WalnutOpsImpl.mesa
Copyright © 1984, 1986 by Xerox Corporation. All rights reserved.
Willie-Sue, September 17, 1986 11:15:42 am PDT
Donahue, May 12, 1986 2:25:09 pm PDT
Implementation of (some of) WalnutOps
Last Edited by: Willie-sue, January 10, 1985 3:45:31 pm PST
Last Edited by: Donahue, December 11, 1984 8:51:42 pm PST
DIRECTORY
BasicTime USING [GMT, nullGMT, Now],
FS USING [Error, ErrorFromStream],
GVBasics USING [RName],
IO,
Process USING [Detach, SecondsToTicks],
RefText USING [New],
Rope,
RuntimeError USING [BoundsFault],
ViewerClasses USING [Viewer],
ViewerTools USING [TiogaContents],
WalnutDB -- USING lots -- ,
WalnutDefs USING [Error, MsgSet, dontCareMsgSetVersion, dontCareDomainVersion,
 SchemaMismatch, Segment, VersionMismatch],
WalnutKernelDefs USING [LogEntry, LogExpungePhase, MsgLogEntry],
WalnutLog -- USING lots -- ,
WalnutLogExpunge  --using lots-- ,
WalnutMiscLog USING [walnutItemFixedLength,
 CloseNewMailLog, CreateReadArchiveLog, GetNewMailLog,
 MiscShutdown],
WalnutOps,
WalnutOpsExtras USING [],
WalnutOpsInternal USING [rootFileName, mailStream, newMailSomewhere,
 statsStream, statsProgressStream, statsProgressTS,
 CarefullyApply, CheckInProgress, CheckReport, DoLogExpunge,
 LongRunningApply, ParseLog, StartStatsReporting, StatsReport],
WalnutParseMsg USING [ParseHeadersFromRope],
WalnutRegistryPrivate USING [NotifyForEvent, NotifyForMove, NotifyForMsgEvent,
 NotifyForMsgSetEvent],
WalnutRoot USING [CloseTransaction, CommitAndContinue, EraseDB,
 Open, Shutdown, StartTransaction, UnregisterStatsProc],
WalnutStream USING [Open];
WalnutOpsImpl: CEDAR MONITOR
IMPORTS
BasicTime, FS, IO, Process, RefText, Rope, RuntimeError,
WalnutDefs,
WalnutDB, WalnutOps, WalnutOpsInternal,
WalnutLog, WalnutLogExpunge, WalnutMiscLog,
WalnutParseMsg, WalnutRegistryPrivate, WalnutRoot, WalnutStream
EXPORTS WalnutOps, WalnutOpsExtras, WalnutOpsInternal
= BEGIN OPEN WalnutOps, WalnutOpsInternal;
Types
TiogaContents: TYPE = ViewerTools.TiogaContents;
ROPE: TYPE = Rope.ROPE;
STREAM: TYPE = IO.STREAM;
GMT: TYPE = BasicTime.GMT;
MsgSet: TYPE = WalnutDefs.MsgSet;
DomainVersion: TYPE = WalnutOps.DomainVersion;
MsgSetVersion: TYPE = WalnutOps.MsgSetVersion;
Public variables
DeletedMsgSetName: PUBLIC ROPE ← "Deleted";
ActiveMsgSetName: PUBLIC ROPE ← "Active";
Private types
EnumeratorForMsgs: TYPE = REF EnumeratorForMsgsObject;
EnumeratorForMsgsObject: PUBLIC TYPE = RECORD[
headers: REF TEXTNIL,
enumerator: SELECT type: * FROM
FromLog => [ createDate: BasicTime.GMT ← BasicTime.nullGMT, scanPos: INT ← 0, endPos: INT ← 0 ],
FromMsgSet => [lazyEnum: WalnutDB.LazyEnumerator],
ENDCASE ];
Variables
Active: PUBLIC ROPE ← "Active";
Deleted: PUBLIC ROPE ← "Deleted";
reporterList: LIST OF IO.STREAMNIL;
checkActivityCondition: CONDITION ← [timeout: Process.SecondsToTicks[5*60]];
replayInProgress: BOOL FALSE;
interference: BOOL FALSE;
walnutRootFile: ROPE;
recentActivity: PUBLIC BOOLFALSE;
started: PUBLIC BOOLFALSE;
isShutdown: PUBLIC BOOLFALSE;
errorInProgress: PUBLIC BOOLFALSE;
walnutSegment: PUBLIC WalnutDefs.Segment;
systemIsReadOnly: PUBLIC BOOLFALSE;
rootFileName: PUBLIC ROPE;
newMailSomewhere: PUBLIC BOOLFALSE;
Procedures
These procedures are all of the primitive atomic actions out of which Walnut is built. More complex operations will be found in WalnutClientOps (someday).
Information about the Walnut database
ReadOnly: PUBLIC ENTRY PROC RETURNS[readonly: BOOL] = {
Is the database readonly?
ENABLE UNWIND => NULL;
WalnutOpsInternal.CheckInProgress[];
readonly ← WalnutDB.IsReadOnly[]; -- doesn't really read DB
};
GetRootInfo: PUBLIC ENTRY PROC RETURNS[createDate: BasicTime.GMT, rootFile, mailFor: ROPE] = {
What is the name of the file storing the database?
ENABLE UNWIND => NULL;
Gri: PROC =
{ [ createDate, , mailFor] ← WalnutDB.GetRootInfo[] };
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Gri, FALSE];
rootFile ← WalnutOpsInternal.rootFileName;
};
FileName: PUBLIC ENTRY PROC RETURNS[fileName: ROPE] = {
ENABLE UNWIND => NULL;
WalnutOpsInternal.CheckInProgress[];
fileName ← WalnutDB.GetDBName[]; -- doesn't read DB
};
SizeOfDatabase: PUBLIC ENTRY PROC RETURNS[messages, msgSets: INT] = {
ENABLE UNWIND => NULL;
Sd: PROC =
{ [messages, msgSets] ← WalnutDB.SizeOfDatabase[] };
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Sd, FALSE];
};
LogLength: PUBLIC ENTRY PROC RETURNS[length: INT] = {
ENABLE UNWIND => NULL;
LLen: PROC =
{ length ← WalnutLog.LogLength[] };
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[LLen, FALSE];
};
MsgSetsInfo: PUBLIC ENTRY PROC RETURNS[version, num: INT] = {
ENABLE UNWIND => NULL;
Msv: PROC =
{ [version, num] ← WalnutDB.MsgSetsInfo[] };
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Msv, FALSE];
};
Adding new messages to the database
CreateMsg: PUBLIC ENTRY PROC [msgName: ROPE, body: TiogaContents] = {
Log a message from some agent other than Grapevine and add it to the database. Body is expected to conform to the syntax for messages. The first message on the log with a given name wins. Any subsequent messages with the same name are dropped on the floor.
