DIRECTORYBasics USING [FWORD, Card32FromF, Card16FromH],BasicTime USING [FromPupTime, GMT, Now, nullGMT, Period],FSBackdoor USING [Version],FSRemoteFileBackdoor USING [ServerHandle],Process USING [Detach, Ticks, SecondsToTicks],Pup USING [Address],PupBuffer USING [Buffer],PupHop USING [InitialTimeout],PupName USING [NameLookup, Error],PupSocket USING [AllocBuffer, CopyRope, CreateEphemeral, Destroy, FreeBuffer, Get, GetUniqueID, Send, SetNoErrors, Socket],PupType USING [fileLookup, fileLookupError, fileLookupReply],PupWKS USING [fileLookup],Rope USING [Equal, ROPE],RuntimeError USING [UNCAUGHT],STPFSRemoteFile USING [LookupResult, ServerData];STPFSRemoteLookupImpl: CEDAR MONITORIMPORTS Basics, BasicTime, Process, PupHop, PupName, PupSocket, Rope, RuntimeErrorEXPORTS STPFSRemoteFile= {CARD: TYPE = LONG CARDINAL;GMT: TYPE = BasicTime.GMT;ROPE: TYPE = Rope.ROPE;Lookup: PUBLIC PROC [h: FSRemoteFileBackdoor.ServerHandle, file: ROPE] RETURNS [result: STPFSRemoteFile.LookupResult, version: FSBackdoor.Version, create: GMT, count: INT] = {sI: REF ServerInfo;[result, sI] _ FindServer[h];IF result = ok THEN {[result, version, create, count] _ DoFileLookup[sI.addr, file];SetState[sI, result];};};serverList: REF ServerInfo _ NIL; -- list of known servers;keepingList: BOOL _ TRUE;packetCount: CARD _ 0; -- outgoing; also used as pup idServerInfo: TYPE = RECORD [name: ROPE,addr: Pup.Address,state: STPFSRemoteFile.LookupResult, -- can be noResponse, noSuchPort, or oktimeOK: GMT, -- GMT of last oktimeErr: GMT, -- GMT of last errornext: REF ServerInfo];FindServer: ENTRY PROC [h: FSRemoteFileBackdoor.ServerHandle] RETURNS [result: STPFSRemoteFile.LookupResult, info: REF ServerInfo] = TRUSTED {ENABLE UNWIND => NULL;server: ROPE _ h.name;result _ ok;FOR info _ serverList, info.next UNTIL info = NIL DOIF Rope.Equal[info.name, server, FALSE] THEN {result _ info.state; RETURN};ENDLOOP;{data: STPFSRemoteFile.ServerData ~ NARROW[h.data];name: ROPE _ data.serverPupName;addr: Pup.Address;addr _ PupName.NameLookup[name, PupWKS.fileLookup! PupName.Error => {SELECT code FROMerrorFromServer => result _ noSuchServer;ENDCASE => result _ noResponse;CONTINUE } ];IF result # noSuchServer THEN {time: GMT _ BasicTime.Now[];info _ NEW [ServerInfo _ [name: server, addr: addr, state: result,timeOK: IF result = ok THEN time ELSE BasicTime.nullGMT,timeErr: IF result # ok THEN time ELSE BasicTime.nullGMT,next: serverList]];IF serverList = NIL THEN