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Diffstat (limited to 'ext/wasm/api/sqlite3-opfs-async-proxy.js')
| -rw-r--r-- | ext/wasm/api/sqlite3-opfs-async-proxy.js | 830 |
1 files changed, 830 insertions, 0 deletions
diff --git a/ext/wasm/api/sqlite3-opfs-async-proxy.js b/ext/wasm/api/sqlite3-opfs-async-proxy.js new file mode 100644 index 0000000..e465748 --- /dev/null +++ b/ext/wasm/api/sqlite3-opfs-async-proxy.js @@ -0,0 +1,830 @@ +/* + 2022-09-16 + + The author disclaims copyright to this source code. In place of a + legal notice, here is a blessing: + + * May you do good and not evil. + * May you find forgiveness for yourself and forgive others. + * May you share freely, never taking more than you give. + + *********************************************************************** + + A Worker which manages asynchronous OPFS handles on behalf of a + synchronous API which controls it via a combination of Worker + messages, SharedArrayBuffer, and Atomics. It is the asynchronous + counterpart of the API defined in sqlite3-api-opfs.js. + + Highly indebted to: + + https://github.com/rhashimoto/wa-sqlite/blob/master/src/examples/OriginPrivateFileSystemVFS.js + + for demonstrating how to use the OPFS APIs. + + This file is to be loaded as a Worker. It does not have any direct + access to the sqlite3 JS/WASM bits, so any bits which it needs (most + notably SQLITE_xxx integer codes) have to be imported into it via an + initialization process. + + This file represents an implementation detail of a larger piece of + code, and not a public interface. Its details may change at any time + and are not intended to be used by any client-level code. +*/ +"use strict"; +const toss = function(...args){throw new Error(args.join(' '))}; +if(self.window === self){ + toss("This code cannot run from the main thread.", + "Load it as a Worker from a separate Worker."); +}else if(!navigator.storage.getDirectory){ + toss("This API requires navigator.storage.getDirectory."); +} + +/** + Will hold state copied to this object from the syncronous side of + this API. +*/ +const state = Object.create(null); + +/** + verbose: + + 0 = no logging output + 1 = only errors + 2 = warnings and errors + 3 = debug, warnings, and errors +*/ +state.verbose = 2; + +const loggers = { + 0:console.error.bind(console), + 1:console.warn.bind(console), + 2:console.log.bind(console) +}; +const logImpl = (level,...args)=>{ + if(state.verbose>level) loggers[level]("OPFS asyncer:",...args); +}; +const log = (...args)=>logImpl(2, ...args); +const warn = (...args)=>logImpl(1, ...args); +const error = (...args)=>logImpl(0, ...args); +const metrics = Object.create(null); +metrics.reset = ()=>{ + let k; + const r = (m)=>(m.count = m.time = m.wait = 0); + for(k in state.opIds){ + r(metrics[k] = Object.create(null)); + } + let s = metrics.s11n = Object.create(null); + s = s.serialize = Object.create(null); + s.count = s.time = 0; + s = metrics.s11n.deserialize = Object.create(null); + s.count = s.time = 0; +}; +metrics.dump = ()=>{ + let k, n = 0, t = 0, w = 0; + for(k in state.opIds){ + const m = metrics[k]; + n += m.count; + t += m.time; + w += m.wait; + m.avgTime = (m.count && m.time) ? (m.time / m.count) : 0; + } + console.log(self.location.href, + "metrics for",self.location.href,":\n", + metrics, + "\nTotal of",n,"op(s) for",t,"ms", + "approx",w,"ms spent waiting on OPFS APIs."); + console.log("Serialization metrics:",metrics.s11n); +}; + +/** + __openFiles is a map of sqlite3_file pointers (integers) to + metadata related to a given OPFS file handles. The pointers are, in + this side of the interface, opaque file handle IDs provided by the + synchronous part of this constellation. Each