diff --git a/lib/internal/streams/writable.js b/lib/internal/streams/writable.js index 5800c9df171ff2..955b6283e6a105 100644 --- a/lib/internal/streams/writable.js +++ b/lib/internal/streams/writable.js @@ -108,6 +108,7 @@ const kWriteCb = 1 << 26; const kExpectWriteCb = 1 << 27; const kAfterWriteTickInfo = 1 << 28; const kAfterWritePending = 1 << 29; +const kIsDuplex = 1 << 30; // TODO(benjamingr) it is likely slower to do it this way than with free functions function makeBitMapDescriptor(bit) { @@ -286,6 +287,7 @@ function WritableState(options, stream, isDuplex) { if (options && options.objectMode) this.state |= kObjectMode; if (isDuplex && options && options.writableObjectMode) this.state |= kObjectMode; + if (isDuplex) this.state |= kIsDuplex; // The point at which write() starts returning false // Note: 0 is a valid value, means that we always return false if @@ -513,13 +515,7 @@ function writeOrBuffer(stream, state, chunk, encoding, callback) { state.length += len; - // stream._write resets state.length - const ret = state.length < state.highWaterMark; - - // We must ensure that previous needDrain will not be reset to false. - if (!ret) { - state.state |= kNeedDrain; - } + const prevLen = state.length; if ((state.state & (kWriting | kErrored | kCorked | kConstructed)) !== kConstructed) { state.buffered.push({ chunk, encoding, callback }); @@ -539,6 +535,16 @@ function writeOrBuffer(stream, state, chunk, encoding, callback) { state.state &= ~kSync; } + const ret = ( + ((state.state & kIsDuplex) === 0 || stream._readableState.ended !== true) ? + state.length < state.highWaterMark : + prevLen < state.highWaterMark + ); + + if (!ret) { + state.state |= kNeedDrain; + } + // Return false if errored or destroyed in order to break // any synchronous while(stream.write(data)) loops. return ret && (state.state & (kDestroyed | kErrored)) === 0;