⟦4ed03be6f⟧

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% run this through SLiTeX with the appropriate wrapper

\f

\begin{bwslide}
\part	{ISSUES IN IMPLEMENTING A CLIENT OF THE VIRTUAL FILESTORE}

\begin{nrtc}\bf
\item	AN INTERACTIVE FTAM INITIATOR FOR UNIX

\item	DIRECTORY HANDLING
\end{nrtc}
\end{bwslide}


\f

\begin{bwslide}
\ctitle	{INITIATORS FOR FTAM}

\begin{nrtc}
\item	IN GENERAL, THREE APPROACHES

\item	THE INTERACTIVE APPROACH: USER (OR PROGRAM) EXPLICITLY INVOKES
	A PROGRAM TO REQUEST FILE SERVICES

\item	THE APPLICATIONS APPROACH: PROGRAM INVOKES OTHER SERVICES
	(e.g., DATABASE ACCESS) WHICH INVOKES FTAM

\item	THE EMBEDDED APPROACH: THE HOST KERNEL USES FTAM AS A PART OF ITS
	FILESYSTEM REPETOIRE
    \begin{nrtc}
    \item	THE USE OF FTAM IS TRANSPARENT TO USERS AND PROGRAMS
    \end{nrtc}

\item	THE EMBEDED APPROACH IS THE MOSE USEFUL, BUT ALSO THE MOST COMPLICATED
\end{nrtc}
\end{bwslide}


\f

\begin{bwslide}
\part*	{AN INTERACTIVE FTAM INITIATOR FOR UNIX}%%%\bf

\begin{nrtc}\small
\item	IMPORTANT TO DISTINGUISH BETWEEN
    \begin{nrtc}
    \item	THE USER INTERFACE: HOW THE PROGRAM INTERACTS WITH THE USER

    \item	THE FTAM INTERFACE: HOW THE PROGRAM ACCESS THE FILE SERVICE
    \end{nrtc}

\item	A ``FRIENDLY'' APPROACH WAS TAKEN FOR THE USER INTERFACE
    \begin{nrtc}
    \item	USER COMMANDS TO THE INITIATOR APPEAR TO BE UNIX COMMANDS
    \end{nrtc}

\item	SUPPORTS FTAM-3, NBS-2, NBS-9
    \begin{nrtc}
    \item	THE SAME DOCUMENT TYPES SUPPORTED BY THE RESPONDER
    \end{nrtc}

\item	ABOUT 6000 LINES OF C CODE AND 150 LINES OF PEPY CODE
\end{nrtc}
\end{bwslide}


\f

\begin{note}\em
the initiator, per se, currently runs on berkeley or at\&t unix
(although only the berkeley version has been extensively tested)

the user interface was heavily inspired by the berkeley unix ftp client
\end{note}


\f

\begin{bwslide}
\ctitle	{COMMAND LOOP}

\begin{nrtc}
\item	ONCE INVOKED, PROGRAM PROMPTS AND ACCEPTS COMMANDS

\item	SOME COMMANDS RESULT IN FILE SERVICE ACTIONS
    \begin{nrtc}
    \item	e.g., ASSOCIATE WITH FILESTORE

    \item	UNEXPECTED DIAGNOSTICS ARE REPORTED TO THE USER
    \end{nrtc}

\item	OTHER COMMANDS SET OPTIONS CONTROLLING USE OF FILE SERVICE

\item	OTHER COMMANDS SET OPTIONS CONTROLLING LOCAL SYSTEM
\end{nrtc}
\end{bwslide}


\f

\begin{bwslide}
\ctitle	{FILESTORE ASSOCIATION COMMANDS}

\begin{nrtc}
\item	OPEN host user [account]
    \begin{nrtc}
    \item	PROMPTS FOR A PASSWORD

    \item	ISSUES AN F-INITIALIZE.REQUEST AND AWAITS THE RESPONSE
    \end{nrtc}

\item	CLOSE
    \begin{nrtc}
    \item	TERMINATES THE ASSOCIATION WITH THE FILESTORE USING
		F-TERMINATE.REQUEST
    \end{nrtc}

\item	ABORT
    \begin{nrtc}
    \item	UPON ENCOUNTERING A FATAL ERROR, F-U-ABORT.REQUEST IS USED
    \end{nrtc}

\item	STATUS
    \begin{nrtc}
    \item	REPORTS SUMMARY OF SERVICE PARAMETERS IN EFFECT OVER FTAM
		REGIME
    \end{nrtc}
\end{nrtc}
\end{bwslide}


