LogViewerImpl.mesa
Copyright © 1983, 1986 by Xerox Corporation. All rights reserved.
Created by Christian Jacobi August 3, 1983 9:54 am
Last edited by: Christian Jacobi, September 2, 1986 1:52:44 pm PDT
DIRECTORY
Commander USING [CommandProc, Register],
EditedStream USING [Rubout],
FS USING [StreamOpen],
Icons USING [IconFlavor, NewIconFromFile],
InputFocus USING [Focus, GetInputFocus, PopInputFocus, PushInputFocus],
IO,
Process USING [Detach, Pause, MsecToTicks, SetTimeout, SecondsToTicks, Abort, CheckForAbort, DisableTimeout],
Rope USING [ROPE, Find, Match, Equal],
RuntimeError USING [UNCAUGHT],
LogViewer,
TypeScript USING [Create, PutRope],
ViewerClasses USING [Viewer],
ViewerIO USING [CreateViewerStreams, GetViewerFromStream],
ViewerOps USING [PaintViewer, OpenIcon, EnumerateViewers, EnumProc],
ViewerTools USING [SetSelection];
LogViewerImpl:
CEDAR
MONITOR
IMPORTS Commander, EditedStream, FS, Icons, InputFocus, IO, Process, Rope, RuntimeError, TypeScript, ViewerIO, ViewerOps, ViewerTools
EXPORTS LogViewer =
BEGIN
ROPE: TYPE = Rope.ROPE;
UserAbort: PUBLIC SIGNAL = CODE;
TimedOut: PUBLIC SIGNAL = CODE;
viewer: ViewerClasses.Viewer ← NIL;
in, out: IO.STREAM ← NIL;
normalName: ROPE = "Log Viewer";
inputName: ROPE = "Log Viewer [Input Expected]";
normalIcon, inputIcon: Icons.IconFlavor;
del: ROPE = "\177";
log:
IO.
STREAM;
--using a backing file for viewer makes log unaccessible
shouldFlush:
BOOL ←
FALSE;
--whether log file should be flushed
-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
--locking procedures
occupied: BOOL ← FALSE; --module occupied
next: CONDITION ← [timeout: Process.MsecToTicks[4000]]; --another client might try entering
Enter:
ENTRY
PROC [] = {
ENABLE UNWIND => NULL;
WHILE occupied DO WAIT next ENDLOOP;
occupied ← TRUE;
};
Leave:
ENTRY
PROC [] = {
ENABLE UNWIND => NULL;
occupied ← FALSE;
BROADCAST next;
};
EnterReader:
PROC [] = {
v: ViewerClasses.Viewer;
Lock[];
Enter[];
v ← viewer;
WHILE v=NIL OR v.destroyed DO InternalCreate[FALSE]; v ← viewer ENDLOOP;
v.inhibitDestroy ← TRUE;
WHILE v=NIL OR v.destroyed DO InternalCreate[TRUE]; v ← viewer ENDLOOP;
v.icon ← inputIcon;
v.name ← inputName;
ViewerOps.PaintViewer[v, caption];
ViewerTools.SetSelection[v];
InputFocus.PushInputFocus[v, $LogViewer];
};
LeaveReader:
PROC [] = {
v: ViewerClasses.Viewer ← viewer;
foc: InputFocus.Focus ← InputFocus.GetInputFocus[];
IF v#
NIL
THEN {
v.icon ← normalIcon;
v.name ← normalName;
v.inhibitDestroy ← FALSE; --conveniant here; usefull in all places where called
ViewerOps.PaintViewer[v, caption];
};
IF foc#NIL AND foc.info = $LogViewer THEN InputFocus.PopInputFocus[];
Leave[];
Free[];
};
ProcList: TYPE = LIST OF PROC;
lockList: ProcList ← NIL;
freeList: ProcList ← NIL;
AddLock:
PUBLIC
ENTRY
PROC [lock, free:
PROC] = {
ENABLE UNWIND => NULL;
IF free#NIL THEN freeList ← CONS[free, freeList];
IF lock#
NIL
THEN
IF lockList=NIL THEN lockList ← LIST[lock]
ELSE
FOR l: ProcList ← lockList, l.rest
DO
IF l.rest=NIL THEN {l.rest ← LIST[lock]; EXIT}
ENDLOOP;
};
Lock:
PROC = {
FOR l: ProcList ← lockList, l.rest
WHILE l#
NIL
DO
l.first[! RuntimeError.UNCAUGHT => CONTINUE]
ENDLOOP
};
Free:
PROC = {
FOR l: ProcList ← freeList, l.rest
WHILE l#
NIL
DO
l.first[! RuntimeError.UNCAUGHT => CONTINUE]
ENDLOOP
};
ReaderProtected:
PROC [p:
PROC] = {
ENABLE UNWIND => LeaveReader[];
