-- File: AlpineInterimDirectoryImpl.mesa
-- Last edited by:
-- MBrown on February 1, 1984 8:09:03 pm PST
-- Kolling on December 16, 1983 3:46 pm


DIRECTORY
AlpineEnvironment
USING[bytesPerPage, ByteCount, FileID, FileStore, maxStringNameChars, nullUniversalFile,
nullVolumeGroupID, Outcome, OwnerName, OwnerPropertyValuePair, PageCount,
PageNumber, PropertyValuePair, UniversalFile, VolumeGroupID, wordsPerPage],
AlpFile
USING[Create, Delete, GetSize, Handle, Open, ReadPages,
ReadProperties, SetSize, VALUEPageBuffer, WritePages, WriteProperties],
AlpInstance
USING[AccessFailed, Create, Failed, Handle, LockFailed, OperationFailed, PossiblyDamaged,
Unknown],
AlpineInterimDirectory
USING[CreateOptions, EnumProc, ErrorType, Inconsistency],
AlpTransaction
USING[Create, CreateWorker, Finish, GetNextVolumeGroup, Handle,
ReadOwnerProperties, WriteOwnerProperties],
Ascii
USING[Upper],
PrincOps
USING[zMISC, zPOP],
PrincOpsUtils
USING[LongCOPY],
RefText
USING[ObtainScratch, ReleaseScratch],
Rope
USING[Equal, Fetch, IsEmpty, Length, Map, Match, ROPE, SkipTo, Substr],
RPC
USING[CallFailed];


AlpineInterimDirectoryImpl: CEDAR PROGRAM
IMPORTS Ascii, AlpF: AlpFile, AlpI: AlpInstance, AlpT: AlpTransaction,
PrincOpsUtils, RefText, Rope, RPC
EXPORTS AlpineInterimDirectory =

BEGIN OPEN AE: AlpineEnvironment;

initialDirSize: INT = 10;
incrementDirSize: INT = 10;

Error: PUBLIC ERROR [why: ErrorType] = CODE;
ErrorType: TYPE = AlpineInterimDirectory.ErrorType;

DirectoryInconsistent: PUBLIC SIGNAL [how: Inconsistency] = CODE;
Inconsistency: TYPE = AlpineInterimDirectory.Inconsistency;

Open: PUBLIC PROCEDURE[fileName: Rope.ROPE, createOptions:
AlpineInterimDirectory.CreateOptions, initialByteAllocation: AE.ByteCount]
RETURNS[instHandle: AlpI.Handle, refUniversalFile: REF AE.UniversalFile,
createdFile: BOOL] =
BEGIN -- errors: DirectoryInconsistent[ownerRootFileNotFound], Error[authenticateFailed, damaged, fileAlreadyExists, fileNotFound, illegalFileName, insufficientPermission, lockFailed, ownerNotFound, ownerRecordFull, quota, regServersUnavailable, remoteCallFailed, serverBusy, serverNotFound, transAborted].
Open1: PROCEDURE[transHandle: AlpT.Handle, fileStore: AE.FileStore, owner:
AE.OwnerName, restOfFileName: Rope.ROPE] = BEGIN
[refUniversalFile, createdFile] ←
OpenUnderTransKernel[transHandle, fileName, fileStore, owner, restOfFileName,
createOptions, initialByteAllocation];
END;
instHandle ← EstablishTransactionContext[fileName, TRUE, Open1];
END;

Delete: PUBLIC PROCEDURE[fileName: Rope.ROPE] =
BEGIN -- errors: DirectoryInconsistent[directoryFileNotFound, ownerRootFileNotFound], Error[authenticateFailed, damaged, fileNotFound, illegalFileName, insufficientPermission, lockFailed, ownerNotFound, regServersUnavailable, remoteCallFailed, serverBusy, serverNotFound, transAborted].
Delete1: PROCEDURE[transHandle: AlpT.Handle, fileStore: AE.FileStore, owner:
AE.OwnerName, restOfFileName: Rope.ROPE] =
BEGIN
DeleteUnderTransKernel[transHandle, fileStore, owner, restOfFileName];
END;
[] ← EstablishTransactionContext[fileName, TRUE, Delete1];
END;

EnumerateDirectory: PUBLIC PROCEDURE[directoryName: Rope.ROPE, enumProc: EnumProc] =
BEGIN -- errors: DirectoryInconsistent[ownerRootFileNotFound], Error[authenticateFailed, damaged, illegalFileName, insufficientPermission, lockFailed, ownerNotFound, regServersUnavailable, remoteCallFailed, serverBusy, serverNotFound, transAborted] plus any errors raised by the enumProc.
EnumerateDirectory1: PROCEDURE[transHandle: AlpT.Handle, fileStore: AE.FileStore,
owner: AE.OwnerName, restOfFileName: Rope.ROPE] =
BEGIN
EnumerateDirectoryUnderTransKernel[transHandle, fileStore, owner, enumProc];
END;
[] ← EstablishTransactionContext[directoryName, FALSE, EnumerateDirectory1];
END;