ENABLE UNWIND => NULL;
Cm: PROC = {
at: INT ← WalnutLog.WriteMessage[msgName, body];
le: WalnutKernelDefs.LogEntry;
mle: WalnutKernelDefs.MsgLogEntry;
WalnutLog.SetIndex[at];
le ← WalnutLog.NextEntry[].le;
mle ← NARROW[le];
mle.show ← TRUE;
[] ← WalnutDB.AddNewMsg[mle];
};
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Cm, TRUE];
};
Primitive message set operations
CreateMsgSet: PUBLIC ENTRY PROC[name: ROPE, msDomainVersion: DomainVersion] = {
Create a message set with name msgSet.
the named message set already exists (return with exists TRUE).
ENABLE UNWIND => NULL;
exists: BOOL;
Cme: INTERNAL PROC = {
exists ← WalnutDB.CreateMsgSet[name, msDomainVersion].existed;
[] ← WalnutLog.CreateMsgSet[name];
};
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Cme, TRUE];
IF ~exists THEN WalnutRegistryPrivate.NotifyForMsgSetEvent[created, name];
};
MsgSetExists: PUBLIC ENTRY PROC[name: ROPE, msDomainVersion: DomainVersion]
RETURNS[exists: BOOL, version: INT] = {
ENABLE UNWIND => NULL;
Mse: INTERNAL PROC =
{ [exists, version] ← WalnutDB.MsgSetExists[name, msDomainVersion] };
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Mse, FALSE];
};
SizeOfMsgSet: PUBLIC ENTRY PROC[name: ROPE] RETURNS[messages, version: INT] = {
ENABLE UNWIND => NULL;
Sms: INTERNAL PROC =
{ [messages, version] ← WalnutDB.NumInMsgSet[name] };
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Sms, FALSE];
};
EmptyMsgSet: PUBLIC ENTRY PROC [msgSet: MsgSet] RETURNS [someInDeleted: BOOL] = {
Remove all messages from msgSet. Messages that are no longer in any message set will be added to "Deleted".
msgSet is "Deleted" (do nothing).
messages added to "Deleted" (return with someInDeleted TRUE).
ENABLE UNWIND => NULL;
Ems: INTERNAL PROC[inProgress: BOOL] = {
someInDeleted ← FALSE;
IF WalnutDB.EqMsgSets[msgSet.name, DeletedMsgSetName] THEN RETURN;
IF ~inProgress THEN {
at: INT;
IF ~WalnutDB.VerifyMsgSet[msgSet] THEN RETURN;
at ← WalnutLog.EmptyMsgSet[msgSet.name].at;
WalnutDB.SetOpInProgressPos[at];
};
someInDeleted ← WalnutDB.EmptyMsgSet[msgSet, CheckReport];
};
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.LongRunningApply[Ems];
};
DestroyMsgSet: PUBLIC ENTRY PROC [msgSet: MsgSet, msDomainVersion: DomainVersion]
RETURNS [someInDeleted: BOOL] = {
Remove the specified message set from the database.
msgSet must exist (ignore otherwise).
msgSet is "Active" (same as EmptyMsgSet).
msgSet is "Deleted" (do nothing).
ENABLE UNWIND => NULL;
isActive: BOOL;
Dms: INTERNAL PROC[inProgress: BOOL] = {
someInDeleted ← FALSE;
IF ~inProgress THEN {
at: INT;
IF ~WalnutDB.VerifyMsgSet[msgSet] THEN RETURN;
WalnutDB.VerifyDomainVersion[msDomainVersion];
at ← IF isActive THEN WalnutLog.EmptyMsgSet[msgSet.name].at
ELSE WalnutLog.DestroyMsgSet[msgSet.name].at;
WalnutDB.SetOpInProgressPos[at];
};
IF isActive THEN someInDeleted ← WalnutDB.EmptyMsgSet[msgSet, CheckReport]
ELSE someInDeleted ←
WalnutDB.DestroyMsgSet[msgSet, msDomainVersion, CheckReport];
};
WalnutOpsInternal.CheckInProgress[];
IF msgSet.name.Equal[DeletedMsgSetName, FALSE] THEN RETURN[FALSE]; -- may not destroy Deleted
isActive ← msgSet.name.Equal[ActiveMsgSetName, FALSE];
WalnutOpsInternal.LongRunningApply[Dms];
IF ~isActive THEN WalnutRegistryPrivate.NotifyForMsgSetEvent[destroyed, msgSet.name];
};
EnumerateMsgs: PUBLIC ENTRY PROC RETURNS[enum: EnumeratorForMsgs] = {
ENABLE UNWIND => NULL;
thisEnum: REF FromLog EnumeratorForMsgsObject;
Em: INTERNAL PROC = {
thisEnum.createDate ← WalnutDB.GetRootFileVersion[];
thisEnum.endPos ← WalnutLog.LogLength[];
};
WalnutOpsInternal.CheckInProgress[];
thisEnum ← NEW[FromLog EnumeratorForMsgsObject];
WalnutOpsInternal.CarefullyApply[Em, FALSE];
RETURN[thisEnum];
};
NextMsg: PUBLIC ENTRY PROC[enum: EnumeratorForMsgs] RETURNS
 [msgID: ROPE, msList: LIST OF ROPE, headers: REF TEXT] = {
ENABLE UNWIND => NULL;
ok: BOOLTRUE;
Nm: INTERNAL PROC = {
skipped: INT;
isAt: INT;
natLen: NAT;
wle: WalnutLog.LogEntry;
TRUSTED { WITH thisEnum: enum SELECT FROM
FromLog => {
IF thisEnum.createDate # WalnutDB.GetRootFileVersion[] THEN
ERROR WalnutDefs.Error[$db, $InvalidEnumerator, "Wrong rootfile referenced"];
