Re: [PATCH 1/3] qemu_monitor: add qemuMonitorQueryStats

Related: https://gitlab.com/libvirt/libvirt/-/issues/276 This patch adds an API for the "query-stats" QMP command. The query returns a JSON containing the statistics based on the target, which can either be vCPU or VM, and the providers. The API deserializes the query result into an array of GHashMaps, which can later be used to extract all the query statistics. GHashMaps are used to avoid traversing the entire array to find the statistics you are looking for. This would be a singleton array if the target is a VM since the returned JSON is also a singleton array in that case. Signed-off-by: Amneesh Singh <natto(a)weirdnatto.in&gt; --- src/qemu/qemu_monitor.c | 70 +++++++++++++++++++ src/qemu/qemu_monitor.h | 45 ++++++++++++ src/qemu/qemu_monitor_json.c | 130 +++++++++++++++++++++++++++++++++++ src/qemu/qemu_monitor_json.h | 6 ++ 4 files changed, 251 insertions(+) diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c index 80696de7..4e228bfb 100644 --- a/src/qemu/qemu_monitor_json.c +++ b/src/qemu/qemu_monitor_json.c @@ -9031,3 +9031,133 @@ qemuMonitorJSONMigrateRecover(qemuMonitor *mon, return qemuMonitorJSONCheckError(cmd, reply); } + +static GPtrArray * +qemuMonitorJSONExtractQueryStats(virJSONValue *arr) +{ + g_autoptr(GPtrArray) queried_stats = NULL; + size_t nstats = virJSONValueArraySize(arr); + size_t i; + + /* Create a GPtrArray for GHashTables */ + queried_stats = g_ptr_array_new_full(nstats, (GDestroyNotify) g_hash_table_destroy); + + for (i = 0; i < nstats; i++) { + virJSONValue *obj = virJSONValueArrayGet(arr, i); + virJSONValue *stats = virJSONValueObjectGetArray(obj, "stats"); + size_t j; + + /* Create a GHashTable for virJSONValues */ + GHashTable *hash_table = virHashNew((GDestroyNotify) virJSONValueFree); + + for (j = 0; j < virJSONValueArraySize(stats); j++) { + virJSONValue *stat = virJSONValueArrayGet(stats, j); + + g_hash_table_insert(hash_table, + g_strdup(virJSONValueObjectGetString(stat, "name")), + virJSONValueObjectGet(stat, "value")); + } + + g_ptr_array_add(queried_stats, hash_table); + } + + return g_steal_pointer(&queried_stats); +} + + +/** + * qemuMonitorJSONQueryStats: + * @mon: monitor object + * @target: the target type for the query + * @vcpus: a list of vCPU QOM paths for filtering the statistics + * @providers: an array of providers to filter statistics + * + * @vcpus is a NULL terminated array of strings. @providers is a GPtrArray + * for qemuMonitorQueryStatsProvider. + * @vcpus and @providers are optional and can be NULL. + * + * Queries for the @target based statistics. + * Returns a GPtrArray of GHashTables containing the statistics on success or + * NULL on failure. + */ + +GPtrArray * +qemuMonitorJSONQueryStats(qemuMonitor *mon, + qemuMonitorQueryStatsTargetType target, + char **vcpus, + GPtrArray *providers) +{ + g_autoptr(virJSONValue) cmd = NULL; + g_autoptr(virJSONValue) reply = NULL; + g_autoptr(virJSONValue) vcpu_list = NULL; + g_autoptr(virJSONValue) provider_list = NULL; + virJSONValue *rv = NULL; + + size_t i; + + if (providers) { + provider_list = virJSONValueNewArray(); + + for (i = 0; i < providers->len; i++) { + g_autoptr(virJSONValue) provider_obj = virJSONValueNewObject(); + qemuMonitorQueryStatsProvider *provider = providers->pdata[i]; + const char *type_str = qemuMonitorQueryStatsProviderTypeToString(provider->provider); + virBitmap *names = provider->names; + int rc; + + rc = virJSONValueObjectAppendString(provider_obj, "provider", type_str); + + if (rc < 0) + return NULL; + + if (names) { + g_autoptr(virJSONValue) provider_names = virJSONValueNewArray(); + int curBit = virBitmapNextSetBit(names, -1); + + while (curBit >= 0) { + const char *name = qemuMonitorQueryStatsNameTypeToString(curBit); + + if (virJSONValueArrayAppendString(provider_names, name) < 0) + return NULL; + + curBit = virBitmapNextSetBit(names, curBit); + }