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// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
import { DEFAULT_CHUNK_SIZE } from "./_common.ts";import type { Closer, Reader } from "../types.d.ts";
function isCloser(value: unknown): value is Closer {  return typeof value === "object" && value != null && "close" in value &&    // deno-lint-ignore no-explicit-any    typeof (value as Record<string, any>)["close"] === "function";}
export interface ReadableStreamFromReaderOptions {  /** If the `reader` is also a `Closer`, automatically close the `reader`   * when `EOF` is encountered, or a read error occurs.   *   * @default {true}   */  autoClose?: boolean;
  /** The size of chunks to allocate to read, the default is ~16KiB, which is   * the maximum size that Deno operations can currently support. */  chunkSize?: number;
  /** The queuing strategy to create the `ReadableStream` with. */  strategy?: { highWaterMark?: number | undefined; size?: undefined };}
/** * Create a `ReadableStream<Uint8Array>` from a `Reader`. * * When the pull algorithm is called on the stream, a chunk from the reader * will be read.  When `null` is returned from the reader, the stream will be * closed along with the reader (if it is also a `Closer`). * * An example converting a `Deno.FsFile` into a readable stream: * * ```ts * import { readableStreamFromReader } from "https://deno.land/std@$STD_VERSION/streams/readable_stream_from_reader.ts"; * * const file = await Deno.open("./file.txt", { read: true }); * const fileStream = readableStreamFromReader(file); * ``` */export function readableStreamFromReader(  reader: Reader | (Reader & Closer),  options: ReadableStreamFromReaderOptions = {},): ReadableStream<Uint8Array> {  const {    autoClose = true,    chunkSize = DEFAULT_CHUNK_SIZE,    strategy,  } = options;
  return new ReadableStream({    async pull(controller) {      const chunk = new Uint8Array(chunkSize);      try {        const read = await reader.read(chunk);        if (read === null) {          if (isCloser(reader) && autoClose) {            reader.close();          }          controller.close();          return;        }        controller.enqueue(chunk.subarray(0, read));      } catch (e) {        controller.error(e);        if (isCloser(reader)) {          reader.close();        }      }    },    cancel() {      if (isCloser(reader) && autoClose) {        reader.close();      }    },  }, strategy);}