(* ------------------- VERSION 19     16.05.86 ------------------- *)
PACKET global manager DEFINES                  (* Autor: J.Liedtke *)
 
  ALL ,
  begin password ,
  call ,
  continue channel ,
  erase ,
  exists ,
  fetch , 
  free global manager ,
  free manager ,
  global manager ,
  list ,
  manager message ,
  manager question ,
  save , 
  std manager :
 
 
LET ack                  = 0 ,
    nak                  = 1 ,
    error nak            = 2 ,
    message ack          = 3 ,
    question ack         = 4 ,
    second phase ack     = 5 ,
    false code           = 6 , 

    begin code           = 4 ,
    password code        = 9 ,
    fetch code           = 11 ,
    save code            = 12 ,
    exists code          = 13 ,
    erase code           = 14 ,
    list code            = 15 ,
    all code             = 17 ,
    free code            = 20 ,
    continue code        = 100,
 

    error pre            = ""7""13""10""5"FEHLER : " , 
    cr lf                = ""13""10"" ;

INT VAR reply , order , last order, phase number ;
 
DATASPACE VAR ds := nilspace ;
 
BOUND STRUCT (TEXT name, write pass, read pass) VAR msg ;
BOUND TEXT VAR reply msg ;
BOUND THESAURUS VAR thesaurus msg ;
 
TASK VAR order task, last order task ; 

FILE VAR list file ;
 
TEXT VAR error message buffer := "" 
        ,record 
        ,received name 
        ,create son password := "" 
        ,save file name 
        ,save write password 
        ,save read password 
        ;
 
 
PROC fetch (TEXT CONST file name) :

  fetch (file name, father)
 
ENDPROC fetch ;
 
PROC fetch (TEXT CONST file name, TASK CONST manager) :
 
  enable stop ;
  last param (file name) ;
  IF NOT exists (file name) 
    THEN call (fetch code, file name, manager)
  ELIF overwrite permitted
    THEN call (fetch code, file name, manager) ;
         forget (file name, quiet) 
  ELSE LEAVE fetch
  FI ;
  IF reply = ack 
    THEN disable stop ;
         copy (ds, file name) ; 
         forget (ds)
    ELSE forget (ds) ; 
         errorstop ("Task """ + name (manager) + """antwortet nicht mit ack")
  FI . 
 
overwrite permitted :
  say ("eigene Datei """) ;
  say (file name) ;
  yes (""" ueberschreiben") .

ENDPROC fetch ;

PROC fetch (DATASPACE VAR dest, TEXT CONST file name, TASK CONST manager) :

  disable stop ;
  call (fetch code, file name, manager) ;
  dest := ds ;
  forget (ds)

ENDPROC fetch ;


PROC save :
 
  save (last param)
 
ENDPROC save ;
 
PROC save (TEXT CONST file name) :
 
  save (file name, father)
 
ENDPROC save ;
 
PROC save (TEXT CONST file name, TASK CONST manager) :
 
  last param (file name) ;
  call (save code, file name, old (file name), manager) ; 
  forget (ds) 
 
ENDPROC save ;

PROC save (DATASPACE CONST source, TEXT CONST file name, TASK CONST manager):

  call (save code, file name, source, manager) ; 
  forget (ds) 

ENDPROC save ;


BOOL PROC exists (TEXT CONST file name, TASK CONST manager) :

  call (exists code, file name, manager) ; 
  forget (ds) ;
  reply = ack .

ENDPROC exists ;


PROC erase :
 
  erase (last param)
 
ENDPROC erase ;
 
PROC erase (TEXT CONST file name) :
 
  erase (file name, father)
 
ENDPROC erase ;
 
PROC erase (TEXT CONST file name, TASK CONST manager) :
 
  call (erase code, file name, manager) ; 
  forget (ds)

ENDPROC erase ;

 
PROC list (TASK CONST manager) :
 
  IF manager = myself
    THEN list
    ELSE list from manager
  FI .

list from manager :
  call (list code, "", manager) ;
  IF reply = ack
    THEN DATASPACE VAR save ds := ds ; 
         forget (ds) ; 
         list file := sequential file (modify, save ds) ;
         insert station and name of task in headline if possible ; 
         show (list file) ;
         forget (save ds)
    ELSE forget (ds) 
  FI . 
 
insert station and name of task in headline if possible :
  IF headline (list file) = "" 
    THEN headline (list file, station number if there is one 
                              + "  Task : " + name (manager))
  FI . 
 
station number if there is one : 
  IF station (manager) > 0 
    THEN "Station : " + text (station (manager)) 
    ELSE "" 
  FI . 
 
