libvirt/src/conf/virdomainmomentobjlist.h

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/*
* virdomainmomentobjlist.h: handle a tree of moment objects
* (derived from snapshot_conf.h)
*
* Copyright (C) 2006-2019 Red Hat, Inc.
* Copyright (C) 2006-2008 Daniel P. Berrange
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
*/
#pragma once
#include "internal.h"
#include "virconftypes.h"
#include "virhash.h"
/* Filter that returns true if a given moment matches the filter flags */
typedef bool (*virDomainMomentObjListFilter)(virDomainMomentObjPtr obj,
unsigned int flags);
/* Struct that allows tracing hierarchical relationships between
* multiple virDomainMoment objects. The opaque type
* virDomainMomentObjList then maintains both a hash of these structs
* (for quick lookup by name) and a metaroot (which is the parent of
* all user-visible roots), so that all other objects always have a
* valid parent object; the tree structure is currently maintained via
* a linked list. */
struct _virDomainMomentObj {
/* Public field */
virDomainMomentDefPtr def; /* non-NULL except for metaroot */
/* Private fields, use accessors instead */
virDomainMomentObjPtr parent; /* non-NULL except for metaroot, before
virDomainMomentUpdateRelations, or
after virDomainMomentDropParent */
virDomainMomentObjPtr sibling; /* NULL if last child of parent */
size_t nchildren;
virDomainMomentObjPtr first_child; /* NULL if no children */
};
int virDomainMomentForEachChild(virDomainMomentObjPtr moment,
virHashIterator iter,
void *data);
int virDomainMomentForEachDescendant(virDomainMomentObjPtr moment,
virHashIterator iter,
void *data);
void virDomainMomentDropParent(virDomainMomentObjPtr moment);
void virDomainMomentDropChildren(virDomainMomentObjPtr moment);
void virDomainMomentMoveChildren(virDomainMomentObjPtr from,
virDomainMomentObjPtr to);
void virDomainMomentLinkParent(virDomainMomentObjListPtr moments,
virDomainMomentObjPtr moment);
virDomainMomentObjListPtr virDomainMomentObjListNew(void);
void virDomainMomentObjListFree(virDomainMomentObjListPtr moments);
virDomainMomentObjPtr virDomainMomentAssignDef(virDomainMomentObjListPtr moments,
virDomainMomentDefPtr def);
/* Various enum bits that map to public API filters. Note that the
backup: Introduce virDomainCheckpoint APIs Introduce a bunch of new public APIs related to backup checkpoints. 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. We may have a future hypervisor that can completely manage checkpoints without libvirt metadata, but the first two planned hypervisors (qemu and test) both always use libvirt for tracking metadata relations between checkpoints, so for now, I've deferred the counterpart of virDomainSnapshotHasMetadata for a separate API addition at a later date if there is ever a need for it. Note that until we allow snapshots and checkpoints to exist simultaneously on the same domain (although the actual prevention of this will be in a separate patch for the sake of an easier revert down the road), that it is not possible to branch out to create more than one checkpoint child to a given parent, although it may become possible later when we revert to a snapshot that coincides with a checkpoint. This also means that for now, the decision of which checkpoint becomes the parent of a newly created one is the only checkpoint with no child (so while there are APIs for dealing with a current snapshot, we do not need those for checkpoints). We may end up exposing a notion of a current checkpoint later, but it's easier to add stuff when proven needed than to blindly support it now and wish we hadn't exposed it. The following map shows the API relations to snapshots, with new APIs on the right: Operate on a domain object to create/redefine