DIRECTORY Basics, BasicTime, IO, Process, RedBlackTree, Rope, STP, STPConnectionCache, UserCredentials;STPConnectionCacheImpl: CEDAR MONITORIMPORTS BasicTime, IO, Process, RedBlackTree, Rope, STP, UserCredentialsEXPORTS STPConnectionCache = {OPEN STPConnectionCache;Time: TYPE = BasicTime.GMT;PrivateStuff: TYPE = REF PrivateStuffRec;PrivateStuffRec: TYPE = RECORD [client: ROPE _ NIL,change: CONDITION,dieAfter: Time _ BasicTime.earliestGMT];cache: RedBlackTree.Table _ RedBlackTree.Create[GetCacheKey, CacheCompare];Get: PUBLIC ENTRY PROC [host, client: ROPE] RETURNS [h: Handle] = {ENABLE UNWIND => NULL;p: PrivateStuff;h _ NARROW[cache.Lookup[host]];IF client = NIL THEN {self: CARDINAL _ LOOPHOLE[Process.GetCurrent[]];client _ IO.PutFR["Process %g", IO.card[self]];};IF h = NIL THEN {h _ NEW [HandleRec _ [host: host,stpHandle: STP.Create[],private: p _ NEW [PrivateStuffRec _ []]]];TRUSTED {Process.InitializeCondition[@p.change, Process.SecondsToTicks[5]];Process.EnableAborts[@p.change];Process.Detach[FORK CloseIt[h, p]];};RedBlackTree.Insert[cache, h, host];}ELSE p _ NARROW[h.private];IF NOT h.stpHandle.IsOpen[] THEN {name, password: ROPE;[name, password] _ UserCredentials.Get[];[] _ h.stpHandle.Open[host];h.stpHandle.Login[name, password];};WHILE p.client # NIL DO WAIT p.change ENDLOOP;p.client _ client;BROADCAST p.change;};Release: PUBLIC ENTRY PROC [h: Handle, timeout: INT--seconds--] = {ENABLE UNWIND => NULL;p: PrivateStuff _ NARROW[h.private];expire: Time _ BasicTime.Update[BasicTime.Now[], timeout];p.client _ NIL;IF BasicTime.Period[from: p.dieAfter, to: expire] > 0 THEN p.dieAfter _ expire;BROADCAST p.change;};CloseIt: ENTRY PROC [h: Handle, p: PrivateStuff] = {ENABLE UNWIND => NULL;DOnow: Time;delta: INT;WAIT p.change;now _ BasicTime.Now[];delta _ BasicTime.Period[from: now, to: p.dieAfter];IF delta <= 0 THEN {--time to be closed--IF p.client = NIL THEN {IF h.stpHandle.IsOpen[] THEN h.stpHandle.Close[];TRUSTED {Process.SetTimeout[@p.change, maxDelay];};}ELSE TRUSTED {Process.SetTimeout[@p.change, minDelay];};}ELSE {TRUSTED {Process.SetTimeout[@p.change, Process.SecondsToTicks[MIN[delta, 60]+1]];};};ENDLOOP;};minDelay: Process.Ticks _ Process.SecondsToTicks[6];maxDelay: Process.Ticks _ Process.SecondsToTicks[600];GetCacheKey: PROC [data: REF ANY] RETURNS [key: ROPE] --RedBlackTree.GetKey-- = {h: Handle _ NARROW[data];key _ h.host};CacheCompare: PROC [k, data: REF ANY] RETURNS [Basics.Comparison] --RedBlackTree.Compare-- = {k1: ROPE _ NARROW[k];k2: ROPE _ GetCacheKey[data];RETURN [k1.Compare[k2, FALSE]];};}.    J  STPConnectionCacheImpl.MesaSpreitzer, July 29, 1985 6:48:17 pm PDTЭ╩  Ц"cedar" styleШ codeЩKЩ'ЧKШ KЪ╧k	ЬЭЬЭЬ&ШgKШ Ъ╨bxЬЭЬЭШ%KЪЭЬЭЬЭЬШHKЪЭЬШKШ KЪЬЭЬШKШ KЪЬЭЬЭЬШKШ KЪЬЭЬЭЬШ)ЪЬЭЬЭЬШ KЪЬЭЬЭЬШKЪЬЭ	ЬШKЪЬ(Ш(ЧKШ KЪЬKШKKШ Ъ╧nЬЭЬЭЬЭЬЭЬЭЬШCKЪЭЬЭЬЭЬШKШKЪЬЭЬШЪЭЬ
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