U.S. patent application number 13/621224 was filed with the patent office on 2013-04-25 for portable storage interface.
This patent application is currently assigned to APPLE INC.. The applicant listed for this patent is CURTIS C. GALLOWAY, Adi Masputra, Kwasi G. Mireku, John Andrew Wright. Invention is credited to CURTIS C. GALLOWAY, Adi Masputra, Kwasi G. Mireku, John Andrew Wright.
Application Number | 20130103860 13/621224 |
Document ID | / |
Family ID | 44278330 |
Filed Date | 2013-04-25 |
United States Patent
Application |
20130103860 |
Kind Code |
A1 |
GALLOWAY; CURTIS C. ; et
al. |
April 25, 2013 |
PORTABLE STORAGE INTERFACE
Abstract
A method and apparatus of a portable storage device that
provides a tethering and portable storage service to a host is
described. In an exemplary method, the portable storage device
configures a tethering and a portable storage service interface for
the host. The portable storage device provides the tethering
service to a network for the host through the tethering interface.
In addition, the portable storage device shares files stored on the
portable storage device through the portable storage interface.
Inventors: |
GALLOWAY; CURTIS C.; (Santa
Cruz, CA) ; Wright; John Andrew; (San Francisco,
CA) ; Masputra; Adi; (San Jose, CA) ; Mireku;
Kwasi G.; (San Jose, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GALLOWAY; CURTIS C.
Wright; John Andrew
Masputra; Adi
Mireku; Kwasi G. |
Santa Cruz
San Francisco
San Jose
San Jose |
CA
CA
CA
CA |
US
US
US
US |
|
|
Assignee: |
APPLE INC.
CUPERTINO
CA
|
Family ID: |
44278330 |
Appl. No.: |
13/621224 |
Filed: |
September 15, 2012 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
12895477 |
Sep 30, 2010 |
8307134 |
|
|
13621224 |
|
|
|
|
61295660 |
Jan 15, 2010 |
|
|
|
Current U.S.
Class: |
710/13 |
Current CPC
Class: |
G06F 16/10 20190101;
G06F 21/74 20130101; H04W 4/50 20180201; G06F 21/6218 20130101;
H04L 63/101 20130101; G06F 9/4411 20130101; G06F 16/176 20190101;
G06F 21/78 20130101; G06F 21/629 20130101; G06F 13/385
20130101 |
Class at
Publication: |
710/13 |
International
Class: |
G06F 9/44 20060101
G06F009/44 |
Claims
1.-15. (canceled)
16. A computerized method, comprising: configuring a portable
storage device to enable a tethering interface, a portable storage
interface and a link interface; detecting a host device via a
wireless link that corresponds to the link interface; configuring
the tethering interface to allow the host device to access a
network coupled to the portable storage device; configuring the
portable storage interface to share data between the host device
and the portable storage device; and transmitting data between the
host device and the portable storage device, including:
communicating data between the host device and the network through
the tethering interface; and sharing files stored on the portable
storage device with the host device through the portable storage
interface.
17. The computerized method of claim 16, wherein the wireless link
is selected from a group consisting of a BLUETOOTH link and a WIFI
link.
18. The computerized method of claim 16, wherein both the tethering
interface and the portable storage interface are Ethernet
interfaces.
19. The computerized method of claim 16, wherein the network is a
cellular network.
20. The computerized method of claim 16, further comprising
transmitting to the host device an advertisement that includes an
identifier of the portable storage device.
21. The computerized method of claim 16, further comprising
assigning an address to the host device.
22. A non-transitory machine-readable medium storing executable
instructions to cause one or more processing units to perform a
method, the method comprising: configuring a portable storage
device to enable a tethering interface, a portable storage
interface and a link interface; detecting a host device via a
wireless link that corresponds to the link interface; configuring
the tethering interface to allow the host device to access a
network coupled to the portable storage device; configuring the
portable storage interface to share data between the host device
and the portable storage device; and transmitting data between the
host device and the portable storage device, including:
communicating data between the host device and the network through
the tethering interface; and sharing files stored on the portable
storage device with the host device through the portable storage
interface.
23. The non-transitory machine-readable medium of claim 22, wherein
the wireless link is selected from a group consisting of a
BLUETOOTH link and a WIFI link.
24. The non-transitory machine-readable medium of claim 22, wherein
both the tethering interface and the portable storage interface are
Ethernet interfaces.
25. The non-transitory machine-readable medium of claim 22, wherein
the network is a cellular network.
26. The non-transitory machine-readable medium of claim 22, further
comprising transmitting to the host device an advertisement that
includes an identifier of the portable storage device.
27. The non-transitory machine-readable medium of claim 22, further
comprising assigning an address to the host device.
28. A system, comprising: a host device; and a portable storage
device that includes a tethering interface, a portable storage
interface and a link interface, wherein the portable storage device
is configured to: enable the tethering interface, the portable
storage interface and the link interface; detect the host device
via a wireless link that corresponds to the link interface;
configure the tethering interface to allow the host device to
access a network coupled to the portable storage device; configure
the portable storage interface to share data between the host
device and the portable storage device; and transmit data between
the host device and the portable storage device, including:
communicating data between the host device and the network through
the tethering interface; and sharing files stored on the portable
storage device with the host device through the portable storage
interface.
29. The system of claim 28, wherein the wireless link is selected
from a group consisting of a BLUETOOTH link and a WIFI link.
30. The system of claim 28, wherein both the tethering interface
and the portable storage interface are Ethernet interfaces.
31. The system of claim 28, wherein the network is a cellular
network.
32. The system of claim 28, wherein the portable storage device is
further configured to transmit to the host device an advertisement
that includes an identifier of the portable storage device.
33. The system of claim 28, wherein the portable storage device is
further configured to assign an address to the host device.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is a continuation of and takes
priority under 35 U.S.C. .sctn.120 to pending U.S. application Ser.
No. 13/460,685, entitled "MULTIPLE COMMUNICATION INTERFACES ON A
PORTABLE STORAGE DEVICE" by Curtis C. Galloway et al. and filed
Sep. 30, 2010, which claims the benefit of U.S. Provisional
Application No. 61/295,660, entitled "PORTABLE STORAGE INTERFACE"
by Curtis C. Galloway et al. and filed Jan. 15, 2010.
FIELD OF THE INVENTION
[0002] This invention relates generally to coupling devices and
more particularly to creating a storage interface between a
portable storage device and host.
