[Qemu-block] [RFC v2 1/4] RollingStats qapi type

[Dr. David Alan Gilbert (git)]

From: "Dr. David Alan Gilbert" <address@hidden>

This adds a QAPI type that holds the results of statistics collected
by RStats.

Signed-off-by: Dr. David Alan Gilbert <address@hidden>
---
 qapi-schema.json | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/qapi-schema.json b/qapi-schema.json
index e16f8eb..9f5cdce 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -353,6 +353,36 @@
 { 'command': 'query-events', 'returns': ['EventInfo'] }
 
 ##
+# @RollingStatsValue:
+#
+# A value/tag tuple used in 'RollingStats'
+#
+# @value: An arbitrary measurement value
+#
+# @tag: An arbitrary integer tag value
+#
+##
+{ 'type': 'RollingStatsValue', 'data': {'value': 'number', 'tag': 'uint64'} }
+
+##
+# @RollingStats:
+#
+# A set of statistics that are measured repeatedly.
+#
+# @count: The number of measurements that have contributed to the statistics
+# @min: The minimum value over the measurement period
+# @max: The maximum value over the measurement period
+# @mean: A rolling mean
+# @weighted-mean: A weighted mean (the weight set at startup)
+# @values: A list of the most recent values stored.  Note that the
+#          stastics above are calculated over the whole set.
+##
+{ 'type': 'RollingStats', 'data': {'count': 'int',
+                                   'min': 'number', 'max': 'number',
+                                   'mean': 'number', 'weighted-mean': 'number',
+                                   'values': ['RollingStatsValue'] } }
+
+##
 # @MigrationStats
 #
 # Detailed migration status.
-- 
2.1.0