apache-arrow
Version:
Apache Arrow columnar in-memory format
84 lines (82 loc) • 4.22 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 { __rest } from "tslib";
import { makeBuilder } from '../../factories.mjs';
/** @ignore */
export function builderThroughDOMStream(options) {
return new BuilderTransform(options);
}
/** @ignore */
export class BuilderTransform {
constructor(options) {
// Access properties by string indexers to defeat closure compiler
this._numChunks = 0;
this._finished = false;
this._bufferedSize = 0;
const { ['readableStrategy']: readableStrategy, ['writableStrategy']: writableStrategy, ['queueingStrategy']: queueingStrategy = 'count' } = options, builderOptions = __rest(options, ['readableStrategy', 'writableStrategy', 'queueingStrategy']);
this._controller = null;
this._builder = makeBuilder(builderOptions);
this._getSize = queueingStrategy !== 'bytes' ? chunkLength : chunkByteLength;
const { ['highWaterMark']: readableHighWaterMark = queueingStrategy === 'bytes' ? Math.pow(2, 14) : 1000 } = Object.assign({}, readableStrategy);
const { ['highWaterMark']: writableHighWaterMark = queueingStrategy === 'bytes' ? Math.pow(2, 14) : 1000 } = Object.assign({}, writableStrategy);
this['readable'] = new ReadableStream({
['cancel']: () => { this._builder.clear(); },
['pull']: (c) => { this._maybeFlush(this._builder, this._controller = c); },
['start']: (c) => { this._maybeFlush(this._builder, this._controller = c); },
}, {
'highWaterMark': readableHighWaterMark,
'size': queueingStrategy !== 'bytes' ? chunkLength : chunkByteLength,
});
this['writable'] = new WritableStream({
['abort']: () => { this._builder.clear(); },
['write']: () => { this._maybeFlush(this._builder, this._controller); },
['close']: () => { this._maybeFlush(this._builder.finish(), this._controller); },
}, {
'highWaterMark': writableHighWaterMark,
'size': (value) => this._writeValueAndReturnChunkSize(value),
});
}
_writeValueAndReturnChunkSize(value) {
const bufferedSize = this._bufferedSize;
this._bufferedSize = this._getSize(this._builder.append(value));
return this._bufferedSize - bufferedSize;
}
_maybeFlush(builder, controller) {
if (controller == null) {
return;
}
if (this._bufferedSize >= controller.desiredSize) {
++this._numChunks && this._enqueue(controller, builder.toVector());
}
if (builder.finished) {
if (builder.length > 0 || this._numChunks === 0) {
++this._numChunks && this._enqueue(controller, builder.toVector());
}
if (!this._finished && (this._finished = true)) {
this._enqueue(controller, null);
}
}
}
_enqueue(controller, chunk) {
this._bufferedSize = 0;
this._controller = null;
chunk == null ? controller.close() : controller.enqueue(chunk);
}
}
/** @ignore */ const chunkLength = (chunk) => { var _a; return (_a = chunk === null || chunk === void 0 ? void 0 : chunk.length) !== null && _a !== void 0 ? _a : 0; };
/** @ignore */ const chunkByteLength = (chunk) => { var _a; return (_a = chunk === null || chunk === void 0 ? void 0 : chunk.byteLength) !== null && _a !== void 0 ? _a : 0; };
//# sourceMappingURL=builder.mjs.map