diff options
| -rw-r--r-- | lib/_stream_readable.js | 39 | ||||
| -rw-r--r-- | lib/internal/streams/from.js | 46 | ||||
| -rw-r--r-- | node.gyp | 1 |
3 files changed, 51 insertions, 35 deletions
diff --git a/lib/_stream_readable.js b/lib/_stream_readable.js index 5d2300cf89..91cf2f75b0 100644 --- a/lib/_stream_readable.js +++ b/lib/_stream_readable.js @@ -47,6 +47,7 @@ const { // Lazy loaded to improve the startup performance. let StringDecoder; let createReadableStreamAsyncIterator; +let from; Object.setPrototypeOf(Readable.prototype, Stream.prototype); Object.setPrototypeOf(Readable, Stream); @@ -1209,40 +1210,8 @@ function endReadableNT(state, stream) { } Readable.from = function(iterable, opts) { - let iterator; - if (iterable && iterable[Symbol.asyncIterator]) - iterator = iterable[Symbol.asyncIterator](); - else if (iterable && iterable[Symbol.iterator]) - iterator = iterable[Symbol.iterator](); - else - throw new ERR_INVALID_ARG_TYPE('iterable', ['Iterable'], iterable); - - const readable = new Readable({ - objectMode: true, - ...opts - }); - // Reading boolean to protect against _read - // being called before last iteration completion. - let reading = false; - readable._read = function() { - if (!reading) { - reading = true; - next(); - } - }; - async function next() { - try { - const { value, done } = await iterator.next(); - if (done) { - readable.push(null); - } else if (readable.push(await value)) { - next(); - } else { - reading = false; - } - } catch (err) { - readable.destroy(err); - } + if (from === undefined) { + from = require('internal/streams/from'); } - return readable; + return from(Readable, iterable, opts); }; diff --git a/lib/internal/streams/from.js b/lib/internal/streams/from.js new file mode 100644 index 0000000000..e809f2658d --- /dev/null +++ b/lib/internal/streams/from.js @@ -0,0 +1,46 @@ +'use strict'; + +const { + ERR_INVALID_ARG_TYPE +} = require('internal/errors').codes; + +function from(Readable, iterable, opts) { + let iterator; + if (iterable && iterable[Symbol.asyncIterator]) + iterator = iterable[Symbol.asyncIterator](); + else if (iterable && iterable[Symbol.iterator]) + iterator = iterable[Symbol.iterator](); + else + throw new ERR_INVALID_ARG_TYPE('iterable', ['Iterable'], iterable); + + const readable = new Readable({ + objectMode: true, + ...opts + }); + // Reading boolean to protect against _read + // being called before last iteration completion. + let reading = false; + readable._read = function() { + if (!reading) { + reading = true; + next(); + } + }; + async function next() { + try { + const { value, done } = await iterator.next(); + if (done) { + readable.push(null); + } else if (readable.push(await value)) { + next(); + } else { + reading = false; + } + } catch (err) { + readable.destroy(err); + } + } + return readable; +} + +module.exports = from; @@ -205,6 +205,7 @@ 'lib/internal/streams/async_iterator.js', 'lib/internal/streams/buffer_list.js', 'lib/internal/streams/duplexpair.js', + 'lib/internal/streams/from.js', 'lib/internal/streams/legacy.js', 'lib/internal/streams/destroy.js', 'lib/internal/streams/state.js', |