skipped ← WalnutLog.SetPosition[thisEnum.scanPos];
DO
wle: WalnutLog.LogEntry;
at: INT;
[wle, at] ← WalnutLog.QuickScan[];
IF at >= thisEnum.endPos OR wle = NIL THEN { ok ← FALSE; RETURN };
TRUSTED { WITH mle: wle SELECT FROM
CreateMsg => {
natLen ← mle.headersLen;  -- this better not cause an error
msgID ← Rope.FromRefText[mle.msg];
isAt ← WalnutDB.GetMsgEntryPosition[msgID];
IF isAt = -1 OR isAt > mle.entryStart THEN LOOP;  -- oops or duplicate
msList ← WalnutDB.GetCategories[msgID];
IF thisEnum.headers = NIL OR thisEnum.headers.maxLength < natLen THEN
thisEnum.headers ← RefText.New[natLen];
WalnutLog.GetRefTextFromLog[mle.entryStart+mle.textOffset, natLen, thisEnum.headers];
headers ← thisEnum.headers;
thisEnum.scanPos ← WalnutLog.NextAt[];
EXIT;
};
ENDCASE => LOOP;
};
ENDLOOP;
};
FromMsgSet => {
valid: BOOL;
[msgID, valid] ← WalnutDB.NextMsgInMsgSet[thisEnum.lazyEnum];
IF NOT valid OR msgID = NIL THEN RETURN;
isAt ← WalnutDB.GetMsgEntryPosition[msgID];
msList ← WalnutDB.GetCategories[msgID];
[] ← WalnutLog.SetPosition[isAt];
wle ← WalnutLog.QuickScan[].le;
TRUSTED { WITH mle: wle SELECT FROM
CreateMsg => {
natLen ← mle.headersLen;
IF thisEnum.headers = NIL OR thisEnum.headers.maxLength < natLen THEN
thisEnum.headers ← RefText.New[natLen];
WalnutLog.GetRefTextFromLog[isAt+mle.textOffset, natLen, thisEnum.headers] }
ENDCASE };
headers ← thisEnum.headers };
ENDCASE =>
ERROR WalnutDefs.Error[$db, $InvalidEnumerator, "Wrong type of enumerator"];
};
};
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Nm, FALSE];
IF ~ok THEN RETURN[NIL, NIL, NIL];
};
EnumerateMsgsInMsgSet: PUBLIC ENTRY PROC[name: ROPE] RETURNS[enum: EnumeratorForMsgs] = {
ENABLE UNWIND => NULL;
Me: INTERNAL PROC = {
msgSet: WalnutDB.MsgSet;
version: INT;
exists: BOOL;
[exists, version] ← WalnutDB.MsgSetExists[name, WalnutDefs.dontCareDomainVersion];
IF NOT exists THEN RETURN;
msgSet.name ← name; msgSet.version ← version;
enum ← NEW[EnumeratorForMsgsObject ← [enumerator: FromMsgSet[lazyEnum: WalnutDB.EnumerateMsgsInMsgSet[msgSet]]]] };
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Me, FALSE];
};
MsgsEnumeration: PUBLIC ENTRY PROC[alphaOrder: BOOL] RETURNS[mL: LIST OF ROPE] = {
ENABLE UNWIND => NULL;
Me: INTERNAL PROC =
{ mL ← WalnutDB.MsgsEnumeration[alphaOrder] };
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Me, FALSE];
};
MsgSetNames: PUBLIC ENTRY PROC[alphaOrder: BOOL]
RETURNS
[mL: LIST OF ROPE, msDomainVersion: DomainVersion] = {
Create an enumeration for a message set.
ENABLE UNWIND => NULL;
Ems: INTERNAL PROC =
{ [mL, msDomainVersion] ← WalnutDB.MsgSetsNames[alphaOrder] };
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Ems, FALSE];
};
MsgsInSetEnumeration: PUBLIC ENTRY PROC[name: ROPE, fromStart: BOOL]
RETURNS [mL: LIST OF ROPE, msVersion: MsgSetVersion] = {
Create an enumeration for the messages in a message set.
ENABLE UNWIND => NULL;
Emis: INTERNAL PROC =
{ [mL, msVersion] ← WalnutDB.MsgsInSetEnumeration[name, fromStart] };
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Emis, FALSE];
};
EnumerateMsgSets: PUBLIC ENTRY PROC [
alphaOrder: BOOLTRUE, proc: PROC[msgSet: MsgSet] ]
RETURNS [msVersion: MsgSetVersion] = {
ENABLE UNWIND => NULL;
Emss: INTERNAL PROC =
{ msVersion ← WalnutDB.EnumerateMsgSets[alphaOrder, proc] };
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Emss, FALSE];
};
EnumerateMsgsInSet: PUBLIC ENTRY PROC [
name: ROPE,
fromStart: BOOL,
proc: PROC[msg, TOCentry: ROPE, hasBeenRead: BOOL, startOfSubject: INT]]
RETURNS [msVersion: MsgSetVersion] = {
ENABLE UNWIND => NULL;
Ems: INTERNAL PROC =
{ msVersion ← WalnutDB.EnumerateMsgsInSet[name, fromStart, proc] };
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Ems, FALSE];
};
Parsing a message
ParseHeaders: PUBLIC ENTRY PROC [headers: ROPE, proc: WalnutOps.ParseProc]
RETURNS[msgHeaders: WalnutOps.MsgHeaders] = {
proc is called for each fieldName encountered in the headers; if proc is NIL then all headers are returned. It is ok to take the REF TEXT returned by NextMsg and use it, wrapped in a RefText.TrustTextAsRope.