EstablishTransactionContext: PROCEDURE[fileOrDirectoryName: Rope.ROPE, file:
BOOLEAN, p: PROCEDURE[transHandle: AlpT.Handle, fileStore: AE.FileStore, owner:
AE.OwnerName, restOfFileName: Rope.ROPE]] RETURNS[instHandle: AlpI.Handle] =
BEGIN -- errors: DirectoryInconsistent[directoryFileNotFound, ownerRootFileNotFound], Error[authenticateFailed, damaged, fileAlreadyExists, fileNotFound, illegalFileName, insufficientPermission, lockFailed, ownerNotFound, ownerRecordFull, quota, remoteCallFailed, regServersUnavailable, serverBusy, serverNotFound, transAborted] plus any errors raised by the enumProc.
whyError: ErrorType;
transHandle: AlpT.Handle ← NIL;
fileStore: AE.FileStore;
owner: AE.OwnerName;
restOfFileName: Rope.ROPE;
BEGIN
ENABLE RPC.CallFailed => BEGIN whyError ← remoteCallFailed; GOTO operationFailed END;
transOutcome: AE.Outcome;
[fileStore, owner, restOfFileName] ← DecomposeFileName[fileOrDirectoryName, NOT file];
instHandle ← AlpI.Create[fileStore, ,
! AlpI.Failed => BEGIN whyError ← (IF why = authenticateFailed THEN authenticateFailed
ELSE remoteCallFailed); GOTO operationFailed END;];
transHandle ← AlpT.Create[instHandle: instHandle, createLocalWorker: TRUE !
AlpI.OperationFailed => SELECT why FROM
busy => BEGIN whyError ← serverBusy; GOTO operationFailed END;
ENDCASE => REJECT];
p[transHandle, fileStore, owner, restOfFileName !
Error => BEGIN whyError ← why; GOTO operationFailed END;
AlpI.Unknown => SELECT what FROM
openFileID, transID => BEGIN whyError ← transAborted; GOTO operationFailed END;
owner => BEGIN whyError ← ownerNotFound; GOTO operationFailed END;
coordinator => BEGIN whyError ← serverNotFound; GOTO operationFailed END;
ENDCASE => REJECT;
AlpI.LockFailed => BEGIN whyError ← lockFailed; GOTO operationFailed; END;
AlpI.AccessFailed => BEGIN whyError ← (IF missingAccess = spaceQuota THEN quota ELSE
insufficientPermission); GOTO operationFailed; END;
AlpI.OperationFailed => SELECT why FROM
damagedLeaderPage => BEGIN whyError ← damaged; GOTO operationFailed; END;
insufficientSpace => BEGIN whyError ← quota; GOTO operationFailed; END;
ownerRecordFull => BEGIN whyError ← ownerRecordFull; GOTO operationFailed; END;
regServersUnavailable => BEGIN whyError ← regServersUnavailable; GOTO
operationFailed; END;
ENDCASE => NULL;
AlpI.PossiblyDamaged => BEGIN whyError ← damaged; GOTO operationFailed; END;
];
transOutcome ← transHandle.Finish[requestedOutcome: commit, continue: FALSE];
IF transOutcome # commit THEN ERROR Error[transAborted];
EXITS
operationFailed => BEGIN
IF whyError # remoteCallFailed AND transHandle # NIL THEN
[] ← transHandle.Finish[abort, FALSE ! RPC.CallFailed => CONTINUE];
ERROR Error[whyError];
END;
END;
END;


OpenUnderTrans: PUBLIC PROCEDURE[transHandle: AlpT.Handle, fileName: Rope.ROPE,
createOptions: AlpineInterimDirectory.CreateOptions, initialByteAllocation: AE.ByteCount]
RETURNS [universalFile: AE.UniversalFile, createdFile: BOOL] =
BEGIN -- errors: DirectoryInconsistent[ownerRootFileNotFound], Error[fileAlreadyExists, fileNotFound, illegalFileName], AlpI.AccessFailed[fileRead, fileModify, handleReadWrite, ownerCreate, spaceQuota], AlpI.LockFailed, AlpI.OperationFailed[damagedLeaderPage, insufficientSpace, ownerRecordFull, regServersUnavailable], AlpI.PossiblyDamaged, AlpI.Unknown[coordinator, openFileID, owner, transID], RPC.CallFailed.
fileStore: AE.FileStore; owner: AE.OwnerName; restOfFileName: Rope.ROPE;
refUniversalFile: REF AE.UniversalFile ← NIL;
[fileStore, owner, restOfFileName] ← DecomposeFileName[fileName, FALSE];
[refUniversalFile, createdFile] ← OpenUnderTransKernel[transHandle, fileName, fileStore,
owner, restOfFileName, createOptions, initialByteAllocation];
universalFile ← refUniversalFile^;
END;

