Re: [libvirt] [RFC]: Snapshot API

Hello,     As some of you know, I've been working on a new snapshot API. This API is heavily based on DanB's earlier API proposed here: https://www.redhat.com/archives/libvir-list/2010-January/msg00626.html I've made some modifications to make it more libvirt-ish, and to add a couple of features I think it lacked.  The full documentation is below. Any comments are appreciated. /* NOTE: struct _virDomainSnapshot is a private structure, ala  * struct _virDomain.  */ typedef struct _virDomainSnapshot virDomainSnapshot; /* Take a snapshot of the current VM state */ virDomainSnapshotPtr virDomainSnapshotCreateXML(virDomainPtr domain,                                                const char *xmlDesc,                                                unsigned int flags); /* Dump the XML of a snapshot */ /* NOTE: see below for proposed XML */ char *virDomainSnapshotGetXMLDesc(virDomainSnapshotPtr snapshot,                                  unsigned int flags); /* Return the number of snapshots for this domain */ int virDomainSnapshotNum(virDomainPtr domain, unsigned int flags);

/* Get the names of all snapshots for this domain */ int virDomainListSnapshotNames(virDomainPtr domain, char **names, int nameslen,                               unsigned int flags); /* Get a handle to a named snapshot */ virDomainSnapshotPtr virDomainSnapshotLookupByName(virDomainPtr domain,                                                   const char *name,                                                   unsigned int flags); /* Set this snapshot as the current one for a domain, to be  * used next time domain is started */ int virDomainSnapshotActivate(virDomainSnapshotPtr snapshot,                              unsigned int flags);

/* Deactivate a snapshot - with no flags, the snapshot is not used anymore,  * but also not removed.  With a MERGE flag, it merges the snapshot into  * the base image.  With a DISCARD flag, it deletes the snapshot.  MERGE  * and DISCARD are mutually-exclusive.  Note that this operation can  * generally only happen when the domain is shut down, though this is  * hypervisor-specific */ typedef enum {    VIR_DOMAIN_SNAPSHOT_DEACTIVATE_MERGE,    VIR_DOMAIN_SNAPSHOT_DEACTIVATE_DISCARD, } virDomainSnapshotDeactivate; int virDomainSnapshotDeactivate(virDomainSnapshotPtr snapshot,                                unsigned int flags);

int virDomainSnapshotFree(virDomainSnapshotPtr snapshot); NOTE: During snapshot creation, *none* of the fields are required.  That is, you can call virDomainSnapshotCreateXML() with an XML of "<domainsnapshot/>". In this case, the individual driver will make up a <name> for you, the <creationdate> will be set to the current time+date, <description> will be empty, <state> will be "off", <compression> will be empty, and <parent> will be empty.  If you do want to specify some fields during virDomainSnapshotCreateXML(), note that the only ones that are settable are <name>, <description>, <compression>, and <parent>; the rest are ignored,