ qemuMonitorJSONBlockStatsUpdateCapacity(qemuMonitorPtr mon,
                                         bool backingChain)
 {
     int ret = -1;
-    int rc;
     size_t i;
-    virJSONValuePtr cmd;
-    virJSONValuePtr reply = NULL;
     virJSONValuePtr devices;
 
-    if (!(cmd = qemuMonitorJSONMakeCommand("query-block", NULL)))
+    if (!(devices = qemuMonitorJSONQueryBlock(mon)))
         return -1;
 
-    if ((rc = qemuMonitorJSONCommand(mon, cmd, &reply)) < 0)
-        goto cleanup;
-
-    if (qemuMonitorJSONCheckError(cmd, reply) < 0)
-        goto cleanup;
-
-    if (!(devices = virJSONValueObjectGetArray(reply, "return"))) {
-        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
-                       _("query-block reply was missing device list"));
-        goto cleanup;
-    }
-
     for (i = 0; i < virJSONValueArraySize(devices); i++) {
         virJSONValuePtr dev = virJSONValueArrayGet(devices, i);
         virJSONValuePtr inserted;
@@ -2111,8 +2115,7 @@ qemuMonitorJSONBlockStatsUpdateCapacity(qemuMonitorPtr mon,
     ret = 0;
 
  cleanup:
-    virJSONValueFree(cmd);
-    virJSONValueFree(reply);
+    virJSONValueFree(devices);
     return ret;
 }
 
@@ -3987,22 +3990,11 @@ qemuMonitorJSONDiskNameLookup(qemuMonitorPtr mon,
                               virStorageSourcePtr target)
 {
     char *ret = NULL;
-    virJSONValuePtr cmd = NULL;
-    virJSONValuePtr reply = NULL;
     virJSONValuePtr devices;
     size_t i;
 
-    cmd = qemuMonitorJSONMakeCommand("query-block", NULL);
-    if (!cmd)
+    if (!(devices = qemuMonitorJSONQueryBlock(mon)))
         return NULL;
-    if (qemuMonitorJSONCommand(mon, cmd, &reply) < 0)
-        goto cleanup;
-
-    if (!(devices = virJSONValueObjectGetArray(reply, "return"))) {
-        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
-                       _("block info reply was missing device list"));
-        goto cleanup;
-    }
 
     for (i = 0; i < virJSONValueArraySize(devices); i++) {
         virJSONValuePtr dev = virJSONValueArrayGet(devices, i);
@@ -4038,8 +4030,7 @@ qemuMonitorJSONDiskNameLookup(qemuMonitorPtr mon,
                        device);
 
  cleanup:
-    virJSONValueFree(cmd);
-    virJSONValueFree(reply);
+    virJSONValueFree(devices);
 
     return ret;
 }
-- 
2.7.4

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