backup: Introduce virDomainCheckpointPtr

Prepare for introducing a bunch of new public APIs related to
backup checkpoints by first introducing a new internal type
and errors associated with that type.  Checkpoints are modeled
heavily after virDomainSnapshotPtr (both represent a point in
time of the guest), although a snapshot exists with the intent
of rolling back to that state, while a checkpoint exists to
make it possible to create an incremental backup at a later
time.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

include/libvirt/libvirt.h

@@ -4,7 +4,7 @@
  * Description: Provides the interfaces of the libvirt library to handle
  *              virtualized domains
  *
- * Copyright (C) 2005-2006, 2010-2014 Red Hat, Inc.
+ * Copyright (C) 2005-2019 Red Hat, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -34,6 +34,10 @@ extern "C" {
 # include <libvirt/libvirt-common.h>
 # include <libvirt/libvirt-host.h>
 # include <libvirt/libvirt-domain.h>
+/* FIXME: Temporary hack until later patch creates new
+ * libvirt-domain-checkpoint.h file */
+typedef struct _virDomainCheckpoint virDomainCheckpoint;
+typedef virDomainCheckpoint *virDomainCheckpointPtr;
 # include <libvirt/libvirt-domain-snapshot.h>
 # include <libvirt/libvirt-event.h>
 # include <libvirt/libvirt-interface.h>

include/libvirt/virterror.h

@@ -4,7 +4,7 @@
  * Description: Provides the interfaces of the libvirt library to handle
  *              errors raised while using the library.
  *
- * Copyright (C) 2006-2016 Red Hat, Inc.
+ * Copyright (C) 2006-2019 Red Hat, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -132,6 +132,7 @@ typedef enum {
     VIR_FROM_LIBSSH = 66,       /* Error from libssh connection transport */
     VIR_FROM_RESCTRL = 67,      /* Error from resource control */
     VIR_FROM_FIREWALLD = 68,    /* Error from firewalld */
+    VIR_FROM_DOMAIN_CHECKPOINT = 69, /* Error from domain checkpoint */
 
 # ifdef VIR_ENUM_SENTINELS
     VIR_ERR_DOMAIN_LAST
@@ -322,11 +323,13 @@ typedef enum {
     VIR_ERR_DEVICE_MISSING = 99,        /* fail to find the desired device */
     VIR_ERR_INVALID_NWFILTER_BINDING = 100,  /* invalid nwfilter binding */
     VIR_ERR_NO_NWFILTER_BINDING = 101,  /* no nwfilter binding */
+    VIR_ERR_INVALID_DOMAIN_CHECKPOINT = 102, /* invalid domain checkpoint */
+    VIR_ERR_NO_DOMAIN_CHECKPOINT = 103, /* domain checkpoint not found */
+    VIR_ERR_NO_DOMAIN_BACKUP = 104,     /* domain backup job id not found */
 
 # ifdef VIR_ENUM_SENTINELS
     VIR_ERR_NUMBER_LAST
 # endif
-
 } virErrorNumber;
 
 /**

src/datatypes.c

@@ -1,7 +1,7 @@
 /*
  * datatypes.c: management of structs for public data types
  *
- * Copyright (C) 2006-2015 Red Hat, Inc.
+ * Copyright (C) 2006-2019 Red Hat, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -36,6 +36,7 @@ VIR_LOG_INIT("datatypes");
 virClassPtr virConnectClass;
 virClassPtr virConnectCloseCallbackDataClass;
 virClassPtr virDomainClass;
+virClassPtr virDomainCheckpointClass;
 virClassPtr virDomainSnapshotClass;
 virClassPtr virInterfaceClass;
 virClassPtr virNetworkClass;
@@ -50,6 +51,7 @@ virClassPtr virStoragePoolClass;
 static void virConnectDispose(void *obj);
 static void virConnectCloseCallbackDataDispose(void *obj);
 static void virDomainDispose(void *obj);
+static void virDomainCheckpointDispose(void *obj);
 static void virDomainSnapshotDispose(void *obj);
 static void virInterfaceDispose(void *obj);
 static void virNetworkDispose(void *obj);
@@ -86,6 +88,7 @@ virDataTypesOnceInit(void)
     DECLARE_CLASS_LOCKABLE(virConnect);
     DECLARE_CLASS_LOCKABLE(virConnectCloseCallbackData);
     DECLARE_CLASS(virDomain);
+    DECLARE_CLASS(virDomainCheckpoint);
     DECLARE_CLASS(virDomainSnapshot);
     DECLARE_CLASS(virInterface);
     DECLARE_CLASS(virNetwork);
@@ -900,6 +903,64 @@ virNWFilterBindingDispose(void *obj)
 }
 
