[RFC PATCH 4/5] qemu_driver: add histograms to the stats

[Amneesh Singh <natto@xxxxxxxxxxxxx>]

This patch adds histograms to the stats which were previously ignored
due to them not being a virTypedParameterType earlier.

Signed-off-by: Amneesh Singh <natto@xxxxxxxxxxxxx>
---
 src/qemu/qemu_driver.c | 41 +++++++++++++++++++++++++++++++++++++++--
 1 file changed, 39 insertions(+), 2 deletions(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 52e1f88568..bc6f484d88 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -17989,13 +17989,50 @@ qemuDomainAddStatsFromHashTable(GHashTable *stats,
         case QEMU_MONITOR_QUERY_STATS_TYPE_INSTANT:
             type = "cur";
             break;
-
         case QEMU_MONITOR_QUERY_STATS_TYPE_PEAK:
             type = "max";
             break;
 
-        case QEMU_MONITOR_QUERY_STATS_TYPE_LOG2_HISTOGRAM:
         case QEMU_MONITOR_QUERY_STATS_TYPE_LINEAR_HISTOGRAM:
+        case QEMU_MONITOR_QUERY_STATS_TYPE_LOG2_HISTOGRAM: {
+            virHistogram *histogram;
+            size_t size;
+            size_t i;
+            int flag = 0;
+
+            if (!virJSONValueIsArray(value))
+                continue;
+
+            if (data->type == QEMU_MONITOR_QUERY_STATS_TYPE_LINEAR_HISTOGRAM &&
+                data->bucket_size == 0)
+                continue;
+
+            size = virJSONValueArraySize(value);
+            histogram = virHistogramNew(size);
+
+            for (i = 0; i < size; i++) {
+                virHistogramBucket *bucket = histogram->buckets + i;
+                virJSONValue *current = virJSONValueArrayGet(value, i);
+
+                bucket->x = (data->type == QEMU_MONITOR_QUERY_STATS_TYPE_LINEAR_HISTOGRAM ?
+                               (i + 1) * data->bucket_size :
+                               1LL << i);
+
+                if (virJSONValueGetNumberLong(current, &(bucket->y)) < 0) {
+                    flag = 1;
+                    break;
+                }
+            }
+
+            if (flag) {
+                virHistogramFree(histogram);
+                continue;
+            }
+
+            ignore_value(virTypedParamListAddHistogram(params, histogram, "%s.%s",
+                                                       prefix, key));
+        }
+
         case QEMU_MONITOR_QUERY_STATS_TYPE_LAST:
         default:
             continue;
-- 
2.37.1