ENABLE UNWIND => NULL;
WalnutOpsInternal.CheckInProgress[];
msgHeaders ← WalnutParseMsg.ParseHeadersFromRope[headers, proc];
};
Primitive message operations
MsgExists: PUBLIC ENTRY PROC [msg: ROPE] RETURNS[exists: BOOL] = {
ENABLE UNWIND => NULL;
Me: INTERNAL PROC =
{ exists ← WalnutDB.MsgExists[msg] };
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Me, FALSE];
};
GetCategories: PUBLIC ENTRY PROC [msg: ROPE] RETURNS[msL: LIST OF ROPE] = {
ENABLE UNWIND => NULL;
GetC: INTERNAL PROC =
{ msL← WalnutDB.GetCategories[msg] };
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[GetC, FALSE];
};
GetDisplayProps: PUBLIC ENTRY PROC[msg: ROPE]
RETURNS[hasBeenRead: BOOL, TOCentry: ROPE, startOfSubject: INT] = {
ENABLE UNWIND => NULL;
GetDP: INTERNAL PROC =
{ [hasBeenRead, TOCentry, startOfSubject] ← WalnutDB.GetDisplayProps[msg] };
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[GetDP, FALSE];
};
GetMsgDate: PUBLIC ENTRY PROC [msg: ROPE] RETURNS[date: BasicTime.GMT] = {
ENABLE UNWIND => NULL;
GetMD: INTERNAL PROC = { date ← WalnutDB.GetMsgDate[msg] };
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[GetMD, FALSE];
};
GetMsg: PUBLIC ENTRY PROC [msg: ROPE]
RETURNS[contents: TiogaContents, herald, shortName: ROPE] = {
ENABLE UNWIND => NULL;
GetMT: INTERNAL PROC = {
textStart, textLen, formatLen, shortNameLen: INT;
[textStart, textLen, formatLen, herald, shortNameLen] ← WalnutDB.GetMsgText[msg];
IF textStart = 0 THEN RETURN;
contents ← WalnutLog.GetTiogaContents[textStart, textLen, formatLen];
shortName ← herald.Substr[0, shortNameLen];
};
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[GetMT, FALSE];
};
GetMsgText: PUBLIC ENTRY PROC [msg: ROPE, text: REF TEXT]
RETURNS[contents: REF TEXT] = {
ENABLE UNWIND => NULL;
CheckForNat: PROC[len: INT] RETURNS[nat: NAT] = { nat ← len };
Gmt: INTERNAL PROC = {
textStart, textLen: INT;
natLen: NAT;
[textStart, textLen, ] ← WalnutDB.GetMsgText[msg];
IF textStart = 0 THEN {
contents ← text;
IF contents # NIL THEN contents.length ← 0;
RETURN};
BEGIN ENABLE RuntimeError.BoundsFault => GOTO oops;
natLen ← CheckForNat[textLen];
IF text = NIL OR (natLen > text.maxLength) THEN
contents ← RefText.New[natLen] ELSE contents ← text;
WalnutLog.GetRefTextFromLog[textStart, textLen, contents];
EXITS
oops =>
ERROR WalnutDefs.Error[$log, $MsgTooLong, "Msg will not fit in a REF TEXT"];
END;
};
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Gmt, FALSE];
};
GetMsgHeaders: PUBLIC ENTRY PROC [msg: ROPE, text: REF TEXT]
RETURNS[headers: REF TEXT] = {
ENABLE UNWIND => NULL;
natLen: NAT;
Gmh: INTERNAL PROC = {
wle: WalnutLog.LogEntry;
isAt: INT = WalnutDB.GetMsgEntryPosition[msg];
headers ← text;
IF isAt = -1 THEN {
IF headers # NIL THEN headers.length ← 0;
RETURN};
[] ← WalnutLog.SetPosition[isAt];
[wle, ] ← WalnutLog.QuickScan[];
BEGIN ENABLE RuntimeError.BoundsFault => GOTO oops;
TRUSTED { WITH mle: wle SELECT FROM
CreateMsg => {
natLen: NAT ← mle.headersLen;
IF headers = NIL OR headers.maxLength < natLen THEN
headers ← RefText.New[natLen];
WalnutLog.GetRefTextFromLog[
mle.entryStart+mle.textOffset, natLen, headers];
};
ENDCASE => NULL;
};
EXITS
oops =>
ERROR WalnutDefs.Error[$log, $MsgHeadersTooLong,
IO.PutFR["Msg headers (%g bytes) will not fit in a REF TEXT", IO.int[natLen]]];
END;
};
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Gmh, FALSE];
};
GetMsgShortName: PUBLIC ENTRY PROC [msg: ROPE] RETURNS[shortName: ROPE] = {
ENABLE UNWIND => NULL;
Gmsn: INTERNAL PROC = {
shortNameLen: INT;
herald: ROPE;
[, , , herald, shortNameLen] ← WalnutDB.GetMsgText[msg];
shortName ← herald.Substr[0, shortNameLen];
};
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Gmsn, FALSE];
};
GetMsgSize: PUBLIC ENTRY PROC [msg: ROPE] RETURNS[textLen, formatLen: INT] = {
ENABLE UNWIND => NULL;
Gms: INTERNAL PROC =
{ [, textLen, formatLen] ← WalnutDB.GetMsgTextInfo[msg] };
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Gms, FALSE];
};
GetHasBeenRead: PUBLIC ENTRY PROC [msg: ROPE] RETURNS[hadBeenRead: BOOL] = {
ENABLE UNWIND => NULL;
Ghbr: INTERNAL PROC = {
hadBeenRead ← WalnutDB.GetHasBeenRead[msg];
};
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Ghbr, FALSE];
};
SetHasBeenRead: PUBLIC ENTRY PROC [msg: ROPE] = {
ENABLE UNWIND => NULL;
Shbr: INTERNAL PROC = {
[] ← WalnutLog.HasBeenRead[msg];
WalnutDB.SetHasBeenRead[msg];
};
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Shbr, TRUE];
WalnutRegistryPrivate.NotifyForMsgEvent[firstRead, msg];
};
More complex message set / message operations
AddMsg: PUBLIC ENTRY PROC [msg: ROPE, from, to: MsgSet] RETURNS [exists: BOOL] = {
Add the message (msg) to the message set (to).
msg must exist (ignore).
to must exist (ignore).
to must not be "Deleted" (ignore).
msg is already in to (return with exists TRUE)
msg had been in "Deleted" (was taken out) (return with undeleted TRUE)
ENABLE UNWIND => NULL;
Am: INTERNAL PROC = {
exists ← WalnutDB.AddMsg[msg, from, to];
[] ← WalnutLog.AddMsg[msg, to.name];
};
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Am, TRUE];
IF ~exists THEN WalnutRegistryPrivate.NotifyForMove[msg: msg, to: to.name, from: NIL];
};
MoveMsg: PUBLIC ENTRY PROC [msg: ROPE, from, to: MsgSet] RETURNS [exists: BOOL] = {
Move the message (msg) from one message set (from) to another (to).
msg must exist (ignore).
from, to must exist (ignore).
msg must be in from (ignore).
msg is already in to (return with exists TRUE).
msg was in "Deleted" (return with undeleted TRUE)
msg is now in "Deleted" (return with deleted TRUE)
ENABLE UNWIND => NULL;
Mm: INTERNAL PROC = {
exists ← WalnutDB.MoveMsg[msg, from, to];
[] ← WalnutLog.MoveMsg[msg, from.name, to.name];
};
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Mm, TRUE];
IF ~exists THEN
WalnutRegistryPrivate.NotifyForMove[msg: msg, to: to.name, from: from.name];
};
RemoveMsg: PUBLIC ENTRY PROC [msg: ROPE, from: MsgSet, deletedVersion: MsgSetVersion]
RETURNS [deleted: BOOL] = {
Remove the message (msg) from the message set (from). If this action results in the message not belonging to any message set, it will be placed in the Deleted message set.
msg must exist (ignore).
from must exist (ignore).
from must not be "Deleted" (ignore).
msg must be in from (ignore).
msg was added to "Deleted" (return with nowInDeleted TRUE).