\f

\begin{bwslide}
\ctitle	{EXAMPLE: FILESTORE ASSOCIATION COMMANDS}\small

\begin{verbatim}
kr:22-- ftam
ftam> open gr
user (gr:mrose): mrose
password (gr:mrose): 

gr... connected
gr> status
associated with virtual filestore on "gr" as user "mrose"
service level: reliable, service class: transfer-and-management
functional units: 0x3b<READ,WRITE,LIMITED,ENHANCED,GROUPING>
attribute groups: 0x3<STORAGE,SECURITY>
document types:
  1.0.8571.6.3  unstructured binary file
  1.17.3.6.1    unstructured text file
  1.17.3.6.8    file directory file
estimated integral FADU size: 65502
\end{verbatim}
\end{bwslide}


\f

\begin{bwslide}
\ctitle	{FILE TRANSFER COMMANDS}

\begin{nrtc}
\item	GET source destination
    \begin{nrtc}
    \item	RETREIVES A FILE FROM THE FILESTORE

    \item	FILE SERVICES
	\begin{nrtc}
	\item	F-BEGIN-GROUP F-SELECT F-OPEN(READ) F-END-GROUP

	\item	BULK DATA TRANSFER FOR READ

	\item	F-BEGIN-GROUP F-CLOSE F-DESELECT F-END-GROUP
	\end{nrtc}
    \end{nrtc}

\item	PUT source destination
    \begin{nrtc}
    \item	STORES A FILE ON THE FILESTORE

    \item	FILE SERVICES
	\begin{nrtc}
	\item	F-BEGIN-GROUP F-CREATE(OVERWRITE) F-OPEN(WRITE) F-END-GROUP

	\item	BULK DATA TRANSFER FOR WRITE

	\item	F-BEGIN-GROUP F-CLOSE F-DESELECT F-END-GROUP
	\end{nrtc}

    \item	OPTION SETTING DETERMINES OVERWRITE MODE
    \end{nrtc}
\end{nrtc}
\end{bwslide}


\f

\begin{note}\em
need to exercise a fair bit of caution in ordering of local file access for
the get command: 

\begin{quote}
ideally don't want to open file for write until remote open
has succeeded; but if local open fails, still have to do a little bit of bulk
data-transfer before backing out.
\end{quote}
\end{note}


\f

\begin{bwslide}
\ctitle	{FILE TRANSFER COMMANDS (cont.)}

\begin{nrtc}
\item	APPEND source destination
    \begin{nrtc}
    \item	APPENDS TO A FILE IN THE FILESTORE

    \item	FILE SERVICES: AS ABOVE, BUT F-CREATE(EXISTING)
    \end{nrtc}

\item	OPTION SETTING DETERMINES EITHER TEXT OR BINARY
	(BUT RESPONSE FROM SERVER OVERRIDES THIS)

\item	INTERRUPT FROM USER DURING TRANFSER INVOKES F-CANCEL SERVICE
\end{nrtc}
\end{bwslide}


\f

\begin{bwslide}
\ctitle	{EXAMPLE: FILE TRANSFER COMMANDS}\small

\begin{verbatim}
gr> set type text
type       = text       - file transfer mode
gr> get manual.dvi manual.dvi
ftam: unstructured binary file transfer
ftam: 613628 bytes received in 10.33 seconds (58.00 Kbytes/s)
gr> get calendar calendar
ftam: 2051 bytes received in 0.13 seconds (15.06 Kbytes/s)
gr> ls
file: .
.               ..              .Xdefaults      .mh_profile     bin        
calendar        lib             manual.dvi      libisode.a      mhbox
gr> get libisode.a libisode.a
ftam: unstructured binary file transfer
^C
ftam: cancelling transfer
ftam: 196506 bytes received in 5.48 seconds (35.00 Kbytes/s)
\end{verbatim}
\end{bwslide}


\f

\begin{note}\em
this is a good example of document type simplification:

manual.dvi was not available as a text file,
hence the responder in the open request returned a simplification of the
document type requested
\end{note}


\f

\begin{bwslide}
\ctitle	{FILE MANAGEMENT COMMANDS}

\begin{nrtc}
\item	MV source destination
    \begin{nrtc}
    \item	CHANGES THE NAME OF A FILE

    \item	FILE SERVICES
	\begin{nrtc}
	\item	F-BEGIN-GROUP F-SELECT F-CHANGE-ATTRIBUTE F-DESELECT
		F-END-GROUP
	\end{nrtc}
    \end{nrtc}

\item	RM file
    \begin{nrtc}
    \item	DELETES A FILE

    \item	FILE SERVICES
	\begin{nrtc}
	\item	F-BEGIN-GROUP F-SELECT F-DELETE F-END-GROUP
	\end{nrtc}
    \end{nrtc}
\end{nrtc}
\end{bwslide}


\f

\begin{bwslide}
\ctitle	{FILE MANAGEMENT COMMANDS (cont.)}

\begin{nrtc}
\item	LS file
    \begin{nrtc}
    \item	LISTS THE ATTRIBUTES OF A FILE (USE DIR FOR LONG LISTING)