EnterReader[]; p[]; LeaveReader[];
};
-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
--creation of viewer
Create:
PROC [protected:
BOOL] = {
--its ok to risk creating accidently too many streams or viewer's
--since this won't cause any wedge but only discomfort [orphaned viewers lying around]
InternalCreate[protected]
};
InternalCreate:
PROC [protected:
BOOL] = {
--afterwards in any case: viewer #NIL (doesnt really mean good, but certainly not NIL)
FindOldGuys: ViewerOps.EnumProc = {
MakeOrphan:
PROC [v: ViewerClasses.Viewer] = {
IF v#
NIL
THEN {
v.inhibitDestroy ← FALSE;
v.icon ← typescript;
v.name ← "orphaned split log viewer";
IO.PutRope[log, "log viewer orphaned\n"]; IO.Flush[log];
ViewerOps.PaintViewer[v, caption];
TypeScript.PutRope[v, "\n... log viewer orphaned ...\n"];
};
};
IF ~v.destroyed
AND v.file=
NIL
AND v.class.flavor=$Typescript
THEN
IF Rope.Equal[v.name, normalName]
OR Rope.Equal[v.name, inputName]
THEN
MakeOrphan[v ! RuntimeError.UNCAUGHT => CONTINUE];
};
ReallyCreate:
PROC [] = {
v: ViewerClasses.Viewer ← TypeScript.Create[info: [name: normalName, inhibitDestroy: protected, iconic: FALSE, icon: normalIcon, column: right]];
[in: in, out: out] ← ViewerIO.CreateViewerStreams[name: normalName, viewer: v, editedStream: TRUE];
viewer ← v;
IO.PutRope[log, "log viewer created\n"];
IO.Flush[log];
};
--try re-using old pieces, but only if not from input
oldOut: IO.STREAM ← out;
oldIn: IO.STREAM ← in;
IF oldOut#
NIL
AND oldIn#
NIL
AND ~protected
THEN {
v: ViewerClasses.Viewer;
err: BOOL ← FALSE;
v ← ViewerIO.GetViewerFromStream[oldOut];
IF v#
NIL
AND ~v.destroyed
AND (v=ViewerIO.GetViewerFromStream[oldIn])
THEN {
--we dare trying to reuse a split viewer,
--but first we try whether it wont cause errors
IO.Flush[oldOut ! RuntimeError.UNCAUGHT => {err ← TRUE; CONTINUE}];
IF ~err THEN IO.Reset[oldOut ! RuntimeError.UNCAUGHT => {err ← TRUE; CONTINUE}];
IF ~err THEN IO.Reset[oldIn ! RuntimeError.UNCAUGHT => {err ← TRUE; CONTINUE}];
IF ~err
THEN {
v.icon ← normalIcon;
IF ~v.destroyed
THEN {
[in: in, out: out] ← ViewerIO.CreateViewerStreams[name: normalName, viewer: v, editedStream: TRUE];
viewer ← v;
IO.PutRope[log, "usage of different LogViewer viewer\n"]; IO.Flush[log];
RETURN;
};
};
};
};
--try to mark other [split] viewers as bad
ViewerOps.EnumerateViewers[FindOldGuys ! RuntimeError.UNCAUGHT => CONTINUE];
--the actual creation
ReallyCreate[]
};
-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
--short cuts
InternalPut:
PROC [text:
ROPE] = {
IF viewer=
NIL
OR viewer.destroyed
THEN InternalCreate[
FALSE];
--asking for viewer.destroyed helps to discover bad splits, but is not mandatory
IO.PutRope[out, text !
IO.Error => {
IF ec=StreamClosed
THEN {
InternalCreate[TRUE];
IO.PutRope[out, text];
CONTINUE
}
}];
IO.PutRope[log, text]; shouldFlush ← TRUE;
};
PutRope:
PUBLIC PROC [text:
ROPE] = {
ENABLE UNWIND => Leave[];
Enter[]; InternalPut[text]; Leave[]
};
PutRopes:
PUBLIC PROC [t1, t2, t3:
ROPE] = {
ENABLE UNWIND => Leave[];
Enter[]; InternalPut[t1]; InternalPut[t2]; InternalPut[t3]; Leave[]
};
PutF:
PUBLIC
PROC [format:
ROPE ←
NIL, v1, v2, v3, v4, v5:
IO.Value] = {
--actual inline usage allow client usage of formatting
ENABLE UNWIND => Leave[];
Enter[];
IF viewer=NIL OR viewer.destroyed THEN InternalCreate[FALSE];
IO.PutF[out, format, v1, v2, v3, v4, v5
!