 
+/**
+ * virGetDomainCheckpoint:
+ * @domain: the domain to checkpoint
+ * @name: pointer to the domain checkpoint name
+ *
+ * Allocates a new domain checkpoint object. When the object is no longer needed,
+ * virObjectUnref() must be called in order to not leak data.
+ *
+ * Returns a pointer to the domain checkpoint object, or NULL on error.
+ */
+virDomainCheckpointPtr
+virGetDomainCheckpoint(virDomainPtr domain,
+                       const char *name)
+{
+    virDomainCheckpointPtr ret = NULL;
+
+    if (virDataTypesInitialize() < 0)
+        return NULL;
+
+    virCheckDomainGoto(domain, error);
+    virCheckNonNullArgGoto(name, error);
+
+    if (!(ret = virObjectNew(virDomainCheckpointClass)))
+        goto error;
+    if (VIR_STRDUP(ret->name, name) < 0)
+        goto error;
+
+    ret->domain = virObjectRef(domain);
+
+    return ret;
+
+ error:
+    virObjectUnref(ret);
+    return NULL;
+}
+
+
+/**
+ * virDomainCheckpointDispose:
+ * @obj: the domain checkpoint to release
+ *
+ * Unconditionally release all memory associated with a checkpoint.
+ * The checkpoint object must not be used once this method returns.
+ *
+ * It will also unreference the associated connection object,
+ * which may also be released if its ref count hits zero.
+ */
+static void
+virDomainCheckpointDispose(void *obj)
+{
+    virDomainCheckpointPtr checkpoint = obj;
+    VIR_DEBUG("release checkpoint %p %s", checkpoint, checkpoint->name);
+
+    VIR_FREE(checkpoint->name);
+    virObjectUnref(checkpoint->domain);
+}
+
+
 /**
  * virGetDomainSnapshot:
  * @domain: the domain to snapshot

src/datatypes.h

@@ -1,7 +1,7 @@
 /*
  * datatypes.h: management of structs for public data types
  *
- * Copyright (C) 2006-2015 Red Hat, Inc.
+ * Copyright (C) 2006-2019 Red Hat, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -31,6 +31,7 @@
 
 extern virClassPtr virConnectClass;
 extern virClassPtr virDomainClass;
+extern virClassPtr virDomainCheckpointClass;
 extern virClassPtr virDomainSnapshotClass;
 extern virClassPtr virInterfaceClass;
 extern virClassPtr virNetworkClass;
@@ -292,6 +293,21 @@ extern virClassPtr virAdmClientClass;
         } \
     } while (0)
 
+# define virCheckDomainCheckpointReturn(obj, retval) \
+    do { \
+        virDomainCheckpointPtr _check = (obj); \
+        if (!virObjectIsClass(_check, virDomainCheckpointClass) || \
+            !virObjectIsClass(_check->domain, virDomainClass) || \
+            !virObjectIsClass(_check->domain->conn, virConnectClass)) { \
+            virReportErrorHelper(VIR_FROM_DOMAIN_CHECKPOINT, \
+                                 VIR_ERR_INVALID_DOMAIN_CHECKPOINT, \
+                                 __FILE__, __FUNCTION__, __LINE__, \
+                                 __FUNCTION__); \
+            virDispatchError(NULL); \
+            return retval; \
+        } \
+    } while (0)
+
 # define virCheckDomainSnapshotReturn(obj, retval) \
     do { \
         virDomainSnapshotPtr _snap = (obj); \
@@ -668,6 +684,19 @@ struct _virStream {
     virFreeCallback ff;
 };
 
+
+/**
+ * _virDomainCheckpoint
+ *
+ * Internal structure associated with a domain checkpoint
+ */
+struct _virDomainCheckpoint {
+    virObject parent;
+    char *name;
+    virDomainPtr domain;
+};
+
+
 /**
  * _virDomainSnapshot
  *
@@ -744,6 +773,8 @@ virNWFilterPtr virGetNWFilter(virConnectPtr conn,
 virNWFilterBindingPtr virGetNWFilterBinding(virConnectPtr conn,
                                             const char *portdev,
                                             const char *filtername);
+virDomainCheckpointPtr virGetDomainCheckpoint(virDomainPtr domain,
+                                              const char *name);
 virDomainSnapshotPtr virGetDomainSnapshot(virDomainPtr domain,
                                           const char *name);
 

src/libvirt_private.syms

@@ -1252,10 +1252,12 @@ virConnectCloseCallbackDataClass;
 virConnectCloseCallbackDataGetCallback;
 virConnectCloseCallbackDataRegister;
 virConnectCloseCallbackDataUnregister;
+virDomainCheckpointClass;
 virDomainClass;
 virDomainSnapshotClass;
 virGetConnect;
 virGetDomain;
+virGetDomainCheckpoint;
 virGetDomainSnapshot;
 virGetInterface;
 virGetNetwork;

src/util/virerror.c

@@ -1,7 +1,7 @@
 /*
  * virerror.c: error handling and reporting code for libvirt
  *
- * Copyright (C) 2006, 2008-2016 Red Hat, Inc.
+ * Copyright (C) 2006-2019 Red Hat, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -139,6 +139,7 @@ VIR_ENUM_IMPL(virErrorDomain, VIR_ERR_DOMAIN_LAST,
               "Libssh transport layer",
               "Resource control",
               "FirewallD",
+              "Domain Checkpoint",
 );
 
 
@@ -1214,6 +1215,15 @@ const virErrorMsgTuple virErrorMsgStrings[VIR_ERR_NUMBER_LAST] = {
     [VIR_ERR_NO_NWFILTER_BINDING] = {
         N_("Network filter binding not found"),
         N_("Network filter binding not found: %s") },
+    [VIR_ERR_INVALID_DOMAIN_CHECKPOINT] = {
+        N_("Invalid domain checkpoint"),
+        N_("Invalid domain checkpoint: %s") },
+    [VIR_ERR_NO_DOMAIN_CHECKPOINT] = {
+        N_("Domain checkpoint not found"),
+        N_("Domain checkpoint not found: %s") },
+    [VIR_ERR_NO_DOMAIN_BACKUP] = {
+        N_("Domain backup job id not found"),
+        N_("Domain backup job id not found: %s") },
 };