    \item	FILE SERVICES
	\begin{nrtc}
	\item	F-BEGIN-GROUP F-SELECT F-READ-ATTRIBUTE F-DESELECT F-END-GROUP
	\end{nrtc}

    \item	THE (APPROPRIATE) FTAM ATTRIBUTES ARE DISPLAYED AS UNIX
		ATTRIBUTES
    \end{nrtc}
\end{nrtc}
\end{bwslide}


\f

\begin{bwslide}
\ctitle	{EXAMPLE: FILE MANAGEMENT COMMANDS}\small

\begin{verbatim}
gr> mv calendar oldcalendar
gr> rm manual.dvi
gr> ls .
.               ..              .Xdefaults      .mh_profile     bin
lib             libisode.a      mhbox           oldcalendar
gr> mv oldcalendar calendar
gr> ls .
.               ..              .Xdefaults      .mh_profile     bin
calendar        lib             libisode.a      mhbox
\end{verbatim}
\end{bwslide}


\f

\begin{bwslide}
\ctitle	{EXAMPLE: FILE MANAGEMENT COMMANDS (cont.)}\small

\begin{verbatim}
gr> dir .
d mrose    csl          1536 Jun  2 23:25 .
d root     wheel         512 May 29 21:50 ..
t mrose    csl           563 May 27 13:09 .Xdefaults
t mrose    csl          1968 Apr 29 09:49 .mh_profile
d mrose    csl          1536 May 29 21:58 bin
t mrose    csl          2051 Jun  2 18:23 calendar
d mrose    csl           512 May  4 19:13 lib
b mrose    csl        691798 Jun  2 23:23 libisode.a
d mrose    csl          1024 Jun  2 17:43 mhbox
\end{verbatim}
\end{bwslide}


\f

\begin{bwslide}
\ctitle	{WHAT THE RESPONDER PROVIDES}\small

\begin{verbatim}
read F-READ-ATTRIB-response, context 1
{
   {
      action-result success,
      attributes {
         { filename { "." } },
         { contents-type { document-type-name 1.17.3.6.8 } },
         { storage-account "csl" },
         { date-and-time-of-creation { actual-values "19870603062745Z" } },
         { date-and-time-of-last-modification
             { actual-values "19870603062745Z" }
         },
         { date-and-time-of-last-read-access
             { actual-values "19870603062743Z" }
         },
         { date-and-time-of-last-attribute-modification
             { actual-values "19870603062745Z" }
         },
         { identity-of-creator { actual-values "mrose" } },
         { identity-of-last-modifier { actual-values "mrose" } },
\end{verbatim}
\end{bwslide}


\f

\begin{bwslide}\small
\begin{verbatim}
         { identity-of-last-reader { no-value-available "" } },
         { identity-of-last-attribute-modifier
             { no-value-available "mrose" }
         },
         { file-availability { actual-values immediate-availability } },
         {
            permitted-actions {
               actual-values { read, insert, replace, extend, erase,
                               read-attribute, change-attribute } }
         },
         { filesize { actual-values 1536 } },
         { future-filesize { no-value-available "" } },
         { encryption-name { no-value-available "" } },
         { legal-qualification { no-value-available "" } }
      }
   }
}
\end{verbatim}
\end{bwslide}


\f

\begin{bwslide}
\ctitle	{LOCAL ENVIRONMENT COMMANDS (AND MISCELLANY)}

\begin{nrtc}
\item	LCD [file]
    \begin{nrtc}
    \item	CHANGES THE WORKING DIRECTORY ON THE LOCAL SYSTEM
    \end{nrtc}

\item	HELP [command]

\item	SET [variable [value]]
\end{nrtc}
\end{bwslide}


\f

\begin{note}\em
also need protocol exception reporting and tracing

for debugging complete stacks
(and resolving episodes of finger-pointing)

good facilities for reporting exceptions and tracing protocol actions
are invaluable
\end{note}


\f

\begin{bwslide}
\part*	{DIRECTORY HANDLING}\bf

\begin{nrtc}
\item	WHAT ARE WE MISSING?

\item	SOME KIND OF RUDIMENTARY DIRECTORY FACILITIES

\item	WILDCARDING OF FILENAMES (GLOBBING)
\end{nrtc}
\end{bwslide}


\f

\begin{bwslide}
\ctitle	{DIRECTORY AND GLOBBING FUNCTIONS}

\begin{nrtc}
\item	CD [dir]
    \begin{nrtc}
    \item	CHANGES THE WORKING DIRECTORY ON THE VIRTUAL FILESTORE
    \end{nrtc}

\item	MKDIR dir
    \begin{nrtc}
    \item	CREATES A DIRECTORY ON THE VIRTUAL FILESTORE
    \end{nrtc}