a child: virDomainSnapshotCreateXML virDomainCheckpointCreateXML Operate on a child object for lifetime management: virDomainSnapshotDelete virDomainCheckpointDelete virDomainSnapshotFree virDomainCheckpointFree virDomainSnapshotRef virDomainCheckpointRef Operate on a child object to learn more about it: virDomainSnapshotGetXMLDesc virDomainCheckpointGetXMLDesc virDomainSnapshotGetConnect virDomainCheckpointGetConnect virDomainSnapshotGetDomain virDomainCheckpointGetDomain virDomainSnapshotGetName virDomainCheckpiontGetName virDomainSnapshotGetParent virDomainCheckpiontGetParent virDomainSnapshotHasMetadata (deferred for later) virDomainSnapshotIsCurrent (no counterpart, see note above) Operate on a domain object to list all children: virDomainSnapshotNum (no counterparts, these are the old virDomainSnapshotListNames racy interfaces) virDomainSnapshotListAllSnapshots virDomainListAllCheckpoints Operate on a child object to list descendents: virDomainSnapshotNumChildren (no counterparts, these are the old virDomainSnapshotListChildrenNames racy interfaces) virDomainSnapshotListAllChildren virDomainCheckpointListAllChildren Operate on a domain to locate a particular child: virDomainSnapshotLookupByName virDomainCheckpointLookupByName virDomainSnapshotCurrent (no counterpart, see note above) virDomainHasCurrentSnapshot (no counterpart, old racy interface) Operate on a snapshot to roll back to earlier state: virDomainSnapshotRevert (no counterpart, instead checkpoints are used in incremental backups via XML to virDomainBackupBegin) Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2019-03-13 19:35:26 +00:00
* values of the internal bits are not the same as the public ones for
* snapshot, however, this list should be kept in sync with the public
* ones for checkpoint. */
typedef enum {
VIR_DOMAIN_MOMENT_LIST_ROOTS = (1 << 0),
VIR_DOMAIN_MOMENT_LIST_DESCENDANTS = (1 << 0),
VIR_DOMAIN_MOMENT_LIST_TOPOLOGICAL = (1 << 1),
VIR_DOMAIN_MOMENT_LIST_LEAVES = (1 << 2),
VIR_DOMAIN_MOMENT_LIST_NO_LEAVES = (1 << 3),
VIR_DOMAIN_MOMENT_LIST_METADATA = (1 << 4),
VIR_DOMAIN_MOMENT_LIST_NO_METADATA = (1 << 5),
} virDomainMomentFilters;
#define VIR_DOMAIN_MOMENT_FILTERS_METADATA \
(VIR_DOMAIN_MOMENT_LIST_METADATA | \
VIR_DOMAIN_MOMENT_LIST_NO_METADATA)
#define VIR_DOMAIN_MOMENT_FILTERS_LEAVES \
(VIR_DOMAIN_MOMENT_LIST_LEAVES | \
VIR_DOMAIN_MOMENT_LIST_NO_LEAVES)
#define VIR_DOMAIN_MOMENT_FILTERS_ALL \
(VIR_DOMAIN_MOMENT_LIST_ROOTS | \
VIR_DOMAIN_MOMENT_LIST_TOPOLOGICAL | \
VIR_DOMAIN_MOMENT_FILTERS_METADATA | \
VIR_DOMAIN_MOMENT_FILTERS_LEAVES)
int virDomainMomentObjListGetNames(virDomainMomentObjListPtr moments,
virDomainMomentObjPtr from,
char **const names,
int maxnames,
unsigned int moment_flags,
virDomainMomentObjListFilter filter,
unsigned int filter_flags);
virDomainMomentObjPtr virDomainMomentFindByName(virDomainMomentObjListPtr moments,
const char *name);
int virDomainMomentObjListSize(virDomainMomentObjListPtr moments);
virDomainMomentObjPtr virDomainMomentGetCurrent(virDomainMomentObjListPtr moments);
const char *virDomainMomentGetCurrentName(virDomainMomentObjListPtr moments);
void virDomainMomentSetCurrent(virDomainMomentObjListPtr moments,
virDomainMomentObjPtr moment);
bool virDomainMomentObjListRemove(virDomainMomentObjListPtr moments,
virDomainMomentObjPtr moment);
void virDomainMomentObjListRemoveAll(virDomainMomentObjListPtr moments);
int virDomainMomentForEach(virDomainMomentObjListPtr moments,
virHashIterator iter,
void *data);
int virDomainMomentUpdateRelations(virDomainMomentObjListPtr moments);
int virDomainMomentCheckCycles(virDomainMomentObjListPtr list,
virDomainMomentDefPtr def,
const char *domname);
virDomainMomentObjPtr virDomainMomentFindLeaf(virDomainMomentObjListPtr list);