OpenUnderTransKernel: PROCEDURE[transHandle: AlpT.Handle, fileName: Rope.ROPE,
fileStore: AE.FileStore, owner: AE.OwnerName, restOfFileName: Rope.ROPE, createOptions:
AlpineInterimDirectory.CreateOptions, initialByteAllocation: AE.ByteCount]
RETURNS[refUniversalFile: REF AE.UniversalFile, createdFile: BOOL] =
BEGIN -- errors: DirectoryInconsistent[ownerRootFileNotFound], Error[fileAlreadyExists, fileNotFound], AlpI.AccessFailed[fileRead, fileModify, handleReadWrite, ownerCreate, spaceQuota], AlpI.LockFailed, AlpI.OperationFailed[damagedLeaderPage, insufficientSpace, ownerRecordFull, regServersUnavailable], AlpI.PossiblyDamaged, AlpI.Unknown[coordinator, openFileID, owner, transID], RPC.CallFailed.
directoryFileHandle: AlpF.Handle;
volumeGroupID: AE.VolumeGroupID;
[directoryFileHandle, volumeGroupID] ← GetOwnerRootFile[transHandle: transHandle,
fileStore: fileStore, owner: owner, createRootFileIfMissing: (createOptions # oldOnly),
openRootFileForWrite: (createOptions # oldOnly)];
[refUniversalFile, createdFile] ← OpenFile[transHandle, directoryFileHandle, fileName,
restOfFileName, createOptions, volumeGroupID, owner, initialByteAllocation];
END;

DeleteUnderTrans: PUBLIC PROCEDURE[transHandle: AlpT.Handle, fileName: Rope.ROPE] =
BEGIN -- errors: DirectoryInconsistent[directoryFileNotFound, ownerRootFileNotFound], Error[fileNotFound, illegalFileName], AlpI.AccessFailed[fileRead, fileModify, handleReadWrite], AlpI.LockFailed, AlpI.OperationFailed[damagedLeaderPage, regServersUnavailable], AlpI.PossiblyDamaged, AlpI.Unknown[coordinator, openFileID, owner, transID], RPC.CallFailed.
fileStore: AE.FileStore; owner: AE.OwnerName; restOfFileName: Rope.ROPE;
[fileStore, owner, restOfFileName] ← DecomposeFileName[fileName, FALSE];
DeleteUnderTransKernel[transHandle, fileStore, owner, restOfFileName];
END;

DeleteUnderTransKernel: PROCEDURE[transHandle: AlpT.Handle, fileStore: AE.FileStore,
owner: AE.OwnerName, restOfFileName: Rope.ROPE] =
BEGIN -- errors: DirectoryInconsistent[directoryFileNotFound, ownerRootFileNotFound], Error[fileNotFound], AlpI.AccessFailed[fileRead, fileModify, handleReadWrite], AlpI.LockFailed, AlpI.OperationFailed[damagedLeaderPage, regServersUnavailable], AlpI.PossiblyDamaged, AlpI.Unknown[coordinator, openFileID, owner, transID], RPC.CallFailed.
directoryFileHandle: AlpF.Handle ← GetOwnerRootFile[transHandle: transHandle, fileStore:
fileStore, owner: owner, createRootFileIfMissing: FALSE, openRootFileForWrite:
TRUE].directoryFileHandle;
DeleteFile[transHandle, directoryFileHandle, restOfFileName];
END;

EnumProc: TYPE = AlpineInterimDirectory.EnumProc;
-- PROC [fileName: ROPE, universalFile: AE.UniversalFile] RETURNS [quit: BOOL]

EnumerateDirectoryUnderTrans: PUBLIC PROCEDURE[transHandle: AlpT.Handle,
directoryName: Rope.ROPE, enumProc: EnumProc] =
BEGIN -- errors: DirectoryInconsistent[ownerRootFileNotFound], Error[illegalFileName], AlpI.AccessFailed[fileRead], AlpI.LockFailed, AlpI.OperationFailed[damagedLeaderPage, regServersUnavailable], AlpI.PossiblyDamaged, AlpI.Unknown[coordinator, openFileID, owner, transID], RPC.CallFailed, plus any errors raised by enumProc.
fileStore: AE.FileStore; owner: AE.OwnerName;
[fileStore, owner, ] ← DecomposeFileName[directoryName, TRUE];
EnumerateDirectoryUnderTransKernel[transHandle, fileStore, owner, enumProc];
END;