value is an object + with a structure demonstrated in the xOpen() impl. +*/ +const __openFiles = Object.create(null); +/** + __autoLocks is a Set of sqlite3_file pointers (integers) which were + "auto-locked". i.e. those for which we obtained a sync access + handle without an explicit xLock() call. Such locks will be + released during db connection idle time, whereas a sync access + handle obtained via xLock(), or subsequently xLock()'d after + auto-acquisition, will not be released until xUnlock() is called. + + Maintenance reminder: if we relinquish auto-locks at the end of the + operation which acquires them, we pay a massive performance + penalty: speedtest1 benchmarks take up to 4x as long. By delaying + the lock release until idle time, the hit is negligible. +*/ +const __autoLocks = new Set(); + +/** + Expects an OPFS file path. It gets resolved, such that ".." + components are properly expanded, and returned. If the 2nd arg is + true, the result is returned as an array of path elements, else an + absolute path string is returned. +*/ +const getResolvedPath = function(filename,splitIt){ + const p = new URL( + filename, 'file://irrelevant' + ).pathname; + return splitIt ? p.split('/').filter((v)=>!!v) : p; +}; + +/** + Takes the absolute path to a filesystem element. Returns an array + of [handleOfContainingDir, filename]. If the 2nd argument is truthy + then each directory element leading to the file is created along + the way. Throws if any creation or resolution fails. +*/ +const getDirForFilename = async function f(absFilename, createDirs = false){ + const path = getResolvedPath(absFilename, true); + const filename = path.pop(); + let dh = state.rootDir; + for(const dirName of path){ + if(dirName){ + dh = await dh.getDirectoryHandle(dirName, {create: !!createDirs}); + } + } + return [dh, filename]; +}; + +/** + An error class specifically for use with getSyncHandle(), the goal + of which is to eventually be able to distinguish unambiguously + between locking-related failures and other types, noting that we + cannot currently do so because createSyncAccessHandle() does not + define its exceptions in the required level of detail. +*/ +class GetSyncHandleError extends Error { + constructor(errorObject, ...msg){ + super(); + this.error = errorObject; + this.message = [ + ...msg, ': Original exception ['+errorObject.name+']:', + errorObject.message + ].join(' '); + this.name = 'GetSyncHandleError'; + } +}; + +/** + Returns the sync access handle associated with the given file + handle object (which must be a valid handle object, as created by + xOpen()), lazily opening it if needed. + + In order to help alleviate cross-tab contention for a dabase, + if an exception is thrown while acquiring the handle, this routine + will wait briefly and try again, up to 3 times. If acquisition + still fails at that point it will give up and propagate the + exception. +*/ +const getSyncHandle = async (fh)=>{ + if(!fh.syncHandle){ + const t = performance.now(); + log("Acquiring sync handle for",fh.filenameAbs); + const maxTries = 4, msBase = 300; + let i = 1, ms = msBase; + for(; true; ms = msBase * ++i){ + try { + //if(i<3) toss("Just testing getSyncHandle() wait-and-retry."); + //TODO? A config option which tells it to throw here + //randomly every now and then, for testing purposes. + fh.syncHandle = await fh.fileHandle.createSyncAccessHandle(); + break; + }catch(e){ + if(i === maxTries){ + throw new GetSyncHandleError( + e, "Error getting sync handle.",maxTries, + "attempts failed.",fh.filenameAbs + ); + } + warn("Error getting sync handle. Waiting",ms, + "ms and trying again.",fh.filenameAbs,e); + Atomics.wait(state.sabOPView, state.opIds.retry, 