BACKGROUND OF THE INVENTION
[0003] A portable storage device, such as a portable music player,
smartphone, etc., can be connected with a host, such as a personal
computer or laptop over a universal serial bus (USB) link. When
these two devices are connected, information between the host and
the portable storage device can be communicated using a
vendor-specific packet-oriented multiplexing protocol. For example,
multimedia files, applications, contact information, etc. can be
transferred between the two devices.
[0004] In one scenario, the host and portable storage device can
multiplex USB and transmission control protocol (TCP)/Internet
protocol (IP) communications over the USB link coupling the two
devices. In this scenario, a network interface is configured on the
USB link to enable TCP/IP-type communication over the USB link.
This network interface can be used to communicate TCP/IP packets on
this link. By enabling the TCP/IP-type communication, a disruption
in the link can be gracefully handled. For example, an application
on each of the host and the portable storage can establish a TCP
session between these two applications, which is used to
communicate data between the two applications. The TCP stack
notifies the applications if there is a disconnection in the
session, presumably caused by a disconnection in the underlying USB
link. The host and portable device applications can use the
notifications to gracefully recover from the communication
disruption.
SUMMARY OF THE DESCRIPTION
[0005] A method and apparatus of a portable storage device that
provides a tethering and portable storage service to a host is
described. In an exemplary method, the portable storage device
configures a tethering and a portable storage service interface for
the host. The portable storage device provides the tethering
service to a network for the host through the tethering interface.
In addition, the portable storage device shares files stored on the
portable storage device through the portable storage interface.
[0006] In one embodiment, a portable storage device is configured
to enable a tethering interface and a portable storage interface on
a link interface. In response to detecting a host coupled to that
link, the method configures the tethering interface to allow the
host access to a network and configures the portable storage
interface to share files between the host and the portable storage
device. The method further communicates data between the host and
the network with the tethering interface and shares files stored on
the portable storage device with the host through the portable
storage interface.
[0007] In another embodiment, the portable storage device retrieves
a list of a plurality of applications resident on the portable
storage device, where each of the plurality of applications has a
private filesystem of files. For the each of the plurality of
applications, the portable storage device determines if that
application will share its private filesystem to a shared
filesystem of the portable storage device. The portable storage
device further adds to the shared filesystem a link to the private
filesystem of that application if the private filesystem is
shareable. In addition, the portable storage device advertises the
shared filesystem of the portable storage device to a host that is
coupled to the portable storage device.
[0008] In a further embodiment, the portable storage device
receives a request to access the shared filesystem from the host,
where the shared filesystem includes files that correspond to a
plurality of applications on the portable storage device and a
security policy that disallows one of the plurality of applications
from accessing a file in the shared filesystem that corresponds to
another one or many of the plurality of applications. In addition,
the portable storage device fulfills that request.
[0009] In another embodiment, the host transmits a request to
access the shared filesystem from the host, where the shared
filesystem includes files that correspond to a plurality of
applications on the portable storage device and a security policy
that disallows one of the plurality of applications from accessing
a file in the shared filesystem that corresponds to another one or
many of the plurality of applications. In addition, the host
receives an indication of the result of the request.
[0010] In one embodiment, the host receives an advertisement from a
portable storage service that a shared filesystem is available for
use. The host determines if the portable storage device
corresponding to the advertised portable storage services is known
to the host. If the portable storage device is known to the host,
the host receives an internet protocol (IP) address to configure a
portable storage interface on the host. Once this interface is
configured, the host transmits a request to the portable storage
service to mount a shared filesystem of the portable storage
service for the host. The host receives a notification that the
shared filesystem is mounted and applications resident on the host
can access the files in the shared filesystem.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present invention is illustrated by way of example and
not limitation in the figures of the accompanying drawings in which
like references indicate similar elements.
[0012] FIG. 1 is a block diagram of one embodiment of a portable
storage device that couples to a host and can provide a tether and
a portable storage service for the host.
[0013] FIG. 2 is a block diagram of one embodiment of a connection
between the portable storage device and the host.
[0014] FIG. 3 is a block diagram of one embodiment of system
components that utilize the portable storage device--host
connection.
[0015] FIG. 4 is a block diagram of one embodiment of a portable
storage service on the portable storage device.
[0016] FIG. 5 is a block diagram of one embodiment of a shared
filesystem in the portable storage device.
[0017] FIG. 6 is a flow diagram of one embodiment of a process to
create a dual Ethernet channel connection between the portable
storage device and the host.
[0018] FIG. 7 is a flow diagram of one embodiment of a process to
build the shared filesystem on the portable storage device.
[0019] FIG. 8 is a flow diagram of one embodiment of a process to
configure the host so as to be able to access the shared filesystem
on the portable storage device.
[0020] FIG. 9 is a flow diagram of one embodiment of a process to
respond to access request for the shared filesystem on the portable
storage device.
[0021] FIG. 10 is a flow diagram of one embodiment of a process to
access the shared filesystem of the portable storage device.
[0022] FIG. 11 is a block diagram of a portable storage
configuration module that creates the dual Ethernet channel
connection between the portable storage device and the host.
[0023] FIG. 12 is a block diagram of a launch portable service
module that creates the shareable filesystem on the portable
storage device.
[0024] FIG. 13 is a block diagram of a host configuration module
that configures the host to be able to access the shared filesystem
on the portable storage device.
[0025] FIG. 14A is a block diagram of a file server module that
handles accesses to the shared filesystem on the portable storage
device.
[0026] FIG. 14B is a block diagram of a file server module that
makes accesses requests to the shared filesystem on the portable
storage device.
[0027] FIG. 15 illustrates one example of a typical computer system
which may be used in conjunction with the embodiments described
herein.
[0028] FIG. 16 shows an example of a data processing system which
may be used with one embodiment of the present invention.
DETAILED DESCRIPTION
[0029] A method and apparatus of a portable storage device that
provides a tethering and a portable storage service to a host is
described. In the following description, numerous specific details
are set forth to provide thorough explanation of embodiments of the
present invention. It will be apparent, however, to one skilled in
the art, that embodiments of the present invention may be practiced
without these specific details. In other instances, well-known
components, structures, and techniques have not been shown in
detail in order not to obscure the understanding of this
description.
[0030] Reference in the specification to "one embodiment" or "an
embodiment" means that a particular feature, structure, or
characteristic described in connection with the embodiment can be
included in at least one embodiment of the invention. The
appearances of the phrase "in one embodiment" in various places in
the specification do not necessarily all refer to the same
embodiment.
