The Be Book The Storage Kit The Storage Kit Index

BVolumeRoster

Derived from: none
Declared in:  be/storage/VolumeRoster.h
Library: libbe.so
Summary:  more...


The BVolumeRoster class keeps track of the volumes that are mounted in the file system hierarchy. It lets you know about volumes in two ways:

How you create your BVolumeRoster object depends on what you're going to do with it:

A single BVolumeRoster object can perform both functions: You can use it to step through the volume list at the same time that it's watching volumes.


Constructor and Destructor


BVolumeRoster()

BVolumeRoster(void)

Creates a new BVolumeRoster object. You don't have to "initialize" the object before using it (as you do with most other Storage Kit classes). You can call GetNextVolume() (or whatever) immediately after constructing.


~BVolumeRoster()

virtual ~BVolumeRoster()

Destroys the object. If this BVolumeRoster object was watching volumes, the watch is called off.


Member Functions


GetBootVolume()

status_t GetBootVolume(BVolume *boot_vol)

Initializes boot_vol to refer to the "boot volume." This is the volume that was used to boot the computer. boot_vol must be allocated before you pass it in. If the boot volume can't be found, the argument is uninitialized.

(Currently, this function looks for the volume that's mounted at /boot. The only way to fool the system into thinking that there isn't a boot volume is to rename /boot—not a smart thing to do.)

RETURN CODES


GetNextVolume() , Rewind()

status_t GetNextVolume(BVolume *volume)
void Rewind(void)

GetNextVolume() retrieves the "next" volume from the volume list and uses it to initialize the argument (which must be allocated). When the function return B_BAD_VALUE, you've reached the end of the list.

Rewind() rewinds the volume list such that the next GetNextVolume() will return the first element in the list.

RETURN CODES


StartWatching() , StopWatching() , Messenger()

status_t StartWatching(BMessenger messenger = be_app_messenger)
void StopWatching(void)
BMessenger Messenger(void) const

These functions start and stop the BVolumeRoster's volume-watching facility. (This is actually just a convenient cover for the Node Monitor.)

There are separate notifications (BMessages) for volume-mounted and volume-unmounted events. See the B_DEVICE_MOUNTED and B_DEVICE_UNMOUNTED descriptions in "The Node Monitor" section of this chapter.

RETURN CODES


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