0, ms); + } + } + log("Got sync handle for",fh.filenameAbs,'in',performance.now() - t,'ms'); + if(!fh.xLock){ + __autoLocks.add(fh.fid); + log("Auto-locked",fh.fid,fh.filenameAbs); + } + } + return fh.syncHandle; +}; + +/** + If the given file-holding object has a sync handle attached to it, + that handle is remove and asynchronously closed. Though it may + sound sensible to continue work as soon as the close() returns + (noting that it's asynchronous), doing so can cause operations + performed soon afterwards, e.g. a call to getSyncHandle() to fail + because they may happen out of order from the close(). OPFS does + not guaranty that the actual order of operations is retained in + such cases. i.e. always "await" on the result of this function. +*/ +const closeSyncHandle = async (fh)=>{ + if(fh.syncHandle){ + log("Closing sync handle for",fh.filenameAbs); + const h = fh.syncHandle; + delete fh.syncHandle; + delete fh.xLock; + __autoLocks.delete(fh.fid); + return h.close(); + } +}; + +/** + A proxy for closeSyncHandle() which is guaranteed to not throw. + + This function is part of a lock/unlock step in functions which + require a sync access handle but may be called without xLock() + having been called first. Such calls need to release that + handle to avoid locking the file for all of time. This is an + _attempt_ at reducing cross-tab contention but it may prove + to be more of a problem than a solution and may need to be + removed. +*/ +const closeSyncHandleNoThrow = async (fh)=>{ + try{await closeSyncHandle(fh)} + catch(e){ + warn("closeSyncHandleNoThrow() ignoring:",e,fh); + } +}; + +/** + Stores the given value at state.sabOPView[state.opIds.rc] and then + Atomics.notify()'s it. +*/ +const storeAndNotify = (opName, value)=>{ + log(opName+"() => notify(",value,")"); + Atomics.store(state.sabOPView, state.opIds.rc, value); + Atomics.notify(state.sabOPView, state.opIds.rc); +}; + +/** + Throws if fh is a file-holding object which is flagged as read-only. +*/ +const affirmNotRO = function(opName,fh){ + if(fh.readOnly) toss(opName+"(): File is read-only: "+fh.filenameAbs); +}; +const affirmLocked = function(opName,fh){ + //if(!fh.syncHandle) toss(opName+"(): File does not have a lock: "+fh.filenameAbs); + /** + Currently a no-op, as speedtest1 triggers xRead() without a + lock (that seems like a bug but it's currently uninvestigated). + This means, however, that some OPFS VFS routines may trigger + acquisition of a lock but never let it go until xUnlock() is + called (which it likely won't be if xLock() was not called). + */ +}; + +/** + We track 2 different timers: the "metrics" timer records how much + time we spend performing work. The "wait" timer records how much + time we spend waiting on the underlying OPFS timer. See the calls + to mTimeStart(), mTimeEnd(), wTimeStart(), and wTimeEnd() + throughout this file to see how they're used. +*/ +const __mTimer = Object.create(null); +__mTimer.op = undefined; +__mTimer.start = undefined; +const mTimeStart = (op)=>{ + __mTimer.start = performance.now(); + __mTimer.op = op; + //metrics[op] || toss("Maintenance required: missing metrics for",op); + ++metrics[op].count; +}; +const mTimeEnd = ()=>( + metrics[__mTimer.op].time += performance.now() - __mTimer.start +); +const __wTimer = Object.create(null); +__wTimer.op = undefined; +__wTimer.start = undefined; +const wTimeStart = (op)=>{ + __wTimer.start = performance.now(); + __wTimer.op = op; + //metrics[op] || toss("Maintenance required: missing metrics for",op); +}; +const wTimeEnd = ()=>( + metrics[__wTimer.op].wait += performance.now() - __wTimer.start +); + +/** + Gets set to true by the 'opfs-async-shutdown' command to