Process.Detach[FORK ServerCollector[]];IF keepingList THEN serverList _ info;};};};DoFileLookup: PROC [addr: Pup.Address, file: ROPE] RETURNS [result: STPFSRemoteFile.LookupResult, version: FSBackdoor.Version, create: GMT, count: INT] = TRUSTED {tries: CARDINAL = 4;msWait: CARDINAL _ PupHop.InitialTimeout[addr.net, 2000];id: Basics.FWORD _ PupSocket.GetUniqueID[];socket: PupSocket.Socket;result _ noResponse; -- assume resultIF msWait = 0 THEN RETURN;socket _ PupSocket.CreateEphemeral[remote: addr, getTimeout: msWait];PupSocket.SetNoErrors[socket];FOR i: NAT IN [0..tries) DOb: PupBuffer.Buffer _ PupSocket.AllocBuffer[socket];b.type _ PupType.fileLookup;b.id _ id;PupSocket.CopyRope[b, file];PupSocket.Send[socket, b, addr];b _ PupSocket.Get[socket];IF b = NIL THEN LOOP; -- no response yetIF b.id # id THEN { PupSocket.FreeBuffer[b]; LOOP; };SELECT b.type FROMPupType.fileLookupReply => {result _ ok;version _ [Basics.Card16FromH[b.fileLookupReply.version]];create _ BasicTime.FromPupTime[Basics.Card32FromF[b.fileLookupReply.createTime]! RuntimeError.UNCAUGHT => {create _ BasicTime.nullGMT; CONTINUE}];count _ Basics.Card32FromF[b.fileLookupReply.length]; };PupType.fileLookupError => result _ noSuchFile;error => SELECT b.error.code FROMnoSocket => result _ noSuchPort;cantGetThere => NULL;ENDCASE => { PupSocket.FreeBuffer[b]; LOOP; };ENDCASE => { PupSocket.FreeBuffer[b]; LOOP; };PupSocket.FreeBuffer[b];EXIT;ENDLOOP;PupSocket.Destroy[socket];};SetState: ENTRY PROC [info: REF ServerInfo, state: STPFSRemoteFile.LookupResult] = {ENABLE UNWIND => NULL;time: GMT _ BasicTime.Now[];IF state = ok THEN info.timeOK _ time ELSE info.timeErr _ time;SELECT state FROMnoResponse, noSuchPort => info.state _ state;ENDCASE;};pollingInterval: NAT _ 5;okTimeout: NAT _ 1800;noResponseTimeout: NAT _ 30;noSuchPortTimeout: NAT _ 30;errorTimeout: NAT _ 30;ServerCollector: ENTRY PROC = {ENABLE UNWIND => NULL;UNTIL serverList = NIL DOlast: REF ServerInfo _ NIL;forPolling: CONDITION _ [Process.SecondsToTicks[pollingInterval]];WAIT forPolling;FOR info: REF ServerInfo _ serverList, info.next UNTIL info = NIL DOtime: GMT = BasicTime.Now[];ageOK: INT = BasicTime.Period[info.timeOK, time];ageErr: INT = BasicTime.Period[info.timeErr, time];{SELECT info.state FROMok => IF ageOK > okTimeout THEN GO TO Splice;noResponse => IF ageErr > noResponseTimeout THEN GO TO Splice;noSuchPort => IF ageErr > noSuchPortTimeout THEN GO TO Splice;ENDCASE => IF ageErr > errorTimeout THEN GO TO Splice;last _ info;EXITS Splice =>IF last=NIL THEN serverList _ info.next ELSE last.next _ info.next; };ENDLOOP;ENDLOOP;};}.   