[0031] The processes depicted in the figures that follow, are
performed by processing logic that comprises hardware (e.g.,
circuitry, dedicated logic, etc.), software (such as is run on a
general-purpose computer system or a dedicated machine), or a
combination of both. Although the processes are described below in
terms of some sequential operations, it should be appreciated that
some of the operations described may be performed in different
order. Moreover, some operations may be performed in parallel
rather than sequentially.
[0032] The term "host" and the term "portable storage device" are
intended to refer generally to data processing systems rather than
specifically to a particular form factor for the host versus a form
factor for the device.
[0033] A method and apparatus of a portable storage device that
provides a tethering and a portable storage service to a host is
described. In an exemplary method, the portable storage device
configures a tethering and a portable storage service interface for
the host. The portable storage device provides the tethering
service to a network for the host through the tethering interface.
In addition, the portable storage device shares files stored on the
portable storage device through the portable storage interface.
[0034] FIG. 1 is a block diagram of one embodiment of a portable
storage device 104 that couples to a host 102 and can provide
tethering for the host 102. As is known in the art, tethering is
the use of a mobile device (e.g., the portable storage device) to
supply network access for another device (e.g., the host). In FIG.
1, the portable storage device 104 couples to the host 102 via a
host-device link 106. A host 102 is one of a personal computer,
smartphone, cellular phone, music player, laptop, notebook, tablet,
personal digital assistant, netbook, palmtop computer, server, etc.
Portable storage device 104 is a mobile device capable of storing
data, such as smartphone, mobile player, cellularphone, tablet,
laptop, notebook, etc. While in one embodiment, the host-device
link 106 is a universal serial bus (USB), in alternate embodiments,
the host-device link 106 is another type of link capable of
communicating data between the host 102 and the portable storage
device 104 (Firewire, Ethernet, wireless, serial connection,
Bluetooth.RTM., etc.). For example, and in one embodiment, the host
102 is a laptop or other type of personal computer and the portable
storage device 104 is a smartphone or tablet that is coupled to the
host 102 using a USB link.
[0035] In one embodiment, the portable storage device provides two
services to the host, a tethering service 114 and a portable
storage service 112 over the host-device link 106. The tethering
service 114 provides network access to network 108 for the host 102
via the portable storage device 104. The portable storage service
112 provides access for the host 102 to files stored on the
portable storage device 104.
[0036] In one embodiment, the portable storage device 104 is
coupled to a network 108 via device-network link 110. In one
embodiment, network 108 is a wide-area-network that provides
network services to the portable storage device 104 and/or host
102. For example, and in one embodiment, network 108 is the
Internet, a cellular network (3G, etc.), or other type of wide area
network known in the art. Device-network link 110 is type of link
that corresponds to the type of network 108. For example, and in
one embodiment, device-network link 110 is a 3G wireless link,
Wi-fi wireless link, WIMAX link, etc. In one embodiment, by
coupling the portable storage device 104 to the network 108, the
portable storage device 104 can tether the host 102 via the
tethering service 114 to the network 108 in order to provide access
to network services supported by network 108. In this embodiment,
the host-device link 106 is utilized to communicate data between
the host 102 and network 108. Setting up the host-device link 110
to tether the host 102 to the network 108 is further discussed in
FIGS. 2, 3, and 6 below.
[0037] In another embodiment, portable storage device 104 includes
file storage that is accessible by host 102 via the host-device
link 106 storage and the portable storage service 112. In this
embodiment, a fileserver is resident on the portable storage device
that can allow access to a filesystem on the portable storage
device 104.
[0038] As described above, the host-device link 106 can support
access by the host 102 to the filesystem on the portable storage
device 104 and access for host 102 to the network 108 via the
portable storage device 104. In one embodiment, two communication
channels are created on the host-device link 106 to support these
functions. FIG. 2 is a block diagram of one embodiment of a
connection 216 between the portable storage device 222 and the host
220 that supports tethering and filesystem access. In FIG. 2, host
220 comprises listener interface 202, tethering interface 224,
Ethernet over USB interface 204, and USB interface 206. Portable
storage device 222 comprises portable storage interface 212,
tethering interface 214, Ethernet over USB interface 210, and USB
interface 208. In this embodiment, the host 220 and the portable
storage device 222 are connected by a USB link that includes these
two Ethernet channels 218A-B.
[0039] In one embodiment, one of the Ethernet channels is used for
the tethering function and the other is used to provide fileserver
functionality. For example and in one embodiment, Ethernet channel
218A is used to provide the tethering service to the host 220 and
Ethernet channel 218B is used to provide fileserver access for the
host. In this embodiment, Ethernet channel 218A couples the
tethering interface 224 on the host 220 and tethering interface 214
on the portable storage device 222. In addition, Ethernet channel
218B couples file browser listener interface 202 on the host 220
and portable storage interface 212 on the portable storage device
222.
[0040] In this embodiment, internet protocol (IP) addresses are
assigned to each Ethernet interface in order to allow data to be
communicated over the each Ethernet channel. For example and in one
embodiment, an IP address is assigned to interfaces 202 and 224. In
one embodiment, other network functions interface 224 is assigned
an IP address that corresponds to Ethernet channel 218A and allows
data communicated over Ethernet channel 218A to reach network that
is tethered to portable storage device 222. For example and in one
embodiment, tethering interface 224 is assigned a public IP address
or a private address known to network 108. In another embodiment,
file browser listener interface 202 is assigned an IP address that
corresponds to Ethernet channel 218B and allows host 220 to access
a shared filesystem on portable storage device 222. For example and
in one embodiment, file browser listener interface 202 is assigned
a private IP address that is used for the shared filesystem, but
does not allow the host 220 to access other network services (e.g.,
tethering) across this interface. In one embodiment, the Ethernet
interfaces for each of the two Ethernet channels are assigned IP
addresses that are from two different networks. For example and in
one embodiment, the tethering network has addresses that allow the
host 102 to access the network 108. The file sharing network has
private addresses that are used for the file sharing between the
host 102 and portable storage device 104.