quit the + wait loop. This is only intended for debugging purposes: we cannot + inspect this file's state while the tight waitLoop() is running and + need a way to stop that loop for introspection purposes. +*/ +let flagAsyncShutdown = false; + + +/** + Asynchronous wrappers for sqlite3_vfs and sqlite3_io_methods + methods, as well as helpers like mkdir(). Maintenance reminder: + members are in alphabetical order to simplify finding them. +*/ +const vfsAsyncImpls = { + 'opfs-async-metrics': async ()=>{ + mTimeStart('opfs-async-metrics'); + metrics.dump(); + storeAndNotify('opfs-async-metrics', 0); + mTimeEnd(); + }, + 'opfs-async-shutdown': async ()=>{ + flagAsyncShutdown = true; + storeAndNotify('opfs-async-shutdown', 0); + }, + mkdir: async (dirname)=>{ + mTimeStart('mkdir'); + let rc = 0; + wTimeStart('mkdir'); + try { + await getDirForFilename(dirname+"/filepart", true); + }catch(e){ + state.s11n.storeException(2,e); + rc = state.sq3Codes.SQLITE_IOERR; + }finally{ + wTimeEnd(); + } + storeAndNotify('mkdir', rc); + mTimeEnd(); + }, + xAccess: async (filename)=>{ + mTimeStart('xAccess'); + /* OPFS cannot support the full range of xAccess() queries sqlite3 + calls for. We can essentially just tell if the file is + accessible, but if it is it's automatically writable (unless + it's locked, which we cannot(?) know without trying to open + it). OPFS does not have the notion of read-only. + + The return semantics of this function differ from sqlite3's + xAccess semantics because we are limited in what we can + communicate back to our synchronous communication partner: 0 = + accessible, non-0 means not accessible. + */ + let rc = 0; + wTimeStart('xAccess'); + try{ + const [dh, fn] = await getDirForFilename(filename); + await dh.getFileHandle(fn); + }catch(e){ + state.s11n.storeException(2,e); + rc = state.sq3Codes.SQLITE_IOERR; + }finally{ + wTimeEnd(); + } + storeAndNotify('xAccess', rc); + mTimeEnd(); + }, + xClose: async function(fid/*sqlite3_file pointer*/){ + const opName = 'xClose'; + mTimeStart(opName); + __autoLocks.delete(fid); + const fh = __openFiles[fid]; + let rc = 0; + wTimeStart(opName); + if(fh){ + delete __openFiles[fid]; + await closeSyncHandle(fh); + if(fh.deleteOnClose){ + try{ await fh.dirHandle.removeEntry(fh.filenamePart) } + catch(e){ warn("Ignoring dirHandle.removeEntry() failure of",fh,e) } + } + }else{ + state.s11n.serialize(); + rc = state.sq3Codes.SQLITE_NOTFOUND; + } + wTimeEnd(); + storeAndNotify(opName, rc); + mTimeEnd(); + }, + xDelete: async function(...args){ + mTimeStart('xDelete'); + const rc = await vfsAsyncImpls.xDeleteNoWait(...args); + storeAndNotify('xDelete', rc); + mTimeEnd(); + }, + xDeleteNoWait: async function(filename, syncDir = 0, recursive = false){ + /* The syncDir flag is, for purposes of the VFS API's semantics, + ignored here. However, if it has the value 0x1234 then: after + deleting the given file, recursively try to delete any empty + directories left behind in its wake (ignoring any errors and + stopping at the first failure). + + That said: we don't know for sure that removeEntry() fails if + the dir is not empty because the API is not documented. It has, + however, a "recursive" flag which defaults to false, so + presumably it will fail if the dir is not empty and that flag + is false. + */ + let rc = 0; + wTimeStart('xDelete'); + try { + while(filename){ + const [hDir, filenamePart] = await getDirForFilename(filename, false); + if(!filenamePart) break; + await hDir.removeEntry(filenamePart, {recursive}); + if(0x1234 !