\item	PWD
    \begin{nrtc}
    \item	PRINTS THE WORKING DIRECTORY ON THE LOCAL SYSTEM AND THE
		VIRTUAL FILESTORE
    \end{nrtc}

\item	ECHO file $\ldots$
    \begin{nrtc}
    \item	EXPANDS WILDCARD EXPRESSIONS
    \end{nrtc}

\item	PLUS: VIRTUAL FILESTORE FILENAME ARGUMENTS FOR ALL COMMANDS ARE
	GLOBBED, DEPENDING ON OPTION SETTING
\end{nrtc}
\end{bwslide}


\f

\begin{bwslide}
\ctitle	{BUT HOW TO DO THIS?}

\begin{nrtc}
\item	MKDIR IS EASY
    \begin{nrtc}
    \item	F-BEGIN F-CREATE(NBS-9) F-DESELECT F-END
    \end{nrtc}

\item	BUT CD AND GLOBBING AREN'T POSSIBLE:
    \begin{nrtc}
    \item	THE VIRTUAL FILESTORE LACKS A DIRECTORY CONCEPT
    \end{nrtc}

\item	SUPPOSITION
    \begin{nrtc}
    \item	IF WE KNOW THE RULES FOR BUILDING FILENAMES ON THE REMOTE
		SYSTEM,

    \item	THEN WE CAN EMULATE THIS CONCEPT IN THE INITIATOR!

    \item	WE CAN ALSO MAKE THE USER INTERFACE SMARTER AS WELL
		(BY DEFAULTING MISSING ARGUMENTS)
    \end{nrtc}
\end{nrtc}
\end{bwslide}


\f

\begin{bwslide}
\ctitle	{APPROACH}

\begin{nrtc}
\item	LET THE ``REALSTORE'' OPTION DETERMINE HOW FILENAMES ARE BUILT

\item	ON A CD COMMAND
    \begin{nrtc}
    \item	REMEMBER THE ARGUMENT

    \item	NORMALIZE FUTURE ARGUMENTS USING THIS STRING
    \end{nrtc}

\item	FOR GLOBBING
    \begin{nrtc}
    \item	BASED ON THE REALSTORE, SELECT A GLOBBING ROUTINE WHICH
		IS INTEGRATED WITH FTAM

    \item	FOR THE UNIX LOCALSTORE THIS IS TRIVIAL
    \end{nrtc}
\end{nrtc}
\end{bwslide}


\f

\begin{note}\em
the globbing facility in the interactive ftam initiator is
based on routines generously supplied by u.c. berkeley
\end{note}


\f

\begin{bwslide}
\ctitle	{EXAMPLE: DIRECTORY HANDLING COMMANDS}\small

\begin{verbatim}
gr> set realstore unix
realstore  = unix       - type of remote realstore
gr> ls
bin             lib             mhbox
calendar        libisode.a      nrtc
gr> ls lib
MakeUpdEnv      ctype           icons           notes           termcap
bfly            emacs           la-template     sl-template     tex82
gr> ls lib/*tem*
lib/la-template:
Makefile        template.bbl    template.tex    text.tex        version.sh

lib/sl-template:
Makefile        figure.pic      template.tex
gr> cd lib/sl-template
gr> pwd
local directory: /f/iso/ftam2
virtual filestore directory: lib/sl-template
gr> ls
Makefile        figure.pic      template.tex
\end{verbatim}
\end{bwslide}


\f

\begin{bwslide}
\ctitle	{THE REALSTORE CONTROVERSY}

\begin{nrtc}
\item	THIS IS AN $M*N$ (RATHER THAN $M+N\/$) APPROACH
    \begin{nrtc}
    \item	THE INITIATOR ON ALL LOCAL SYSTEMS MUST POTENTIALLY KNOW ABOUT
		ALL LOCAL SYSTEMS HOSTING A VIRTUAL FILESTORE
    \end{nrtc}

\item	NEEDLESS TO SAY THIS IS CONTRARY TO THE OSI PHILOSOPHY
    \begin{nrtc}
    \item	IT'S PROBABLY WORSE THAN THE PRIVATE ATTRIBUTE GROUP IN
		THE FILESTORE
    \end{nrtc}

\item	IT'S ALSO AMAZINGLY USEFUL\\ (THE FOREWARD PROGRESS ARGUMENT)

\item	THE BEST SOLUTION, HOWEVER, WOULD BE FOR FTAM TO BE FIXED
\end{nrtc}
\end{bwslide}


\f

\begin{bwslide}
\part*	{SUMMARY}\bf

\begin{nrtc}
\item	AN INTERACTIVE FTAM CLIENT WITH REASONABLE CAPABILITIES CAN BE
	IMPLEMENTED IN A STRAIGHT-FORWARD FASHION

\item	DIRECTORY HANDLING CAN BE IMPLEMENTED, BUT AT A CONCEPTUAL COST
\end{nrtc}
\end{bwslide}
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