ENABLE UNWIND => NULL;
Rm: INTERNAL PROC = {
deleted ← WalnutDB.RemoveMsg[msg, from, deletedVersion];
[] ← WalnutLog.RemoveMsg[msg, from.name];
};
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Rm, TRUE];
IF deleted THEN WalnutRegistryPrivate.NotifyForMsgEvent[deleted, msg]
ELSE WalnutRegistryPrivate.NotifyForMove[msg: msg, to: NIL, from: from.name];
};
Adding new messages from grapevine to the database
used by newMail process
StartNewMail: PUBLIC ENTRY PROC[] RETURNS[newMailStream: IO.STREAM] = {
ENABLE UNWIND => NULL;
newMailLogLength: INT ← -1;
expungeInProgress: BOOLFALSE;
Gnml: PROC = {
newMailLogLength ← WalnutDB.GetNewMailLogLength[];
expungeInProgress ← WalnutDB.GetLogExpungePhase[] # idle;
};
WalnutOpsInternal.CheckInProgress[];
IF WalnutOpsInternal.mailStream # NIL THEN RETURN[NIL];
WalnutOpsInternal.CarefullyApply[proc: Gnml, didUpdate: FALSE];
IF newMailLogLength = -1 OR expungeInProgress THEN RETURN[NIL];
RETURN[WalnutOpsInternal.mailStream ← WalnutMiscLog.GetNewMailLog[newMailLogLength, -1]];
};
RecordNewMailInfo: PUBLIC ENTRY PROC[logLen: INT, server: ROPE, num: INT] = {
ENABLE UNWIND => NULL;
when: BasicTime.GMT;
Snml: PROC = {
now: INT ← WalnutDB.GetServerInfo[server] + num;
[] ← WalnutLog.RecordNewMailInfo[logLen, when ← BasicTime.Now[], server, now];
WalnutDB.SetNewMailInfo[logLen, when, server, now];
};
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[proc: Snml, didUpdate: TRUE];
WalnutOpsInternal.newMailSomewhere ← TRUE;
};
EndNewMail: PUBLIC ENTRY PROC = {
ENABLE UNWIND => NULL;
strm: IO.STREAM ← WalnutOpsInternal.mailStream;
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.mailStream ← NIL;
IF strm # NIL THEN
WalnutMiscLog.CloseNewMailLog[ ! WalnutDefs.Error , IO.Error, FS.Error => CONTINUE];
IF WalnutOpsInternal.newMailSomewhere THEN
WalnutRegistryPrivate.NotifyForEvent[mailRead];
};
used by higher levels
GetNewMail: PUBLIC ENTRY PROC[
activeVersion: INT,
proc: PROC[msg, TOCentry: ROPE, startOfSubject: INT]]
RETURNS[responses: LIST OF WalnutOps.ServerInfo, complete: BOOL] = {
ENABLE UNWIND => NULL;
someEntries: BOOL;
Cml: PROC = {
IF activeVersion # WalnutDefs.dontCareMsgSetVersion THEN
[] ← WalnutDB.VerifyMsgSet[ [ActiveMsgSetName, activeVersion] ];
someEntries ← WalnutDB.GetNewMailLogLength[] # 0;
};
Cml2: PROC[inProgress: BOOL] = {
fromPos: INT ← 0;
complete ← WalnutLog.PrepareToCopyTempLog[which: newMail, pagesAlreadyCopied: 0, reportProc: WalnutOpsInternal.CheckReport];
IF ~complete THEN RETURN;
IF ~inProgress THEN {
at: INT ← WalnutLog.StartCopyNewMail[].at;
WalnutDB.SetOpInProgressPos[at];
WalnutDB.SetCopyMailLogPos[at];
}
ELSE {
at: INT = WalnutDB.GetCopyMailLogPos[];
WalnutOpsInternal.CheckReport["\n Continue copying the newMailLog\n"];
[] ← WalnutLog.SetPosition[at];
[] ← WalnutLog.NextEntry[];  -- skip the copy entry
fromPos ← WalnutLog.LogLength[] - WalnutLog.NextAt[];
};
WalnutDB.SetAddingServerMsgs[TRUE];
WalnutLog.CopyTempLog[newMail, WalnutDB.GetCopyMailLogPos[], fromPos, WalnutOpsInternal.CheckReport];
-- raises error if problem
WalnutOpsInternal.CheckReport["\n"];
WalnutDB.SetParseLogInProgress[TRUE];
WalnutDB.SetParseLogPos[WalnutDB.GetOpInProgressPos[]];
WalnutDB.SetOpInProgressPos[-1];
};
Gnm: PROC = {
IF proc # NIL THEN WalnutDB.EnumerateUnacceptedMsgs[activeVersion, proc];
responses ← WalnutDB.EnumerateServers[];
};
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Cml, FALSE];
IF WalnutOpsInternal.mailStream # NIL THEN RETURN[NIL, FALSE];  -- file is busy
IF someEntries THEN {
WalnutOpsInternal.LongRunningApply[Cml2];
IF complete THEN {
WalnutLog.ForgetLogStreams[];
WalnutLog.OpenLogStreams[];
WalnutOpsInternal.CheckReport["Adding new mail to the database\n"];
[] ← WalnutOpsInternal.ParseLog[TRUE];  -- "see" messages
};
}
ELSE complete ← TRUE;
WalnutOpsInternal.CarefullyApply[Gnm, FALSE];
};
AcceptNewMail: PUBLIC ENTRY PROC[activeVersion: INT] = {
ENABLE UNWIND => NULL;
Anm: PROC[inProgress: BOOL] = {
at: INT;
IF ~inProgress THEN {
[] ← WalnutDB.VerifyMsgSet[[ActiveMsgSetName, activeVersion]];
at ← WalnutLog.AcceptNewMail[].at;
WalnutDB.SetOpInProgressPos[at];
}
ELSE at ← WalnutDB.GetAcceptNewMailPos[];
WalnutDB.AcceptNewMail[at, activeVersion];
};
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.LongRunningApply[Anm];
WalnutOpsInternal.newMailSomewhere ← FALSE;
};
Starting and stopping Walnut
Startup: PUBLIC ENTRY PROC [rootFile: ROPE, wantReadOnly: BOOLFALSE]
RETURNS[isReadOnly, newMailExists: BOOL, mailFor: GVBasics.RName, key: ROPE] = {
Start up Walnut with a reference to a Walnut log file. This may involve replaying any actions specified in the "tail" of the log (that portion beyond the lastCommit) so that the database and log agree (in fact, if the database does not exist, it may involve reconstruction of the database in its entirety). If fullScavenge is TRUE, the database is emptied and reconstructed using information from the log. If wantReadOnly is TRUE, the log and the database are opened for reading only. If the log or the database cannot be written, readOnly is TRUE upon return.
already started ($AlreadyStarted).
database or log has become inaccessible ($DatabaseInaccessible, $LogInaccessible)
cannot write the log or the database (return with isReadOnly TRUE).