ENDPROC list ;
        
PROC list (FILE VAR f, TASK CONST manager) :
 
  IF manager = myself
    THEN list (f)
    ELSE list from manager
  FI .

list from manager :
  call (list code, "", manager) ;
  IF reply = ack
    THEN DATASPACE VAR save ds := ds ; 
         forget (ds) ; 
         list file := sequential file (input, save ds) ;
         copy attributes (list file, f) ;
         insert station and name of task in headline if possible ;
         REP
           getline (list file, record) ;
           putline (f, record)
         UNTIL eof (list file) PER ; 
         forget (save ds)
    ELSE forget (ds) 
  FI . 

insert station and name of task in headline if possible :
  IF headline (list file) = "" 
    THEN headline (list file, station number if there is one 
                              + "  Task : " + name (manager))
  FI . 
 
station number if there is one : 
  IF station (manager) > 0 
    THEN "Station : " + text (station (manager)) 
    ELSE "" 
  FI . 
 
ENDPROC list ;

THESAURUS OP ALL (TASK CONST manager) :

  THESAURUS VAR result ;
  IF manager = myself
    THEN result := all
    ELSE get all from manager
  FI ;
  result .

get all from manager :
  call (all code, "", manager) ;
  IF reply = ack
    THEN get result thesaurus
    ELSE result := empty thesaurus
  FI .

get result thesaurus :
  thesaurus msg := ds ;
  result := CONCR (thesaurus msg) ;
  forget (ds) .
 
ENDOP ALL ; 
 
 
PROC call (INT CONST op code, TEXT CONST file name, TASK CONST manager) :
 
  DATASPACE VAR dummy space ;
  call (op code, file name, dummy space, manager) 

ENDPROC call ;

PROC call (INT CONST op code, TEXT CONST file name,
           DATASPACE CONST save space, TASK CONST manager) :
 
  enable stop ;
  send first order first time ;
  send second order if required first time ;
  WHILE order restart required REP
    pause (10) ;
    send first order (op code, file name, manager) ;
    send second order if required
  PER ;
  error or message if required .

send first order first time :
  send first order (op code, file name, manager) ;
  WHILE order restart required REP
    pause (10) ;
    send first order (op code, file name, manager)
  PER .

send second order if required first time :
  IF reply = question ack
    THEN reply msg := ds ;
         IF NOT yes (reply msg)
           THEN LEAVE call 
           ELSE send second order (op code, file name, save space, manager)
         FI
  ELIF reply = second phase ack
    THEN send second order (op code, file name, save space, manager)
  FI .

send second order if required :
    IF reply = second phase ack OR reply = question ack
      THEN send second order (op code, file name, save space, manager)
    FI .

error or message if required :
  IF reply = message ack
    THEN reply msg := ds ;
         say (reply msg) ;
         say (cr lf)
  ELIF reply = error nak
    THEN reply msg := ds ;
         errorstop (reply msg)
  FI .

order restart required : reply = nak .

ENDPROC call ;

PROC send first order (INT CONST op code, TEXT CONST file name,
                       TASK CONST manager) :

  forget (ds) ;
  ds := nilspace ;
  msg := ds ;
  msg.name := file name ;
  msg.write pass := write password ;
  msg.read pass  := read password ;
  call (manager, op code, ds, reply) ;
  IF reply < 0
    THEN errorstop ("Task nicht vorhanden")
  FI .

ENDPROC send first order ;

PROC send second order (INT CONST op code, TEXT CONST file name,
                        DATASPACE CONST save space, TASK CONST manager) :

  IF op code = save code
    THEN send save space
    ELSE send first order (second phase ack, file name, manager)
  FI .

send save space :
  forget (ds) ;
  ds := save space ;
  call (manager, second phase ack, ds, reply) .