== syncDir) break; + recursive = false; + filename = getResolvedPath(filename, true); + filename.pop(); + filename = filename.join('/'); + } + }catch(e){ + state.s11n.storeException(2,e); + rc = state.sq3Codes.SQLITE_IOERR_DELETE; + } + wTimeEnd(); + return rc; + }, + xFileSize: async function(fid/*sqlite3_file pointer*/){ + mTimeStart('xFileSize'); + const fh = __openFiles[fid]; + let rc; + wTimeStart('xFileSize'); + try{ + affirmLocked('xFileSize',fh); + rc = await (await getSyncHandle(fh)).getSize(); + state.s11n.serialize(Number(rc)); + rc = 0; + }catch(e){ + state.s11n.storeException(2,e); + rc = state.sq3Codes.SQLITE_IOERR; + } + wTimeEnd(); + storeAndNotify('xFileSize', rc); + mTimeEnd(); + }, + xLock: async function(fid/*sqlite3_file pointer*/, + lockType/*SQLITE_LOCK_...*/){ + mTimeStart('xLock'); + const fh = __openFiles[fid]; + let rc = 0; + const oldLockType = fh.xLock; + fh.xLock = lockType; + if( !fh.syncHandle ){ + wTimeStart('xLock'); + try { + await getSyncHandle(fh); + __autoLocks.delete(fid); + }catch(e){ + state.s11n.storeException(1,e); + rc = state.sq3Codes.SQLITE_IOERR_LOCK; + fh.xLock = oldLockType; + } + wTimeEnd(); + } + storeAndNotify('xLock',rc); + mTimeEnd(); + }, + xOpen: async function(fid/*sqlite3_file pointer*/, filename, + flags/*SQLITE_OPEN_...*/){ + const opName = 'xOpen'; + mTimeStart(opName); + const deleteOnClose = (state.sq3Codes.SQLITE_OPEN_DELETEONCLOSE & flags); + const create = (state.sq3Codes.SQLITE_OPEN_CREATE & flags); + wTimeStart('xOpen'); + try{ + let hDir, filenamePart; + try { + [hDir, filenamePart] = await getDirForFilename(filename, !!create); + }catch(e){ + state.s11n.storeException(1,e); + storeAndNotify(opName, state.sq3Codes.SQLITE_NOTFOUND); + mTimeEnd(); + wTimeEnd(); + return; + } + const hFile = await hDir.getFileHandle(filenamePart, {create}); + /** + wa-sqlite, at this point, grabs a SyncAccessHandle and + assigns it to the syncHandle prop of the file state + object, but only for certain cases and it's unclear why it + places that limitation on it. + */ + wTimeEnd(); + __openFiles[fid] = Object.assign(Object.create(null),{ + fid: fid, + filenameAbs: filename, + filenamePart: filenamePart, + dirHandle: hDir, + fileHandle: hFile, + sabView: state.sabFileBufView, + readOnly: create + ? false : (state.sq3Codes.SQLITE_OPEN_READONLY & flags), + deleteOnClose: deleteOnClose + }); + storeAndNotify(opName, 0); + }catch(e){ + wTimeEnd(); + error(opName,e); + state.s11n.storeException(1,e); + storeAndNotify(opName, state.sq3Codes.SQLITE_IOERR); + } + mTimeEnd(); + }, + xRead: async function(fid/*sqlite3_file pointer*/,n,offset64){ + mTimeStart('xRead'); + let rc = 0, nRead; + const fh = __openFiles[fid]; + try{ + affirmLocked('xRead',fh); + wTimeStart('xRead'); + nRead = (await getSyncHandle(fh)).read( + fh.sabView.subarray(0, n), + {at: Number(offset64)} + ); + wTimeEnd(); + if(nRead < n){/* Zero-fill remaining bytes */ + fh.sabView.fill(0, nRead, n); + rc = state.sq3Codes.SQLITE_IOERR_SHORT_READ; + } + }catch(e){ + if(undefined===nRead) wTimeEnd(); + error("xRead() failed",e,fh); + state.s11n.storeException(1,e); + rc = state.sq3Codes.SQLITE_IOERR_READ; + } + storeAndNotify('xRead',rc); + mTimeEnd(); + }, + xSync: async function(fid/*sqlite3_file pointer*/,flags/*ignored*/){ + mTimeStart('xSync'); + const fh = __openFiles[fid]; + let rc = 0; + if(!fh.readOnly && fh.syncHandle){ + try { + wTimeStart('xSync'); + await fh.syncHandle.flush(); + }catch(e){ + state.s11n.storeException(2,e); + rc = state.sq3Codes.SQLITE_IOERR_FSYNC; + } + wTimeEnd(); + } + storeAndNotify('xSync',rc); + mTimeEnd(); + }, + xTruncate: async function(fid/*sqlite3_file pointer*/,size){ + mTimeStart('xTruncate'); + let rc = 0; + const fh = __openFiles[fid]; + wTimeStart('xTruncate'); + try{ + affirmLocked('xTruncate',fh); + affirmNotRO('xTruncate', fh); + await (await getSyncHandle(fh)).truncate(size); + }catch(e){ + error("xTruncate():",e,fh); + state.s11n.storeException(2,e); + rc = state.sq3Codes.SQLITE_IOERR_TRUNCATE; + } + wTimeEnd(); + storeAndNotify('xTruncate',rc); + mTimeEnd(); + }, + xUnlock: async function(fid/*sqlite3_file pointer*/, + lockType/*SQLITE_LOCK_...