apache-arrow
Version:
Apache Arrow columnar in-memory format
91 lines (89 loc) • 4.34 kB
JavaScript
// 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 { __awaiter } from "tslib";
import { toUint8Array } from '../../util/buffer.mjs';
import { isIterable, isAsyncIterable } from '../../util/compat.mjs';
/** @ignore */
export function toDOMStream(source, options) {
if (isAsyncIterable(source)) {
return asyncIterableAsReadableDOMStream(source, options);
}
if (isIterable(source)) {
return iterableAsReadableDOMStream(source, options);
}
/* istanbul ignore next */
throw new Error(`toDOMStream() must be called with an Iterable or AsyncIterable`);
}
/** @ignore */
function iterableAsReadableDOMStream(source, options) {
let it = null;
const bm = ((options === null || options === void 0 ? void 0 : options.type) === 'bytes') || false;
const hwm = (options === null || options === void 0 ? void 0 : options.highWaterMark) || (Math.pow(2, 24));
return new ReadableStream(Object.assign(Object.assign({}, options), { start(controller) { next(controller, it || (it = source[Symbol.iterator]())); },
pull(controller) { it ? (next(controller, it)) : controller.close(); },
cancel() { ((it === null || it === void 0 ? void 0 : it.return) && it.return() || true) && (it = null); } }), Object.assign({ highWaterMark: bm ? hwm : undefined }, options));
function next(controller, it) {
let buf;
let r = null;
let size = controller.desiredSize || null;
while (!(r = it.next(bm ? size : null)).done) {
if (ArrayBuffer.isView(r.value) && (buf = toUint8Array(r.value))) {
size != null && bm && (size = size - buf.byteLength + 1);
r.value = buf;
}
controller.enqueue(r.value);
if (size != null && --size <= 0) {
return;
}
}
controller.close();
}
}
/** @ignore */
function asyncIterableAsReadableDOMStream(source, options) {
let it = null;
const bm = ((options === null || options === void 0 ? void 0 : options.type) === 'bytes') || false;
const hwm = (options === null || options === void 0 ? void 0 : options.highWaterMark) || (Math.pow(2, 24));
return new ReadableStream(Object.assign(Object.assign({}, options), { start(controller) {
return __awaiter(this, void 0, void 0, function* () { yield next(controller, it || (it = source[Symbol.asyncIterator]())); });
},
pull(controller) {
return __awaiter(this, void 0, void 0, function* () { it ? (yield next(controller, it)) : controller.close(); });
},
cancel() {
return __awaiter(this, void 0, void 0, function* () { ((it === null || it === void 0 ? void 0 : it.return) && (yield it.return()) || true) && (it = null); });
} }), Object.assign({ highWaterMark: bm ? hwm : undefined }, options));
function next(controller, it) {
return __awaiter(this, void 0, void 0, function* () {
let buf;
let r = null;
let size = controller.desiredSize || null;
while (!(r = yield it.next(bm ? size : null)).done) {
if (ArrayBuffer.isView(r.value) && (buf = toUint8Array(r.value))) {
size != null && bm && (size = size - buf.byteLength + 1);
r.value = buf;
}
controller.enqueue(r.value);
if (size != null && --size <= 0) {
return;
}
}
controller.close();
});
}
}
//# sourceMappingURL=iterable.mjs.map