ENDPROC send second order ;
 
 
PROC global manager :

  global manager 
  (PROC (DATASPACE VAR, INT CONST, INT CONST, TASK CONST) std manager)

ENDPROC global manager ;

PROC free global manager :

  global manager 
  (PROC (DATASPACE VAR, INT CONST, INT CONST, TASK CONST) free manager)

ENDPROC free global manager ;


PROC global manager (PROC (DATASPACE VAR, 
                     INT CONST, INT CONST, TASK CONST) manager) :
 
  DATASPACE VAR local ds := nilspace ;
  break ; 
  set autonom ;
  disable stop ;
  command dialogue (FALSE) ;
  remember heap size ;
  last order task := niltask ;
  REP
    forget (local ds) ; 
    wait (local ds, order, order task) ;
    IF order <> second phase ack
      THEN prepare first phase ;
           manager (local ds, order, phase number, order task)
    ELIF order task = last order task
      THEN prepare second phase ;
           manager (local ds, order, phase number, order task)
    ELSE   send nak
    FI ;
    send error if necessary ;
    collect heap garbage if necessary
  PER .

prepare first phase :
  phase number := 1 ;
  last order := order ;
  last order task := order task .

prepare second phase :
  phase number INCR 1 ;
  order := last order .

send nak :
  forget (local ds) ;
  local ds := nilspace ;
  send (order task, nak, local ds) .

send error if necessary :
  IF is error
    THEN forget (local ds) ;
         local ds := nilspace ;
         reply msg := local ds ;
         CONCR (reply msg) := error message ;
         clear error ;
         send (order task, error nak, local ds)
  FI .
 
remember heap size :
  INT VAR old heap size := heap size .

collect heap garbage if necessary :
  IF heap size > old heap size + 8
    THEN collect heap garbage ;
         old heap size := heap size
  FI .

ENDPROC global manager ;

PROC std manager (DATASPACE VAR ds, 
                  INT CONST order, phase, TASK CONST order task) :

  IF order task < myself OR order = begin code OR order task = supervisor
    THEN free manager (ds, order, phase, order task)
    ELSE errorstop ("kein Zugriffsrecht auf Task """ + name (myself) + """")
  FI .

ENDPROC std manager ;

PROC free manager (DATASPACE VAR ds, 
                   INT CONST order, phase, TASK CONST order task):

  enable stop ;
  IF   order > continue code   AND
       order task = supervisor THEN y maintenance
  ELIF order = begin code      THEN y begin
  ELSE                              file manager order
  FI .

file manager order :
  get message text if there is one ;
  SELECT order OF
    CASE fetch code       : y fetch
    CASE save code        : y save
    CASE exists code      : y exists
    CASE erase code       : y erase
    CASE list code        : y list
    CASE all code         : y all
    OTHERWISE errorstop ("falscher Auftrag fuer Task """+name(myself)+"""")
  ENDSELECT .
 
get message text if there is one :
  IF order >= fetch code AND order <= erase code AND phase = 1
    THEN msg := ds ;
         received name := msg.name
  FI .
 
y begin :
  BOUND STRUCT (TEXT tname, tpass, TASK task, PROCA start proc) VAR sv msg := ds ;
  IF create son password = sv msg.tpass AND create son password <> "-"
    THEN create son task
  ELIF sv msg.tpass = ""
    THEN ask for password
  ELSE   errorstop ("Passwort falsch")
  FI .

create son task :
  begin (ds, PROC std begin, reply) ;
  send (order task, reply, ds) .

ask for password :
  send (order task, password code, ds) .


y fetch :
  IF read permission (received name, msg.read pass)
    THEN forget (ds) ;
         ds := old (received name) ;
         send (order task, ack, ds)
    ELSE errorstop ("Passwort falsch")
  FI .
 
y erase :
  msg := ds ;
  received name := msg.name ;
  IF NOT exists (received name)
    THEN manager message ("""" + received name + """ existiert nicht", order task)
  ELIF phase = 1
    THEN manager question ("""" + received name + """ loeschen", order task)
  ELIF write permission (received name, msg.write pass)
    THEN forget (received name, quiet) ;
         send (order task, ack, ds)
    ELSE errorstop ("Passwort falsch")
  FI .
 
y save :
  IF phase = 1
    THEN y save pre
    ELSE y save post
  FI .