IO.Error => {
IF ec=StreamClosed
THEN {
InternalCreate[TRUE];
IO.PutF[out, format, v1, v2, v3, v4, v5];
CONTINUE
}
}
];
IO.PutF[log, format, v1, v2, v3, v4, v5]; shouldFlush ← TRUE;
Leave[]
};
PutF1:
PUBLIC
PROC [format:
ROPE ←
NIL, value:
IO.Value] = {
--actual inline usage to allow client usage of formatting
ENABLE UNWIND => Leave[];
Enter[];
IF viewer=NIL OR viewer.destroyed THEN InternalCreate[FALSE];
IO.PutF1[out, format, value
!
IO.Error => {
IF ec=StreamClosed
THEN {
InternalCreate[TRUE];
IO.PutF1[out, format, value];
CONTINUE
}
}
];
IO.PutF[log, format, value]; shouldFlush ← TRUE;
Leave[]
};
-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
--input procedures
RequestRope:
PUBLIC
PROC [prompt:
ROPE ←
NIL, timeOut:
NAT]
RETURNS [
ROPE] = {
RETURN [IF timeOut=0 THEN RequestRope0[prompt] ELSE RequestRope1[prompt, timeOut]]
};
IOState: TYPE = {ok, repeat, abort, undef};
InternalGetLine:
PROC [promp:
ROPE]
RETURNS [line:
ROPE, state: IOState←ok] = {
ENABLE {
IO.Error => IF ec=StreamClosed THEN {state←repeat; CONTINUE};
EditedStream.Rubout => {state�ort; IO.Reset[in]; CONTINUE};
RuntimeError.UNCAUGHT => {state←repeat; CONTINUE};
};
IF viewer.iconic THEN ViewerOps.OpenIcon[viewer];
InternalPut[promp];
IO.Flush[out ! RuntimeError.UNCAUGHT => CONTINUE];
ViewerTools.SetSelection[viewer];
line ← IO.GetLineRope[in];
IF Rope.Find[line, del]>=0 THEN state�ort;
};
RequestRope0:
PROC [prompt:
ROPE ←
NIL]
RETURNS [r:
ROPE] = {
DoIt: PROC [] = {[r, state] ← InternalGetLine[prompt]};
state: IOState;
DO
ReaderProtected[DoIt];
SELECT state
FROM
ok => RETURN;
repeat => PutRope["XXX\n"];
abort => {PutRope[" ..user abort\n"]; SIGNAL UserAbort} ;
ENDCASE => {PutRope[" ..??\n"]; SIGNAL UserAbort};
ENDLOOP;
};
xProcess: PROCESS;
xStateCondition: CONDITION;
xState: IOState ← undef;
xResult: ROPE;
RequestRope1:
PUBLIC
PROC [prompt:
ROPE, timeOut:
NAT]
RETURNS [result:
ROPE] = {
state: IOState;
DoIt:
PROC [] = {
xState ← undef;
IF timeOut=0 THEN TRUSTED {Process.DisableTimeout[@xStateCondition]}
ELSE
TRUSTED {
Process.SetTimeout[@xStateCondition, Process.SecondsToTicks[timeOut]]
};
ForkRopeGetter[prompt];
TRUSTED {JOIN xProcess};
state ← xState;
result ← xResult;
IF state=ok THEN IF Rope.Find[result, del]>=0 THEN state ← abort
};
DO
ReaderProtected[DoIt];
SELECT state
FROM
ok => RETURN;
repeat => PutRope["XXX\n"];
abort => {PutRope[" ..user abort\n"]; SIGNAL UserAbort} ;
undef => SIGNAL TimedOut
ENDCASE => {PutRope[" ..??\n"]; SIGNAL UserAbort};
ENDLOOP
};
ForkRopeGetter:
ENTRY PROC [prompt:
ROPE←
NIL] = {
ENABLE UNWIND => NULL;
xProcess ← FORK ForkedTryToGetRope[prompt];
WAIT xStateCondition;
IF xState#ok AND xState#abort THEN TRUSTED {Process.Abort[xProcess]};
};
SetGlobalState:
ENTRY
PROC [s: IOState] = {
ENABLE UNWIND => NULL;
Process.CheckForAbort[];
xState ← s;
BROADCAST xStateCondition;
};
ForkedTryToGetRope:
PROC [prompt:
ROPE←
NIL] = {
ReallyTryToGetRope:
PROC [prompt:
ROPE] = {
d: IOState;
DoIt:
PROC [] = {
ENABLE {
UNWIND => IO.Reset[in];
IO.Error => IF ec=StreamClosed THEN {d←repeat; IO.Reset[in]; CONTINUE};
EditedStream.Rubout => {d�ort; IO.Reset[in]; CONTINUE};
};
InternalPut[prompt];
IF viewer.iconic THEN ViewerOps.OpenIcon[viewer];
xResult ← IO.GetLineRope[in];
d ← ok;
};
DO
d ← undef;
DoIt[];
IF d=ok OR d=abort THEN {SetGlobalState[d]; RETURN};
IF d=repeat THEN InternalPut["XXX\n"]
ENDLOOP;
};
ReallyTryToGetRope[prompt ! ABORTED => GOTO NeverMind]
EXITS NeverMind => NULL;
};
-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
--stream output stuff
CreateStream:
PUBLIC
PROC []
RETURNS [stream:
IO.
