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| // Licensed to the Apache Software Foundation (ASF) under one | |
| // or more contributor license agreements. See the NOTICE file | |
| // distributed with this work for additional information | |
| // regarding copyright ownership. The ASF licenses this file | |
| // to you under the Apache License, Version 2.0 (the | |
| // "License"); you may not use this file except in compliance | |
| // with the License. You may obtain a copy of the License at | |
| // | |
| // http://www.apache.org/licenses/LICENSE-2.0 | |
| // | |
| // Unless required by applicable law or agreed to in writing, | |
| // software distributed under the License is distributed on an | |
| // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY | |
| // KIND, either express or implied. See the License for the | |
| // specific language governing permissions and limitations | |
| // under the License. | |
| import { Duplex, DuplexOptions } from 'stream'; | |
| import { AsyncByteStream } from '../../io/stream.js'; | |
| import { RecordBatchWriter } from '../../ipc/writer.js'; | |
| import { TypeMap } from '../../type.js'; | |
| /** @ignore */ | |
| export function recordBatchWriterThroughNodeStream<T extends TypeMap = any>(this: typeof RecordBatchWriter, options?: DuplexOptions & { autoDestroy: boolean }) { | |
| return new RecordBatchWriterDuplex(new this<T>(options)); | |
| } | |
| /** @ignore */ | |
| type CB = (error?: Error | null | undefined) => void; | |
| /** @ignore */ | |
| class RecordBatchWriterDuplex<T extends TypeMap = any> extends Duplex { | |
| private _pulling = false; | |
| private _reader: AsyncByteStream | null; | |
| private _writer: RecordBatchWriter | null; | |
| constructor(writer: RecordBatchWriter<T>, options?: DuplexOptions) { | |
| super({ allowHalfOpen: false, ...options, writableObjectMode: true, readableObjectMode: false }); | |
| this._writer = writer; | |
| this._reader = new AsyncByteStream(writer); | |
| } | |
| _final(cb?: CB) { | |
| const writer = this._writer; | |
| writer?.close(); | |
| cb && cb(); | |
| } | |
| _write(x: any, _: string, cb: CB) { | |
| const writer = this._writer; | |
| writer?.write(x); | |
| cb && cb(); | |
| return true; | |
| } | |
| _read(size: number) { | |
| const it = this._reader; | |
| if (it && !this._pulling && (this._pulling = true)) { | |
| (async () => this._pulling = await this._pull(size, it))(); | |
| } | |
| } | |
| _destroy(err: Error | null, cb: (error: Error | null) => void) { | |
| const writer = this._writer; | |
| if (writer) { err ? writer.abort(err) : writer.close(); } | |
| cb(this._reader = this._writer = null); | |
| } | |
| async _pull(size: number, reader: AsyncByteStream) { | |
| let r: IteratorResult<Uint8Array> | null = null; | |
| while (this.readable && !(r = await reader.next(size || null)).done) { | |
| if (size != null && r.value) { | |
| size -= r.value.byteLength; | |
| } | |
| if (!this.push(r.value) || size <= 0) { break; } | |
| } | |
| if ((r?.done || !this.readable)) { | |
| this.push(null); | |
| await reader.cancel(); | |
| } | |
| return !this.readable; | |
| } | |
| } | |