EnumerateDirectoryUnderTransKernel: PROCEDURE[transHandle: AlpT.Handle,
fileStore: AE.FileStore, owner: AE.OwnerName, enumProc: EnumProc] =
BEGIN -- errors: DirectoryInconsistent[ownerRootFileNotFound], AlpI.AccessFailed[fileRead], AlpI.LockFailed, AlpI.OperationFailed[damagedLeaderPage, regServersUnavailable], AlpI.PossiblyDamaged, AlpI.Unknown[coordinator, openFileID, owner, transID], RPC.CallFailed, plus any errors raised by enumProc.
directoryFileHandle: AlpF.Handle ← GetOwnerRootFile[transHandle: transHandle, fileStore:
fileStore, owner: owner, createRootFileIfMissing: FALSE, openRootFileForWrite:
FALSE].directoryFileHandle;
EnumerateFiles[transHandle, directoryFileHandle, enumProc];
END;

DecomposeFileName: PROCEDURE[fileName: Rope.ROPE, expectRestOfFileNameEmpty: BOOL]
RETURNS[fileStore, owner, restOfFileName: Rope.ROPE] =
BEGIN -- errors: Error[illegalFileName].
IsIllegal: SAFE PROCEDURE[c: CHAR] RETURNS [quit: BOOL] = CHECKED BEGIN
RETURN [NOT IsLegal[c]] END;
rightSquareBracket, rightAngleBracket: INT;
IF fileName.Map[action: IsIllegal] THEN ERROR Error[illegalFileName];
IF fileName.Length[] > AE.maxStringNameChars THEN
ERROR Error[illegalFileName];
IF NOT Rope.Match[pattern: "[*]<*>*", object: fileName, case: FALSE] THEN
ERROR Error[illegalFileName];
rightSquareBracket ← fileName.SkipTo[1, "]"];
fileStore ← fileName.Substr[start: 1, len: rightSquareBracket-1];
rightAngleBracket ← fileName.SkipTo[1, ">"];
owner ← fileName.Substr[start: rightSquareBracket+2, len:
rightAngleBracket-rightSquareBracket-2];
restOfFileName ← fileName.Substr[start: rightAngleBracket+1];
IF fileStore.IsEmpty[] OR owner.IsEmpty[] OR
(restOfFileName.IsEmpty[] # expectRestOfFileNameEmpty) THEN
ERROR Error[illegalFileName];
END;

IsLegal: PACKED ARRAY CHAR OF BOOL;

InitIsLegal: PROCEDURE[] = BEGIN
IsLegal ← ALL [FALSE];
FOR c: CHAR IN ['a .. 'z] DO IsLegal[c] ← TRUE ENDLOOP;
FOR c: CHAR IN ['A .. 'Z] DO IsLegal[c] ← TRUE ENDLOOP;
FOR c: CHAR IN ['0 .. '9] DO IsLegal[c] ← TRUE ENDLOOP;
IsLegal['+] ← TRUE; IsLegal['-] ← TRUE; IsLegal['.] ← TRUE; IsLegal['$] ← TRUE;
IsLegal['[] ← TRUE; IsLegal[']] ← TRUE; IsLegal['<] ← TRUE; IsLegal['>] ← TRUE; IsLegal[''] ← TRUE;

END;

