[libvirt] [PATCH 3/9] lib: introduce virDomainGetStateParams function

[Bjoern Walk]

This API function extends and generalizes the virDomainGetState function
by returning a dictionary of typed parameters.

In later commits, the domain state, reason and the previously introduced
additional state information are returned.

Reviewed-by: Stefan Zimmermann <stzi at linux.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy at linux.ibm.com>
Signed-off-by: Bjoern Walk <bwalk at linux.ibm.com>
---
 include/libvirt/libvirt-domain.h | 24 ++++++++++++++
 src/driver-hypervisor.h          |  7 ++++
 src/libvirt-domain.c             | 56 ++++++++++++++++++++++++++++++++
 src/libvirt_public.syms          |  5 +++
 4 files changed, 92 insertions(+)

diff --git a/include/libvirt/libvirt-domain.h b/include/libvirt/libvirt-domain.h
index 796f2e14..c7b85cd0 100644
--- a/include/libvirt/libvirt-domain.h
+++ b/include/libvirt/libvirt-domain.h
@@ -1254,6 +1254,30 @@ int                     virDomainGetState       (virDomainPtr domain,
                                                  int *reason,
                                                  unsigned int flags);
 
+/**
+ * VIR_DOMAIN_STATE_PARAMS_STATE:
+ * state of the domain (cf. virDomainState) as an int
+ */
+# define VIR_DOMAIN_STATE_PARAMS_STATE "state"
+
+/**
+ * VIR_DOMAIN_STATE_PARAMS_REASON:
+ * state reason of the domain (one of virDomain*Reason) as an int
+ */
+# define VIR_DOMAIN_STATE_PARAMS_REASON "reason"
+
+/**
+ * VIR_DOMAIN_STATE_PARAMS_INFO:
+ * additional information for certain state reasons as a string
+ */
+# define VIR_DOMAIN_STATE_PARAMS_INFO "info"
+
+int                     virDomainGetStateParams(virDomainPtr domain,
+                                                virTypedParameterPtr *params,
+                                                int *nparams,
+                                                unsigned int flags);
+
+
 /**
  * VIR_DOMAIN_CPU_STATS_CPUTIME:
  * cpu usage (sum of both vcpu and hypervisor usage) in nanoseconds,
diff --git a/src/driver-hypervisor.h b/src/driver-hypervisor.h
index eef31eb1..2b3fe725 100644
--- a/src/driver-hypervisor.h
+++ b/src/driver-hypervisor.h
@@ -220,6 +220,12 @@ typedef int
                         int *reason,
                         unsigned int flags);
 
+typedef int
+(*virDrvDomainGetStateParams)(virDomainPtr domain,
+                              virTypedParameterPtr *params,
+                              int *nparams,
+                              unsigned int flags);
+
 typedef int
 (*virDrvDomainGetControlInfo)(virDomainPtr domain,
                               virDomainControlInfoPtr info,
@@ -1383,6 +1389,7 @@ struct _virHypervisorDriver {
     virDrvDomainGetBlkioParameters domainGetBlkioParameters;
     virDrvDomainGetInfo domainGetInfo;
     virDrvDomainGetState domainGetState;
+    virDrvDomainGetStateParams domainGetStateParams;
     virDrvDomainGetControlInfo domainGetControlInfo;
     virDrvDomainSave domainSave;
     virDrvDomainSaveFlags domainSaveFlags;
diff --git a/src/libvirt-domain.c b/src/libvirt-domain.c
index ab7266dc..78d95bf6 100644
--- a/src/libvirt-domain.c
+++ b/src/libvirt-domain.c
@@ -2502,6 +2502,62 @@ virDomainGetState(virDomainPtr domain,
 }
 
 
+/**
+ * virDomainGetStateParams:
+ * @domain: a domain object
+ * @params: where to store domain statistics, must be freed by the caller
+ * @nparams: number of items in @params
+ * @flags: bitwise-OR of virDomainGetStateFlags,
+ *         not currently used yet, callers should always pass 0
+ *
+ * Extract domain state. Each state is accompanied by a reason (if known)
+ * and optional detailed information.
+ *
+ * Possible fields returned in @params are defined by VIR_DOMAIN_STATE_PARAMS_*
+ * macros and new fields will likely be introduced in the future so callers
+ * may receive fields that they do not understand in case they talk to a newer
+ * server. The caller is responsible to free allocated memory returned in
+ * @params by calling virTypedParamsFree.
+ *
+ * Returns 0 in case of success and -1 in case of failure.
+ */
+int
+virDomainGetStateParams(virDomainPtr domain,
+                        virTypedParameterPtr *params,
+                        int *nparams,
+                        unsigned int flags)
+{
+    virConnectPtr conn;
+
+    VIR_DOMAIN_DEBUG(domain, "params=%p, nparams=%p, flags=0x%x",
+                     params, nparams, flags);
+
+    virResetLastError();
+
+    virCheckDomainReturn(domain, -1);
+    virCheckNonNullArgGoto(params, error);
+    virCheckNonNullArgGoto(nparams, error);
+
+    conn = domain->conn;
+    if (conn->driver->domainGetStateParams) {
+        int ret;
+        ret = conn->driver->domainGetStateParams(domain,
+                                                 params,
+                                                 nparams,
+                                                 flags);
+        if (ret < 0)
+            goto error;
+        return ret;
+    }
+
+    virReportUnsupportedError();
+
+ error:
+    virDispatchError(domain->conn);
+    return -1;
+}
+
+
 /**
  * virDomainGetControlInfo:
  * @domain: a domain object
diff --git a/src/libvirt_public.syms b/src/libvirt_public.syms
index d4cdbd8b..866c2e99 100644
--- a/src/libvirt_public.syms
+++ b/src/libvirt_public.syms
@@ -809,4 +809,9 @@ LIBVIRT_4.5.0 {
         virNWFilterBindingGetFilterName;
 } LIBVIRT_4.4.0;
 
+LIBVIRT_4.6.0 {
+     global:
+        virDomainGetStateParams;
+} LIBVIRT_4.5.0;
+
 # .... define new API here using predicted next version number ....
-- 
2.17.0