af_saverev, af_newgen, af_setbusy, af_sstate, af_svnum - version
control in AtFS
int af_saverev (Af_key *busyAso, Af_key *saveAso, int generation, int
int af_newgen (Af_key *aso, Af_key *newAso)
int af_setbusy (Af_key *busyAso, Af_key *aso, Af_key *prevAso)
int af_sstate (Af_key *aso, int state)
int af_svnum (Af_key *aso, int gen, int rev)
int af_predsucc (Af_key *inAso, int mode, Af_key *outAso)
af_saverev makes a copy of the ASO identified by busyAso. This new ASO
gets the status saved and a version number according to the following
The initial revision is numbered by generation number 1 and
revision number 0. All other saved versions get version numbers
built from these of their predecessors by preserving the
generation number and increasing the revision number by 1.
Usually, versions are added to the most recent generation. This is
indicated by giving the generation parameter AF_LASTVERS. It is also
possible to add the new version to an older generation, indicated by an
explicit generation number. In this case, the predecessor of the new
version is the most recent version of the named generation and the
version number is built accordingly.
The storeType argument says, whether the new version shall be stored as
delta (difference) to its predecessor version or completely. Valid
values are AF_STORE_DELTA (default) and AF_STORE_COMPLETE.
All attributes except version status and version number (including user
defined attributes) are inherited from the busy version. The key of
the generated ASO is returned in saveAso. Use af_dropkey to free the
allocated memory associated with saveAso.
Creating a new version in the most recent generation of a history
requires reserving the update permissions by setting a lock on the most
recent version (see af_lock(3)). For adding a new version to an old
generation, a version lock on the most recent version of the concerned
generation is needed. Subsequent calls of af_saverev for the same
object history each need a new lock, as the most recent version becomes
a new one with every call of af_saverev.
af_newgen opens a new generation in a object history. The last saved
version will be duplicated. This creates a new ASO, that is numbered by
a new generation number (increased by 1) and the initial revision
number (0). All other attributes remain unchanged. af_newgen requires
a lock (see af_lock(3)) set on the ASO specified by aso.
With af_setbusy an application can inform AtFS, that the data file of a
busy version (a busy versions data always sits in a UNIX file) has been
exchanged. This is usually the case, after having reinstalled an old
version to be basis for further development. The argument aso denotes
the version, from which the new contents of the busy version was taken.
busyAso points to the current busy version, if there is any. It may
also be omitted by giving a NULL pointer. af_setbusy returns prevAso
the key of the version that previously was set as origin of the busy
af_sstate sets the state of the identified ASO. Only state transitions
from one state to the next or previous state (according to the list
below) are allowed. Possible states are:
busy The version is under development and its contents may be
saved The version is saved and may be used for later backup.
The version has been submitted for publication by the developer
but still needs formal approval by a quality assurance board to
become publicly visible and accessible in the official
The version has passed the formal approval and is now
accessible to every member of the project. It is not yet
accessed and may therefore be withdrawn if necessary.
The version has been published, and is now accessed by some
members of the project.
frozen The version may be part of a system configuration that has been
released to the outside world. This means it must, under no
circumstances, be destroyed.
af_svnum sets the version number of the identified ASO to the given
generation (gen) and revision (rev) number. The version number of
source objects can only be increased - the version number of derived
objects can be set to any value. af_svnum requires a lock (see
af_lock(3)) set on the ASO specified by aso.
af_predsucc returns the predecessor or successor version of inAso. The
result is passed in the buffer outAso. The value for the mode parameter
may be one of the following
logical successor AF_LOGICAL_PRED logical predecessor
AF_PHYSICAL_SUCC physical successor AF_PHYSICAL_PRED physical
af_intro (3), af_lock(3)
Upon error, -1 is returned and af_errno is set to the corresponding
Due to limitations in the UNIX filesystem, only the creator (author) of
a derived object may save ASOs to a derived object cache.
Empty files cannot be inserted in a derived object cache.
The modes AF_LOGICAL_PRED and AF_LOGICAL_SUCC for af_predsucc are not