X-Git-Url: http://git.annexia.org/?a=blobdiff_plain;f=lib%2Fdiskimage.mli;h=f16703cda8bc80cb2eb3ad3fb4563e7df082f072;hb=71536ae75dceb08e0f3c3403033fb2eb25a08883;hp=0689a6913fd7c4525f71ebf0ff9c47ae015b05d4;hpb=de49d4605c37574f38b55b400db310f368640c94;p=virt-df.git

diff --git a/lib/diskimage.mli b/lib/diskimage.mli
index 0689a69..f16703c 100644
--- a/lib/diskimage.mli
+++ b/lib/diskimage.mli
@@ -202,7 +202,7 @@ and disk_content =
     ]
 
 and partitions = {
-  parts_plugin_id : parts_plugin_id;	(** Partitioning scheme. *)
+  parts_cb : partitioner_callbacks;	(** Partitioning scheme. *)
   parts_dev : device;			(** Partitions (whole) device. *)
   parts : partition list;		(** Partitions. *)
 }
@@ -222,7 +222,7 @@ and partition_content =
     ]
 
 and filesystem = {
-  fs_plugin_id : fs_plugin_id;		(** Filesystem type. *)
+  fs_cb : filesystem_callbacks;		(** Filesystem type. *)
   fs_dev : device;			(** Device containing the filesystem. *)
   fs_blocksize : Int63.t;		(** Block size (bytes). *)
   fs_blocks_total : Int63.t;		(** Total blocks. *)
@@ -238,7 +238,7 @@ and filesystem = {
     (** A filesystem, with superblock contents. *)
 
 and pv = {
-  lvm_plugin_id : lvm_plugin_id;        (** The LVM plug-in which detected
+  pv_cb : lvm_callbacks;	        (** The LVM plug-in which detected
 					    this. *)
   pv_dev : device;			(** Device covering whole PV. *)
   pv_uuid : string;			(** UUID. *)
@@ -248,18 +248,17 @@ and lv = {
 }
     (** Physical and logical volumes as used by LVM plug-ins. *)
 
-and parts_plugin_id
-and fs_plugin_id
-and lvm_plugin_id
-  (** Opaque IDs used to refer to the plug-ins. *)
-
-val name_of_parts : parts_plugin_id -> string
-val name_of_filesystem : fs_plugin_id -> string
-val name_of_lvm : lvm_plugin_id -> string
-  (** Convert plug-in IDs to printable strings. *)
+and partitioner_callbacks
+and filesystem_callbacks
+and lvm_callbacks
 
 (** {2 Functions} *)
 
+val name_of_filesystem : filesystem -> string
+  (** [name_of_filesystem fs] returns a printable name for
+      the filesystem.
+  *)
+
 (** {3 Create 'machine'} *)
 
 val open_machine : string -> (string * string) list -> machine
@@ -296,11 +295,52 @@ val scan_machine : machine -> machine
 
 (** {3 Create ownership tables} *)
 
-val create_ownership : machine -> (*ownership*)unit
+type ownership
+
+val create_ownership : machine -> ownership
   (** This creates the ownership tables (mapping disk blocks to the
-      ultimate filesystem, etc., which owns each).
+      ultimate filesystem, etc., which owns each one).
   *)
 
+type owner =
+    [ `Filesystem of filesystem
+    | `Partitions of partitions
+    | `PhysicalVolume of pv ]
+
+val get_owners_lookup : machine -> ownership -> block_device ->
+  (Int63.t -> (owner * Int63.t) list)
+  (** [get_owners_lookup machine disk] returns a specialized
+      function for looking up owners (filesystems, etc.)
+      which reside on block device [disk].
+
+      [disk] must be a block device of the machine.
+
+      The specialized lookup function that is returned
+      can be called as [lookup offset] to look up the
+      owners of byte offset [offset].
+
+      Returns a list of [(owner, owner_offset)] where [owner]
+      is the filesystem, etc., and [owner_offset] is the byte
+      offset relative to the owner.
+
+      It is common for there to be multiple owners: for example
+      in the case where a filesystem is created on a partition,
+      both the filesystem ([`Filesystem fs]) and
+      partition scheme ([`Partitions parts]) will be returned.
+
+      The specialized function is efficient.  {!create_ownership}
+      creates a tree structure which allows ownership to be determined
+      in just a few steps. *)
+
+val offset_is_free : (owner * Int63.t) list -> bool
+  (** [offset_is_free owners] tests if the offset is free (unused).
+
+      If an offset is free, then it may be discarded without
+      changing the semantics of the disk image.  In normal cases
+      this extends to the end of the current block, but blocksize
+      will differ for each owner, so what this really means is
+      tricky in practice. *)
+
 (** {2 Debugging} *)
 
 val debug : bool ref