]>
Commit | Line | Data |
---|---|---|
1d09f67e TL |
1 | // Licensed to the Apache Software Foundation (ASF) under one |
2 | // or more contributor license agreements. See the NOTICE file | |
3 | // distributed with this work for additional information | |
4 | // regarding copyright ownership. The ASF licenses this file | |
5 | // to you under the Apache License, Version 2.0 (the | |
6 | // "License"); you may not use this file except in compliance | |
7 | // with the License. You may obtain a copy of the License at | |
8 | // | |
9 | // http://www.apache.org/licenses/LICENSE-2.0 | |
10 | // | |
11 | // Unless required by applicable law or agreed to in writing, | |
12 | // software distributed under the License is distributed on an | |
13 | // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY | |
14 | // KIND, either express or implied. See the License for the | |
15 | // specific language governing permissions and limitations | |
16 | // under the License. | |
17 | ||
18 | import { DataType } from '../../type'; | |
19 | import { Vector } from '../../vector'; | |
20 | import { VectorType as V } from '../../interfaces'; | |
21 | import { Builder, BuilderOptions } from '../../builder/index'; | |
22 | ||
23 | /** @ignore */ | |
24 | export interface BuilderTransformOptions<T extends DataType = any, TNull = any> extends BuilderOptions<T, TNull> { | |
25 | queueingStrategy?: 'bytes' | 'count'; | |
26 | dictionaryHashFunction?: (value: any) => string | number; | |
27 | readableStrategy?: { highWaterMark?: number; size?: any; type?: 'bytes' }; | |
28 | writableStrategy?: { highWaterMark?: number; size?: any; type?: 'bytes' }; | |
29 | valueToChildTypeId?: (builder: Builder<T, TNull>, value: any, offset: number) => number; | |
30 | } | |
31 | ||
32 | /** @ignore */ | |
33 | export function builderThroughDOMStream<T extends DataType = any, TNull = any>(options: BuilderTransformOptions<T, TNull>) { | |
34 | return new BuilderTransform(options); | |
35 | } | |
36 | ||
37 | /** @ignore */ | |
38 | export class BuilderTransform<T extends DataType = any, TNull = any> { | |
39 | ||
40 | public readable: ReadableStream<V<T>>; | |
41 | public writable: WritableStream<T['TValue'] | TNull>; | |
42 | public _controller: ReadableStreamDefaultController<V<T>> | null; | |
43 | ||
44 | private _numChunks = 0; | |
45 | private _finished = false; | |
46 | private _bufferedSize = 0; | |
47 | private _builder: Builder<T, TNull>; | |
48 | private _getSize: (builder: Builder<T, TNull>) => number; | |
49 | ||
50 | constructor(options: BuilderTransformOptions<T, TNull>) { | |
51 | ||
52 | // Access properties by string indexers to defeat closure compiler | |
53 | ||
54 | const { | |
55 | ['readableStrategy']: readableStrategy, | |
56 | ['writableStrategy']: writableStrategy, | |
57 | ['queueingStrategy']: queueingStrategy = 'count', | |
58 | ...builderOptions | |
59 | } = options; | |
60 | ||
61 | this._controller = null; | |
62 | this._builder = Builder.new<T, TNull>(builderOptions); | |
63 | this._getSize = queueingStrategy !== 'bytes' ? chunkLength : chunkByteLength; | |
64 | ||
65 | const { ['highWaterMark']: readableHighWaterMark = queueingStrategy === 'bytes' ? 2 ** 14 : 1000 } = { ...readableStrategy }; | |
66 | const { ['highWaterMark']: writableHighWaterMark = queueingStrategy === 'bytes' ? 2 ** 14 : 1000 } = { ...writableStrategy }; | |
67 | ||
68 | this['readable'] = new ReadableStream<V<T>>({ | |
69 | ['cancel']: () => { this._builder.clear(); }, | |
70 | ['pull']: (c) => { this._maybeFlush(this._builder, this._controller = c); }, | |
71 | ['start']: (c) => { this._maybeFlush(this._builder, this._controller = c); }, | |
72 | }, { | |
73 | 'highWaterMark': readableHighWaterMark, | |
74 | 'size': queueingStrategy !== 'bytes' ? chunkLength : chunkByteLength, | |
75 | }); | |
76 | ||
77 | this['writable'] = new WritableStream({ | |
78 | ['abort']: () => { this._builder.clear(); }, | |
79 | ['write']: () => { this._maybeFlush(this._builder, this._controller); }, | |
80 | ['close']: () => { this._maybeFlush(this._builder.finish(), this._controller); }, | |
81 | }, { | |
82 | 'highWaterMark': writableHighWaterMark, | |
83 | 'size': (value: T['TValue'] | TNull) => this._writeValueAndReturnChunkSize(value), | |
84 | }); | |
85 | } | |
86 | ||
87 | private _writeValueAndReturnChunkSize(value: T['TValue'] | TNull) { | |
88 | const bufferedSize = this._bufferedSize; | |
89 | this._bufferedSize = this._getSize(this._builder.append(value)); | |
90 | return this._bufferedSize - bufferedSize; | |
91 | } | |
92 | ||
93 | private _maybeFlush(builder: Builder<T, TNull>, controller: ReadableStreamDefaultController<V<T>> | null) { | |
94 | if (controller === null) { return; } | |
95 | if (this._bufferedSize >= controller.desiredSize!) { | |
96 | ++this._numChunks && this._enqueue(controller, builder.toVector()); | |
97 | } | |
98 | if (builder.finished) { | |
99 | if (builder.length > 0 || this._numChunks === 0) { | |
100 | ++this._numChunks && this._enqueue(controller, builder.toVector()); | |
101 | } | |
102 | if (!this._finished && (this._finished = true)) { | |
103 | this._enqueue(controller, null); | |
104 | } | |
105 | } | |
106 | } | |
107 | ||
108 | private _enqueue(controller: ReadableStreamDefaultController<V<T>>, chunk: V<T> | null) { | |
109 | this._bufferedSize = 0; | |
110 | this._controller = null; | |
111 | chunk === null ? controller.close() : controller.enqueue(chunk); | |
112 | } | |
113 | } | |
114 | ||
115 | /** @ignore */ const chunkLength = <T extends DataType = any>(chunk: Vector<T> | Builder<T>) => chunk.length; | |
116 | /** @ignore */ const chunkByteLength = <T extends DataType = any>(chunk: Vector<T> | Builder<T>) => chunk.byteLength; |