STREAM] = {
IF viewer=NIL OR viewer.destroyed THEN Create[FALSE];
RETURN[IO.CreateStream[streamProcs: myStreamProcs, streamData: NIL]];
};
myStreamProcs:
REF
IO.StreamProcs ←
IO.CreateStreamProcs[
variety: $output,
class: $LogViewer,
putChar: MyPutChar,
putBlock: MyPutBlock,
unsafePutBlock: MyUnsafePutBlock,
flush: MyFlush,
eraseChar: MyEraseChar,
reset: MyFlush,
close: MyClose
];
MyPutChar:
PROC [self:
IO.
STREAM, char:
CHAR] = {
ENABLE UNWIND => Leave[];
Enter[];
IO.PutChar[out, char !
IO.Error => {
IF ec=StreamClosed
THEN {
InternalCreate[TRUE];
IO.PutChar[out, char];
CONTINUE
}
}];
IO.PutChar[log, char]; shouldFlush ← TRUE;
Leave[];
};
MyPutBlock:
PROC [self:
IO.
STREAM, block:
REF
READONLY
TEXT, startIndex:
NAT, count:
NAT] = {
ENABLE UNWIND => Leave[];
Enter[];
IO.PutBlock[out, block, startIndex, count !
IO.Error => {
IF ec=StreamClosed
THEN {
InternalCreate[TRUE];
IO.PutBlock[out, block, startIndex, count];
CONTINUE
}
}];
IO.PutBlock[log, block, startIndex, count]; shouldFlush ← TRUE;
Leave[];
};
MyUnsafePutBlock:
PROC [self:
IO.
STREAM, block:
IO.UnsafeBlock] = {
ENABLE UNWIND => Leave[];
Enter[];
IO.UnsafePutBlock[out, block !
IO.Error => {
IF ec=StreamClosed
THEN {
InternalCreate[TRUE];
IO.UnsafePutBlock[out, block];
CONTINUE
}
}];
IO.UnsafePutBlock[log, block]; shouldFlush ← TRUE;
Leave[];
};
MyFlush:
PROC [self:
IO.
STREAM] = {
IO.Flush[log];
};
MyEraseChar:
PROC [self:
IO.
STREAM, char:
CHAR] = {
};
MyClose:
PROC [self:
IO.
STREAM, abort:
BOOL] = {
IO.Flush[log];
};
-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
--log and commands
CreateLog:
PROC [] = {
log ← FS.StreamOpen[fileName: "LogViewer.log", accessOptions: create, keep: 5];
IO.PutF1[log, "log file for LogViewer created %g\n", IO.time[]]
};
Command: Commander.CommandProc = {
IF Rope.Match["*open*", cmd.commandLine,
FALSE]
THEN {
PutRope["open LogViewer viewer\n"]; --side effect: creates viewer
ViewerOps.OpenIcon[viewer];
};
IF Rope.Match["*new*", cmd.commandLine,
FALSE]
THEN {
oldLog: IO.STREAM ← log;
PutRope["start new LogViewer.log file\n"];
CreateLog[];
IO.Close[oldLog];
};
};
CheckInhibitDestroy:
ENTRY
PROC [] = {
v: ViewerClasses.Viewer ← viewer;
IF v#NIL AND ~occupied THEN v.inhibitDestroy ← FALSE;
};
Flusher:
PROC [] = {
--directly flushing after each output would make LogViewer far to slow
flush: BOOL;
DO
Process.Pause[Process.SecondsToTicks[40]];
IF flush ← shouldFlush
THEN {
shouldFlush ← FALSE;
IO.Flush[log ! RuntimeError.UNCAUGHT => CONTINUE];
};
CheckInhibitDestroy[];
ENDLOOP
};
CreateLog[];
normalIcon ← Icons.NewIconFromFile["LogViewer.icons", 0 ! RuntimeError.UNCAUGHT => CONTINUE];
inputIcon ← Icons.NewIconFromFile["LogViewer.icons", 1 ! RuntimeError.UNCAUGHT => CONTINUE];
Commander.Register["///Commands/LogViewer", Command, "usage {LogViewer ~ | open | new}"];
TRUSTED {Process.Detach[FORK Flusher]};
END.