183 const getSyncHandle = async (fh)=>{  argument
184   if(!fh.syncHandle){
186     log("Acquiring sync handle for",fh.filenameAbs);
194         fh.syncHandle = await fh.fileHandle.createSyncAccessHandle();
200             "attempts failed.",fh.filenameAbs
204               "ms and trying again.",fh.filenameAbs,e);
208     log("Got sync handle for",fh.filenameAbs,'in',performance.now() - t,'ms');
209     if(!fh.xLock){
210       __autoLocks.add(fh.fid);
211       log("Auto-locked",fh.fid,fh.filenameAbs);
214   return fh.syncHandle;
227 const closeSyncHandle = async (fh)=>{  argument
228   if(fh.syncHandle){
229     log("Closing sync handle for",fh.filenameAbs);
230     const h = fh.syncHandle;
231     delete fh.syncHandle;
232     delete fh.xLock;
233     __autoLocks.delete(fh.fid);
249 const closeSyncHandleNoThrow = async (fh)=>{  argument
250   try{await closeSyncHandle(fh)}
252     warn("closeSyncHandleNoThrow() ignoring:",e,fh);
269 const affirmNotRO = function(opName,fh){  argument
270   if(fh.readOnly) toss(opName+"(): File is read-only: "+fh.filenameAbs);
272 const affirmLocked = function(opName,fh){  argument
385     const fh = __openFiles[fid];
388     if(fh){
390       await closeSyncHandle(fh);
391       if(fh.deleteOnClose){
392         try{ await fh.dirHandle.removeEntry(fh.filenamePart) }
393         catch(e){ warn("Ignoring dirHandle.removeEntry() failure of",fh,e) }
444     const fh = __openFiles[fid];
448       affirmLocked('xFileSize',fh);
449       rc = await (await getSyncHandle(fh)).getSize();
463     const fh = __openFiles[fid];
465     const oldLockType = fh.xLock;
466     fh.xLock = lockType;
467     if( !fh.syncHandle ){
470         await getSyncHandle(fh);
475         fh.xLock = oldLockType;
531     const fh = __openFiles[fid];
533       affirmLocked('xRead',fh);
535       nRead = (await getSyncHandle(fh)).read(
536         fh.sabView.subarray(0, n),
541         fh.sabView.fill(0, nRead, n);
546       error("xRead() failed",e,fh);
555     const fh = __openFiles[fid];
557     if(!fh.readOnly && fh.syncHandle){
560         await fh.syncHandle.flush();
573     const fh = __openFiles[fid];
576       affirmLocked('xTruncate',fh);
577       affirmNotRO('xTruncate', fh);
578       await (await getSyncHandle(fh)).truncate(size);
580       error("xTruncate():",e,fh);
592     const fh = __openFiles[fid];
594         && fh.syncHandle ){
596       try { await closeSyncHandle(fh) }
609     const fh = __openFiles[fid];
612       affirmLocked('xWrite',fh);
613       affirmNotRO('xWrite', fh);
615         n === (await getSyncHandle(fh))
616           .write(fh.sabView.subarray(0, n),
620       error("xWrite():",e,fh);
760             const fh = __openFiles[fid];
761             await closeSyncHandleNoThrow(fh);
762             log("Auto-unlocked",fid,fh.filenameAbs);