[0041] FIG. 3 is a block diagram of one embodiment of system
components that utilize the portable storage device--host
connection. In FIG. 3, the host 314 is coupled to a portable
storage device 316 with a USB link 338. In one embodiment, the host
314 is host 102 of FIG. 1 that couples with the portable storage
device 104 to access network 108 and the portable storage service
112 of the portable storage device 104. The host 314 includes a USB
interface 308, Ethernet input/output interface 344, and two
Ethernet interfaces 306A-B in kernel space 312 and a set of
components in user space 310. In one embodiment, Ethernet
input/output 344 is an Ethernet over USB interface, such as
Ethernet over USB interface 204 as described in FIG. 2 above. The
individual Ethernet interfaces 306A-B are defined on top of
Ethernet input/output 344. In one embodiment, this set of
components includes a tether component 302, listener 304, and host
file browser 340. The tether component 302 uses Ethernet interface
eth1 306A to tether with the portable storage device 316 as
described above in FIGS. 1 and 2. Listener 304 listens for
filesystem advertisements. If the listener 304 receives a
filesystem advertisement, listener 306 mounts the filesystem as a
shared volume on host 314. For example and in one embodiment,
listener 304 listens for a new filesystem that is mounted and
shared on the portable storage device 316. File browser 340 makes
requests to the shared filesystem on the portable storage device
316. In one embodiment, user space is a memory and operating mode
where user programs and applications run, e.g. a word processing
application. Kernel space is where the operating system itself and
device drivers run, which has full privileges to access the
hardware.
[0042] The portable storage device 316 includes a USB interface
318, the Ethernet input/output 320, and two Ethernet interfaces
322A-B in kernel space 334 and a set of components in user space
336. In one embodiment, Ethernet input/output 320 is an Ethernet
over USB interface, such as Ethernet over USB interface 210 as
described in FIG. 2 above. The individual Ethernet interfaces
322A-B are defined on top of Ethernet input/output 320. In one
embodiment, the portable storage device 316 is a device that
provides tethering and portable storage services to the host 314.
In one embodiment, the set of components on the portable storage
device 316 include tether 326, network file server 328, a set of
applications 332, and a configuration process, configd, 330. Tether
component 326 uses the Ethernet eth0 interface 322A to provide
tethering services to the host 314. In one embodiment, network file
server 332 builds and exports the shared filesystem for the
portable storage device 316 that is used by the host 314. Network
file server 328 builds the filesystem by determining which of the
applications will share the files in the private filesystem of
those applications 332 and adds links to each of those shared
private filesystems. In this embodiment, each application resident
on the portable storage device 316 has its own private filesystem
that is not shared with other applications on the portable storage
device 316. Further discussion of how the network file server 328
builds and exports the shared filesystem is in FIGS. 4 and 5
below.
[0043] The portable storage device 316 further includes a set of
USB configuration files 340 and an Ethernet configuration file 324.
In one embodiment, the different USB configuration files are used
for different configurations of the USB link. For example and in
one embodiment, there is a configuration for the USB having two
Ethernet channel on the USB link (e.g., tethering and file serving
Ethernet channel), one Ethernet channel on the USB link (e.g.
tethering or file serving Ethernet channel), and no Ethernet
channels (e.g., USB link configured to have USB capability as known
in the art). In one embodiment, the USB configuration is chosen
based on the model of the portable storage device (e.g. media
player, smartphone, etc), and the services running on the device.
For example and in one embodiment, when tethering is turned on
through preferences on the device, then the portable device
operating system will select the USB configuration that includes
the tethering interface. In one embodiment, the Ethernet
configuration file is used to attach a property to each of the
Ethernet interfaces 322A and 332B to indicate which one of the
interfaces 3222A-B is the tethering interface and which is the
portable storage interface. This property is then examined by the
configd 330 so that it can attach the portable storage user space
daemon to the correct Ethernet interface.
[0044] In one embodiment, the user space configuration daemon
configd 330 configures the Network file server based on the USB
configuration files used to configure the USB link. In one
embodiment, configd 330 configures and starts the Network file
server 328 upon coupling of the portable storage device 316 to the
host 314. In an alternate embodiment, configd 330 configures and
starts the Network file server upon the portable storage device 316
booting up. In a further embodiment, configd 330 configures and
starts the Network file server if the USB link is configured (or to
be configured) with an Ethernet channel that is used for file
serving.
[0045] As described above, the portable storage device can include
a portable storage service resident on the portable storage device.
In one embodiment, the portable storage service is a network file
server and the shared filesystem used by the portable storage
service is constructed from the private file systems of
applications resident on the portable storage device. FIG. 4 is a
block diagram of one embodiment of a portable storage service 400
on the portable storage device. In FIG. 4, the portable storage
service 400 includes network file server 402 and a shared
filesystem that is coupled to applications 404A-N, application
private storage 406A-N, application sandboxes 410A-N, and a host
application 412 that can access the shared filesystem 408. An
application 404A-N can be any type of application known in the art
that can be run on a computer or portable storage device (e.g.,
e-mail, web browsing, multimedia use/manipulation, note taking,
work processing, spreadsheet, etc.). In one embodiment, an
application private storage 406A-N includes files that are used by
the application, such as user-created documents, library files,
object files, executables, configuration files, cached data,
database files, images displayed by the application etc. In one
embodiment, each application 404A-N and corresponding private
storage 406A-N is enclosed within an application sandbox 410A-N
that prevents an application from accessing files created by
another application. For example and in one embodiment, application
404A access files in application private storage 406A, but cannot
access files in another application private storage 406B-N.
[0046] In one embodiment, the network file server 402 constructs
the shared filesystem 408 from the applications 404A-N and the
corresponding application private storage 406A-N. In one
embodiment, for each application 404A-N that allows access to the
corresponding private storage 406A-N, the network file server 402
adds a link to the shared filesystem 408 for that accessible
private storage. For example and in one embodiment, the network
file server 402 links to the application private storage 406A-N for
each application 404A-N that participates in the portable storage
service 400. This added link can allow access to a part or all of
the application's private storage 406A-N. In one embodiment, the
added link allows access to user-created files in the application
private storage. For example and in one embodiment, a note-taking
application on the portable storage device creates and stores user
created notes in files in the private storage for that note-taking
application. If the note-taking application is configured to share
the user created notes, network file server 402 links the shared
filesystem 408 to a directory in the note taking application
private storage that stores the user created notes. In this
embodiment, the user created notes can be accessed by the host
application 412.
[0047] Once the network file server 402 constructs the shared
filesystem 408, the network file server 402 advertises the
existence of the shared filesystem 408 to the host. In one
embodiment, portable storage service uses the Bonjour service
discovery protocol to advertise the portable storage service 400 to
the host. In this embodiment, the host receives the advertisements
and sends a request to the network file server 402 to mount the
shared filesystem 408.