-- A result of directoryFileHandle = NIL means that the owner root file does not exist.
GetOwnerRootFile: PROCEDURE[transHandle: AlpT.Handle, fileStore: AE.FileStore, owner:
AE.OwnerName, createRootFileIfMissing: BOOL, openRootFileForWrite: BOOL] RETURNS
[directoryFileHandle: AlpF.Handle, volumeGroupID: AE.VolumeGroupID] =
BEGIN -- errors: DirectoryInconsistent[ownerRootFileNotFound], AlpI.AccessFailed[fileRead, fileModify, ownerCreate, spaceQuota], AlpI.LockFailed, AlpI.OperationFailed[damagedLeaderPage, ownerRecordFull, regServersUnavailable], AlpI.PossiblyDamaged, AlpI.Unknown[coordinator, owner, transID], RPC.CallFailed.
refDirectoryFile: REF AE.UniversalFile ← NEW[AE.UniversalFile ← AE.nullUniversalFile];
ownerProperties: LIST OF AE.OwnerPropertyValuePair;
IF (NOT Rope.Equal[transHandle.inst.fileStore, fileStore, FALSE])
THEN ERROR; -- until filestores and volumegroups get straightened out.
transHandle.CreateWorker[fileStore];
volumeGroupID ← transHandle.GetNextVolumeGroup[previousGroup:
AE.nullVolumeGroupID, lock: [none, wait]]; -- temporary.
ownerProperties ← transHandle.ReadOwnerProperties[volumeGroupID: volumeGroupID,
owner: owner, desiredProperties: [rootFile: TRUE]];
refDirectoryFile^ ← NARROW[ownerProperties.first,
AE.OwnerPropertyValuePair.rootFile].rootFile;
DO --loop to allow directory create after Open failure.
IF refDirectoryFile^ = AE.nullUniversalFile THEN
BEGIN
IF NOT createRootFileIfMissing
THEN RETURN [NIL, AE.nullVolumeGroupID];
[directoryFileHandle, refDirectoryFile] ← AlpF.Create[transHandle, volumeGroupID, owner,
initialDirSize];
transHandle.WriteOwnerProperties[volumeGroupID: volumeGroupID, owner: owner,
properties: LIST[[rootFile[rootFile: refDirectoryFile^]]]];
RETURN [directoryFileHandle, volumeGroupID];
END
ELSE BEGIN
fileID: AE.FileID;
[directoryFileHandle, fileID] ← AlpF.Open[transHandle, refDirectoryFile^,
(IF openRootFileForWrite THEN readWrite ELSE readOnly),
[IF openRootFileForWrite THEN write ELSE read, wait], log, sequential !
AlpI.Unknown => SELECT what FROM
volumeID, fileID => BEGIN
SIGNAL DirectoryInconsistent[ownerRootFileNotFound];
refDirectoryFile^ ← AE.nullUniversalFile;
LOOP;
END;
ENDCASE => REJECT;];
IF refDirectoryFile^.fileID # fileID
THEN BEGIN
refDirectoryFile^.fileID ← fileID;
transHandle.WriteOwnerProperties[volumeGroupID: volumeGroupID, owner:
owner, properties: LIST[[rootFile[rootFile: refDirectoryFile^]]]];
END;
RETURN [directoryFileHandle, volumeGroupID];
END;
ENDLOOP;
END;

DirEntry: TYPE = MACHINE DEPENDENT RECORD [wordCount(0): NAT, --number of words in the entire entry
universalFile(1): AE.UniversalFile,
length(10): NAT, --number of characters in the file name
char(11): PACKED SEQUENCE COMPUTED CARDINAL OF CHAR
];
-- The format of a directory entry. Entries are word-aligned, do not cross page
--boundaries, and are stored in arbitrary order. Unless a page is full, its final
--DirEntry has wordCount = 0. A page is empty if its first DirEntry has wordCount = 0.
DirEntryPtr: TYPE = LONG POINTER TO DirEntry;