ENABLE {
WalnutDefs.Error => { errorInProgress ← TRUE; REJECT};
UNWIND => NULL;
};
rootFileCreateDate: GMT;
schemaInvalid: BOOLTRUE;
InitialCheck: INTERNAL PROC = {
rootCreateDate: GMT;
rootFileKey, mailForFromDB: ROPE;
IF key.Length[] # 0 THEN {
[rootCreateDate, rootFileKey, mailForFromDB] ← WalnutDB.GetRootInfo[];
IF rootCreateDate = BasicTime.nullGMT OR
(rootCreateDate = rootFileCreateDate AND
rootFileKey.Length[] = 0 AND
mailForFromDB.Length[] = 0) THEN {
WalnutDB.SetRootInfo[rootFileCreateDate, key, mailFor];
WalnutRoot.CommitAndContinue[];
}
ELSE {
IF ~rootFileKey.Equal[key, FALSE] THEN
WalnutDefs.Error[$db, $WrongRootFile,
IO.PutFR["RootFile has key %g, database says %g",
IO.rope[key], IO.rope[rootFileKey]]];
IF ~mailForFromDB.Equal[mailFor, FALSE] THEN
WalnutDefs.Error[$db, $WrongRootFile,
IO.PutFR["RootFile says mailFor %g, database says %g",
IO.rope[mailFor], IO.rope[mailForFromDB]]];
IF rootCreateDate # rootFileCreateDate THEN
WalnutDefs.Error[$db, $WrongRootFile,
IO.PutFR["RootFile has date %g, database says %g",
IO.time[rootFileCreateDate], IO.time[rootCreateDate]]];
};
};
IF (WalnutOpsInternal.newMailSomewhere ← WalnutDB.GetNewMailLogLength[] # 0)
THEN RETURN;
check for unaccepted mail
BEGIN
serverList: LIST OF ServerInfo ← WalnutDB.EnumerateServers[];
FOR sL: LIST OF ServerInfo ← serverList, sL.rest UNTIL sL = NIL DO
IF (WalnutOpsInternal.newMailSomewhere ← sL.first.num#0) THEN RETURN;
ENDLOOP;
END;
};
IF started THEN RETURN WITH ERROR WalnutDefs.Error[$db, $AlreadyStarted];
StartStatsReporting[];
[key, mailFor, rootFileCreateDate, walnutSegment, systemIsReadOnly] ←
WalnutRoot.Open[rootName: rootFile, readOnly: wantReadOnly];
rootFileName ← rootFile;
BEGIN
exp: ROPE;
BEGIN
schemaInvalid ← WalnutRoot.StartTransaction[ ! WalnutDefs.Error => {
IF code # $MismatchedSegment THEN REJECT;
exp ← explanation;
GOTO mismatched;
}];
EXITS
mismatched => RETURN WITH ERROR WalnutDefs.Error[$db, $SchemaMismatch, exp];
END;
END;
schemaInvalid ← WalnutRoot.StartTransaction[];
WalnutLog.OpenLogStreams[];
walnutRootFile ← rootFile;
isReadOnly ← systemIsReadOnly;
BEGIN
exp: ROPE;
BEGIN
WalnutDB.DeclareDB[walnutSegment, schemaInvalid !
WalnutDefs.SchemaMismatch => { exp ← explanation; GOTO mismatch}];
StatsReport[IO.PutFR["\n\n ***** Startup called with rootFile: %g", IO.rope[rootFile]]];
EXITS
mismatch => RETURN WITH ERROR WalnutDefs.Error[$db, $SchemaMismatch, exp];
END;
END;
started ← TRUE;
errorInProgress ← FALSE;
CarefullyApply[InitialCheck, FALSE];
CheckInProgress[];
newMailExists ← WalnutOpsInternal.newMailSomewhere;
WalnutRegistryPrivate.NotifyForEvent[started];
};
Shutdown: PUBLIC ENTRY PROC = {
Save the Walnut state and shutdown Walnut.
ENABLE {
WalnutDefs.Error => { errorInProgress ← TRUE; REJECT};
UNWIND => NULL;
};
WalnutRoot.UnregisterStatsProc[StatsReport];
WalnutLogExpunge.ExpShutdown[];  -- clear its variables
WalnutMiscLog.MiscShutdown[];  -- clear its variables
WalnutLog.ShutdownLog[];
WalnutRoot.Shutdown[];  -- takes care of database
StatsReport["\n *** Shutdown"];
IF statsProgressTS # NIL THEN { statsProgressTS.inhibitDestroy ← FALSE };
IF statsStream # NIL THEN { statsStream.Close[]; statsStream ← NIL };
IF statsProgressStream # NIL THEN
{ statsProgressStream.Close[]; statsProgressStream ← NIL };
started ← FALSE;
recentActivity← FALSE;
isShutdown ← FALSE;
errorInProgress ← FALSE;
mailStream ← NIL;
WalnutRegistryPrivate.NotifyForEvent[stopped];
};
Scavenge: PUBLIC ENTRY PROC[rootFile: ROPE]
RETURNS[newMailExists: BOOL, mailFor: GVBasics.RName, key: ROPE] = {
ENABLE {
WalnutDefs.Error => { errorInProgress ← TRUE; REJECT};
UNWIND => NULL;
};
rootFileCreateDate: GMT;
WalnutLog.ShutdownLog[];
WalnutRoot.Shutdown[];
StartStatsReporting[];
StatsReport["\n *** Scavenge"];
[key, mailFor, rootFileCreateDate, walnutSegment, systemIsReadOnly] ←
WalnutRoot.Open[rootName: rootFile, readOnly: FALSE, newSegmentOk: TRUE];
IF systemIsReadOnly THEN
ERROR WalnutDefs.Error[$DB, $IsReadOnly, "Can't erase a readonly database"];
rootFileName ← rootFile;
[] ← WalnutRoot.StartTransaction[openDB: FALSE];  -- don't care if schema is invalid
WalnutLog.OpenLogStreams[];
WalnutLog.AcquireWriteLock[];
started ← TRUE;
errorInProgress ← FALSE;
WalnutRoot.EraseDB[];
WalnutDB.InitSchema[walnutSegment];
WalnutDB.SetRootInfo[rootFileCreateDate, key, mailFor];
WalnutDB.SetParseLogInProgress[TRUE];
WalnutDB.SetParseLogPos[0];
WalnutRoot.CommitAndContinue[];
WalnutOpsInternal.newMailSomewhere ← FALSE;
[] ← WalnutOpsInternal.ParseLog[TRUE];
WalnutDB.SetTimeOfLastScavenge[BasicTime.Now[]];
newMailExists ← WalnutOpsInternal.newMailSomewhere;
};
Procedures
Space conservation (removing unreferenced messages)
GetExpungeInfo: PUBLIC ENTRY PROC RETURNS[
firstDestroyedMsgPos, bytesInDestroyedMsgs: INT] = {
ENABLE UNWIND => NULL;
Gei: PROC =
{ [ firstDestroyedMsgPos, bytesInDestroyedMsgs] ← WalnutDB.GetExpungeInfo[] };
