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diskFileSystemProvider.ts ×17

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13 tests · 14162 LOC · 64 files · introduces 0 tests · 105 LOC · 1 file

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1 file ranked by introduced lines: 105 introduced LOC across 17 ranges. Expand a file to inspect source; the > gutter marks introduced lines.

src/vs/platform/files/node/diskFileSystemProvider.ts 105 introduced LOC · 17 ranges

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350
351 async open(resource: URI, opts: IFileOpenOptions, disableWriteLock?: boolean): Promise<number> {
352 > const filePath = this.toFilePath(resource); diskFileSystemProvider.ts
353 >
354 > // Writes: guard multiple writes to the same resource
355 > // behind a single lock to prevent races when writing
356 > // from multiple places at the same time to the same file
357 > let lock: IDisposable | undefined = undefined;
358 > if (isFileOpenForWriteOptions(opts) && !disableWriteLock) {
359 lock = await this.createResourceLock(resource);
360 }
361 > diskFileSystemProvider.ts
362 > let fd: number | undefined = undefined;
363 > try {
364 >
365 > // Determine whether to unlock the file (write only)
366 > if (isFileOpenForWriteOptions(opts) && opts.unlock) {
367 try {
368 const { stat } = await SymlinkSupport.stat(filePath);
376 }
377 }
378 > diskFileSystemProvider.ts
379 > // Windows gets special treatment (write only, but not for append)
380 > if (isWindows && isFileOpenForWriteOptions(opts) && !opts.append) {
381 try {
382
409 }
410 }
411 > diskFileSystemProvider.ts
412 > if (typeof fd !== 'number') {
413 > fd = await Promises.open(filePath, isFileOpenForWriteOptions(opts) ?
414 // We take `opts.create` as a hint that the file is opened for writing
415 // as such we use 'w' to truncate an existing or create the
421 // the file.
422 'r'
423 > ); diskFileSystemProvider.ts
424 > }
425 >
426 > } catch (error) {
427
428 // Release lock because we have no valid handle
437 }
438 }
439 > diskFileSystemProvider.ts
440 > // Remember this handle to track file position of the handle
441 > // we init the position to 0 since the file descriptor was
442 > // just created and the position was not moved so far (see
443 > // also http://man7.org/linux/man-pages/man2/open.2.html -
444 > // "The file offset is set to the beginning of the file.")
445 > this.mapHandleToPos.set(fd, 0);
446 >
447 > // remember that this handle was used for writing
448 > if (isFileOpenForWriteOptions(opts)) {
449 this.writeHandles.set(fd, resource);
450 }
451 > diskFileSystemProvider.ts
452 > if (lock) {
453 const previousLock = this.mapHandleToLock.get(fd);
454
468 }
469 }
470 > diskFileSystemProvider.ts
471 > return fd;
472 > }
473
474 async close(fd: number): Promise<void> {
475 > diskFileSystemProvider.ts
476 > // It is very important that we keep any associated lock
477 > // for the file handle before attempting to call `fs.close(fd)`
478 > // because of a possible race condition: as soon as a file
479 > // handle is released, the OS may assign the same handle to
480 > // the next `fs.open` call and as such it is possible that our
481 > // lock is getting overwritten
482 > const lockForHandle = this.mapHandleToLock.get(fd);
483 >
484 > try {
485 >
486 > // Remove this handle from map of positions
487 > this.mapHandleToPos.delete(fd);
488 >
489 > // If a handle is closed that was used for writing, ensure
490 > // to flush the contents to disk if possible.
491 > if (this.writeHandles.delete(fd) && DiskFileSystemProvider.canFlush) {
492 try {
493 await Promises.fdatasync(fd); // https://github.com/microsoft/vscode/issues/9589
499 }
500 }
501 > diskFileSystemProvider.ts
502 > return await Promises.close(fd);
503 > } catch (error) {
504 throw this.toFileSystemProviderError(error);
505 > } finally { diskFileSystemProvider.ts
506 > if (lockForHandle) {
507 if (this.mapHandleToLock.get(fd) === lockForHandle) {
508 this.traceLock(`[Disk FileSystemProvider]: close() - resource lock removed from handle-lock map ${fd}`);
513 lockForHandle.dispose();
514 }
515 > } diskFileSystemProvider.ts
516 > }
517
518 async read(fd: number, pos: number, data: Uint8Array, offset: number, length: number): Promise<number> {
532
533 private normalizePos(fd: number, pos: number): number | null {
534 > diskFileSystemProvider.ts
535 > // When calling fs.read/write we try to avoid passing in the "pos" argument and
536 > // rather prefer to pass in "null" because this avoids an extra seek(pos)
537 > // call that in some cases can even fail (e.g. when opening a file over FTP -
538 > // see https://github.com/microsoft/vscode/issues/73884).
539 > //
540 > // as such, we compare the passed in position argument with our last known
541 > // position for the file descriptor and use "null" if they match.
542 > if (pos === this.mapHandleToPos.get(fd)) {
543 > return null;
544 > }
545
546 return pos;
547 > } diskFileSystemProvider.ts
548
549 private updatePos(fd: number, pos: number | null, bytesLength: number | null): void {
550 > const lastKnownPos = this.mapHandleToPos.get(fd); diskFileSystemProvider.ts
551 > if (typeof lastKnownPos === 'number') {
552 >
553 > // pos !== null signals that previously a position was used that is
554 > // not null. node.js documentation explains, that in this case
555 > // the internal file pointer is not moving and as such we do not move
556 > // our position pointer.
557 > //
558 > // Docs: "If position is null, data will be read from the current file position,
559 > // and the file position will be updated. If position is an integer, the file position
560 > // will remain unchanged."
561 > if (typeof pos === 'number') {
562 // do not modify the position
563 }
564 > diskFileSystemProvider.ts
565 > // bytesLength = number is a signal that the read/write operation was
566 > // successful and as such we need to advance the position in the Map
567 > //
568 > // Docs (http://man7.org/linux/man-pages/man2/read.2.html):
569 > // "On files that support seeking, the read operation commences at the
570 > // file offset, and the file offset is incremented by the number of
571 > // bytes read."
572 > //
573 > // Docs (http://man7.org/linux/man-pages/man2/write.2.html):
574 > // "For a seekable file (i.e., one to which lseek(2) may be applied, for
575 > // example, a regular file) writing takes place at the file offset, and
576 > // the file offset is incremented by the number of bytes actually
577 > // written."
578 > else if (typeof bytesLength === 'number') {
579 > this.mapHandleToPos.set(fd, lastKnownPos + bytesLength);
580 > }
581
582 // bytesLength = null signals an error in the read/write operation
586 this.mapHandleToPos.delete(fd);
587 }
588 > } diskFileSystemProvider.ts
589 > }
590
591 async write(fd: number, pos: number, data: Uint8Array, offset: number, length: number): Promise<number> {

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