x  STPFSRemoteLookupImpl.mesaCopyright س 1984, 1985, 1986 by Xerox Corporation.  All rights reserved.Schroeder, November 8, 1983 1:53 pmLevin, June 24, 1983 5:38 pmRuss Atkinson, March 18, 1985 10:41:54 pm PSTBob Hagmann November 14, 1986 8:23:59 am PSTHal Murray, June 3, 1986 4:33:20 pm PDTDoug Wyatt, December 12, 1986 3:00:45 pm PSTDemers, October 27, 1987 0:46:09 am PSTExported to STPFSRemoteFileThis really ought to be fixed to use the server cache in STPFSRemoteFileImpl.  For now it does its own cacheing of server names and states.FileLookup protocol implementationkeepingList => cache responses to try to reduce name lookup traffic and useless traffic when a server is obviously downDidn't find an entry, so make oneDKW: formerly IF state = noSuchPort THEN info.state _ noSuchPort;seconds to wait before polling seconds to wait before having a cached OK server evaporateseconds to wait before having a noResponse evaporateseconds to wait before having a noSuchPort evaporateseconds to wait before having any other error evaporateBob Hagmann April 29, 1985 10:25:49 am PDTchanges to: DIRECTORY, FindServer‌ت‚  ک ڑœ™JڑœH™HJ™#J™J™-Icode™,K™'K™,K™'—code1ڑدk	ک	Lڑœ‌œ‌œک/Lڑœ
‌œ‌œک9Lڑœ‌œکLڑœ‌œک*Lڑœ‌œ!ک.Lڑœ‌œکLڑœ
‌œ
کLڑœ‌œکLڑœ‌œک"Lڑœ
‌œlک{Lڑœ‌œ0ک=Lڑœ‌œکLڑœ‌œ	‌œکLڑœ‌œ‌œکLڑœ‌œک0Lک—ڑدnœ‌œ‌ک$Lڑ‌œKکRLڑ‌œکLڑœکLک Lڑ‌œ‌œ‌œ‌œکLڑ‌œ‌œ‌œکLڑ‌œ‌œ‌œک—™Icode2™‹ڑ‍œ‌œ‌œ.‌œ‌œM‌œ	‌œک¯Mڑœ‌œکMڑœکڑ‌œ‌œکMڑœ?ک?MڑœکMڑœک—Mڑœک——™"Mڑœ‌œ‌œدcœک;ڑœ‌œ‌œکMڑœw™w—Mڑœ‌œں ک7ڑœ‌œ‌œکMڑœ‌œکMڑœکMڑœ%ں'کLMڑœ‌œںکMڑœ	‌œںک"Mڑœ‌œک—ڑ‍
œ‌œ‌œ(‌œ.‌œ‌œکژMڑ‌œ‌œ‌œکMڑœ‌œ
کMڑœکڑ‌œ‌œ‌œ‌ک4Mڑ‌œ‌œ‌œ‌œکKMڑ‌œک—M™!ڑœکMڑœ#‌œ	ک2Mڑœ‌œک Mڑœکڑœ1ک1ڑœکڑ‌œ‌کMڑœ)ک)Mڑ‌œک—Mڑ‌œک——ڑ‌œ‌œکMڑœ‌œکڑœ‌œکMڑœ(ک(Mڑœ‌œ‌œ‌œک8Mڑœ	‌œ‌œ‌œک9Mڑœک—Mڑ‌œ‌œ‌œ‌œک@Mڑ‌œ‌œک&Mڑœک—Mڑœک—Mڑœک—ڑ‍œ‌œ‌œ‌œM‌œ	‌œ‌œک£Mڑœ‌œکMڑœ‌œ)ک9Mڑœ‌œک+MڑœکMڑœںک%Mڑ‌œ‌œ‌œکMڑœEکEKڑœکڑ‌œ‌œ‌œ‌کMڑœ4ک4MڑœکMڑœ
ک
MڑœکMڑœ ک MڑœکMڑ	‌œ‌œ‌œ‌œںک(Mڑ‌œ‌œ‌œک5ڑ‌œ‌کڑœکMڑœکMڑœ:ک:ڑœOکOMڑœ‌œ!‌œکC—Mڑœ8ک8—Mڑœ/ک/ڑœ	‌œ‌ک!Mڑœ ک Mڑœ‌œکMڑ‌œ‌œک.—Mڑ‌œ‌œک.—MڑœکMڑ‌œکMڑ‌œک—MڑœکMڑœک—ڑ‍œ‌œ‌œ‌œ5کTMڑ‌œ‌œ‌œکMڑœ‌œکMڑ‌œ‌œ‌œک?ڑ‌œ‌کMڑœ-ک-Mڑ‌œک—Mڑœ‌œ‌œ™AMڑœکMک —ڑœ‌œکMڑœ™—ڑœ‌œکMڑœ:™:—ڑœ‌œکMڑœ4™4—ڑœ‌œکMڑœ4™4—ڑœ‌œکMڑœ7™7—ڑ‍œ‌œ‌œکMڑ‌œ‌œ‌œکڑ‌œ‌œ‌کMڑœ‌œ‌œکMڑœ‌	œ-کBMڑ‌œکڑ	‌œ‌œ$‌œ‌œ‌کDMڑœ‌œکMڑœ‌œ'ک1Mڑœ‌œ(ک3Mڑœکڑ‌œ‌کMڑ	œ‌œ‌œ‌œ‌œک-Mڑ	œ‌œ‌œ‌œ‌œک>Mڑ	œ‌œ‌œ‌œ‌œک>Mڑ
‌œ‌œ‌œ‌œ‌œک6—Mڑœکڑ‌œ
کMڑ‌œ‌œ‌œ‌œکF—Mڑ‌œک—Mڑ‌œک—Mڑœک——LڑœکK™ K™ ™*Kڑœدr™!—K™ K™ Jک — …—    H   B  