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Gei, FALSE]
};
ExpungeMsgs: PUBLIC ENTRY PROC[deletedVersion: INT]
RETURNS[bytesInDestroyedMsgs: INT] = {
ENABLE UNWIND => NULL;
Expm: INTERNAL PROC[inProgress: BOOL] = {
IF ~inProgress THEN {
at: INT;
[] ← WalnutDB.VerifyMsgSet[[WalnutOps.DeletedMsgSetName, deletedVersion]];
at ← WalnutLog.ExpungeMsgs[].at;
WalnutDB.SetOpInProgressPos[at];
};
WalnutDB.ExpungeMsgs[deletedVersion, CheckReport];
bytesInDestroyedMsgs ← WalnutDB.GetExpungeInfo[].bytesInDestroyedMsgs
};
WalnutOpsInternal.CheckInProgress[];
CheckReport["\nDeleting msgs"];
WalnutOpsInternal.LongRunningApply[Expm];
};
CopyToExpungeLog: PUBLIC ENTRY PROC = {
ENABLE UNWIND => NULL;
ExpL: INTERNAL PROC[inProgress: BOOL] = {
IF ~inProgress THEN {
at: INT ← WalnutLog.WriteExpungeLog[].at;   -- write log entry of intent
WalnutDB.SetOpInProgressPos[at];
};
WalnutOpsInternal.DoLogExpunge[0]
};
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.LongRunningApply[ExpL];
};
GetTimeOfLastExpunge: PUBLIC ENTRY PROC RETURNS[when: BasicTime.GMT] = {
ENABLE UNWIND => NULL;
Gdle: PROC =
{ when ← WalnutDB.GetTimeOfLastExpunge[] };
WalnutOpsInternal.CheckInProgress[];
WalnutOpsInternal.CarefullyApply[Gdle, FALSE]
};
Producing and reading archive files
Reading an archive file is a long operation; it is resilient, so that it will complete when restarted. The file is first copied to the current log (if the archive file exists) and then the tail of the log is "replayed", which may involve creating new messages and shuffling them around in the database.
ReadArchiveFile: PUBLIC ENTRY PROC[file: ROPE, msgSet: WalnutDefs.MsgSet ← [NIL, -1]]
  RETURNS[numNew: INT] = {
Write a "readArchiveFile" log entry; if the archiveFile exists, parses it and writes the appropriate entries (new msgs and moves if msgSet is not "Active" (NIL defaults to categories specified in the file). Then replays the log. If the file couldn't be read, numNew = -1;
ENABLE UNWIND => NULL;
ok: BOOLFALSE;
fStream: STREAM;
reason: ROPE;
Raf: PROC = {
at: INT;
IF msgSet.name # NIL THEN [] ← WalnutDB.VerifyMsgSet[msgSet];
at ← WalnutLog.StartReadArchiveFile[file, msgSet.name].at;
WalnutDB.SetReadArchivePos[at];
};
Raf2: PROC = {
[] ← WalnutLog.EndReadArchiveFile[];
WalnutDB.SetReadArchivePos[0];
};
Caf: PROC[inProgress: BOOL] = {
fromPos: INT ← 0;
IF ~inProgress THEN {
at: INT;
ok ← WalnutLog.PrepareToCopyTempLog[ which: readArchive, pagesAlreadyCopied: 0, reportProc: WalnutOpsInternal.CheckReport];
IF ~ok THEN RETURN;
at ← WalnutLog.StartCopyReadArchive[].at;
WalnutDB.SetCopyReadArchivePos[at];
WalnutDB.SetOpInProgressPos[at];
WalnutRoot.CommitAndContinue[];
}
ELSE {  -- calculate fromPos
logLen: INT ← WalnutLog.LogLength[];
startedCopyAt, startCopyPos: INT;
startCopyPos ← WalnutDB.GetCopyReadArchivePos[];
IF WalnutLog.SetPosition[startCopyPos] # 0 THEN
ERROR WalnutDefs.Error[$log, $BadLog, IO.PutFR["no entry at %g",
IO.int[startCopyPos]]];
[] ← WalnutLog.NextEntry[];   -- skip the copy entry
startedCopyAt ← WalnutLog.NextAt[];
fromPos ← logLen - startedCopyAt;
};
CheckReport[
IO.PutFR["\nCopying the ReadArchiveTempLog, starting at bytePos %g\n",
IO.int[fromPos]]];
WalnutLog.CopyTempLog[
readArchive, WalnutDB.GetCopyReadArchivePos[], fromPos, CheckReport];
CheckReport["\n"];
WalnutDB.SetParseLogInProgress[TRUE];
WalnutDB.SetParseLogPos[WalnutDB.GetOpInProgressPos[]];
WalnutDB.SetOpInProgressPos[-1];
};
WalnutOpsInternal.CheckInProgress[];
fStream ← WalnutStream.Open[name: file, readOnly: TRUE ! FS.Error =>
{ CheckReport[error.explanation]; fStream ← NIL; CONTINUE} ].strm;
IF fStream = NIL THEN RETURN[-1];
WalnutOpsInternal.CarefullyApply[proc: Raf, didUpdate: TRUE];
BEGIN ENABLE BEGIN
FS.Error => { reason ← error.explanation; GOTO exit };
IO.Error => {
reason ← FS.ErrorFromStream[stream].explanation;
IF reason = NIL THEN reason ← "IO Error creating readArchiveLog";
GOTO exit
};
END;
[ok, reason] ←
WalnutMiscLog.CreateReadArchiveLog[fStream, msgSet.name, CheckReport];
EXITS
exit => ok ← FALSE;
END;
fStream.Close[ ! IO.Error, FS.Error => CONTINUE];
IF ~ok THEN {
CheckReport[IO.PutFR[" Archive Read of %g failed", IO.rope[file]]];
IF reason # NIL THEN CheckReport[" Error reported as: ", reason];
RETURN[-1];
}
ELSE Raf2[];
WalnutOpsInternal.LongRunningApply[Caf];
IF ~ok THEN {
CheckReport[IO.PutFR[" Out of space trying to copy readArchiveLog for file %g",
IO.rope[file]]];
RETURN[-1];
};
CheckReport["\nAdding messages to database\n"];
numNew ← WalnutOpsInternal.ParseLog[TRUE];
};
WriteArchiveFile: PUBLIC ENTRY PROC[
file: ROPE, msgSetList: LIST OF WalnutDefs.MsgSet, append: BOOL] RETURNS[ok: BOOL]= {
Write an archive file that contains the messages from the given message sets. No log entry is written and no updates are made to the database (we just hold the monitor to guarantee that no changes to the message sets occur).