y save pre :
  IF write permission (received name, msg.write pass)
    THEN save file name := received name ;
         save write password  := msg.write pass ;
         save read password   := msg.read pass ;
         IF exists (received name)
           THEN manager question 
                ("""" + received name + """ ueberschreiben", order task)
           ELSE send (order task, second phase ack, ds) 
         FI
    ELSE errorstop ("Passwort falsch")
  FI .
 
y save post :
  forget (save file name, quiet) ;
  copy (ds, save file name) ;
  enter password (save file name, save write password, save read password) ;
  forget (ds) ;
  ds := nilspace ;
  send (order task, ack, ds) ;
  cover tracks of save passwords .

cover tracks of save passwords :
  replace (save write password, 1, LENGTH save write password * " ") ;
  replace (save read password, 1, LENGTH save read password * " ") .

y exists :
  IF exists (received name)
    THEN send (order task, ack, ds)
    ELSE send (order task, false code, ds)
  FI .

y list :
  forget (ds) ;
  ds := nilspace ;
  list file := sequential file (output, ds) ;
  list (list file) ;
  send (order task, ack, ds) .
 
y all :
  BOUND THESAURUS VAR all names := ds ;
  all names := all ;
  send (order task, ack, ds) .
 
y maintenance :
  disable stop ;
  call (supervisor, order, ds, reply) ;
  forget (ds) ;
  IF reply = ack
    THEN put error message if there is one ; 
         REP 
           command dialogue (TRUE) ;
           get command ("maintenance :") ;
           reset editor ; 
           do command
         UNTIL NOT on line PER ;
         command dialogue (FALSE) ;
         break ;
         set autonom ;
         save error message if there is one 
  FI ;
  enable stop .

put error message if there is one : 
  IF error message buffer <> "" 
    THEN  out (error pre) ; 
          out (error message buffer) ; 
          out (cr lf) ; 
          error message buffer := ""
  FI . 
 
reset editor :
  WHILE aktueller editor > 0 REP
    quit
  PER ;
  clear error .

save error message if there is one : 
  IF is error 
    THEN error message buffer := error message ; 
         clear error 
  FI . 
 
ENDPROC free manager ;
 
PROC manager message (TEXT CONST message) :

  forget (ds) ;
  ds := nilspace ;
  reply msg := ds ;
  reply msg := message ;
  send (order task, message ack, ds)

ENDPROC manager message ;

PROC manager question (TEXT CONST question) :

  forget (ds) ;
  ds := nilspace ;
  reply msg := ds ;
  reply msg := question ;
  send (order task, question ack, ds)

ENDPROC manager question ;

PROC manager message (TEXT CONST message, TASK CONST receiver) :

  forget (ds) ;
  ds := nilspace ;
  reply msg := ds ;
  reply msg := message ;
  send (receiver, message ack, ds)

ENDPROC manager message ;

PROC manager question (TEXT CONST question, TASK CONST receiver) :

  forget (ds) ;
  ds := nilspace ;
  reply msg := ds ;
  reply msg := question ;
  send (receiver, question ack, ds)

ENDPROC manager question ;

PROC std begin :

  do ("monitor")

ENDPROC std begin ;

PROC begin password (TEXT CONST password) :

  cover tracks of old create son password ;
  create son password := password ;
  say (""3""13""5"") ;
  cover tracks .

cover tracks of old create son password :
  replace (create son password, 1, LENGTH create son password * " ") .

ENDPROC begin password ;


PROC continue channel (INT CONST channel number) : 

  TASK CONST channel owner := task (channel number) ; 
  IF i am not channel owner 
    THEN IF NOT is niltask (channel owner)
           THEN ask channel owner to release the channel ;
                IF channel owner does not release channel
                  THEN errorstop ("Task """ + name (channel owner)
                                            + """ gibt Kanal " 
                                            + text (channel number)
                                            + " nicht frei") 
                FI 
         FI ; 
         continue (channel number) 
  FI .
  
i am not channel owner : 
  channel <> channel number . 
 
ask channel owner to release the channel :
  forget (ds) ; 
  ds := nilspace ; 
  pingpong (channel owner, free code, ds, reply) . 

channel owner does not release channel : 
  (reply <> ack) AND task exists . 
 
task exists : 
  reply <> -1 . 
 
ENDPROC continue channel ;


END PACKET global manager ;