[0048] As described above, the shared filesystem of the portable
storage service is constructed by linking to the private storage of
applications that participate in the portable storage service. FIG.
5 is a block diagram of one embodiment of a shared filesystem 502
on the portable storage device. In FIG. 5, the shared filesystem
502 links to application private filesystems 506A-N. Each of the
links 504A-N is used to construct the shared filesystem 502. In one
embodiment, the network file server 502 advertises this shared
filesystem 502 to the host coupled to the client.
[0049] In one embodiment, the network file server 502 links to part
of an application private filesystem 506A. In this embodiment, the
application private filesystem 506A includes shared files 510A,
library files 510B, configuration files 510C, and other non-shared
files 510D. In one embodiment, the shared files 510A are
user-created files that have been created using the corresponding
application on the client. Alternatively, these user-created files
were created on another device (e.g., the host or some other
device, etc.) and downloaded via the shared filesystem 502 to the
shared files 510A portion of the application private filesystem
506A. In one embodiment, the shared files 510A is a directory in
the application private filesystem 506A. By linking to the shared
files 510A, a host can access the files in the shared files 510A
via the shared volume 508.
[0050] In one embodiment, an application 514 on the host can access
files on the client via the shared filesystem 502. In this
embodiment, the application 514 can perform any of the operations
on these files that are known in the art (e.g., reading from,
writing to, listing file characteristics, creating, deleting,
etc.). In another embodiment, some of the file operations are
restricted as known in the art (e.g., able to read the file, but
not write to the file, etc.). In another embodiment, a host
application of a different type can perform file operations on one
of the shared file associated with a different type of application.
For example and in one embodiment, a word processing application on
the host could access files through the shared filesystem 502 that
are associated with a note-taking application resident on the
client. In addition, in one embodiment, a word processing
application resident on the client that is the same as the one on
the host would not be able to access those files because of the
security sandbox that envelops each of the applications resident on
the client. In another embodiment, the one type of application on
the host can access application files 506A-N on the client
associated with the same type of client. For example and in one
embodiment, a note-taking application on the host could access
files through the shared filesystem 502 that are associated with a
note-taking application resident on the client. In one embodiment,
the same type of application can mean two applications the same
type of functionality on the host and client, but these programs
are specialized for one or both devices. For example and in one
embodiment, a photo processing application on the host can access
files of a specialized version of that photo processing program
that is resident on the client.
[0051] FIG. 6 is a flow diagram of one embodiment of a process 600
to create a dual Ethernet channel connection between the portable
storage device and the host. In FIG. 6, process 600 enables
portable storage on the portable storage device at block 602. In
one embodiment, a configuration variable is set to "true." At block
604, process 600 publishes a portable storage key that signals to
the configuration daemon that the storage server is enabled. In one
embodiment, when the portable storage device boots up, process 600
inspects that configuration variable and publishes the key.
[0052] Process 600 configures the portable storage Ethernet
interface at block 606. In one embodiment, process 600 changes the
portable storage device's USB configuration to include an Ethernet
profile. In this embodiment, including the Ethernet profile in the
USB configuration allows the USB interface to be configured with
Ethernet running on top of the USB link as described with reference
to FIGS. 1 and 2 above. In one embodiment, the Ethernet interface
is not quite up and running, but will come up when until the host
couples with the portable storage device.
[0053] At block 608, process 600 detects that the portable storage
device 608 is coupled to the host. In one embodiment, process 600
detects the coupling by detecting a physical USB connection being
made to the USB interface of the portable storage device. In
another embodiment, the host detects that the device has joined the
local area network by receiving network packets over WiFi or
Ethernet interfaces.
[0054] Process 600 determines if tethering is enabled at block 610.
In one embodiment, process 600 determines if tethering is enabled
by querying a configuration parameter or key for tethering. If
tethering is not enabled, execution proceeds to block 614. If
tethering is enabled, process 600 configures the Ethernet interface
for tethering to the host on the USB link at block 612. In one
embodiment, process 600 brings this interface up and assigns an IP
address suitable to support the tethering functionality. In one
embodiment, process 600 receives an IP address and other
configuration information (nameserver address, gateway, etc.) from
a network that is being used for the tethering and assigns this IP
address to the tethering Ethernet interface. Execution proceeds to
block 614.
[0055] At block 614, process 600 configures an Ethernet interface
for the portable storage service. In one embodiment, assigns a
private IP address that is to be used on a private network between
the portable storage device and the host for file sharing. For
example and in one embodiment, process 600 assigns an IP address of
192.168.20.1.
[0056] Process 600 launches the portable storage server at block
616. In one embodiment, process 600 creates a file that signals the
network file server to start. When this file exists, the portable
storage Ethernet interface is up and available to use. In addition,
process 600 launches the network file server and turns on the
Dynamic Host Configuration Protocol (DHCP) server on the portable
storage device. In one embodiment, this DHCP server is used to
assign a private IP address to the host Ethernet interface used for
the file serving as described in FIG. 2 above. In addition, process
600 advertises the portable storage service. In one embodiment, the
portable storage service is the shared filesystem served by the
network file server as described above with reference to FIG. 4
above. In one embodiment, process 600 advertises the portable
storage service with a service discovery protocol known in the art
(e.g., Bonjour, Zeroconf, universal plug and play (UPnP),
etc.).
[0057] Furthermore, process 600 builds the sharable filesystem used
by the network file server at block 616. In one embodiment, for
each application resident on the portable storage device that wants
to opt-in to the portable storage service, the network file server
creates a link to the shared files for that application. Building
of the shared filesystem is further described in FIG. 7 below.
[0058] At block 618, process 600 mounts the shared filesystem so
that the host can in turn mount the shared filesystem on the host.
In one embodiment, an SMB client on the host mounts one volume from
a shared volume on each portable storage device coupled to the
host. In one embodiment, upon the host coupling with the portable
storage device, process 600 communicates the data associated with
the tethering and portable storage service over the USB link and
corresponding Ethernet channels with the host at block 620.