ENABLE UNWIND => NULL;
wStream: STREAM;
someMsgWasTooBig: BOOLFALSE;
walnutItemForm: ROPE = "@%05d 00525 %05d\n";  -- 20 chars, tioga formatting
startHeaderForm: ROPE = "*start*\n%05d %05d US \n";
thisMsgSet, exp: ROPE;
startHeaderFixedLen: INT = 24;
first: BOOLTRUE;
WriteProc: PROC[msg, TOCentry: ROPE, hasBeenRead: BOOL, startOfSubject: INT] = {
textStart, textLen, formatLen, prefixLen: INT;
length, walnutItemLen: INT ← 0;
walnutItem: ROPE;
[textStart, textLen, formatLen, , ] ← WalnutDB.GetMsgText[msg];
walnutItem ← Rope.Cat[msg, "\n", thisMsgSet, "\n"];
walnutItemLen ←
WalnutMiscLog.walnutItemFixedLength + walnutItem.Length[] + formatLen;
IF formatLen # 0 THEN walnutItemLen ← walnutItemLen + 1; -- for extra CR after formatting
prefixLen ← startHeaderFixedLen + walnutItemLen;
length ← prefixLen + textLen + 1;  -- extra CR after text
IF length > 99999 THEN {
CheckReport[IO.PutFR["\nLength of msg %g is too big (%g bytes) - skipping",
IO.rope[msg], IO.int[length]] ];
someMsgWasTooBig ← TRUE;
RETURN
};
-- the -2 below are because the bytecount within the prefix item does not include the surrounding @'s
wStream.PutRope[
IO.PutFR[startHeaderForm, IO.int[length], IO.int[prefixLen]] ];
wStream.PutRope[
IO.PutFR[walnutItemForm, IO.int[walnutItemLen-2], IO.int[formatLen] ]];
wStream.PutRope[walnutItem];
IF formatLen # 0 THEN {
WalnutLog.CopyBytesToArchive[wStream, textStart+textLen, formatLen];
wStream.PutChar['\n];
};
wStream.PutChar['@];
WalnutLog.CopyBytesToArchive[wStream, textStart, textLen];
wStream.PutChar['\n];
};
ok ← FALSE;
WalnutOpsInternal.CheckInProgress[];
BEGIN ENABLE BEGIN
WalnutDefs.Error => {
IF wStream # NIL THEN wStream.Close[ ! IO.Error, FS.Error => CONTINUE];
REJECT;
};
WalnutDefs.VersionMismatch => {
IF wStream # NIL THEN wStream.Close[ ! IO.Error, FS.Error => CONTINUE];
REJECT;
};
IO.Error => { CheckReport[exp ← FS.ErrorFromStream[stream].explanation]; GOTO err };
FS.Error => { CheckReport[exp ← error.explanation]; GOTO err };
END;
BEGIN
wStream ← WalnutStream.Open[
name: file, useOldIfFound: append, exclusive: TRUE ! FS.Error =>
{ CheckReport[error.explanation]; GOTO none }].strm;
EXITS
none => wStream ← NIL;
END;
IF wStream = NIL THEN {
CheckReport[IO.PutFR["\nCould not open %g", IO.rope[file]]];
RETURN
};
IF append THEN wStream.SetIndex[wStream.GetLength[]]
ELSE {
wStream.SetIndex[0];
wStream.SetLength[0];
};
CheckReport["\n Archiving: "];
FOR mL: LIST OF WalnutDefs.MsgSet ← msgSetList, mL.rest UNTIL mL=NIL DO
thisMsgSet ← mL.first.name;
IF ~WalnutDB.VerifyMsgSet[mL.first] THEN {
CheckReport["\n MsgSet ", thisMsgSet, " doesn't exist - continuing"];
LOOP;
};
IF first THEN first ← FALSE ELSE CheckReport[", "];
CheckReport[thisMsgSet];
[] ← WalnutDB.EnumerateMsgsInSet[name: thisMsgSet, proc: WriteProc];
ENDLOOP;
EXITS
err => {
wStream.Close[];
ERROR WalnutDefs.Error[$log, $ErrorDuringWriteArchive, exp];
};
END;
wStream.Close[];
ok ← TRUE;
CheckReport["\n Finished writing archive file\n"];
};
-- * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
RegisterReporter: PUBLIC ENTRY PROC[reportStream: IO.STREAM] = {
ENABLE UNWIND => NULL;
FOR rL: LIST OF IO.STREAM← reporterList, rL.rest UNTIL rL= NIL DO
IF rL.first = reportStream THEN RETURN;
ENDLOOP;
reporterList← CONS[reportStream, reporterList];
};
UnregisterReporter: PUBLIC ENTRY PROC[reportStream: IO.STREAM] = {
ENABLE UNWIND => NULL;
prev: LIST OF IO.STREAM;
IF reporterList = NIL OR reportStream = NIL THEN RETURN;
IF reporterList.first = reportStream THEN {reporterList← reporterList.rest; RETURN};
prev← reporterList;
FOR rL: LIST OF IO.STREAM← reporterList, rL.rest UNTIL rL= NIL DO
IF rL.first = reportStream THEN { prev.rest← rL.rest; RETURN};
prev← rL;
ENDLOOP;
};
CheckReport: PUBLIC PROC[msg1, msg2, msg3: ROPE← NIL] = {
IF reporterList = NIL THEN RETURN;
FOR rL: LIST OF IO.STREAM← reporterList, rL.rest UNTIL rL= NIL DO
IF msg1 # NIL THEN rL.first.PutRope[msg1];
IF msg2 # NIL THEN rL.first.PutRope[msg2];
IF msg3 # NIL THEN rL.first.PutRope[msg3];
ENDLOOP;
};
Communicating with WalnutOpsInternal
CheckForRecentActivity: ENTRY PROC = {
ENABLE UNWIND => recentActivity ← FALSE;
DO
WAIT checkActivityCondition;
IF started THEN {
IF recentActivity = TRUE THEN recentActivity ← FALSE
ELSE IF ~isShutdown THEN {
isShutdown ← TRUE;
WalnutLog.ForgetLogStreams[];
WalnutRoot.CloseTransaction[];
isShutdown ← TRUE;
StatsReport[" $$ Close transactions due to inactivity"];
};
};
ENDLOOP;
};
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
recentActivity ← FALSE;
TRUSTED {Process.Detach[FORK CheckForRecentActivity] };
END.