Inital build

frontend/node_modules/tus-js-client/lib/node/sources/FileSource.js

@@ -0,0 +1,57 @@
+import { createReadStream, promises as fsPromises } from 'fs'
+
+export default async function getFileSource(stream) {
+  const path = stream.path.toString()
+  const { size } = await fsPromises.stat(path)
+
+  // The fs.ReadStream might be configured to not read from the beginning
+  // to the end, but instead from a slice in between. In this case, we consider
+  // that range to indicate the actual uploadable size.
+  // This happens, for example, if a fs.ReadStream is used with the `parallelUploads`
+  // option. There, the ReadStream is sliced into multiple ReadStreams to fit the number
+  // of number of `parallelUploads`. Each ReadStream has `start` and `end` set.
+  // Note: `stream.end` is Infinity by default, so we need the check `isFinite`.
+  // Note: `stream.end` is treated inclusively, so we need to add 1 here.
+  // See the comment in slice() for more context.
+  const start = stream.start ?? 0
+  const end = Number.isFinite(stream.end) ? stream.end + 1 : size
+  const actualSize = end - start
+
+  return new FileSource(stream, path, actualSize)
+}
+
+class FileSource {
+  constructor(stream, path, size) {
+    this._stream = stream
+    this._path = path
+    this.size = size
+  }
+
+  slice(start, end) {
+    // The fs.ReadStream might be configured to not read from the beginning,
+    // but instead start at a different offset. The start value from the caller
+    // does not include the offset, so we need to add this offset to our range later.
+    // This happens, for example, if a fs.ReadStream is used with the `parallelUploads`
+    // option. First, the ReadStream is sliced into multiple ReadStreams to fit the number
+    // of number of `parallelUploads`. Each ReadStream has `start` set.
+    const offset = this._stream.start ?? 0
+
+    const stream = createReadStream(this._path, {
+      start: offset + start,
+      // The `end` option for createReadStream is treated inclusively
+      // (see https://nodejs.org/api/fs.html#fs_fs_createreadstream_path_options).
+      // However, the Buffer#slice(start, end) and also our Source#slice(start, end)
+      // method treat the end range exclusively, so we have to subtract 1.
+      // This prevents an off-by-one error when reporting upload progress.
+      end: offset + end - 1,
+      autoClose: true,
+    })
+    stream.size = Math.min(end - start, this.size)
+    const done = stream.size >= this.size
+    return Promise.resolve({ value: stream, done })
+  }
+
+  close() {
+    this._stream.destroy()
+  }
+}