[0059] As described above, the process 600 builds a shared
filesystem for the portable storage service. FIG. 7 is a flow
diagram of one embodiment of a process 700 to build the shared
filesystem on the portable storage device. In one embodiment,
process 700 is executed by process 600 at block 616 in FIG. 6
above. In FIG. 7, process 700 retrieves the list of applications
resident on the portable storage device. In one embodiment, the
server on the portable storage device gets the list from an
application installation service built into the portable storage
device operating system. It receives information about each
application, including the flag that says whether the application
participates in portable storage service. Process 700 further
executes a processing loop (blocks 704-712) to generate a set of
links to the applications shared files. At block 706, process 700
determines if an application will shares its files. In one
embodiment, an application that shares its files adds a key to an
application configuration file to indicate the application file
sharing is turned on. In this embodiment, process 700 reads this
key that indicates this application wishes to shares that files. If
the key is present, execution proceeds to block 708. If this key is
not present, the application does not share its files and execution
proceeds to block 712.
[0060] At block 708, process 700 generates a link to the directory
of the shared files of the application. In one embodiment, the
shared files directory is a directory created when the application
sets the key indicating that its files are shareable. Process 700
adds the application storage link to the shared filesystem at block
710. The processing loop ends at block 712.
[0061] With the portable storage service started and the storage
Ethernet interface available, the host will configure itself to
take advantage of the portable storage service. FIG. 8 is flow
diagrams of one embodiment of a process 800 to configure the host
so as to be able to access the shared filesystem on the portable
storage device. In one embodiment, on the host side, a listener
executes process 800. At block 802, process 800 starts a listening
process. In one embodiment, the listening process listens for the
service discovery protocol advertisements of the portable storage
service.
[0062] Process 800 receives an advertisement of the portable
storage service at block 804. In one embodiment, the advertisement
is an advertisement using a service discovery protocol known in the
art (Bonjour, Zeroconf, etc.). In another embodiment, the
advertisement includes an identifier of the portable storage
device. For example and in one embodiment, the received
advertisement identifier is the serial number of the portable
storage device.
[0063] At block 806, process 800 determines if the portable storage
device is known to process 800. In one embodiment, process compares
the portable storage device identifier received in the
advertisement with a list of known devices. For example and in one
embodiment, process 800 determines if the portable storage device
has been paired with the host. If the portable storage device is
not known to process 800, process 800 signals a failure at block
818 For example an in one embodiment, if the portable storage
device is not paired with the host, the network interface on the
device will not be activated by configd, and no connection will be
possible from the host.
[0064] If the portable storage device is known to process 800,
process 800 waits to receive an IP address that can be used to
configure the portable storage Ethernet interface at block 808. If
process 800 does not receive an IP address, process 800 signals a
failure at block 818. However, if process 800 receives the IP
address, process 800 configures the portable storage Ethernet
interface at block 810. In one embodiment, process 800 applies the
received IP address along with other configuration information for
that interface as described above in FIG. 3 (nameserver address,
gateway, etc.).
[0065] At block 812, process 800 transmits a mount request to the
portable storage service to mount the shared filesystem on the
host. In one embodiment, process 800 sends a request using the user
name "guest" and no password. In this embodiment, no username and
password is used because portable storage device is known to the
host. Process 800 receives a notification that the shared
filesystem is mounted at block 814. At block 816, process 800
displays the shared filesystem in a file browser application
running on the host. In one embodiment, the shared filesystem is
also available to other applications running on the host.
[0066] FIG. 9 is flow diagrams of one embodiment of a process 900
to respond to an access request for the shared filesystem on the
portable storage device. In one embodiment, process 900 receives
requests from an application on the host. In this embodiment,
process 900 does not receive filesystem request from applications
on the portable storage device because the portable storage service
is made available to the host and not to applications running on
the portable storage device. In FIG. 9, at block 902, process 900
receives a filesystem access request. In one embodiment, the
filesystem request is a SMB request to access the sharable
filesystem. As is known in the art, a SMB request can be used to
open, close, read, write, lock, unlock, etc. files as well as
retrieve or set file characteristics. At block 904, process 900
fulfills the filesystem request. In one embodiment, process 900
performs a file operation (open, close, read, write, lock, unlock,
list, etc.) and returns a return code indicating success/failure to
the host and other relevant data for the request (data read,
pointer, lock, etc.).
[0067] FIG. 10 is a flow diagram of one embodiment of a process
1000 to access the shared filesystem of the portable storage
device. In FIG. 10, at block 1002, process 1000 transmits a
filesystem access request to the portable storage service. In one
embodiment, the filesystem request is a SMB request to access the
sharable filesystem. As is known in the art, a SMB request can be
used to open, close, read, write, lock, unlock, etc. files as well
as retrieve or set file characteristics. At block 1004, process
1000 receives the result of the filesystem access. In one
embodiment, process 1000 receives a return code indicating
success/failure of the operation and other relevant data for the
request (data read, pointer, lock, etc.).
[0068] FIG. 11 is a block diagram of a portable storage
configuration module 1000 that creates the dual Ethernet channel
connection between the portable storage device and the host. In one
embodiment, the portable storage configuration module 1000 is the
configd 330 of FIG. 3 above. In FIG. 11, portable storage
configuration module 1000 comprises an enable portable storage
modules 1102, publish portable storage key 1104, configure Ethernet
interface module 1106, host link detection module 1108, tethering
module 1110, portable storage Ethernet module 1112, launch portable
storage service module 1114, and communication module 1116. Enable
portable storage module 1102 enables the portable storage as
described in FIG. 6, block 602. Publish portable storage key 1104
publishes the portable storage key that enables portable storage as
described in FIG. 6, block 604. Configure Ethernet interface module
1106 configures the portable storage Ethernet interface as
described in FIG. 6, block 606. Host link detection module 1108
detects that the portable storage device is coupled to a host as
described in FIG. 6, block 608. Tethering module 1110 configures
the tethering Ethernet interface as described in FIG. 6, block 612.
Portable storage Ethernet module 1112 configures the Ethernet
interface for portable storage as described in FIG. 6, block 614.
Launch portable storage service module 1114 launches the portable
storage service as described in FIG. 6, block 616. Communication
module 1116 communicates data as described in FIG. 6, block
620.
[0069] FIG. 12 is a block diagram of launch portable storage module
1114 that launches the portable storage service on the portable
storage device. In FIG. 12, launch portable storage module 1114
includes application list module 1202, application storage module
1204, application link module 1206, and shared filesystem 1208.
Application list module 1202 retrieves the list of applications
resident on the portable storage device as described in FIG. 7,
block 702. Application storage module 1204 determines if the
application private storage is shareable as described in FIG. 7,
block 706. Application link module 1206 generates an application
storage link as described in FIG. 7, block 708. Shared filesystem
1208 adds the application storage link to the shared filesystem as
described in FIG. 7, block 710.