OpenFile: PROCEDURE[transHandle: AlpT.Handle, directoryFileHandle: AlpF.Handle,
fullFileName, fileName: Rope.ROPE, createOptions: AlpineInterimDirectory.CreateOptions,
createVolume: AE.VolumeGroupID, owner: AE.OwnerName, initialByteAllocation:
AE.ByteCount] RETURNS [refUniversalFile: REF AE.UniversalFile, createdFile: BOOL] =
BEGIN -- errors: Error[fileAlreadyExists, fileNotFound], AlpI.AccessFailed[handleReadWrite, ownerCreate, spaceQuota], AlpI.LockFailed, AlpI.OperationFailed[insufficientSpace], AlpI.Unknown[openFileID, transID], RPC.CallFailed.
state: {searching, inserting, done} ← searching;
fileNameBuffer: REF TEXT;
ExamineItem: PROCEDURE[directoryEntryPtr: DirEntryPtr]
RETURNS [quit: BOOL, kill: BOOL] = BEGIN
-- Called for each entry of a page examined by ExaminePage until quit: TRUE returned.
SELECT state FROM
searching =>
IF FileNameEqual[directoryEntryPtr, fileNameBuffer] THEN BEGIN
IF createOptions = newOnly THEN ERROR Error[fileAlreadyExists];
TRUSTED BEGIN refUniversalFile^ ← directoryEntryPtr.universalFile; END;
createdFile ← FALSE;
state ← done;
RETURN [quit: TRUE, kill: FALSE];
END
ELSE RETURN [quit: FALSE, kill: FALSE];
inserting => RETURN [quit: FALSE, kill: FALSE];
done => RETURN [quit: TRUE, kill: FALSE];
ENDCASE => ERROR;
END;
nWordsForDirEntry: CARDINAL; -- Free words needed for inserting DirEntry.
spaceFound: BOOL ← FALSE; -- TRUE if some page seen with enough free words.
spacePage: AE.PageNumber; -- If spaceFound, this is the page with enough free words.
AppendItem: PROCEDURE[directoryEntryPtr: DirEntryPtr, nWordsAvailable: CARDINAL]
RETURNS [nwordsWritten: CARDINAL] = BEGIN -- errors: AlpI.AccessFailed[ownerCreate, spaceQuota], AlpI.LockFailed, AlpI.OperationFailed[insufficientSpace], AlpI.Unknown[openFileID, transID], RPC.CallFailed;
-- Called for each page examined by ExaminePage, after all ExamineItem calls made.
DO -- loop to simulate GOTO
SELECT state FROM
searching => BEGIN
IF NOT spaceFound AND nWordsAvailable >= nWordsForDirEntry THEN BEGIN
spacePage ← currentPage;
spaceFound ← TRUE;
END;
IF currentPage = dirFilePages-1 THEN
BEGIN
-- fileName not found.
fileHandle: AlpF.Handle;
IF createOptions = oldOnly THEN ERROR Error[fileNotFound];
[fileHandle, refUniversalFile] ← AlpF.Create[transHandle, createVolume, owner,
PagesForBytes[initialByteAllocation]];
fileHandle.WriteProperties[LIST[[stringName[fullFileName]]]];
createdFile ← TRUE;
state ← inserting;
LOOP; -- GOTO inserting
END;
RETURN [0];
END;
inserting => IF nWordsAvailable >= nWordsForDirEntry THEN TRUSTED BEGIN
directoryEntryPtr.wordCount ← nWordsForDirEntry;
directoryEntryPtr.universalFile ← refUniversalFile^;
directoryEntryPtr.length ← fileNameBuffer.length;
FOR i: CARDINAL IN [0 .. fileNameBuffer.length) DO
directoryEntryPtr[i] ← fileName.Fetch[i];
ENDLOOP;
state ← done;
RETURN [nWordsForDirEntry];
END;
done => RETURN [0];
ENDCASE => ERROR;
ENDLOOP;
END;
ExtendFile: PROCEDURE[] = BEGIN -- errors: AlpI.AccessFailed[handleReadWrite, ownerCreate, spaceQuota], AlpI.LockFailed, AlpI.OperationFailed[insufficientSpace], AlpI.Unknown[openFileID, transID], RPC.CallFailed.
IF dirFilePages = dirFileSize THEN BEGIN
-- change the file size
dirFileSize ← dirFileSize + incrementDirSize;
directoryFileHandle.SetSize[dirFileSize];
END;
-- change the byte length
dirFilePages ← dirFilePages+1;
directoryFileHandle.WriteProperties[LIST[[byteLength[dirFilePages*AE.bytesPerPage]]]];
END;
pageBufferArray: ARRAY [0 .. AE.wordsPerPage) OF WORD;
currentPage: AE.PageNumber ← 0;
clearPage: BOOL ← FALSE;
dirFilePages, dirFileSize: AE.PageCount;
refUniversalFile ← NEW[AE.UniversalFile ← AE.nullUniversalFile];
IF createOptions = oldOnly AND directoryFileHandle = NIL THEN
ERROR Error[fileNotFound];
[dirFilePages, dirFileSize] ← GetPageLength[directoryFileHandle];
IF dirFilePages = 0 THEN BEGIN
IF createOptions = oldOnly THEN ERROR Error[fileNotFound];
ExtendFile[];
clearPage ← TRUE;
END;
fileNameBuffer ← FillBuffer[fileName];
nWordsForDirEntry ← SIZE[DirEntry[fileNameBuffer.length]];
DO
TRUSTED BEGIN ExaminePage[directoryFileHandle, currentPage, clearPage,
@pageBufferArray, ExamineItem, AppendItem]; END;
IF clearPage AND state # done THEN ERROR;
SELECT state FROM
searching => currentPage ← currentPage + 1;
inserting =>
IF spaceFound THEN currentPage ← spacePage
ELSE BEGIN ExtendFile[]; clearPage ← TRUE; currentPage ← dirFilePages-1 END;
done => EXIT;
ENDCASE;
ENDLOOP;
RefText.ReleaseScratch[fileNameBuffer];
RETURN [refUniversalFile, createdFile];
END;--OpenFile