*/){ + mTimeStart('xUnlock'); + let rc = 0; + const fh = __openFiles[fid]; + if( state.sq3Codes.SQLITE_LOCK_NONE===lockType + && fh.syncHandle ){ + wTimeStart('xUnlock'); + try { await closeSyncHandle(fh) } + catch(e){ + state.s11n.storeException(1,e); + rc = state.sq3Codes.SQLITE_IOERR_UNLOCK; + } + wTimeEnd(); + } + storeAndNotify('xUnlock',rc); + mTimeEnd(); + }, + xWrite: async function(fid/*sqlite3_file pointer*/,n,offset64){ + mTimeStart('xWrite'); + let rc; + const fh = __openFiles[fid]; + wTimeStart('xWrite'); + try{ + affirmLocked('xWrite',fh); + affirmNotRO('xWrite', fh); + rc = ( + n === (await getSyncHandle(fh)) + .write(fh.sabView.subarray(0, n), + {at: Number(offset64)}) + ) ? 0 : state.sq3Codes.SQLITE_IOERR_WRITE; + }catch(e){ + error("xWrite():",e,fh); + state.s11n.storeException(1,e); + rc = state.sq3Codes.SQLITE_IOERR_WRITE; + } + wTimeEnd(); + storeAndNotify('xWrite',rc); + mTimeEnd(); + } +}/*vfsAsyncImpls*/; + +const initS11n = ()=>{ + /** + ACHTUNG: this code is 100% duplicated in the other half of this + proxy! The documentation is maintained in the "synchronous half". + */ + if(state.s11n) return state.s11n; + const textDecoder = new TextDecoder(), + textEncoder = new TextEncoder('utf-8'), + viewU8 = new Uint8Array(state.sabIO, state.sabS11nOffset, state.sabS11nSize), + viewDV = new DataView(state.sabIO, state.sabS11nOffset, state.sabS11nSize); + state.s11n = Object.create(null); + const TypeIds = Object.create(null); + TypeIds.number = { id: 1, size: 8, getter: 'getFloat64', setter: 'setFloat64' }; + TypeIds.bigint = { id: 2, size: 8, getter: 'getBigInt64', setter: 'setBigInt64' }; + TypeIds.boolean = { id: 3, size: 4, getter: 'getInt32', setter: 'setInt32' }; + TypeIds.string = { id: 4 }; + const getTypeId = (v)=>( + TypeIds[typeof v] + || toss("Maintenance required: this value type cannot be serialized.",v) + ); + const getTypeIdById = (tid)=>{ + switch(tid){ + case TypeIds.number.id: return TypeIds.number; + case TypeIds.bigint.id: return TypeIds.bigint; + case TypeIds.boolean.id: return TypeIds.boolean; + case TypeIds.string.id: return TypeIds.string; + default: toss("Invalid type ID:",tid); + } + }; + state.s11n.deserialize = function(clear=false){ + ++metrics.s11n.deserialize.count; + const t = performance.now(); + const argc = viewU8[0]; + const rc = argc ? [] : null; + if(argc){ + const typeIds = []; + let offset = 1, i, n, v; + for(i = 0; i < argc; ++i, ++offset){ + typeIds.push(getTypeIdById(viewU8[offset])); + } + for(i = 0; i < argc; ++i){ + const t = typeIds[i]; + if(t.getter){ + v = viewDV[t.getter](offset, state.littleEndian); + offset += t.size; + }else{/*String*/ + n = viewDV.getInt32(offset, state.littleEndian); + offset += 4; + v = textDecoder.decode(viewU8.slice(offset, offset+n)); + offset += n; + } + rc.push(v); + } + } + if(clear) viewU8[0] = 0; + //log("deserialize:",argc, rc); + metrics.s11n.deserialize.time += performance.now() - t; + return rc; + }; + state.s11n.serialize = function(...args){ + const t = performance.now(); + ++metrics.s11n.serialize.count; + if(args.length){ + //log("serialize():",args); + const typeIds = []; + let i = 0, offset = 1; + viewU8[0] = args.length & 0xff /* header = # of args */; + for(; i < args.length; ++i, ++offset){ + /* Write the TypeIds.id value into the next args.length + bytes. */ + typeIds.push(getTypeId(args[i])); + viewU8[offset] = typeIds[i].id; + } + for(i = 0; i < args.length; ++i) { + /* Deserialize the following bytes based on their + corresponding TypeIds.id from the header. */ + const t = typeIds[i]; + if(t.setter){ + viewDV[t.setter](offset, args[i], state.littleEndian); + offset += t.size; + }else{/*String*/ + const s = textEncoder.encode(args[i]); + viewDV.setInt32(offset, s.byteLength, state.littleEndian); + offset += 4; + viewU8.set(s, offset); + offset += s.byteLength; + } + } + //log("serialize() result:",viewU8.slice(0,offset)); + }else{ + viewU8[0] = 0; + } + metrics.s11n.serialize.time += performance.now() - t; + }; + + state.s11n.storeException = state.asyncS11nExceptions + ? ((priority,e)=>{ + if(priority<=state.asyncS11nExceptions){ + state.s11n.serialize([e.name,': ',e.message].join("")); + } + }) + : ()=>{}; + + return state.s11n; +}/*initS11n()*/; + +const waitLoop = async function f(){ + const opHandlers = Object.create(null); + for(let k of Object.keys(state.opIds)){ + const vi = vfsAsyncImpls[k]; + if(!vi) continue; + const o = Object.create(null); + opHandlers[state.opIds[k]] = o; + o.key = k; + o.f = vi; + } + /** + waitTime is how long (ms) to wait for each Atomics.wait(). + We need to wake up periodically to give the thread a chance + to do other things. + */ + const waitTime = 500; + while(!flagAsyncShutdown){ + try { + if('timed-out'===Atomics.wait( + state.sabOPView, state.opIds.whichOp, 0, waitTime + )){ + if(__autoLocks.size){ + /* Release all auto-locks. */ + for(const fid of __autoLocks){ + const fh = __openFiles[fid]; + await closeSyncHandleNoThrow(fh); + log("Auto-unlocked",fid,fh.filenameAbs); + } + } + continue; + } + const opId = Atomics.load(state.sabOPView, state.opIds.whichOp); + Atomics.store(state.sabOPView, state.opIds.whichOp, 0); + const hnd = opHandlers[opId] ?? toss("No waitLoop handler for whichOp #",opId); + const args = state.s11n.deserialize( + true /* clear s11n to keep the caller from confusing this with + an exception string written by the upcoming + operation */ + ) || []; + //warn("waitLoop() whichOp =",opId, hnd, args); + if(hnd.f) await hnd.f(...args); + else error("Missing callback for opId",opId); + }catch(e){ + error('in waitLoop():',e); + } + } +}; + +navigator.storage.getDirectory().then(function(d){ + const wMsg = (type)=>postMessage({type}); + state.rootDir = d; + self.onmessage = function({data}){ + switch(data.type){ + case 'opfs-async-init':{ + /* Receive shared state from synchronous partner */ + const opt = data.args; + state.littleEndian = opt.littleEndian; + state.asyncS11nExceptions = opt.asyncS11nExceptions; + state.verbose = opt.verbose ?? 2; + state.fileBufferSize = opt.fileBufferSize; + state.sabS11nOffset = opt.sabS11nOffset; + state.sabS11nSize = opt.sabS11nSize; + state.sabOP = opt.sabOP; + state.sabOPView = new Int32Array(state.sabOP); + state.sabIO = opt.sabIO; + state.sabFileBufView = new Uint8Array(state.sabIO, 0, state.fileBufferSize); + state.sabS11nView = new Uint8Array(state.sabIO, state.sabS11nOffset, state.sabS11nSize); + state.opIds = opt.opIds; + state.sq3Codes = opt.sq3Codes; + Object.keys(vfsAsyncImpls).forEach((k)=>{ + if(!Number.isFinite(state.opIds[k])){ + toss("Maintenance required: missing state.opIds[",k,"]"); + } + }); + initS11n(); + metrics.reset(); + log("init state",state); + wMsg('opfs-async-inited'); + waitLoop(); + break; + } + case 'opfs-async-restart': + if(flagAsyncShutdown){ + warn("Restarting after opfs-async-shutdown. Might or might not work."); + flagAsyncShutdown = false; + waitLoop(); + } + break; + case 'opfs-async-metrics': + metrics.dump(); + break; + } + }; + wMsg('opfs-async-loaded'); +}).catch((e)=>error("error initializing OPFS asyncer:",e)); |