[0070] FIG. 13 is a block diagram of host configuration module 1300
that configures the host to be able to access the shared filesystem
on the portable storage device. In one embodiment, the host
configuration module is the host configuration component 342 as
described in FIG. 3 above. In FIG. 13, host configuration module
1300 includes start listener module 1302, receive advertisement
module 1304, check portable storage device module 1306, receive
Ethernet configuration module 1308, configuration Ethernet
interface module 1308, filesystem mount request module 1312,
receive filesystem mount module 1314, display mounted filesystem
module 1316, and signal failure module 1318. Start listener module
1302 starts the listener as described in FIG. 8, block 802. Receive
advertisement module 1304 receive the portable storage service
advertisement as described in FIG. 8, block 804. Check portable
storage device module 1306 checks the portable storage device
identifier as described in FIG. 8, block 806. Receive Ethernet
configuration module 1308 receives the Ethernet configuration for
the portable storage interface as described in FIG. 8, block 808.
Configuration Ethernet interface module 1308 as described in FIG.
8, block 810. Filesystem mount request module 1312 transmits a
filesystem mount request to the portable storage device as
described in FIG. 8, block 812. Receive filesystem mount module
1314 receives notification that the requested filesystem was
mounted as described in FIG. 8, block 814. Display mounted
filesystem module 1316 displays the shared filesystem as described
in FIG. 8, block 816. Signal failure module 1318 signals a failure
as described in FIG. 8, block 818.
[0071] FIG. 14A is a block diagram of network file server 1400 that
handles accesses to the shared filesystem on the portable storage
device. In one embodiment, network file server 1400 is the network
file server that is part of the portable storage service as
described in FIGS. 3-5 above. Network file server comprises
filesystem request receiving module 1402 and filesystem fulfillment
module 1404. Filesystem request receiving module 1402 receives
filesystem requests as described in FIG. 9, block 902. Filesystem
fulfillment module 1404 fulfills those requests as described in
FIG. 9, block 904.
[0072] FIG. 14B is a block diagram of host application 1450 that
makes accesses requests to the shared filesystem on the portable
storage device. In one embodiment, host application is a file
browsing application or other host application as described in
FIGS. 3-5 above. Host application 1450 includes filesystem request
transmission module 1452 and filesystem request notification module
1454. Filesystem request transmission module 1452 transmits a
request to access the shared filesystem of the portable storage
device as described in FIG. 10, block 1002. Filesystem request
notification module 1454 a receives a notification of a result to
the filesystem access request as described in FIG. 10, block
1002.
[0073] FIG. 15 shows one example of a data processing system 1500,
which may be used with one embodiment of the present invention. For
example, the system 1500 may be implemented including a host as
shown in FIG. 1. Note that while FIG. 15 illustrates various
components of a computer system, it is not intended to represent
any particular architecture or manner of interconnecting the
components as such details are not germane to the present
invention. It will also be appreciated that network computers and
other data processing systems or other consumer electronic devices
which have fewer components or perhaps more components may also be
used with the present invention.
[0074] As shown in FIG. 15, the computer system 1500, which is a
form of a data processing system, includes a bus 1503 which is
coupled to a microprocessor(s) 1505 and a ROM (Read Only Memory)
1507 and volatile RAM 1509 and a non-volatile memory 1511. The
microprocessor 1505 may retrieve the instructions from the memories
1507, 1509, 1511 and execute the instructions to perform operations
described above. The bus 1503 interconnects these various
components together and also interconnects these components 1505,
1507, 1509, and 1511 to a display controller and display device
1513 and to peripheral devices such as input/output (I/O) devices
which may be mice, keyboards, modems, network interfaces, printers
and other devices which are well known in the art. Typically, the
input/output devices 1515 are coupled to the system through
input/output controllers 1517. The volatile RAM (Random Access
Memory) 1509 is typically implemented as dynamic RAM (DRAM) which
requires power continually in order to refresh or maintain the data
in the memory.
[0075] The mass storage 1511 is typically a magnetic hard drive or
a magnetic optical drive or an optical drive or a DVD RAM or a
flash memory or other types of memory systems which maintain data
(e.g. large amounts of data) even after power is removed from the
system. Typically, the mass storage 1511 will also be a random
access memory although this is not required. While FIG. 15 shows
that the mass storage 1511 is a local device coupled directly to
the rest of the components in the data processing system, it will
be appreciated that the present invention may utilize a
non-volatile memory which is remote from the system, such as a
network storage device which is coupled to the data processing
system through a network interface such as a modem, an Ethernet
interface or a wireless network. The bus 1503 may include one or
more buses connected to each other through various bridges,
controllers and/or adapters as is well known in the art.
[0076] FIG. 16 shows an example of another data processing system
1600 which may be used with one embodiment of the present
invention. For example, system 1600 may be implemented as a
portable storage device as shown in FIG. 1. The data processing
system 1600 shown in FIG. 16 includes a processing system 1611,
which may be one or more microprocessors, or which may be a system
on a chip integrated circuit, and the system also includes memory
1601 for storing data and programs for execution by the processing
system. The system 1600 also includes an audio input/output
subsystem 1605 which may include a microphone and a speaker for,
for example, playing back music or providing telephone
functionality through the speaker and microphone.
[0077] A display controller and display device 1607 provide a
visual user interface for the user; this digital interface may
include a graphical user interface which is similar to that shown
on a Macintosh computer when running OS X operating system
software. The system 1600 also includes one or more wireless
transceivers 1603 to communicate with another data processing
system, such as the system 1600 of FIG. 16. A wireless transceiver
may be a WLAN transceiver, an infrared transceiver, a Bluetooth
transceiver, and/or a wireless cellular telephony transceiver. It
will be appreciated that additional components, not shown, may also
be part of the system 1600 in certain embodiments, and in certain
embodiments fewer components than shown in FIG. 16 may also be used
in a data processing system. The system 1600 further includes one
or more communications ports 1617 to communicate with another data
processing system, such as the system 1500 of FIG. 15. The
communications port may be a USB port, Firewire port, Bluetooth
interface, etc.
[0078] The data processing system 1600 also includes one or more
input devices 1613 which are provided to allow a user to provide
input to the system. These input devices may be a keypad or a
keyboard or a touch panel or a multi touch panel. The data
processing system 1600 also includes an optional input/output
device 1615 which may be a connector for a dock. It will be
appreciated that one or more buses, not shown, may be used to
interconnect the various components as is well known in the art.