DeleteFile: PROCEDURE[transHandle: AlpT.Handle, directoryFileHandle: AlpF.Handle,
fileName: Rope.ROPE] =
BEGIN -- errors: Error[fileNotFound], DirectoryInconsistent[directoryFileNotFound], AlpI.AccessFailed[fileRead, fileModify, handleReadWrite], AlpI.LockFailed, AlpI.OperationFailed[damagedLeaderPage], AlpI.PossiblyDamaged, AlpI.Unknown[openFileID, transID], RPC.CallFailed.
state: {searching, done} ← searching;
fileNameBuffer: REF TEXT;
ExamineItem: PROCEDURE[directoryEntryPtr: DirEntryPtr]
RETURNS [quit: BOOL, kill: BOOL] = BEGIN -- errors: DirectoryInconsistent[directoryFileNotFound], AlpI.AccessFailed[fileRead, fileModify, handleReadWrite], AlpI.LockFailed, AlpI.OperationFailed[damagedLeaderPage], AlpI.PossiblyDamaged, AlpI.Unknown[openFileID, transID], RPC.CallFailed.
-- Called for each entry of a page examined by ExaminePage until quit: TRUE returned.
IF NOT FileNameEqual[directoryEntryPtr, fileNameBuffer] THEN
RETURN [quit: FALSE, kill: FALSE]
ELSE BEGIN
fileHandle: AlpF.Handle ← NIL;
universalFile: AE.UniversalFile;
TRUSTED BEGIN universalFile ← directoryEntryPtr.universalFile; END;
[fileHandle, ] ← AlpF.Open[transHandle: transHandle,
universalFile: universalFile,
access: readWrite, lock: [write, wait] !
AlpI.Unknown => SELECT what FROM
fileID, volumeID => BEGIN
SIGNAL DirectoryInconsistent[directoryFileNotFound];
CONTINUE;
END;
ENDCASE => REJECT];
IF fileHandle # NIL THEN fileHandle.Delete;
state ← done;
RETURN [quit: TRUE, kill: TRUE];
END;
END;
pageBufferArray: ARRAY [0 .. AE.wordsPerPage) OF WORD;
currentPage: AE.PageNumber ← 0;
dirFilePages: AE.PageCount;
IF directoryFileHandle = NIL THEN ERROR Error[fileNotFound];
[dirFilePages, ] ← GetPageLength[directoryFileHandle];
fileNameBuffer ← FillBuffer[fileName];
DO
IF currentPage = dirFilePages THEN ERROR Error[fileNotFound];
TRUSTED BEGIN ExaminePage[directoryFileHandle, currentPage, FALSE, @pageBufferArray,
ExamineItem, NIL]; END;
SELECT state FROM
searching => currentPage ← currentPage + 1;
done => EXIT;
ENDCASE;
ENDLOOP;
RefText.ReleaseScratch[fileNameBuffer];
END;--DeleteFile

EnumerateFiles: PROCEDURE[transHandle: AlpT.Handle, directoryFileHandle: AlpF.Handle,
enumProc: EnumProc] =
BEGIN -- errors: AlpI.AccessFailed[handleReadWrite], AlpI.LockFailed, AlpI.Unknown[openFileID, transID], RPC.CallFailed, plus any errors raised by enumProc.
state: {searching, done} ← searching;
fileName: REF TEXT = RefText.ObtainScratch[AE.maxStringNameChars];
ExamineItem: PROCEDURE[directoryEntryPtr: DirEntryPtr]
RETURNS [quit: BOOL, kill: BOOL] = BEGIN-- errors: any errors raised by enumProc.
universalFile: AE.UniversalFile;
TRUSTED BEGIN universalFile ← directoryEntryPtr.universalFile; END;
kill ← FALSE;
CopyDirEntry[fileName, directoryEntryPtr];
quit ← enumProc[fileName, universalFile];
IF quit THEN state ← done;
END;
pageBufferArray: ARRAY [0 .. AE.wordsPerPage) OF WORD;
currentPage: AE.PageNumber ← 0;
dirFilePages: AE.PageCount;
IF directoryFileHandle = NIL THEN RETURN;
[dirFilePages, ] ← GetPageLength[directoryFileHandle];
DO
IF currentPage = dirFilePages THEN RETURN;
TRUSTED BEGIN ExaminePage[directoryFileHandle, currentPage, FALSE,
@pageBufferArray, ExamineItem, NIL]; END;
SELECT state FROM
searching => currentPage ← currentPage + 1;
done => EXIT;
ENDCASE;
ENDLOOP;
RefText.ReleaseScratch[fileName];
END;

GetPageLength: PROCEDURE[directoryFileHandle: AlpF.Handle] RETURNS[AE.PageCount,
AE.PageCount] =
BEGIN -- errors: AlpI.LockFailed, AlpI.Unknown[openFileID, transID], RPC.CallFailed.
dirFileSize: AE.PageCount ← directoryFileHandle.GetSize;
dirFileLengthProperty: LIST OF AE.PropertyValuePair =
directoryFileHandle.ReadProperties[[byteLength: TRUE]];
dirFileLength: AE.ByteCount ← NARROW[dirFileLengthProperty.first,
AE.PropertyValuePair.byteLength].byteLength;
dirFilePages: AE.PageCount ← dirFileLength/AE.bytesPerPage;
IF dirFilePages > dirFileSize THEN ERROR;
RETURN [dirFilePages, dirFileSize];
END;

FillBuffer: PROCEDURE[fileName: Rope.ROPE] RETURNS [fileNameBuffer: REF TEXT]
= INLINE
BEGIN
-- Copies chars of fileName to a scratch REF TEXT, converts to upper case.
len: NAT = fileName.Length[];
fileNameBuffer ← RefText.ObtainScratch[len];
FOR i: NAT IN [0 .. len) DO
fileNameBuffer[i] ← Ascii.Upper[fileName.Fetch[i]];
ENDLOOP;
fileNameBuffer.length ← len;
RETURN [fileNameBuffer];
END;

