apache-arrow/io/whatwg/writer.js

Apache Arrow columnar in-memory format

"use strict";
// 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.
Object.defineProperty(exports, "__esModule", { value: true });
exports.recordBatchWriterThroughDOMStream = void 0;
const tslib_1 = require("tslib");
const stream_js_1 = require("../../io/stream.js");
/** @ignore */
function recordBatchWriterThroughDOMStream(writableStrategy, readableStrategy) {
    const writer = new this(writableStrategy);
    const reader = new stream_js_1.AsyncByteStream(writer);
    const readable = new ReadableStream({
        // type: 'bytes',
        cancel() {
            return tslib_1.__awaiter(this, void 0, void 0, function* () { yield reader.cancel(); });
        },
        pull(controller) {
            return tslib_1.__awaiter(this, void 0, void 0, function* () { yield next(controller); });
        },
        start(controller) {
            return tslib_1.__awaiter(this, void 0, void 0, function* () { yield next(controller); });
        },
    }, Object.assign({ 'highWaterMark': Math.pow(2, 14) }, readableStrategy));
    return { writable: new WritableStream(writer, writableStrategy), readable };
    function next(controller) {
        return tslib_1.__awaiter(this, void 0, void 0, function* () {
            let buf = null;
            let size = controller.desiredSize;
            while (buf = yield reader.read(size || null)) {
                controller.enqueue(buf);
                if (size != null && (size -= buf.byteLength) <= 0) {
                    return;
                }
            }
            controller.close();
        });
    }
}
exports.recordBatchWriterThroughDOMStream = recordBatchWriterThroughDOMStream;

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