The data processing system shown in FIG. 16 may be a handheld
computer or a personal digital assistant (PDA), or a cellular
telephone with PDA like functionality, or a handheld computer which
includes a cellular telephone, or a media player, such as an iPod,
or devices which combine aspects or functions of these devices,
such as a media player combined with a PDA and a cellular telephone
in one device or an embedded device or other consumer electronic
devices. In other embodiments, the data processing system 1600 may
be a network computer or an embedded processing device within
another device, or other types of data processing systems which
have fewer components or perhaps more components than that shown in
FIG. 16.
[0079] At least certain embodiments of the inventions may be part
of a digital media player, such as a portable music and/or video
media player, which may include a media processing system to
present the media, a storage device to store the media and may
further include a radio frequency (RF) transceiver (e.g., an RF
transceiver for a cellular telephone) coupled with an antenna
system and the media processing system. In certain embodiments,
media stored on a remote storage device may be transmitted to the
media player through the RF transceiver. The media may be, for
example, one or more of music or other audio, still pictures, or
motion pictures.
[0080] The portable media player may include a media selection
device, such as a click wheel input device on an iPod.RTM. or iPod
Nano.RTM. media player from Apple, Inc. of Cupertino, Calif., a
touch screen input device, pushbutton device, movable pointing
input device or other input device. The media selection device may
be used to select the media stored on the storage device and/or the
remote storage device. The portable media player may, in at least
certain embodiments, include a display device which is coupled to
the media processing system to display titles or other indicators
of media being selected through the input device and being
presented, either through a speaker or earphone(s), or on the
display device, or on both display device and a speaker or
earphone(s). Examples of a portable media player are described in
published U.S. Pat. No. 7,345,671 and U.S. published patent number
2004/0224638, both of which are incorporated herein by
reference.
[0081] Portions of what was described above may be implemented with
logic circuitry such as a dedicated logic circuit or with a
microcontroller or other form of processing core that executes
program code instructions. Thus processes taught by the discussion
above may be performed with program code such as machine-executable
instructions that cause a machine that executes these instructions
to perform certain functions. In this context, a "machine" may be a
machine that converts intermediate form (or "abstract")
instructions into processor specific instructions (e.g., an
abstract execution environment such as a "virtual machine" (e.g., a
Java Virtual Machine), an interpreter, a Common Language Runtime, a
high-level language virtual machine, etc.), and/or, electronic
circuitry disposed on a semiconductor chip (e.g., "logic circuitry"
implemented with transistors) designed to execute instructions such
as a general-purpose processor and/or a special-purpose processor.
Processes taught by the discussion above may also be performed by
(in the alternative to a machine or in combination with a machine)
electronic circuitry designed to perform the processes (or a
portion thereof) without the execution of program code.
[0082] The present invention also relates to an apparatus for
performing the operations described herein. This apparatus may be
specially constructed for the required purpose, or it may comprise
a general-purpose computer selectively activated or reconfigured by
a computer program stored in the computer. Such a computer program
may be stored in a computer readable storage medium, such as, but
is not limited to, any type of disk including floppy disks, optical
disks, CD-ROMs, and magnetic-optical disks, read-only memories
(ROMs), RAMs, EPROMs, EEPROMs, magnetic or optical cards, or any
type of media suitable for storing electronic instructions, and
each coupled to a computer system bus.
[0083] A machine readable medium includes any mechanism for storing
or transmitting information in a form readable by a machine (e.g.,
a computer). For example, a machine readable medium includes read
only memory ("ROM"); random access memory ("RAM"); magnetic disk
storage media; optical storage media; flash memory devices;
etc.
[0084] An article of manufacture may be used to store program code.
An article of manufacture that stores program code may be embodied
as, but is not limited to, one or more memories (e.g., one or more
flash memories, random access memories (static, dynamic or other)),
optical disks, CD-ROMs, DVD ROMs, EPROMs, EEPROMs, magnetic or
optical cards or other type of machine-readable media suitable for
storing electronic instructions. Program code may also be
downloaded from a remote computer (e.g., a server) to a requesting
computer (e.g., a client) by way of data signals embodied in a
propagation medium (e.g., via a communication link (e.g., a network
connection)).
[0085] The preceding detailed descriptions are presented in terms
of algorithms and symbolic representations of operations on data
bits within a computer memory. These algorithmic descriptions and
representations are the tools used by those skilled in the data
processing arts to most effectively convey the substance of their
work to others skilled in the art. An algorithm is here, and
generally, conceived to be a self-consistent sequence of operations
leading to a desired result. The operations are those requiring
physical manipulations of physical quantities. Usually, though not
necessarily, these quantities take the form of electrical or
magnetic signals capable of being stored, transferred, combined,
compared, and otherwise manipulated. It has proven convenient at
times, principally for reasons of common usage, to refer to these
signals as bits, values, elements, symbols, characters, terms,
numbers, or the like.
[0086] It should be kept in mind, however, that all of these and
similar terms are to be associated with the appropriate physical
quantities and are merely convenient labels applied to these
quantities. Unless specifically stated otherwise as apparent from
the above discussion, it is appreciated that throughout the
description, discussions utilizing terms such as "configuring,"
"communicating," "advertising," "sharing," "detecting,"
"associating," "initiating," "assigning," "receiving,"
"retrieving," "enabling," "adding," "coupling," "fulfilling,"
"transmitting," or the like, refer to the action and processes of a
computer system, or similar electronic computing device, that
manipulates and transforms data represented as physical
(electronic) quantities within the computer system's registers and
memories into other data similarly represented as physical
quantities within the computer system memories or registers or
other such information storage, transmission or display
devices.
[0087] The processes and displays presented herein are not
inherently related to any particular computer or other apparatus.
Various general-purpose systems may be used with programs in
accordance with the teachings herein, or it may prove convenient to
construct a more specialized apparatus to perform the operations
described. The required structure for a variety of these systems
will be evident from the description below. In addition, the
present invention is not described with reference to any particular
programming language. It will be appreciated that a variety of
programming languages may be used to implement the teachings of the
invention as described herein.
[0088] The foregoing discussion merely describes some exemplary
embodiments of the present invention. One skilled in the art will
readily recognize from such discussion, the accompanying drawings
and the claims that various modifications can be made without
departing from the spirit and scope of the invention.
* * * * *