FileNameEqual: PROCEDURE[directoryEntryPtr: DirEntryPtr, fileNameBuffer: REF TEXT]
RETURNS[BOOL] = TRUSTED INLINE
BEGIN
IF directoryEntryPtr.length # fileNameBuffer.length THEN RETURN [FALSE];
FOR i: NAT IN [0 .. directoryEntryPtr.length) DO
IF Ascii.Upper[directoryEntryPtr[i]] # fileNameBuffer[i] THEN RETURN [FALSE];
ENDLOOP;
RETURN [TRUE];
END;

CopyDirEntry: PROCEDURE[to: REF TEXT, from: DirEntryPtr] =
TRUSTED BEGIN
FOR i: NAT IN [0 .. from.length) DO
to[i] ← from[i];
ENDLOOP;
to.length ← from.length;
END;

PagesForBytes: PROCEDURE[byteLength: AE.ByteCount] RETURNS[pageCount:
AE.PageCount] =
BEGIN
RETURN [(byteLength+AE.bytesPerPage-1)/AE.bytesPerPage];
END;

ExamineItemProc: TYPE = PROCEDURE[directoryEntryPtr: DirEntryPtr] RETURNS[quit: BOOL,
kill: BOOL];
AppendItemProc: TYPE = PROCEDURE[directoryEntryPtr: DirEntryPtr, nWordsAvailable:
CARDINAL] RETURNS[nWordsWritten: CARDINAL];

ExaminePage: PROCEDURE[fileHandle: AlpF.Handle, page: AE.PageNumber, clearPage: BOOL,
pageBuffer: LONG POINTER TO ARRAY [0..AE.wordsPerPage) OF WORD,
examineItem: ExamineItemProc, appendItem: AppendItemProc] =
TRUSTED BEGIN -- errors: AlpI.AccessFailed[handleReadWrite], AlpI.LockFailed, AlpI.Unknown[openFileID, transID], RPC.CallFailed, plus any errors raised by examineItem and appendItem.
currentWord: INT [0..AE.wordsPerPage] ← 0;
directoryEntryPtr: DirEntryPtr ← LOOPHOLE[pageBuffer];
pageDirty: BOOL ← FALSE;
quit: BOOL ← FALSE;
IF clearPage THEN BEGIN
LongZero[where: pageBuffer, nWords: AE.wordsPerPage];
pageDirty ← TRUE;
END
ELSE fileHandle.ReadPages[pageRun: [page], pageBuffer: DESCRIPTOR
[pageBuffer, AE.wordsPerPage]];
UNTIL quit OR currentWord = AE.wordsPerPage OR directoryEntryPtr.wordCount = 0 DO
killItem: BOOL ← FALSE;
wordCount: CARDINAL = directoryEntryPtr.wordCount;
IF examineItem # NIL THEN [quit, killItem] ← examineItem[directoryEntryPtr];
IF killItem THEN BEGIN
wordsToCopy: CARDINAL = AE.wordsPerPage-currentWord-wordCount;
PrincOpsUtils.LongCOPY[from: directoryEntryPtr+wordCount, nwords: wordsToCopy, to:
directoryEntryPtr];
LongZero[where: directoryEntryPtr+wordsToCopy, nWords: wordCount];
pageDirty ← TRUE;
END
ELSE BEGIN
directoryEntryPtr ← directoryEntryPtr + wordCount;
currentWord ← currentWord + wordCount;
END;
ENDLOOP;
IF appendItem # NIL
THEN BEGIN
nWordsWritten: CARDINAL = appendItem[directoryEntryPtr, AE.wordsPerPage -
currentWord];
IF nWordsWritten # 0
THEN BEGIN IF currentWord + nWordsWritten # AE.wordsPerPage
THEN LOOPHOLE [directoryEntryPtr+nWordsWritten,
DirEntryPtr].wordCount ← 0;
pageDirty ← TRUE;
END;
END;
IF pageDirty THEN fileHandle.WritePages[pageRun: [page], pageBuffer: DESCRIPTOR
[pageBuffer, AE.wordsPerPage]];
END;

LongZero: PROCEDURE[where: LONG POINTER, nWords: CARDINAL] =
TRUSTED MACHINE CODE BEGIN -- errors: none.
PrincOps.zMISC, 102B; PrincOps.zPOP; PrincOps.zPOP
END;

InitIsLegal[];

END.

CHANGE LOG


Created by MBrown on January 13, 1983 1:19 pm

Changed by MBrown on January 18, 1983 11:53 pm
-- Define record type DirEntry to make things cleaner.